USRE42558E1 - Joint adaptive optimization of soft decision device and feedback equalizer - Google Patents
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- USRE42558E1 USRE42558E1 US12/390,368 US39036809A USRE42558E US RE42558 E1 USRE42558 E1 US RE42558E1 US 39036809 A US39036809 A US 39036809A US RE42558 E USRE42558 E US RE42558E
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/3052—Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/3089—Control of digital or coded signals
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L25/03012—Arrangements for removing intersymbol interference operating in the time domain
- H04L25/03019—Arrangements for removing intersymbol interference operating in the time domain adaptive, i.e. capable of adjustment during data reception
- H04L25/03057—Arrangements for removing intersymbol interference operating in the time domain adaptive, i.e. capable of adjustment during data reception with a recursive structure
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/06—Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection
- H04L25/067—Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection providing soft decisions, i.e. decisions together with an estimate of reliability
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/08—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/0335—Arrangements for removing intersymbol interference characterised by the type of transmission
- H04L2025/03375—Passband transmission
- H04L2025/03388—ASK
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/0335—Arrangements for removing intersymbol interference characterised by the type of transmission
- H04L2025/03375—Passband transmission
- H04L2025/0342—QAM
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/03433—Arrangements for removing intersymbol interference characterised by equaliser structure
- H04L2025/03439—Fixed structures
- H04L2025/03445—Time domain
- H04L2025/03471—Tapped delay lines
- H04L2025/03484—Tapped delay lines time-recursive
- H04L2025/0349—Tapped delay lines time-recursive as a feedback filter
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/03592—Adaptation methods
- H04L2025/03598—Algorithms
- H04L2025/03611—Iterative algorithms
- H04L2025/03617—Time recursive algorithms
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/03592—Adaptation methods
- H04L2025/03598—Algorithms
- H04L2025/03611—Iterative algorithms
- H04L2025/03617—Time recursive algorithms
- H04L2025/0363—Feature restoration, e.g. constant modulus
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0024—Carrier regulation at the receiver end
- H04L2027/0026—Correction of carrier offset
- H04L2027/003—Correction of carrier offset at baseband only
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0044—Control loops for carrier regulation
- H04L2027/0053—Closed loops
- H04L2027/0055—Closed loops single phase
Definitions
- the present invention relates to adaptive optimization techniques for Decision Feedback Equalizers in order to compensate for distortions introduced in digital communications systems using modulation techniques such as Quadrature Amplitude Modulation (QAM) or Pulse Amplitude Modulation (PAM).
- modulation techniques such as Quadrature Amplitude Modulation (QAM) or Pulse Amplitude Modulation (PAM).
- the digital information bits are mapped to symbols drawn from a finite set of discrete real or complex numbers. These symbols are used to modulate a radio frequency (RF) carrier's frequency, amplitude and/or phase.
- RF radio frequency
- a quadrature oscillator can be used to modulate the complex symbols onto the amplitude and phase of the RF carrier, and the signaling is referred to as Quadrature Amplitude Modulation (QAM).
- QAM Quadrature Amplitude Modulation
- the time interval between symbols is referred to as the symbol or baud interval, and the inverse of this interval is referred to as the symbol or baud rate.
- ISI inter-symbol interference
- an equalizer is used to mitigate the effects of ISI and noise induced in the entire channel, including transmitter, propagation medium, and front-end receiver processing. Since the exact channel characteristics are not known apriori at the receiver, the equalizer is usually implemented with adaptive methods.
- a common type of equalizer uses adaptive filters, and the adjustment of filter coefficients can be done in a variety of ways.
- Trained equalization methods rely on the embedding of a pre-determined sequence in the transmitted data, referred to as a training or reference sequence.
- the receiver stores or generates a replica of the training sequence, and to the extent that the received sequence differs from the training sequence, an error measure is derived to adjust equalizer coefficients.
- equalizer coefficient convergence relies on multiple transmissions of the training sequence, and the channel characteristics are also time varying. Hence, periodic re-training is necessary.
- LMS Least Mean Squares
- MSE Mean Squared Error
- blind equalization methods A common blind equalization method replaces the reference signal in the LMS algorithm with the receiver's best guess at the data, and is therefore referred to as Decision Directed LMS (DD-LMS), as proposed in a paper entitled “Techniques for adaptive equalization of digital communication systems,” by R. W. Lucky, in the Bell Systems Technical Journal, vol. 45, no. 2, pp. 255-286, February 1966.
- DD-LMS Decision Directed LMS
- DD-LMS needs a reasonably low percentage of incorrect decisions to prevent algorithm divergence, and is therefore impractical from a cold-start initialization.
- Other blind algorithms are usually used from a cold-start.
- CMA Constant Modulus Algorithm
- CMA minimizes a quartic Constant Modulus (CM) cost function that penalizes dispersion at the equalizer output.
- a Decision Feedback Equalizer is generally believed to provide superior ISI cancellation with less noise gain than an FIR equalizer structure.
- a DFE acts to additively cancel ISI by subtracting filtered decisions (or best guesses, also known as hard decisions) from the sampled received signals.
- the feedback structure embeds a FIR filter in a feedback loop, fed by symbol estimates, and therefore has infinite impulse response (IIR).
- IIR infinite impulse response
- the DFE architecture requires a low percentage of incorrect decisions to prevent algorithm divergence and error propagation, a phenomenon whereby an incorrect decision causes more incorrect decisions due to the recursive structure of the DFE.
- a DFE requires alternative adaptive strategies from a cold-start.
- Several techniques based on adaptive IIR filtering have been proposed as summarized in a chapter entitled “Current approaches to blind decision feedback equalization,” by R. A. Casas et al., in the textbook, “Signal processing advances in wireless and mobile communications: trends in channel estimation and equalization,” edited by G. Giannakis, et al., Prentice Hall, Upper Saddle River, N.J., 2000.
- the present invention combines the soft decision device approach and the seamless transition between IIR adaptation and DD-LMS adaptation. Unlike the linear combination of IIR and DD-LMS adaptations, this present invention uses a family of non-linear soft decision devices approximating the optimal soft decision device studied in soft-decision DFE literatures. According to the selection rule inferred from the non-linear soft decision device, DFE coefficients are updated by selected error signals between IIR adaptation and DD-LMS adaptation on a symbol-by-symbol basis, which jointly optimizes the soft decision device and DFE adaptation.
- a Decision Feedback Equalizer uses input samples to the feedback filter that are generated from a novel adaptive soft decision device.
- the soft decision device receives the input and output samples of the slicer and generates a feedback sample based on a novel non-linear decision rule.
- the soft decision device provides novel error terms used to adapt equalizer coefficients.
- FIG. 1 shows a typical prior art communication system that may be employed for transmission of digital signals
- FIG. 2 shows an exemplary embodiment of the present invention, showing a self-initializing decision feedback equalizer operating at precise baseband;
- FIG. 3 describes the Soft Decision Device in the present invention
- FIG. 4 shows a 16-QAM constellation selection regions for Soft Decision Device in the present invention
- FIG. 5a shows the in-phase component of the equalizer output from a computer simulation of the preferred embodiment of the present invention
- FIG. 5b shows the soft decision parameter ⁇ (n) trajectory from a computer simulation of the preferred embodiment of the present invention
- FIG. 5c illustrates the input-output relation of the Soft Decision Device for a given ⁇ (n) and constellation
- FIG. 6 shows an alternative embodiment of the present invention, with equalizer forward and feedback filters operating on passband samples
- FIG. 7 shows an alternative embodiment of the present invention, with equalizer forward filter operating on passband samples, and equalizer feedback filter operating on baseband samples.
- FIG. 1 depicts a typical prior art digital communication system.
- Transmitter station 100 is coupled to receiver 150 by propagation medium 147 .
- the propagation medium could be a cable, telephone twisted-pair wire, satellite link, terrestrial link, or fiber optic connection, for example.
- Transmitter station 100 includes an information source 110 , that contains the content such as data, audio, or video, which is to be communicated to the receiver 150 .
- the information source 110 is coupled to encoder 120 , which formats the information in a manner suitable for digital communication, typically in accordance with a given standard or protocol.
- the encoder 120 is coupled to modulator 140 , which is also coupled to a quadrature oscillator 130 .
- the modulator 140 uses the signal from the quadrature oscillator 130 to modulate the encoded information provided by encoder 120 onto a suitable Radio Frequency (RF) carrier frequency in amplitude and phase.
- RF Radio Frequency
- the receiver 150 receives the RF signal from propagation medium 147 via receiver antenna 149 .
- Receiver antenna 149 is coupled to tuner 160 .
- Tuner 160 is set to receive the RF signal in the desired frequency range, while rejecting signals in nearby or adjacent frequency ranges.
- Tuner 160 may provide automatic gain control at the RF frequency and also downconvert the received signal to an intermediate frequency (IF) before passing the signal to the Front End Processing block 165 .
- Front End Processing block 165 samples the signal with an analog-to-digital converter and contains an automatic gain control circuit that scales the signal to the proper dynamic range in accordance with the analog-to-digital converter.
- Front End Processing block 165 may further include a digital downconversion in frequency, and performs a quadrature demodulation to split the signal into in-phase (I) and quadrature-phase (Q) samples.
- Front End Processing block 165 is coupled to Timing Recovery module 170 that determines a correct sampling phase. Timing Recovery module 170 may adjust the sampling phase by interpolating the data samples, or adjusting the phase and sampling frequency of the analog-to-digital converter in Front End Processing block 165 .
- Timing Recovery module 170 is coupled to Equalizer 175 , which is used to mitigate the distortions, such as inter-symbol interference and noise, that are introduced by the propagation medium 147 , transmitter 100 , receiver Tuner 160 , receiver Front End Processing block 165 , and receiver Timing Recovery module 170 .
- Equalizer 175 is coupled to Carrier Recovery module 180 , which detects residual offset in frequency and phase. The detected carrier offset in Carrier Recovery module may be supplied back to the Equalizer 175 for translation of equalized samples to precise baseband, or used to adjust the downconversion process in Front End Processing block 165 , or both.
- the output of Equalizer 175 is coupled to Error Correction module 185 , which detects and corrects bit errors in the recovered bit stream.
- the Error Correction module 185 is coupled to Decoder 190 , which decodes the bit stream in accordance with the standard or protocol used in the Encoder 120 of Transmitter 100 .
- the decoded bits from Decoder 190 represent the recovered information source, consisting of data, audio, or video, and are supplied to a user interface 195 .
- the present invention is embodied in the Equalizer 175 portion of the communication system.
- FIG. 2 shows an exemplary embodiment of the present invention.
- An Equalizer 200 receives complex data ⁇ tilde over (r) ⁇ (n) that is input to mixer 285 .
- the mixer 285 also receives a signal from carrier recovery loop 280 , e ⁇ j ⁇ (n) , that is an estimate of the conjugate of the carrier offset.
