WO2008007428A1

WO2008007428A1 - Radio transmitting apparatus and transmission power control method

Info

Publication number: WO2008007428A1
Application number: PCT/JP2006/313888
Authority: WO
Inventors: Tadahiro Sato
Original assignee: Fujitsu Limited
Priority date: 2006-07-12
Filing date: 2006-07-12
Publication date: 2008-01-17

Abstract

A radio transmitting apparatus and a transmission power control method thereof wherein the transmission power control is performed with high accuracy. A radio transmitting apparatus, which varies the transmission levels of transport signals for transmission, comprises a determining means that determines the transmission levels of transport signals; a calculating means that uses a part, for which the expected value of the transmission level is constant, of the transmission levels determined by the determining means to calculate a gain correction value; and a correcting means that performs, based on the gain correction value, a gain correction of the transport signal.

Description

Specification

Radio transmission apparatus and transmission power control method

Technical field

The present invention relates to a radio transmission apparatus that performs transmission power control and a transmission power control method thereof.

Background art

[0002] Some wireless transmission devices have an automatic gain correction function in order to maintain a transmission level of a signal transmitted from an antenna at a predetermined power level. FIG. 15 is a block diagram showing a functional configuration of a conventional wireless transmission device. As shown in FIG. 15, a conventional wireless transmission apparatus includes a signal processing unit 300, a digital Z analog conversion unit (hereinafter referred to as a DZA conversion unit) 301 and 302, a TPC (Transmit Power Control) amplification unit 303, a power amplifier. (Power Amplifier) 304, coupler 305, transmission level monitor circuit 306, analog / digital converter (hereinafter referred to as AZD converter) 307, antenna 320, and the like.

[0003] The main signal generated by the signal processing unit 300 is converted into an analog signal by the DZA conversion unit 301 and sent to the TPC amplification unit 303. This analog signal is quadrature modulated by the TPC amplifier 303 (orthogonal modulator 311), converted to a radio frequency (frequency converter 31 2), amplified by the power amplifier 304, and then via the coupler 305. Transmitted from antenna 320.

At this time, the transmission level of the signal transmitted from antenna 320 may not be the power level expected by signal processing unit 300. This is because the main signal is subjected to gain fluctuations from the analog circuit that constitutes the wireless transmission device. In order to eliminate such a phenomenon, the wireless transmission device performs the following automatic gain correction.

[0005] Transmission level monitor circuit 306 receives a signal obtained by branching modulated wave signal to be transmitted from antenna 320 by cutter 305, and sequentially generates a transmission level feedback signal indicating the transmission level of this signal. . The transmission level monitor circuit 306 includes a diode detection circuit and the like for detecting the transmission level, and outputs a transmission level feedback signal according to the characteristics shown in FIG. 16 of the detection circuit. Figure 16 shows the transmission level mode. The relationship between the transmission level of the signal input to the Utah circuit 306 (dBm (absolute power with 1 milliwatt (mW) as the reference (0))) and the transmission level feedback signal output from the transmission level monitor circuit 306 is shown. FIG. The transmission level feedback signal output from the transmission level monitor circuit 306 is converted into a digital signal by the AZD conversion unit 307 and fed back to the signal processing unit 300. Since the transmission level monitor circuit 306 is configured so that the gain fluctuation due to the operating environment conditions is extremely small, a transmission level feedback signal based on a transmission level substantially the same as the transmission level at the actual antenna end is used. Can be generated.

[0006] The signal processing unit 300 includes a signal generation unit 330, an automatic gain correction unit 331, and the like. The automatic gain correction unit 331 receives this transmission level feedback signal and checks whether the transmission signal has a desired transmission level (output power setting value). In this inspection, automatic gain correction section 331 obtains the average transmission power from the transmission level feedback signal received within a predetermined time according to the characteristics shown in FIG. 16, and compares this average transmission power with the output power setting value. .

[0007] The automatic gain correction unit 331 outputs a predetermined TPC signal for controlling the variable attenuator 313 according to the inspection result. The variable attenuator 313 adjusts the signal level output from the power amplifier 304 (gain correction) according to the analog signal (control voltage) obtained by converting the TPC signal by the DZ A conversion unit 302. As a result, the signal output from the power amplifier 304 becomes a signal having a desired transmission level and is transmitted from the antenna 320.