- Methods of carrier recovery are well known to one skilled in the art, and may be found, for example, in chapter 16 of the text “Digital Communication” by E. A. Lee and D. G. Messerschmitt, Kluwer Academic Publishers, 1994, which is incorporated herein by reference.
- the carrier recovery loop 280 and mixer 285 are shown as dashed lines, to represent that translation to precise baseband is done prior to equalization, and may be done anywhere prior to equalization in the signal processing chain. For example, some systems embed pilot tones or pulses to aid synchronization, allowing translation to precise baseband in the receiver front end, prior to equalization. In this exemplary embodiment of the invention, the equalizer 200 operates on samples that have been translated to precise baseband.
- the output of mixer 285 is a received signal, r(n), that is at precise baseband, and is input to forward filter 210 .
- Forward filter 210 may operate at the baud rate or faster, in which case the equalizer is said to be fractionally-spaced, and exploits temporal diversity. Also, the forward filter 210 may receive multiple inputs, as from multiple antennae, to exploit spatial diversity. Temporal or spatial diversity uses a multi-channel forward filter. For simplicity, however, a single forward filter 210 is shown, and extension to a multi-channel model is understood by one skilled in the art.
- r(n) is the sample sequence input to forward filter 210
- x(n) is the output sample sequence of forward filter 210
- f i are the forward filter coefficients (or parameters,)
- L f is the number of forward filter coefficients. Note that the forward filter coefficients are also shown with time index n to indicate that the forward filter 210 is adaptive.
- v(n) is the sample sequence input to feedback filter 220
- y(n) is the output sample sequence of feedback filter 220
- g i are the feedback filter coefficients (or parameters,)
- L g is the number of feedback filter coefficients.
- the feedback filter coefficients are also shown with time index n to indicate that the feedback filter 220 is adaptive.
- the feedback filter 220 is a FIR filter, it is embedded in a feedback loop, so that the equalizer has an overall impulse response that is infinite.
- Adder 275 combines the outputs of forward filter 210 and feedback filter 220 , x(n) and y(n), respectively, to form sample sequence w(n).
- Sample sequence w(n) is referred to as slicer inputs.
- the slicer inputs, w(n) are input to slicer 240 .
- Slicer 240 is a nearest-element decision device that outputs a hard decision, ⁇ (n), corresponding to the source alphabet member with closest Euclidean distance to its input sample.
- the slicer input w(n) and the hard decisions, ⁇ (n), from slicer 240 are input to the Soft Decision Device 230 .
- FIG. 3 describes the Soft Decision Device in accordance with the present invention.
- the slicer input w(n) is splitted into real and imaginary components.
- the Boundary Value Generator 320 produces the nearest decision boundary values ⁇ hacek over (w) ⁇ re (n) and ⁇ hacek over (w) ⁇ im (n) by treating w re (n) and w im (n) as a Pulse Amplitude Modulated (PAM) signals, which belong to a alphabet set ⁇ (2M ⁇ 1) ⁇ , . . . , ⁇ 3 ⁇ , ⁇ ,3 ⁇ , . . . (2M ⁇ 1) ⁇ where the constellation unit ⁇ and PAM level M are determined from the QAM level.
- PAM Pulse Amplitude Modulated
- FIG. 4 illustrates the relation among w(n) ( 420 ), ⁇ (n) ( 430 ), ⁇ hacek over (w) ⁇ re (n) ( 440 ), and ⁇ hacek over (w) ⁇ im (n) ( 440 ) for a 16-QAM constellation.
- the Soft Decision Generator 330 generates the soft decision based on the comparison between the distance between the nearest boundary values from the slicer input,
- the soft decision device is made adaptive by adaptation of the decision reference parameter ⁇ (n).
- the Soft Decision Optimizer 350 optimizes the decision reference parameter ⁇ (n).
- 2 with E ⁇ denoting statistical expectation) and can be adjusted each symbol instance using the leakage integrator ⁇ (n) (1 ⁇ ⁇ ) ⁇ (n ⁇ 1)+ ⁇ ⁇ ⁇
- 2 (for example average signal power, ⁇ E
- ⁇ (n) can be updated on a block by block base based on the block estimation of E
- the combining weight ⁇ (n) may be compared to two thresholds, T U and T L . If ⁇ (n)>T U , then ⁇ (n) is set to one; if ⁇ (n) ⁇ T L , then ⁇ (n) is set to zero
- the baseband error term e(n) that updates the forward filter 210 and feedback filter 220 at each baud instance is selected by Error Signal Generator 340 in Soft Decision Device 300 and is calculated according to
- e ⁇ ( n ) ⁇ e 1 ⁇ ( n ) if ⁇ ⁇ ⁇ w re ⁇ ( n ) - w ⁇ re ⁇ ( n ) ⁇ ⁇ ⁇ ⁇ ( n ) ⁇ ⁇ or ⁇ ⁇ ⁇ w im ⁇ ( n ) - w ⁇ im ⁇ ( n ) ⁇ ⁇ ⁇ ⁇ ( n ) ⁇ e 2 ⁇ ( n ) else .
- CMA Constant Modulus Algorithm
- DD-LMS Decision-Directed LMS
- the Error Signal Generator 340 separates the unreliable signals and reliable signals, and apply IIR adaptation for the unreliable signals after proper resealing. For the reliable signals the conventional DD-LMS is applied.
- FIGS. 5a and 5b illustrate the equalizer output and soft decision reference parameter ⁇ (n) in operation from a computer simulation of the preferred embodiment of the present invention.
- the source signal is 4-QAM (QPSK) data passed through a closed-eye channel that has rapid time variation at the 5,000 th baud sample. There are 10,000 baud samples, with adaptation of equalizer coefficients and decision reference parameter at the start of the simulation.
- FIG. 5a shows the real part of slicer inputs converging to correct decisions as adaptation is processed. Sudden dispersion at the 5,000 th baud sample is due to sudden change of the multipath channel.
- FIG. 5b shows the trajectory of decision reference parameter ⁇ (n), initialized to unity, and converging towards zero when channel is static, and optimizing the adaptation and soft decision device when channel is varying.
- FIG. 5c draws the soft decision device as a function of slicer input for various choice of decision reference parameter ⁇ (n) in this simulation.
- ⁇ (n) increases the region of unreliable signals are increased too and DFE is operating with the conventional CMA in that region.
- Equalizer 500 operates in the passband; that is, not at precise baseband.
- Equalizer 500 is similar to equalizer 200 in FIG. 2 , so only the differences in equalizer 500 of FIG. 5 are described.
- Forward filter 510 and feedback filter 520 produce data by convolution sums in an analogous manner to that described for the exemplary embodiment in FIG. 2 , yielding passband signals x(n) and y(n), respectively.
- the outputs of forward filter 510 and feedback filter 520 are combined in adder 590 , yielding the passband sample ⁇ tilde over (w) ⁇ (n).
- This sample is translated to precise baseband (or de-rotated) slicer input w(n) in multiplier 555 by multiplication with the conjugate of the carrier offset, e ⁇ j ⁇ (n) , provided by carrier recovery loop 585 .
- the slicer 540 is a nearest-element decision device that outputs a hard decision, ⁇ (n), corresponding to the source alphabet member with closest Euclidean distance to its input sample.
- the slicer input and hard decision samples are input to the Soft Decision Device and the soft decision v(n) is translated back to the passband in multiplier 560 by multiplication with the carrier offset e j ⁇ (n) , provided by the carrier recovery loop 585 .
- e dd - lms passband e dd - lms ⁇ e ?? ⁇ ⁇ ( n )
- e CMA passband e CMA ⁇ e ?? ⁇ ⁇ ⁇ ⁇ ( n )
- FIG. 6 shows equalizer 600 , an alternative embodiment of the present invention, in which the forward filter 610 operates on passband data, while the feedback filter 650 , and all processing after multiplier 645 , operate at precise baseband.
- Forward filter 610 operates on received passband data r(n) and calculates output x pb (n) via the convolution sum discussed for the filtering process of equalizer 200 in FIG. 2 .
- Multiplier 645 translates the output of forward filter 610 to precise baseband by multiplication with the conjugate of the carrier offset estimate, e ⁇ j ⁇ (n) , provided by carrier recovery loop 685 .
- the remainder of the equalizer 600 operates analogously to the equalizer 200 in FIG. 2 , except that the equalizer control module 630 receives also the carrier offset estimate from carrier recovery loop 685 to produce a passband error term, e pb (n), as well as a baseband error term, e(n).
- Feedback filter 620 operates on baseband data, and thus is adapted with the baseband error terms described for operation of equalizer 200 in FIG. 2 . However, since forward filter 610 in FIG. 6 processes passband data, it is adapted by passband error terms that are generated by rotating the baseband error term with the current offset of the carrier recovery estimate, e j ⁇ (n) .
- equations described herein may include scaling, change of sign, or similar constant modifications that are not shown for simplicity.
- One skilled in the art would realize that such modifications can be readily determined or derived for the particular implementation.
- the described equations may be subject to such modifications, and are not limited to the exact forms presented herein.
- Quadrature Amplitude Modulation signals with complex signal processing, unless specifically noted.
- QAM Quadrature Amplitude Modulation
- PSK Phase-Shift Keyed
- PAM Pulse Amplitude Modulation
- equalization may be implemented with circuit elements or may also be implemented in the digital domain as processing steps in a software program.
- Such software may be employed in, for example, a digital signal processor, microcontroller, or general-purpose computer.
- the present invention can be embodied in the form of methods and apparatuses for practicing those methods.
- the present invention can also be embodied in the form of program code embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention.
- the present invention can also be embodied in the form of program code, for example, whether stored in a storage medium, loaded into and/or executed by a machine, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention.
- program code When implemented on a general-purpose processor, the program code segments combine with the processor to provide a unique device that operates analogously to specific logic circuits.
Abstract
Description
x(n)=f0(n)r(n)+f1(n)r(n−1)+f2(n)r(n−2)+. . . +fL
where r(n) is the sample sequence input to
y(n)=g0(n)v(n)+g1(n)v(n−1)+g2(n)v(n−2)+. . . +gL
where v(n) is the sample sequence input to
{−(2M−1)Γ, . . . , −3Γ,−Γ,3Γ, . . . (2M−1)Γ}
where the constellation unit Γ and PAM level M are determined from the QAM level.
for k=−M+1, . . . , M−1.
with |·| denoting absolute value, or magnitude. Remind that the hard decision of a PAM signal is defined by
for k=−M+1, . . . ,M−1.
where {hacek over (w)}(n)={hacek over (w)}re+j{hacek over (w)}im.
λ(n)=(1−ρλ)·λ(n−1)+ρλ·|w(n)−ŵ|2/Δ
where Δ is chosen to normalize |w(n)−ŵ|2 (for example average signal power, Δ=E|w(n)|2) and ρλ is the leakage term and is chosen less than or equal to one and greater than or equal to zero.
fi(n+1)=fi(n)−μfΦ*(n)e(n)
gi(n+1)=gi(n)−μgφ*(n)e(n)
where (·)* represents complex conjugation, and μf and μg are small, positive stepsizes governing algorithm convergence rate, tracking capabilities and stochastic jitter. Using simplified updates, the data used in the adaptation equations are set to Φ(n)=r(n) and φ(n)=v(n). The baseband error term e(n) that updates the
edid-lms=w(n)−ŵ(n)
where γ is a real scalar referred to as the CM dispersion constant or Godard radius, and is usually calculated as γ=E{|s(n)|4}/E{|s(n)|2} for source sequence s(n), (These error terms are said to be baseband, since they are derived from samples at precise baseband.)
Claims (9)
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US10/322,299 US20030219085A1 (en) | 2001-12-18 | 2002-12-17 | Self-initializing decision feedback equalizer with automatic gain control |
US10/327,280 US7180942B2 (en) | 2001-12-18 | 2002-12-20 | Joint adaptive optimization of soft decision device and feedback equalizer |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8576903B2 (en) * | 2011-10-18 | 2013-11-05 | Transwitch Corporation | Techniques for adaptively adjusting decision levels of a PAM-N decision feedback equalizer |
Families Citing this family (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7180942B2 (en) | 2001-12-18 | 2007-02-20 | Dotcast, Inc. | Joint adaptive optimization of soft decision device and feedback equalizer |
JP4666920B2 (en) * | 2002-04-16 | 2011-04-06 | トムソン ライセンシング | Decision feedback equalizer |
US7385913B2 (en) * | 2002-04-24 | 2008-06-10 | Motorola, Inc. | Method and apparatus for compensating for variations in a receive portion of a wireless communication device |
US8761321B2 (en) * | 2005-04-07 | 2014-06-24 | Iii Holdings 1, Llc | Optimal feedback weighting for soft-decision cancellers |
US7876810B2 (en) | 2005-04-07 | 2011-01-25 | Rambus Inc. | Soft weighted interference cancellation for CDMA systems |
US7808937B2 (en) * | 2005-04-07 | 2010-10-05 | Rambus, Inc. | Variable interference cancellation technology for CDMA systems |
US7715508B2 (en) * | 2005-11-15 | 2010-05-11 | Tensorcomm, Incorporated | Iterative interference cancellation using mixed feedback weights and stabilizing step sizes |
US8005128B1 (en) | 2003-09-23 | 2011-08-23 | Rambus Inc. | Methods for estimation and interference cancellation for signal processing |
US7293057B2 (en) * | 2002-10-02 | 2007-11-06 | Plexus Networks, Inc. | Method and apparatus for cancelling inter-symbol interference (ISI) within a communication channel |
US7324616B2 (en) * | 2004-03-01 | 2008-01-29 | Motorola, Inc. | Low cost and high performance narrowband interference cancellation system |
US7526022B2 (en) * | 2004-05-19 | 2009-04-28 | Harris Corporation | Low complexity equalizer |
US7924910B2 (en) * | 2005-01-04 | 2011-04-12 | Vitesse Semiconductor Corporation | Adaptive equalization with group delay |
US7522663B2 (en) * | 2005-03-10 | 2009-04-21 | Stmicroelectronics, Inc. | Burst error limiting feedback equalizer system and method for multidimensional modulation systems |
US7826516B2 (en) | 2005-11-15 | 2010-11-02 | Rambus Inc. | Iterative interference canceller for wireless multiple-access systems with multiple receive antennas |
US7991088B2 (en) | 2005-11-15 | 2011-08-02 | Tommy Guess | Iterative interference cancellation using mixed feedback weights and stabilizing step sizes |
US7711075B2 (en) | 2005-11-15 | 2010-05-04 | Tensorcomm Incorporated | Iterative interference cancellation using mixed feedback weights and stabilizing step sizes |
US7702048B2 (en) * | 2005-11-15 | 2010-04-20 | Tensorcomm, Incorporated | Iterative interference cancellation using mixed feedback weights and stabilizing step sizes |
US20070110135A1 (en) * | 2005-11-15 | 2007-05-17 | Tommy Guess | Iterative interference cancellation for MIMO-OFDM receivers |
US7623602B2 (en) * | 2005-11-15 | 2009-11-24 | Tensorcomm, Inc. | Iterative interference canceller for wireless multiple-access systems employing closed loop transmit diversity |
US7826523B2 (en) * | 2006-03-31 | 2010-11-02 | Intel Corporation | Effective adaptive filtering techniques |
US9553743B2 (en) * | 2014-08-25 | 2017-01-24 | Broadcom Corporation | Two-dimensional (2D) decision feedback equalizer (DFE) slicer within communication systems |
US9992044B2 (en) | 2015-05-28 | 2018-06-05 | King Fahd University Of Petroleum And Minerals | System and method for applying adaptive frequency-domain RLS DFE for uplink SC-FDMA |
US10560289B1 (en) | 2018-09-13 | 2020-02-11 | Viasat, Inc. | Adaptive equalizer system |
TWI739661B (en) * | 2020-11-13 | 2021-09-11 | 瑞昱半導體股份有限公司 | Method of configuring decision feedback equalizer and related decision feedback equalizer thereof |
Citations (144)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2138330A (en) | 1937-07-19 | 1938-11-29 | Harold E Thompson | Radio frequency coil |
US2977551A (en) | 1957-03-18 | 1961-03-28 | Nat Res Dev | Microwave modulator |
US3386033A (en) | 1965-02-11 | 1968-05-28 | Univ Ohio State Res Found | Amplifier using antenna as a circuit element |
US3703685A (en) | 1969-09-10 | 1972-11-21 | Labtron Corp Of America | Multiband antenna with associated r.f. amplifier |
US3714659A (en) | 1968-12-10 | 1973-01-30 | C Firman | Very low frequency subminiature active antenna |
US3774218A (en) | 1972-01-18 | 1973-11-20 | C Fowler | Coaxial cable loop antenna with unidirectional current amplifier opposite the output |
US3838444A (en) | 1972-10-30 | 1974-09-24 | Hazeltine Research Inc | System for transmitting auxiliary information in low energy density portion of color tv spectrum |
US3873771A (en) | 1972-04-11 | 1975-03-25 | Telescan Communications System | Simultaneous transmission of a video and an audio signal through an ordinary telephone transmission line |
US3924060A (en) | 1974-06-24 | 1975-12-02 | Hazeltine Research Inc | Continuous information add-on system |
US3974449A (en) | 1975-03-21 | 1976-08-10 | Bell Telephone Laboratories, Incorporated | Joint decision feedback equalization and carrier recovery adaptation in data transmission systems |
US3984624A (en) | 1974-07-25 | 1976-10-05 | Weston Instruments, Inc. | Video system for conveying digital and analog information |
US3999005A (en) | 1974-12-26 | 1976-12-21 | Ecom Corporation | Secure transmission of AM or FM signals |
US4081497A (en) | 1975-07-09 | 1978-03-28 | Idemitsu Petrochemical Co., Ltd. | Method for producing a high impact polystyrene |
US4115778A (en) | 1976-11-18 | 1978-09-19 | Jfd Electronics Corporation | Electronic solid state FM dipole antenna |
US4128880A (en) | 1976-06-30 | 1978-12-05 | Cray Research, Inc. | Computer vector register processing |
US4302626A (en) | 1977-03-21 | 1981-11-24 | Magnavox Consumer Electronics Company | Low frequency AM stereophonic broadcast and receiving apparatus |
US4310920A (en) | 1977-01-05 | 1982-01-12 | Hayes William A | Single sideband AM-FM stereo modulation system |
US4316215A (en) | 1979-09-26 | 1982-02-16 | Matsushita Electric Industrial Co., Ltd. | System for improving reproduction of images in a color television receiver |
US4322842A (en) | 1979-10-23 | 1982-03-30 | Altran Electronics | Broadcast system for distribution automation and remote metering |
US4337479A (en) | 1979-09-13 | 1982-06-29 | Matsushita Electric Industrial Co., Ltd. | Color resolution compensator |
US4379947A (en) | 1979-02-02 | 1983-04-12 | Teleprompter Corporation | System for transmitting data simultaneously with audio |
US4459681A (en) | 1981-04-02 | 1984-07-10 | Nippon Electric Co., Ltd. | FIFO Memory device |
US4459595A (en) | 1981-12-18 | 1984-07-10 | Rockwell International Corporation | Condition responsive RF transmitting device |
US4469437A (en) | 1982-03-02 | 1984-09-04 | Minolta Camera Kabushiki Kaisha | Light measurement and light control data calculation device for a photographic enlarger |
US4476484A (en) | 1982-06-24 | 1984-10-09 | At&T Bell Laboratories | Technique for providing compatibility between high-definition and conventional color television |
US4523225A (en) | 1982-05-13 | 1985-06-11 | Matsushita Electric Industrial Co., Ltd. | Image display apparatus |
US4535352A (en) | 1984-04-16 | 1985-08-13 | At&T Bell Laboratories | Technique for generating semi-compatible high definition television signals for transmission over two cable TV channels |
US4551011A (en) | 1981-12-11 | 1985-11-05 | Minolta Camera Kabushiki Kaisha | Light source for exposure |
US4575225A (en) | 1982-09-16 | 1986-03-11 | Minolta Camera Kabushiki Kaisha | Color enlarger |
US4587495A (en) | 1982-05-21 | 1986-05-06 | Hitachi, Ltd. | Cascode amplifier with an improved biasing arrangement |
US4589011A (en) | 1984-01-16 | 1986-05-13 | At&T Bell Laboratories | Single sideband modulated chrominance information for compatible high-definition television |
US4602260A (en) | 1983-04-28 | 1986-07-22 | Hans Kolbe & Co. | Windshield antenna |
US4607230A (en) | 1984-08-29 | 1986-08-19 | Fujitsu Limited | Receiver unit having synchronous pull-in circuit |
US4754233A (en) | 1987-06-22 | 1988-06-28 | Motorola, Inc. | Low noise ultra high frequency amplifier having automatic gain control |
EP0308241A2 (en) | 1987-09-18 | 1989-03-22 | Matsushita Electric Industrial Co., Ltd. | Multiplex signal processing apparatus |
US4821097A (en) | 1987-03-05 | 1989-04-11 | General Instrument Corporation | Apparatus and method for providing digital audio on the sound carrier of a standard television signal |
US4870489A (en) | 1987-07-23 | 1989-09-26 | Ducret Robert P | NTSC compatible HDTV transmission system |
US4879606A (en) | 1988-06-06 | 1989-11-07 | General Electric Company | EDTV recording apparatus |
US4882614A (en) | 1986-07-14 | 1989-11-21 | Matsushita Electric Industrial Co., Ltd. | Multiplex signal processing apparatus |