[0008] Specifically, the automatic gain correction unit 331 described above, when the average transmission power obtained from the transmission level feedback signal is smaller than the output power setting value, the gain (analog gain) of the TPC amplification unit 303 ) Is increased, and when the average transmission power obtained from the transmission level feedback signal is larger than the output power setting value, a TPC signal is generated so that the gain of the TPC amplification section 303 is decreased. In other words, the automatic gain correction unit 331 generates a TPC signal based on the feedback signal from the transmission level motor circuit 306 so that the transmission level of the signal to which the antenna force is transmitted becomes a desired power level.

[0009] Here, the transmission level feed generated from the main signal gain-corrected by the TPC signal The expected value of the transmission level indicated by the back signal changes according to the average power (DZA input power) of the main signal input to the DZA converter 301. This is apparent from the fact that the average output power at the antenna 320 end changes according to the average power of the main signal input to the D ZA converter 301 even when the analog circuit such as the variable attenuator 313 has a constant gain. It is.

[0010] Meanwhile, the conventional radio transmitting apparatus performs radio communication using a radio frame format as shown in FIG. In the example shown in Fig. 17, each frame consists of one reference channel and five data channels. The reference channel is time-multiplexed with the data channel at regular intervals, and is used for channel estimation and channel quality information measurement. The signal generation unit 330 of the signal processing unit 300 generates such a radio frame and sends it to the DZA conversion unit 301 as a main signal.

[0011] When transmitting such a radio frame while performing the automatic gain correction described above, a conventional radio transmission apparatus may set the analog gain update cycle, that is, the TPC signal update cycle to one frame interval. is there. FIG. 18 is a conceptual diagram when one frame interval is set as the TPC signal update period. In this case, the above-described wireless transmission device calculates the average transmission power from the transmission level feedback signal during the update period, and executes gain correction according to the average transmission power.

[0012] With this, in the configuration in which the conventional radio transmission apparatus has a constant transmission power in each channel in the frame (see FIG. 19), the power level of the transmission signal is set to an appropriate power by the automatic gain correction function. Can keep.

[0013] There are some prior arts according to the present invention disclosed in the following documents.

Patent Document 1: Japanese Patent Laid-Open No. 7-221700

Disclosure of the invention

Problems to be solved by the invention

However, at present, as shown in FIG. 20, the transmission power is often varied for each channel in the frame. In such a case, it is difficult for the conventional wireless transmission apparatus to estimate the transmission level of the actual output signal, and there is a problem that the automatic gain correction function does not operate as expected! For each channel in the frame as shown in Figure 20. Even though the transmission power fluctuates, the TPC signal is updated at the update cycle shown in Fig. 18, so the TPC signal is not generated based on the power value approximating the actual transmission level. Because.

[0015] Therefore, in such a case, the conventional wireless transmission device needs to prevent the automatic gain correction function from operating. That is, it is necessary to switch whether or not to operate the gain correction function depending on whether the transmission power is constant or varied in a frame.

However, if the gain correction function is not operated when the transmission power is varied in the frame in this way, there is no one that corrects the gain variation of the analog circuit or the like, and therefore the transmission power accuracy is improved. The problem of deterioration arises.

An object of the present invention is to provide a radio transmission apparatus that performs highly accurate transmission power control and a transmission power control method thereof.

Means for solving the problem

The present invention adopts the following configuration in order to solve the above-described problems. That is, the present invention relates to a wireless transmission apparatus that transmits a transmission signal by varying the transmission level of the transmission signal, and a detection means for detecting the transmission level of the transmission signal and an expectation of the transmission level of the transmission levels detected by the detection means. A calculation unit that calculates a gain correction value using a transmission level in a section in which the value is constant; and a correction unit that performs gain correction of a transmission signal based on the gain correction value.