US4882725A (en) | 1987-01-30 | 1989-11-21 | Hitachi, Ltd. | Multiplex transmission method and apparatus |
US4926244A (en) | 1987-09-14 | 1990-05-15 | General Electric Company | Extended definition widescreen television signal processing system with alternate subcarrier |
US4928177A (en) | 1988-04-11 | 1990-05-22 | Cooper Industries, Inc. | Two-way data broadcast networks |
US4958230A (en) | 1989-08-11 | 1990-09-18 | General Electric Company | Method of transmitting auxiliary information in a television signal |
US4985769A (en) | 1988-03-23 | 1991-01-15 | Matsushita Electric Industrial Co., Ltd. | Multiplex TV signal processing apparatus |
US5006926A (en) | 1988-10-03 | 1991-04-09 | North American Philips Corporation | High definition multiple analog component amplitude modulated television transmission system |
US5019830A (en) | 1989-03-13 | 1991-05-28 | Harada Kogyo Kabushiki Kaisha | Amplified FM antenna with parallel radiator and ground plane |
US5036386A (en) | 1988-07-22 | 1991-07-30 | Matsushita Electric Industrial Co., Ltd. | Television signal processing apparatus |
US5038402A (en) | 1988-12-06 | 1991-08-06 | General Instrument Corporation | Apparatus and method for providing digital audio in the FM broadcast band |
US5087975A (en) | 1990-11-09 | 1992-02-11 | Zenith Electronics Corporation | VSB HDTV transmission system with reduced NTSC co-channel interference |
US5093718A (en) | 1990-09-28 | 1992-03-03 | Inteletext Systems, Inc. | Interactive home information system |
US5103310A (en) | 1990-07-20 | 1992-04-07 | General Electric Company | Interference reduction for extra-spectrum, compatible television system |
US5103295A (en) | 1989-04-28 | 1992-04-07 | Matsushita Electric Industrial Co., Ltd. | Television signal processor for eliminating quality differences between portions of television images having different aspect ratios |
US5126998A (en) | 1990-05-16 | 1992-06-30 | U.V. Satellite Resources, Inc. | Method and apparatus for transmitting and receiving a carrier signal which is simultaneously frequency and phase modulated |
US5132988A (en) | 1990-12-03 | 1992-07-21 | Board Of Trustees, Leland Stanford Jr. University | Adaptive decision feedback equalizer apparatus for processing information stored on digital storage media |
US5134464A (en) | 1990-11-16 | 1992-07-28 | North American Philips Corporation | Method and apparatus for the transmission and reception of a multicarrier digital television signal |
US5142353A (en) | 1987-12-23 | 1992-08-25 | Matsushita Electric Industrial Co., Ltd. | Television signal processing apparatus |
US5151783A (en) | 1991-06-05 | 1992-09-29 | Faroudja Y C | Digital television with enhancement |
US5172126A (en) | 1988-08-12 | 1992-12-15 | Kabushiki Kaisha Enu Esu | Low noise lumped parameter active receiving antenna |
WO1992022983A2 (en) | 1991-06-11 | 1992-12-23 | Browne H Lee | Large capacity, random access, multi-source recorder player |
US5177604A (en) | 1986-05-14 | 1993-01-05 | Radio Telcom & Technology, Inc. | Interactive television and data transmission system |
US5214501A (en) | 1988-10-03 | 1993-05-25 | North American Philips Corporation | Method and apparatus for the transmission and reception of a multicarrier high definition television signal |
US5220420A (en) | 1990-09-28 | 1993-06-15 | Inteletext Systems, Inc. | Interactive home information system for distributing compressed television programming |
US5235619A (en) | 1990-03-20 | 1993-08-10 | Scientific-Atlanta, Inc. | Cable television radio frequency subscriber data transmission apparatus and rf return method |
US5243423A (en) | 1991-12-20 | 1993-09-07 | A. C. Nielsen Company | Spread spectrum digital data transmission over TV video |
US5247351A (en) | 1989-11-09 | 1993-09-21 | Samsung Electronics Co., Ltd. | High definition television system compatible with NTSC system |
US5270817A (en) | 1992-04-21 | 1993-12-14 | Matsushita Electric Industrial Co., Ltd. | Television signal processing apparatus for separating an auxiliary signal from a letterbox signal |
US5276507A (en) | 1990-03-23 | 1994-01-04 | Matsushita Electric Industrial Co., Ltd. | Multiplex TV signal processing apparatus |
EP0577351A2 (en) | 1992-06-30 | 1994-01-05 | Matsushita Electric Industrial Co., Ltd. | Television signal processing apparatus |
US5287180A (en) | 1991-02-04 | 1994-02-15 | General Electric Company | Modulator/demodulater for compatible high definition television system |
US5327460A (en) | 1992-07-07 | 1994-07-05 | National Semiconductor Corporation | Method and apparatus for filtering post decision feedback equalization noise |
WO1994023470A1 (en) | 1993-03-26 | 1994-10-13 | Superconductor Technologies, Inc. | Low noise amplifier |
US5357284A (en) | 1990-03-29 | 1994-10-18 | Dolby Laboratories Licensing Corporation | Compatible digital audio for NTSC television |
US5379324A (en) | 1991-07-02 | 1995-01-03 | Motorola, Inc. | System and method for calculating channel gain and noise variance of a communication channel |
WO1995001676A1 (en) | 1993-07-02 | 1995-01-12 | Motorola, Inc. | Radio frequency amplifier with variable gain control |
US5386239A (en) | 1993-05-03 | 1995-01-31 | Thomson Consumer Electronics, Inc. | Multiple QAM digital television signal decoder |
US5430661A (en) | 1990-12-03 | 1995-07-04 | Board Of Trustees Leland Stanford, Jr. University | Adaptive decision feedback equalizer apparatus for processing information stored on digital storage media |
US5442403A (en) | 1989-12-18 | 1995-08-15 | Matsushita Electric Industrial Co., Ltd. | Wide-screen TV signal transmission apparatus |
US5448299A (en) | 1994-01-05 | 1995-09-05 | Samsung Electronics Co., Ltd. | Apparatus for processing BPSK signals transmitted with NTSC TV on quadrature-phase video carrier |
US5461426A (en) | 1993-08-20 | 1995-10-24 | Samsung Electronics Co., Ltd. | Apparatus for processing modified NTSC television signals, with digital signals buried therewithin |
US5534933A (en) | 1993-10-26 | 1996-07-09 | Samsung Electronics Co., Ltd. | Apparatus for processing NTSC TV signals having digital signals on quadrature-phase video carrier |
US5550579A (en) | 1986-05-14 | 1996-08-27 | Radio Telecom & Technology, Inc. | Two-way cable tv conversion system |
US5550578A (en) | 1990-09-28 | 1996-08-27 | Ictv, Inc. | Interactive and conventional television information system |
US5557316A (en) | 1990-09-28 | 1996-09-17 | Ictv, Inc. | System for distributing broadcast television services identically on a first bandwidth portion of a plurality of express trunks and interactive services over a second bandwidth portion of each express trunk on a subscriber demand basis |
US5559559A (en) | 1991-06-14 | 1996-09-24 | Wavephore, Inc. | Transmitting a secondary signal with dynamic injection level control |
US5563664A (en) | 1994-01-05 | 1996-10-08 | Samsung Electronics Co., Ltd. | Pre-frame-comb as well as pre-line-comb partial-response filtering of BPSK buried in a TV signal |
US5579055A (en) | 1993-06-07 | 1996-11-26 | Scientific-Atlanta, Inc. | Electronic program guide and text channel data controller |
US5585975A (en) | 1994-11-17 | 1996-12-17 | Cirrus Logic, Inc. | Equalization for sample value estimation and sequence detection in a sampled amplitude read channel |
US5586121A (en) | 1995-04-21 | 1996-12-17 | Hybrid Networks, Inc. | Asymmetric hybrid access system and method |
US5587743A (en) | 1991-06-14 | 1996-12-24 | Wavephore, Inc. | Signal processors for transparent and simultaneous transmission and reception of a data signal in a video signal |
US5600573A (en) | 1992-12-09 | 1997-02-04 | Discovery Communications, Inc. | Operations center with video storage for a television program packaging and delivery system |
US5617148A (en) | 1991-06-14 | 1997-04-01 | Wavephore, Inc. | Filter by-pass for transmitting an additional signal with a video signal |
US5694424A (en) | 1996-03-15 | 1997-12-02 | Ariyavisitakul; Sirikiat | Pre-cancelling postcursors in decision feedback equalization |
US5714965A (en) | 1995-01-27 | 1998-02-03 | Nippon Mektron, Ltd | Active reception antenna with coplanar feeder |
US5734853A (en) | 1992-12-09 | 1998-03-31 | Discovery Communications, Inc. | Set top terminal for cable television delivery systems |
USRE35774E (en) | 1991-09-10 | 1998-04-21 | Hybrid Networks, Inc. | Remote link adapter for use in TV broadcast data transmission system |
US5742902A (en) | 1996-03-29 | 1998-04-21 | Gmi Holdings, Inc. | Super-regenerative circuit apparatus for a door operator receiver and door operator incorporating the same |
US5809086A (en) | 1996-03-20 | 1998-09-15 | Lucent Technologies Inc. | Intelligent timing recovery for a broadband adaptive equalizer |
US5818441A (en) | 1995-06-15 | 1998-10-06 | Intel Corporation | System and method for simulating two-way connectivity for one way data streams |
US5881302A (en) | 1994-05-31 | 1999-03-09 | Nec Corporation | Vector processing unit with reconfigurable data buffer |
US5909253A (en) | 1997-12-09 | 1999-06-01 | Sarnoff Corporation | Reducing video crosstalk in a data carrier located within a vestigial sideband of a standard television signal |
US5946048A (en) | 1997-03-12 | 1999-08-31 | Hybrid Networks, Inc. | Network device for handling digital data over a TV channel |
US5946047A (en) | 1997-03-12 | 1999-08-31 | Hybrid Networks, Inc. | Network system for handling digital data over a TV channel |
US5946351A (en) | 1996-12-27 | 1999-08-31 | At&T Corporation | Tap selectable decision feedback equalizer |
US5956346A (en) | 1996-10-22 | 1999-09-21 | Hybrid Networks, Inc. | Broadband communication system using TV channel roll-off spectrum |
US5959660A (en) | 1996-08-26 | 1999-09-28 | Hybrid Networks, Inc. | Subchannelization scheme for use in a broadband communications system |
WO1999055087A1 (en) | 1998-04-17 | 1999-10-28 | Encamera Sciences Corporation | Expanded information capacity for existing communication transmission systems |
US5994891A (en) | 1994-09-26 | 1999-11-30 | The Boeing Company | Electrically small, wideband, high dynamic range antenna having a serial array of optical modulators |