In the present invention, a transmission level (for example, transmission power or transmission voltage) relating to a signal that is actually transmitted is detected, and the expected value of the transmission level is constant among the detected transmission levels. The gain correction value is calculated using the transmission level of the signal. Then, the gain correction of the transmission signal is executed based on the gain correction value. Here, the expected value of the transmission level is a value that can be obtained by a signal processing unit or the like that determines the fluctuation of the transmission level, and is an ideal value when there is no gain fluctuation of an analog circuit or the like.

[0020] Therefore, according to the present invention, even when the transmission level varies within a radio frame, it is possible to perform appropriate automatic gain correction, and thus to perform highly accurate transmission power control. It becomes. [0021] In addition, the present invention provides at least a reference channel and a control channel among the plurality of channels when the transmission signal is multiplexed with a plurality of channels as a section in which the expected value of the transmission level is constant. One section may be used.

[0022] In general, the transmission level of the reference channel and the control channel is often kept constant. Therefore, using the transmission level of such a channel makes it appropriate even if the transmission level fluctuates. Automatic gain correction can be performed.

[0023] The calculation means according to the present invention includes an average calculation means for calculating an average transmission level in a section in which an expected value of the transmission level is constant, and a transmission level in a section in which the expected value of the transmission level is constant. Holding means for holding an average expected value; comparing means for calculating a difference between the average transmission level and the average expected value; and correcting means for correcting the gain correction value using the difference obtained by the comparing means as a change amount; Even if it is realized to be equipped with. Further, the correction means may use a predetermined correction value corresponding to the difference obtained by the comparison means as the change amount.

[0024] The average calculating means may use a symbol time as a section for calculating the average transmission level. This makes it possible to calculate a substantially uniform average transmission level even when the frame configuration includes a guard interval or the like in the multiplexed channel.

Note that the present invention may be a method for causing a computer to realize any one of the functions described above. Further, the present invention may be a program or a circuit for realizing any of the above functions. In the present invention, such a program may be recorded on a computer-readable storage medium.

The invention's effect

[0026] According to the present invention, it is possible to realize a radio transmission apparatus that performs highly accurate transmission power control and a transmission power control method thereof.

Brief Description of Drawings

FIG. 1 is a functional configuration diagram of a signal processing unit in the first embodiment.

FIG. 2 is a diagram showing a radio frame format in the first embodiment.

FIG. 3 is a diagram showing an example of output power setting values in the first embodiment. [4] FIG. 4 is a diagram showing an example of the DZA input power value of the main signal in the first embodiment.

FIG. 5 is a data transition diagram showing gain correction in the first embodiment.

FIG. 6 is a diagram illustrating a functional configuration example of a signal processing unit in the second embodiment.

FIG. 7 is a diagram showing an example of output power setting values in the second embodiment.

FIG. 8 is a diagram showing an example of the DZA input power value of the main signal in the second embodiment.

FIG. 9 is a data transition diagram showing gain correction in the second embodiment.

FIG. 10 is a diagram illustrating a functional configuration example of a signal processing unit in the third embodiment.

FIG. 11 is a diagram showing an example of the DZA input power value of the main signal.

FIG. 12 is a diagram showing a radio frame format.

FIG. 13 is a diagram showing an average feedback value calculation interval.

FIG. 14 is a data transition diagram showing gain correction in the third modified example.

FIG. 15 is a diagram showing a functional configuration of a conventional wireless transmission device.

FIG. 16 is a diagram showing a correlation characteristic between a transmission level and a transmission level feedback signal.

FIG. 17 is a diagram showing a radio frame format.

[FIG. 18] FIG. 18 is a conceptual diagram in which one frame interval is set as a TPC signal update period.

FIG. 19 is a diagram showing average transmission power that does not vary within a frame.

FIG. 20 is a diagram showing average transmission power that fluctuates within a frame.

Explanation of symbols

300 Signal processor

301, 302 Digital Z analog converter (DZA converter)

303 TPC amplifier

311 Modulator

312 Frequency converter

323 variable attenuator

304 power amplifier 305 Coupler

306 Transmission level monitor circuit

307 Analog Z digital converter (AZD converter)

320 antenna

330 Signal generator

331 Automatic gain correction unit

101 Expected value calculator

103, 111 noffer

120 Correction value calculator

113 Average transmission power calculator

121, 123 Adder

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a radio transmission apparatus according to the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings. The configuration of each of the following embodiments is an exemplification, and the present invention is not limited to the configuration of each of the following embodiments.