US6012161A (en) | 1997-11-26 | 2000-01-04 | At&T Corp. | System and method for joint coding and decision feedback equalization |
US6018764A (en) | 1996-12-10 | 2000-01-25 | General Instrument Corporation | Mapping uniform resource locators to broadcast addresses in a television signal |
US6018526A (en) | 1997-02-20 | 2000-01-25 | Macronix America, Inc. | Bridge device with self learning between network media and integrated circuit and method based on the same |
US6034678A (en) | 1991-09-10 | 2000-03-07 | Ictv, Inc. | Cable television system with remote interactive processor |
US6047159A (en) | 1996-06-03 | 2000-04-04 | Scientific-Atlanta, Inc. | Reconfigurable node for a communications network |
US6066993A (en) | 1998-01-16 | 2000-05-23 | Mitsubishi Denki Kabushiki Kaisha | Duplexer circuit apparatus provided with amplifier and impedance matching inductor |
US6073030A (en) | 1995-02-13 | 2000-06-06 | Intel Corporation | Use of RSSI indication for improved data transmission over amps network |
US6192384B1 (en) | 1998-09-14 | 2001-02-20 | The Board Of Trustees Of The Leland Stanford Junior University | System and method for performing compound vector operations |
US6201536B1 (en) | 1992-12-09 | 2001-03-13 | Discovery Communications, Inc. | Network manager for cable television system headends |
US6226323B1 (en) | 1998-11-03 | 2001-05-01 | Broadcom Corporation | Technique for minimizing decision feedback equalizer wordlength in the presence of a DC component |
US6240133B1 (en) | 1998-02-05 | 2001-05-29 | Texas Instruments Incorporated | High stability fast tracking adaptive equalizer for use with time varying communication channels |
US6268774B1 (en) | 1999-11-05 | 2001-07-31 | Intel Corporation | Self-tuning amplifier |
US20010022813A1 (en) | 1998-11-03 | 2001-09-20 | Broadcom Corporation | Technique for minimizing decision feedback equalizer wordlength in the presence of a DC component |
US6305020B1 (en) | 1995-11-01 | 2001-10-16 | Ictv, Inc. | System manager and hypertext control interface for interactive cable television system |
US6310548B1 (en) | 2000-05-30 | 2001-10-30 | Rs Group, Inc. | Method and system for door alert |
US6314134B1 (en) | 1998-04-24 | 2001-11-06 | Lucent Technologies Inc. | Blind equalization algorithm with joint use of the constant modulus algorithm and the multimodulus algorithm |
EP1156634A1 (en) | 2000-05-15 | 2001-11-21 | Lucent Technologies Inc. | Sequence estimator and equaliser |
WO2002007425A2 (en) | 2000-07-14 | 2002-01-24 | Chinook Communications, Inc. | System for variable-rate modulation and demodulation of data using information embedding in television signals |
US6356586B1 (en) | 1999-09-03 | 2002-03-12 | Lucent Technologies, Inc. | Methods and apparatus for parallel decision-feedback decoding in a communication system |
US6370571B1 (en) | 1997-03-05 | 2002-04-09 | At Home Corporation | System and method for delivering high-performance online multimedia services |
US6377529B1 (en) | 2000-06-01 | 2002-04-23 | Calimetrics, Inc. | Method for providing improved equalization for the reading of marks on optical data-storage media |
US6385237B1 (en) | 1995-04-27 | 2002-05-07 | Wavetek Wandell And Goltermann | Non-invasive digital cable test system |
US20020056140A1 (en) | 2000-03-01 | 2002-05-09 | Sony Corporation | Television signal distributor apparatus, receiver apparatus, television signal transmission system and method |
US20020059597A1 (en) | 2000-06-30 | 2002-05-16 | Dan Kikinis | Method and apparatus for notifying users of interactive functions |
US6426973B1 (en) | 1999-04-29 | 2002-07-30 | The Board Of Trustees Of The University Of Illinois | Differential minimum mean squared error communication signal compensation method |
US20020104083A1 (en) | 1992-12-09 | 2002-08-01 | Hendricks John S. | Internally targeted advertisements using television delivery systems |
WO2002084965A1 (en) | 2001-04-10 | 2002-10-24 | Koninklijke Philips Electronics N.V. | A two stage equalizer for trellis coded systems |
US20020186764A1 (en) | 2001-04-06 | 2002-12-12 | Sarnoff Corporation | Method and apparatus for equalizing a radio frequency signal |
US6510553B1 (en) | 1998-10-26 | 2003-01-21 | Intel Corporation | Method of streaming video from multiple sources over a network |
US20030095590A1 (en) | 2001-11-16 | 2003-05-22 | Fuller Arthur T. G. | Symbol-directed weighting in parallel interference cancellation |
US20030156603A1 (en) | 1995-08-25 | 2003-08-21 | Rakib Selim Shlomo | Apparatus and method for trellis encoding data for transmission in digital data transmission systems |
US6680971B1 (en) | 1998-05-18 | 2004-01-20 | Sarnoff Corporation | Passband equalizer for a vestigial sideband signal receiver |
US6754277B1 (en) | 1998-10-06 | 2004-06-22 | Texas Instruments Incorporated | Error protection for compressed video |
US6754715B1 (en) | 1997-01-30 | 2004-06-22 | Microsoft Corporation | Methods and apparatus for implementing control functions in a streamed video display system |
US6829298B1 (en) | 1999-03-17 | 2004-12-07 | Pioneer Corporation | Signal processing circuit for a digital signal receiving system |
US6834039B1 (en) | 2000-03-10 | 2004-12-21 | Hughes Electronics Corporation | Apparatus and method for efficient TDMA bandwidth allocation for TCP/IP satellite-based networks |
US7180942B2 (en) | 2001-12-18 | 2007-02-20 | Dotcast, Inc. | Joint adaptive optimization of soft decision device and feedback equalizer |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4750036A (en) * | 1986-05-14 | 1988-06-07 | Radio Telcom & Technology, Inc. | Interactive television and data transmission system |
US5006296A (en) * | 1988-09-01 | 1991-04-09 | The Dow Chemical Company | Process for the preparation of fibers of stereoregular polystyrene |
US5291289A (en) * | 1990-11-16 | 1994-03-01 | North American Philips Corporation | Method and apparatus for transmission and reception of a digital television signal using multicarrier modulation |
US5961603A (en) * | 1996-04-10 | 1999-10-05 | Worldgate Communications, Inc. | Access system and method for providing interactive access to an information source through a networked distribution system |
-
2002
- 2002-12-20 US US10/327,280 patent/US7180942B2/en not_active Ceased
-
2003
- 2003-12-18 WO PCT/US2003/040672 patent/WO2004059932A2/en not_active Application Discontinuation
- 2003-12-18 AU AU2003301141A patent/AU2003301141A1/en not_active Abandoned
-
2009
- 2009-02-20 US US12/390,368 patent/USRE42558E1/en active Active
Patent Citations (168)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2138330A (en) | 1937-07-19 | 1938-11-29 | Harold E Thompson | Radio frequency coil |
US2977551A (en) | 1957-03-18 | 1961-03-28 | Nat Res Dev | Microwave modulator |
US3386033A (en) | 1965-02-11 | 1968-05-28 | Univ Ohio State Res Found | Amplifier using antenna as a circuit element |
US3714659A (en) | 1968-12-10 | 1973-01-30 | C Firman | Very low frequency subminiature active antenna |
US3703685A (en) | 1969-09-10 | 1972-11-21 | Labtron Corp Of America | Multiband antenna with associated r.f. amplifier |
US3774218A (en) | 1972-01-18 | 1973-11-20 | C Fowler | Coaxial cable loop antenna with unidirectional current amplifier opposite the output |
US3873771A (en) | 1972-04-11 | 1975-03-25 | Telescan Communications System | Simultaneous transmission of a video and an audio signal through an ordinary telephone transmission line |
US3838444A (en) | 1972-10-30 | 1974-09-24 | Hazeltine Research Inc | System for transmitting auxiliary information in low energy density portion of color tv spectrum |
US3924060A (en) | 1974-06-24 | 1975-12-02 | Hazeltine Research Inc | Continuous information add-on system |
US3984624A (en) | 1974-07-25 | 1976-10-05 | Weston Instruments, Inc. | Video system for conveying digital and analog information |
US3999005A (en) | 1974-12-26 | 1976-12-21 | Ecom Corporation | Secure transmission of AM or FM signals |
US3974449A (en) | 1975-03-21 | 1976-08-10 | Bell Telephone Laboratories, Incorporated | Joint decision feedback equalization and carrier recovery adaptation in data transmission systems |
US4081497A (en) | 1975-07-09 | 1978-03-28 | Idemitsu Petrochemical Co., Ltd. | Method for producing a high impact polystyrene |
US4128880A (en) | 1976-06-30 | 1978-12-05 | Cray Research, Inc. | Computer vector register processing |
US4115778A (en) | 1976-11-18 | 1978-09-19 | Jfd Electronics Corporation | Electronic solid state FM dipole antenna |
US4310920A (en) | 1977-01-05 | 1982-01-12 | Hayes William A | Single sideband AM-FM stereo modulation system |
US4302626A (en) | 1977-03-21 | 1981-11-24 | Magnavox Consumer Electronics Company | Low frequency AM stereophonic broadcast and receiving apparatus |
US4379947A (en) | 1979-02-02 | 1983-04-12 | Teleprompter Corporation | System for transmitting data simultaneously with audio |
US4337479A (en) | 1979-09-13 | 1982-06-29 | Matsushita Electric Industrial Co., Ltd. | Color resolution compensator |
US4316215A (en) | 1979-09-26 | 1982-02-16 | Matsushita Electric Industrial Co., Ltd. | System for improving reproduction of images in a color television receiver |
US4322842A (en) | 1979-10-23 | 1982-03-30 | Altran Electronics | Broadcast system for distribution automation and remote metering |
US4513415A (en) | 1979-10-23 | 1985-04-23 | Mcgraw-Edison Company | Broadcast synchronization and supervision system |
US4459681A (en) | 1981-04-02 | 1984-07-10 | Nippon Electric Co., Ltd. | FIFO Memory device |
US4551011A (en) | 1981-12-11 | 1985-11-05 | Minolta Camera Kabushiki Kaisha | Light source for exposure |
US4459595A (en) | 1981-12-18 | 1984-07-10 | Rockwell International Corporation | Condition responsive RF transmitting device |
US4469437A (en) | 1982-03-02 | 1984-09-04 | Minolta Camera Kabushiki Kaisha | Light measurement and light control data calculation device for a photographic enlarger |
US4523225A (en) | 1982-05-13 | 1985-06-11 | Matsushita Electric Industrial Co., Ltd. | Image display apparatus |
US4587495A (en) | 1982-05-21 | 1986-05-06 | Hitachi, Ltd. | Cascode amplifier with an improved biasing arrangement |
US4476484A (en) | 1982-06-24 | 1984-10-09 | At&T Bell Laboratories | Technique for providing compatibility between high-definition and conventional color television |
US4575225A (en) | 1982-09-16 | 1986-03-11 | Minolta Camera Kabushiki Kaisha | Color enlarger |
US4576470A (en) | 1982-09-16 | 1986-03-18 | Minolta Camera Kabushiki Kaisha | Enlarger for use in photography |
US4602260A (en) | 1983-04-28 | 1986-07-22 | Hans Kolbe & Co. | Windshield antenna |
US4589011A (en) | 1984-01-16 | 1986-05-13 | At&T Bell Laboratories | Single sideband modulated chrominance information for compatible high-definition television |
US4535352A (en) | 1984-04-16 | 1985-08-13 | At&T Bell Laboratories | Technique for generating semi-compatible high definition television signals for transmission over two cable TV channels |
US4607230A (en) | 1984-08-29 | 1986-08-19 | Fujitsu Limited | Receiver unit having synchronous pull-in circuit |
US5589872A (en) | 1986-05-14 | 1996-12-31 | Radio Telecom & Technology, Inc. | Compatible interactive TV and multimedia delivery system two-way cable TV conversion system for data transmission over a dedicated frequency band |
US5596361A (en) | 1986-05-14 | 1997-01-21 | Radio Telecom & Technology, Inc. | Two-way cable TV conversion system for data transmission over a dedicated frequency band |
US5812184A (en) | 1986-05-14 | 1998-09-22 | Radio Telecom & Technology, Inc. | Transmission of frame-to-frame reversed polarity signals in a two-way cable TV conversion system |
US5177604A (en) | 1986-05-14 | 1993-01-05 | Radio Telcom & Technology, Inc. | Interactive television and data transmission system |
US5321514A (en) | 1986-05-14 | 1994-06-14 | Radio Telecom & Technology, Inc. | Interactive television and data transmission system |
US5550579A (en) | 1986-05-14 | 1996-08-27 | Radio Telecom & Technology, Inc. | Two-way cable tv conversion system |
US4882614A (en) | 1986-07-14 | 1989-11-21 | Matsushita Electric Industrial Co., Ltd. | Multiplex signal processing apparatus |
US4944032A (en) | 1986-07-14 | 1990-07-24 | Matsushita Electric Industrial Co., Ltd. | Multiplex signal processing apparatus |
US4882725A (en) | 1987-01-30 | 1989-11-21 | Hitachi, Ltd. | Multiplex transmission method and apparatus |
US4821097A (en) | 1987-03-05 | 1989-04-11 | General Instrument Corporation | Apparatus and method for providing digital audio on the sound carrier of a standard television signal |
US4754233A (en) | 1987-06-22 | 1988-06-28 | Motorola, Inc. | Low noise ultra high frequency amplifier having automatic gain control |
US4870489A (en) | 1987-07-23 | 1989-09-26 | Ducret Robert P | NTSC compatible HDTV transmission system |
US4926244A (en) | 1987-09-14 | 1990-05-15 | General Electric Company | Extended definition widescreen television signal processing system with alternate subcarrier |
EP0308241B1 (en) | 1987-09-18 | 1994-02-02 | Matsushita Electric Industrial Co., Ltd. | Multiplex signal processing apparatus |
US4907218A (en) | 1987-09-18 | 1990-03-06 | Matsushita Electric Industrial Co., Ltd. | Multiplex signal processing apparatus |
EP0308241A2 (en) | 1987-09-18 | 1989-03-22 | Matsushita Electric Industrial Co., Ltd. | Multiplex signal processing apparatus |
US5142353A (en) | 1987-12-23 | 1992-08-25 | Matsushita Electric Industrial Co., Ltd. | Television signal processing apparatus |
US4985769A (en) | 1988-03-23 | 1991-01-15 | Matsushita Electric Industrial Co., Ltd. | Multiplex TV signal processing apparatus |
US4928177A (en) | 1988-04-11 | 1990-05-22 | Cooper Industries, Inc. | Two-way data broadcast networks |
US4879606A (en) | 1988-06-06 | 1989-11-07 | General Electric Company | EDTV recording apparatus |
US5036386A (en) | 1988-07-22 | 1991-07-30 | Matsushita Electric Industrial Co., Ltd. | Television signal processing apparatus |
US5172126A (en) | 1988-08-12 | 1992-12-15 | Kabushiki Kaisha Enu Esu | Low noise lumped parameter active receiving antenna |
US5214501A (en) | 1988-10-03 | 1993-05-25 | North American Philips Corporation | Method and apparatus for the transmission and reception of a multicarrier high definition television signal |
US5006926A (en) | 1988-10-03 | 1991-04-09 | North American Philips Corporation | High definition multiple analog component amplitude modulated television transmission system |
US5293633A (en) | 1988-12-06 | 1994-03-08 | General Instrument Corporation | Apparatus and method for providing digital audio in the cable television band |
US5038402A (en) | 1988-12-06 | 1991-08-06 | General Instrument Corporation | Apparatus and method for providing digital audio in the FM broadcast band |
US5019830A (en) | 1989-03-13 | 1991-05-28 | Harada Kogyo Kabushiki Kaisha | Amplified FM antenna with parallel radiator and ground plane |
US5103295A (en) | 1989-04-28 | 1992-04-07 | Matsushita Electric Industrial Co., Ltd. | Television signal processor for eliminating quality differences between portions of television images having different aspect ratios |
US4958230A (en) | 1989-08-11 | 1990-09-18 | General Electric Company | Method of transmitting auxiliary information in a television signal |
US5247351A (en) | 1989-11-09 | 1993-09-21 | Samsung Electronics Co., Ltd. | High definition television system compatible with NTSC system |
US5442403A (en) | 1989-12-18 | 1995-08-15 | Matsushita Electric Industrial Co., Ltd. | Wide-screen TV signal transmission apparatus |
US5235619A (en) | 1990-03-20 | 1993-08-10 | Scientific-Atlanta, Inc. | Cable television radio frequency subscriber data transmission apparatus and rf return method |
US5276507A (en) | 1990-03-23 | 1994-01-04 | Matsushita Electric Industrial Co., Ltd. | Multiplex TV signal processing apparatus |
US5357284A (en) | 1990-03-29 | 1994-10-18 | Dolby Laboratories Licensing Corporation | Compatible digital audio for NTSC television |
US5126998A (en) | 1990-05-16 | 1992-06-30 | U.V. Satellite Resources, Inc. | Method and apparatus for transmitting and receiving a carrier signal which is simultaneously frequency and phase modulated |
US5103310A (en) | 1990-07-20 | 1992-04-07 | General Electric Company | Interference reduction for extra-spectrum, compatible television system |
US5550578A (en) | 1990-09-28 | 1996-08-27 | Ictv, Inc. | Interactive and conventional television information system |
US5557316A (en) | 1990-09-28 | 1996-09-17 | Ictv, Inc. | System for distributing broadcast television services identically on a first bandwidth portion of a plurality of express trunks and interactive services over a second bandwidth portion of each express trunk on a subscriber demand basis |
US5220420A (en) | 1990-09-28 | 1993-06-15 | Inteletext Systems, Inc. | Interactive home information system for distributing compressed television programming |
US6100883A (en) | 1990-09-28 | 2000-08-08 | Ictv, Inc. | Home interface controller for providing interactive cable television |
US5093718A (en) | 1990-09-28 | 1992-03-03 | Inteletext Systems, Inc. | Interactive home information system |
US5087975A (en) | 1990-11-09 | 1992-02-11 | Zenith Electronics Corporation | VSB HDTV transmission system with reduced NTSC co-channel interference |
US5134464A (en) | 1990-11-16 | 1992-07-28 | North American Philips Corporation | Method and apparatus for the transmission and reception of a multicarrier digital television signal |
US5430661A (en) | 1990-12-03 | 1995-07-04 | Board Of Trustees Leland Stanford, Jr. University | Adaptive decision feedback equalizer apparatus for processing information stored on digital storage media |
US5132988A (en) | 1990-12-03 | 1992-07-21 | Board Of Trustees, Leland Stanford Jr. University | Adaptive decision feedback equalizer apparatus for processing information stored on digital storage media |
US5287180A (en) | 1991-02-04 | 1994-02-15 | General Electric Company | Modulator/demodulater for compatible high definition television system |
US5151783A (en) | 1991-06-05 | 1992-09-29 | Faroudja Y C | Digital television with enhancement |
WO1992022983A2 (en) | 1991-06-11 | 1992-12-23 | Browne H Lee | Large capacity, random access, multi-source recorder player |
WO1992022983A3 (en) | 1991-06-11 | 1993-04-15 | H Lee Browne | Large capacity, random access, multi-source recorder player |
US5559559A (en) | 1991-06-14 | 1996-09-24 | Wavephore, Inc. | Transmitting a secondary signal with dynamic injection level control |
US5587743A (en) | 1991-06-14 | 1996-12-24 | Wavephore, Inc. | Signal processors for transparent and simultaneous transmission and reception of a data signal in a video signal |
US5617148A (en) | 1991-06-14 | 1997-04-01 | Wavephore, Inc. | Filter by-pass for transmitting an additional signal with a video signal |
US5666168A (en) | 1991-06-14 | 1997-09-09 | Wavephore, Inc. | System for transmitting facsimile data in the upper vestigial chrominance sideband of a video signal |
US5379324A (en) | 1991-07-02 | 1995-01-03 | Motorola, Inc. | System and method for calculating channel gain and noise variance of a communication channel |
USRE35774E (en) | 1991-09-10 | 1998-04-21 | Hybrid Networks, Inc. | Remote link adapter for use in TV broadcast data transmission system |
US6034678A (en) | 1991-09-10 | 2000-03-07 | Ictv, Inc. | Cable television system with remote interactive processor |
US5243423A (en) | 1991-12-20 | 1993-09-07 | A. C. Nielsen Company | Spread spectrum digital data transmission over TV video |
US5270817A (en) | 1992-04-21 | 1993-12-14 | Matsushita Electric Industrial Co., Ltd. | Television signal processing apparatus for separating an auxiliary signal from a letterbox signal |
EP0577351A2 (en) | 1992-06-30 | 1994-01-05 | Matsushita Electric Industrial Co., Ltd. | Television signal processing apparatus |
US5327460A (en) | 1992-07-07 | 1994-07-05 | National Semiconductor Corporation | Method and apparatus for filtering post decision feedback equalization noise |
US6201536B1 (en) | 1992-12-09 | 2001-03-13 | Discovery Communications, Inc. | Network manager for cable television system headends |
US20020104083A1 (en) | 1992-12-09 | 2002-08-01 | Hendricks John S. | Internally targeted advertisements using television delivery systems |
US5600573A (en) | 1992-12-09 | 1997-02-04 | Discovery Communications, Inc. | Operations center with video storage for a television program packaging and delivery system |
US5734853A (en) | 1992-12-09 | 1998-03-31 | Discovery Communications, Inc. | Set top terminal for cable television delivery systems |
WO1994023470A1 (en) | 1993-03-26 | 1994-10-13 | Superconductor Technologies, Inc. | Low noise amplifier |
US5386239A (en) | 1993-05-03 | 1995-01-31 | Thomson Consumer Electronics, Inc. | Multiple QAM digital television signal decoder |
US5579055A (en) | 1993-06-07 | 1996-11-26 | Scientific-Atlanta, Inc. | Electronic program guide and text channel data controller |
WO1995001676A1 (en) | 1993-07-02 | 1995-01-12 | Motorola, Inc. | Radio frequency amplifier with variable gain control |
US5461426A (en) | 1993-08-20 | 1995-10-24 | Samsung Electronics Co., Ltd. | Apparatus for processing modified NTSC television signals, with digital signals buried therewithin |
US5534933A (en) | 1993-10-26 | 1996-07-09 | Samsung Electronics Co., Ltd. | Apparatus for processing NTSC TV signals having digital signals on quadrature-phase video carrier |
US5563664A (en) | 1994-01-05 | 1996-10-08 | Samsung Electronics Co., Ltd. | Pre-frame-comb as well as pre-line-comb partial-response filtering of BPSK buried in a TV signal |
US5448299A (en) | 1994-01-05 | 1995-09-05 | Samsung Electronics Co., Ltd. | Apparatus for processing BPSK signals transmitted with NTSC TV on quadrature-phase video carrier |
US5881302A (en) | 1994-05-31 | 1999-03-09 | Nec Corporation | Vector processing unit with reconfigurable data buffer |
US5994891A (en) | 1994-09-26 | 1999-11-30 | The Boeing Company | Electrically small, wideband, high dynamic range antenna having a serial array of optical modulators |
US5585975A (en) | 1994-11-17 | 1996-12-17 | Cirrus Logic, Inc. | Equalization for sample value estimation and sequence detection in a sampled amplitude read channel |
US5714965A (en) | 1995-01-27 | 1998-02-03 | Nippon Mektron, Ltd | Active reception antenna with coplanar feeder |
US6073030A (en) | 1995-02-13 | 2000-06-06 | Intel Corporation | Use of RSSI indication for improved data transmission over amps network |
US6005850A (en) | 1995-04-21 | 1999-12-21 | Hybrid Networks, Inc. | Hybrid access system with remote device monitoring scheme |
US5586121A (en) | 1995-04-21 | 1996-12-17 | Hybrid Networks, Inc. | Asymmetric hybrid access system and method |
US6016316A (en) | 1995-04-21 | 2000-01-18 | Hybrid Networks, Inc. | Hybrid access system employing packet suppression scheme |
US5818845A (en) | 1995-04-21 | 1998-10-06 | Hybrid Networks, Inc. | Hybrid access system having channel allocation and prioritized polling schemes |
US5828655A (en) | 1995-04-21 | 1998-10-27 | Hybrid Networks, Inc. | Hybrid access system with quality-based channel switching |
US5946322A (en) | 1995-04-21 | 1999-08-31 | Hybrid Networks, Inc. | Hybrid access system utilizing credit/done polling protocols |
US6104727A (en) | 1995-04-21 | 2000-08-15 | Hybrid Networks, Inc. | Asymmetric communication system with regulated upstream channel |
US5859852A (en) | 1995-04-21 | 1999-01-12 | Hybrid Networks, Inc. | Hybrid access system with automated client-side configuration |
US5959997A (en) | 1995-04-21 | 1999-09-28 | Hybrid Networks, Inc. | Hybrid access system with AGC control of upstream channel transmit power |
US6385237B1 (en) | 1995-04-27 | 2002-05-07 | Wavetek Wandell And Goltermann | Non-invasive digital cable test system |
US5818441A (en) | 1995-06-15 | 1998-10-06 | Intel Corporation | System and method for simulating two-way connectivity for one way data streams |
US20030156603A1 (en) | 1995-08-25 | 2003-08-21 | Rakib Selim Shlomo | Apparatus and method for trellis encoding data for transmission in digital data transmission systems |
US6305020B1 (en) | 1995-11-01 | 2001-10-16 | Ictv, Inc. | System manager and hypertext control interface for interactive cable television system |
US5694424A (en) | 1996-03-15 | 1997-12-02 | Ariyavisitakul; Sirikiat | Pre-cancelling postcursors in decision feedback equalization |
US5809086A (en) | 1996-03-20 | 1998-09-15 | Lucent Technologies Inc. | Intelligent timing recovery for a broadband adaptive equalizer |
US5742902A (en) | 1996-03-29 | 1998-04-21 | Gmi Holdings, Inc. | Super-regenerative circuit apparatus for a door operator receiver and door operator incorporating the same |
US6047159A (en) | 1996-06-03 | 2000-04-04 | Scientific-Atlanta, Inc. | Reconfigurable node for a communications network |
US5959660A (en) | 1996-08-26 | 1999-09-28 | Hybrid Networks, Inc. | Subchannelization scheme for use in a broadband communications system |
US5956346A (en) | 1996-10-22 | 1999-09-21 | Hybrid Networks, Inc. | Broadband communication system using TV channel roll-off spectrum |
US6018764A (en) | 1996-12-10 | 2000-01-25 | General Instrument Corporation | Mapping uniform resource locators to broadcast addresses in a television signal |
US5946351A (en) | 1996-12-27 | 1999-08-31 | At&T Corporation | Tap selectable decision feedback equalizer |
US6754715B1 (en) | 1997-01-30 | 2004-06-22 | Microsoft Corporation | Methods and apparatus for implementing control functions in a streamed video display system |
US6018526A (en) | 1997-02-20 | 2000-01-25 | Macronix America, Inc. | Bridge device with self learning between network media and integrated circuit and method based on the same |
US6370571B1 (en) | 1997-03-05 | 2002-04-09 | At Home Corporation | System and method for delivering high-performance online multimedia services |
US5946047A (en) | 1997-03-12 | 1999-08-31 | Hybrid Networks, Inc. | Network system for handling digital data over a TV channel |
US5946048A (en) | 1997-03-12 | 1999-08-31 | Hybrid Networks, Inc. | Network device for handling digital data over a TV channel |
US6012161A (en) | 1997-11-26 | 2000-01-04 | At&T Corp. | System and method for joint coding and decision feedback equalization |
US5909253A (en) | 1997-12-09 | 1999-06-01 | Sarnoff Corporation | Reducing video crosstalk in a data carrier located within a vestigial sideband of a standard television signal |
US6066993A (en) | 1998-01-16 | 2000-05-23 | Mitsubishi Denki Kabushiki Kaisha | Duplexer circuit apparatus provided with amplifier and impedance matching inductor |
US6240133B1 (en) | 1998-02-05 | 2001-05-29 | Texas Instruments Incorporated | High stability fast tracking adaptive equalizer for use with time varying communication channels |
US6366613B2 (en) | 1998-02-05 | 2002-04-02 | Texas Instruments Incorporated | High stability fast tracking adaptive equalizer for use with time varying communication channels |
US6433835B1 (en) | 1998-04-17 | 2002-08-13 | Encamera Sciences Corporation | Expanded information capacity for existing communication transmission systems |
WO1999055087A1 (en) | 1998-04-17 | 1999-10-28 | Encamera Sciences Corporation | Expanded information capacity for existing communication transmission systems |
US6314134B1 (en) | 1998-04-24 | 2001-11-06 | Lucent Technologies Inc. | Blind equalization algorithm with joint use of the constant modulus algorithm and the multimodulus algorithm |
US6680971B1 (en) | 1998-05-18 | 2004-01-20 | Sarnoff Corporation | Passband equalizer for a vestigial sideband signal receiver |
US6192384B1 (en) | 1998-09-14 | 2001-02-20 | The Board Of Trustees Of The Leland Stanford Junior University | System and method for performing compound vector operations |
US6754277B1 (en) | 1998-10-06 | 2004-06-22 | Texas Instruments Incorporated | Error protection for compressed video |
US6510553B1 (en) | 1998-10-26 | 2003-01-21 | Intel Corporation | Method of streaming video from multiple sources over a network |
US20010022813A1 (en) | 1998-11-03 | 2001-09-20 | Broadcom Corporation | Technique for minimizing decision feedback equalizer wordlength in the presence of a DC component |
US6226323B1 (en) | 1998-11-03 | 2001-05-01 | Broadcom Corporation | Technique for minimizing decision feedback equalizer wordlength in the presence of a DC component |
US6829298B1 (en) | 1999-03-17 | 2004-12-07 | Pioneer Corporation | Signal processing circuit for a digital signal receiving system |
US6426973B1 (en) | 1999-04-29 | 2002-07-30 | The Board Of Trustees Of The University Of Illinois | Differential minimum mean squared error communication signal compensation method |
US6356586B1 (en) | 1999-09-03 | 2002-03-12 | Lucent Technologies, Inc. | Methods and apparatus for parallel decision-feedback decoding in a communication system |
US6268774B1 (en) | 1999-11-05 | 2001-07-31 | Intel Corporation | Self-tuning amplifier |
US20020056140A1 (en) | 2000-03-01 | 2002-05-09 | Sony Corporation | Television signal distributor apparatus, receiver apparatus, television signal transmission system and method |
US6834039B1 (en) | 2000-03-10 | 2004-12-21 | Hughes Electronics Corporation | Apparatus and method for efficient TDMA bandwidth allocation for TCP/IP satellite-based networks |
EP1156634A1 (en) | 2000-05-15 | 2001-11-21 | Lucent Technologies Inc. | Sequence estimator and equaliser |
US6310548B1 (en) | 2000-05-30 | 2001-10-30 | Rs Group, Inc. | Method and system for door alert |
US6377529B1 (en) | 2000-06-01 | 2002-04-23 | Calimetrics, Inc. | Method for providing improved equalization for the reading of marks on optical data-storage media |
US20020059597A1 (en) | 2000-06-30 | 2002-05-16 | Dan Kikinis | Method and apparatus for notifying users of interactive functions |
WO2002007425A2 (en) | 2000-07-14 | 2002-01-24 | Chinook Communications, Inc. | System for variable-rate modulation and demodulation of data using information embedding in television signals |
WO2002007425A3 (en) | 2000-07-14 | 2002-06-13 | Chinook Communications Inc | System for variable-rate modulation and demodulation of data using information embedding in television signals |
US20020186764A1 (en) | 2001-04-06 | 2002-12-12 | Sarnoff Corporation | Method and apparatus for equalizing a radio frequency signal |
WO2002084965A1 (en) | 2001-04-10 | 2002-10-24 | Koninklijke Philips Electronics N.V. | A two stage equalizer for trellis coded systems |
US20030095590A1 (en) | 2001-11-16 | 2003-05-22 | Fuller Arthur T. G. | Symbol-directed weighting in parallel interference cancellation |
US7180942B2 (en) | 2001-12-18 | 2007-02-20 | Dotcast, Inc. | Joint adaptive optimization of soft decision device and feedback equalizer |
Non-Patent Citations (73)
Title |
---|
"Digital Data Transmission Within the Video Portion of Television Broadcast Station Transmissions". |
"Digital Data Transmission Within the Video Portion of Television Broadcast Station Transmissions," MM. |
"HDTV & Vestigal Sideband Syndrome," IEEE Transactions on Broadcasting, Mar. 1990, p. 8. |
"HDTV & Vestigal Sidebank Syndrome" in the IEEE Transactions on Broadcasting, Mar. 1990, p. 8. |
"Intel and WavePhore Sign Technology and Investment Agreement," Press Release, May 5, 1995. |
"Motivated CEO Leads WavePhone," Arizona Business Gazette, Jul. 13, 1995. |
"Skyway System Rides TV Signals to Distribute Data Speed Key to WavePhone Technology," Arizona Business Gazette, Jul. 13, 1995. |
"Technology Offers TV Broadcasters An Avenue Into Interactive Services," Investor's Business Daily, Apr. 19, 1993. |
"Tempe Firm, Intel Team Up to Send Data Via TV," Advertisement, May 6, 1995. |
"Wave Generation & Shaping," Leonard Strauss, Chapters 1 and 2, 1970, McGraw-Hill. |
"WavePhore and Arizona State University Launch Distance Learning Services," Aug. 17, 1995, WavePhore Press Release. |
"WavePhore and Belcom Sign Agreement to Co-Develop Russian Data Broadcasting System," Apr. 10, 1995, WavePhore Press Release. |
"WavePhore and the Canadian Broadcasting Corporation," Mar. 29, 1995, WavePhore Press Release. |
"WavePhore Develops Data Casting System for Television Azteca in Mexico," Aug. 8, 1995, Press Release. |
"WavePhore Set Technology Alliance," the Business Daily, May 8, 1995. |
"WavePhore Stock is On Roll," The Indianapolis News, May 23, 1995. |
Adverstisement in Investor's Business Daily, Intel, WavePhore Set Technology Alliance, dated Monday, May 8, 1995. |
Adverstisement in The Indianapolis News, WavePhore Stock Is On Roll, dated May 23, 1995. |
Advertisement in Investor's Business Daily, "Technology Offers TV Broadcasters An Avenue Into Interactive Services", Monday, Apr. 19, 1993. |
Advertisement, Arizona Business Gazette, entitle "Skyway System Rides TV Signals to Distribute Data-Speed Key to WavePhore Technology", dated Jul. 13, 1995. |
Advertisement, Arizona Business Gazette, entitled "Motivated CEO Leads WavePhore", dated Jul. 13, 1995. |
Advertisement, The Arizona Republic Business, "Tempe firm, Intel Team Up to Send Data via TV", dated Saturday, May 6, 1995. |
Ariyavisitakul et al., "Joint Coding and Decision Feedback Equalization for Broadband Wireless Channels", Dec. 1998, IEEE Journal on Selected Areas in Communications, vol. 16, No. 9, pp. 1670-1678. * |
Ariyavisitakul et al., "Joint Coding and Decision Feedback Equalization for Broadband Wireless Channels," IEEE, Dec. 1998, pp. 1670-1678, vol. 19, No. 9. |
C.G. Eilers, "TV Multichannel Sound-The BTSC System," IEEE Transactions on Consumer electronics, Aug. 1984. |
Casas et al., "Current approaches to blind decision feedback equalization," Signal processing advances in wireless and mobile communications: trends in channel estimation and equalization, Aug. 1999, 45 pgs. |
Casas R. A., et al.: "Current approaches to blind decision feedback equalization," in the textbook, "Signal processing advances in wireless and mobile communications: trends in channel estimation and equalization," edited by G. Giannakis, et al., Prentice Hall, Upper Saddle River, NJ, 2000. |
CED Magazine, Dec. 2001. http://www.cedmagazine.com/ced/2001/1201/12f.htm. |
Chen, B. "The Key to Unlocking Network Assets: Increasing Capacity by Embedding Content in Current Video Transmission," CED Magazine, Dec. 2001, http://www.cedmagazine.com/ced/2001/1201/12f.htm. |
Ciciora et al., "A Tutorial on Ghost Cancelling in Television Systems," IEEE Transactions on Consumer Electronics, vol. CE-25, No. 1, Feb. 1979, pp. 9-44. |
Ciciora et al., "Embedding high-speed data in analog signals," CED Magazine, Dec. 2001, pp. 92-100. |
Ciciora et al., "Modem Cable Television Technology, Video, Voice and Data Communications," 1999. |
Ciciora, Dukes, Hartson, Hoarty, Embeddings high-speed data in analog signals CED Magazine, Dec. 2001, p. 92-100. |
Communications, 1994. Supercomm/ICC '94, Conference Record, 'Serving Humanity Through Communications,' May 1, 1994. ISBN:0780318250. |
D.G. Fink, Television Engineering, 2nd Edition, McGraw-Hill 1952. |
Daneshard et al., "Finite Wordlength Requirements for Adaptive Signal Processing Elements in Digital QAM ADSL Systems," Communications, 1994, Supercomm/ICC 94, Conference Record Serving Humanity Through Communications, May 1, 1994. |
Eilers, "TV Multichannel Sound-The BTSC System," IEEE Transactions on Consumer Electronics, Aug. 1984. |
Evans, G. "More Tools of the Trade: Modulators, Inside Custom A/V," http://www.hometeam.com/beta/0009customav.shtml. |
Fink, "Television Engineering," 2nd Ed., 1952, McGraw-Hill. |
G.M. Glasford, Fundamentals of Television Engineering, McGraw-Hill 1955. |
Glasford, "Fundamentals of Television Engineering," 1995, McGraw-Hill, 1995. |
Godard, D. N.: "Self-recovering equalization and carrier tracking in two-dimensional data communication systems," IEEE Transactions on Communications, vol. 28, No. 11, pp. 1867-1875, Nov. 1980. |
Godard, D.N, "Self-recovering equalization and carrier tracking in two-dimensional data communication systems," IEEE Transactions on Communications, 1980, vol. 28, No. 11, pp. 1867-1875. |
Hill et al., "Introduction to Switching Theory & Logical Design," 1968, John Wiley & Sons. |
Hill, et al.-Introduction to Switching Theory & Logical Design, John Wiley & Sons 1968, SBN 471 39880 K. |
Kaufman, C., "Network Security," 1995, Prentice-Hall. |
Kaufman, C., "Network Security," Printice Hall, 1995 ISBN 0-13-061466-1. |
Lucky, R.W.: "Techniques for adaptive equalization of digital communication systems" Bell Systems Technical Journal, vol. 45, No. 2, pp. 255-286, Feb. 1966. |
Modern Cable television Technology: Video, Voice, and Data Communications, 1999 Walter Ciciora, James Farmer, David Large, Morgan Kaufman ISBN I-55860-416-2. |
Naito et al., "Adaptive Equalization Based on Internal Model Principle for Time-Varying Fading Channels," IEEE, Oct. 1, 2001, p. 363-368. |
NetMedia, MM73/NMOD3 Triple Play Modulator Installation Manual, Net Media, Tuson AZ (undated). |
News Release of WavePhore, entitled "WavePhore and Belcom Sign Agreement to Co-Develop Russian Data Broadcasting System" (two pages, believed to have been released Apr. 10, 1995). |
Nordholt, et al., "A New Approach to Active Antenna Design," IEEE Transactions on Ant. And Prop., Nov. 1980, vol. AP-28, No. 6. |
Nordholt, et al.: "A New Approach to Active Antenna Design", IEEE Transactions on Ant. And Prop., Nov. 1980, vol. AP-28, No. 6. |
Ormiston et al., "Compact Low Noise Receiving Antenna," IEEE Electronics Letters, Jul. 9, 1998, vol. 34, No. 14, pp. 1367-1368. |
Press Release of WavePhore entitled FCC Proposed to Allow Digital Data Transmission Within the Video Portion of TV Broadcasts, in Response to WavePhore's Request, (two pages believed to have been released Apr. 25, 1995). |
Press Release of WavePhore, entitled WavePhore and Arizona State University Launch Distance Learning Service, (two pages, believed to have been released Aug. 17, 1995). |
Press Release of WavePhore, entitled WavePhore Develops Data Casting System for Television Azteca in Mexico (two pages, believed to have been released Aug. 8, 1995). |
Press Release of WavePhore, Inc. entitled "WavePhore and the Canadian Broadcasting Corporation Enter an Agreement to Deliver Data Broadcasting Nationwide in Canada," dated Mar. 29, 1995. |
Press Release, entitled Intel and WavePhore Sign Technology And Investment Agreement, (two pages, believed to have been released May 5, 1995). |
Rhyne, "Fundamentals of Digital Systems Design," Basic Concepts, Ch 1, pp. 1-27, 1973, Prentice-Hall, Inc. |
Spohn, D.L., "Data Network Design," 1993, McGaw-Hill. |
Spohn, D.L., "Data Network Design," McGraw Hill, 1993 ISBN 0-07-06-360-X. |
Tanenbaum, A. "Computer Networks," Prentice Hall 1996, ISBN 0-1-349945-6. |
Tanenbaum, A., "Computer Networks," 1996, Prentice-Hall. |
Taylor, "The Vestigal Sideband and Other Tribulations," National Cable Television Association, 1988, Technical Papers, p. 203. |
Taylor, "The Vestigal Sideband and Other Tribulations," p. 203 of the 1988 National Cable Television Association Technical Papers. |
Tooley et al., "Active Receiving Antenna," Practical Wireless, Mar. 1981 vol. 57, No. 3, pp. 52-55. |
Treichler, J. R., and Agee, B.G.: "A new approach to multipath correction of constant modulus signals," IEEE Transactins on Acoustics, Speech, and Signal Processing, vol. ASSP-31, No. 2, pp. 459-472, Apr. 1983. |
Treichler, J.R. et al. "A new approach to multipath correction of constant modulus signals," IEEE Transactions on Acoustics, Speech, and Signal Processing, Apr. 1983 vol. ASSP-31, No. 2, pp. 459-472. |
V. Thomas Rhyme, Fundamentals of Digital System Design. |
W. Ciclora et al., "A Tutorial on Ghost Canceling in Television Systems," IEEE Transactions on Consumer Electronics, vol. CE-25, No. 1, Feb. 1979, pp. 9-44. |
Wave Generation & Shaping, Leonard Strauss, McGraw-Hill 1970, Chapters 1 and 2. |
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US8576903B2 (en) * | 2011-10-18 | 2013-11-05 | Transwitch Corporation | Techniques for adaptively adjusting decision levels of a PAM-N decision feedback equalizer |
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