[0030] [First embodiment]

A wireless transmission device according to a first embodiment of the present invention will be described below with reference to the drawings. The wireless transmission device in the first embodiment includes the same functional units as those of the conventional wireless transmission device shown in FIG. That is, the radio transmission apparatus according to the first embodiment includes a signal processing unit 300, DZ A conversion units 301 and 302, a TPC amplification unit 303, a power amplifier 304, a coupler 305, and a transmission level monitor circuit 306 (in the detection means of the present invention). Equivalent), AZD converter 307, antenna 320, etc. The TPC amplification unit 303 includes an orthogonal modulation unit 311, a frequency conversion unit 312, and a variable attenuator 313.

[0031] Since the configuration of the signal processing unit 300 in the wireless transmission device in the first embodiment is different from that of the conventional wireless transmission device, the configuration of the signal processing unit 300 will be described in detail below. The other functional units are as described in the background art section, so the explanation is omitted here.

[0032] The signal processing unit 300 executes a program stored in the memory with a DSP (Digital Signal Processor). It is a functional unit that realizes digital signal processing by being executed on a processor such as. FIG. 1 is a diagram illustrating a functional configuration example of a signal processing unit in the first embodiment. As shown in FIG. 1, the signal processing unit 300 in the first embodiment includes a signal generation unit 330 and an automatic gain correction unit 331. The automatic gain correction unit 331 includes an expected value calculation unit 101, buffers 103 and 111. , Average transmission power calculation section 113, correction value calculation section 120, addition sections 121 and 123, and the like. Hereinafter, each of these functional units will be described.

[Signal generator]

The signal generator 330 generates a main signal having the radio frame format shown in FIG. 2, for example. FIG. 2 is a diagram showing a radio frame format in the first embodiment. In the format shown in Fig. 2, reference channels are arranged at two locations in one frame.

The signal generation unit 330 sends the generated main signal to the DZA conversion unit 301. At this time, when the main signal sent to the DZA conversion unit 301 is a reference signal, the signal generation unit 330 notifies the automatic gain correction unit 331 of the sending timing. Here, the reference signal is a signal arranged in the reference channel in the format shown in FIG. In the present embodiment, the signal generation unit 330 notifies the automatic gain correction unit 331 of the transmission timing of the reference signal arranged at the head of each frame. Note that the signal generator 330 may notify the transmission timing of the other reference signal!

[0035] Further, in the present embodiment, the power of using the radio frame format shown in Fig. 2 as an example. The present invention is not limited to such a radio frame format.

A radio frame format such as the example shown in FIG. 17 may be used.

The signal generation unit 330 further notifies the automatic gain correction unit 331 of the power level (hereinafter referred to as DZA input power value) and the output power setting value of the main signal sent to the DZA conversion unit 301. . Here, the output power setting value is an expected value of the transmission level of the signal transmitted from the antenna 320.

[Automatic Gain Correction Unit]

Hereinafter, each functional unit of the automatic gain correction unit 331 will be described.

<Expected value calculation unit 101> The expected value calculation unit 101 receives the output power setting value from the signal generation unit 330 and calculates an expected value of the transmission level feedback signal corresponding to the output power setting value related to the reference signal. The expected value calculation unit 101 obtains an expected value of the transmission level feedback signal using the correlation characteristic (see FIG. 16) between the transmission level and the transmission level feedback signal. The calculated expected value is sent to the buffer 103. The expected value calculation unit 101 corresponds to the holding means of the present invention.

The nofers 103 and 111 are holding units for delaying received data for a predetermined time and sending them to other functional units. The nofer 103 delays the expected value of the transmission level feedback signal sent from the expected value calculation unit 101 by a predetermined time and sends it to the correction value calculation unit 120. The notch 111 delays the reference signal transmission timing notification sent from the signal generation unit 330 by a predetermined time and sends it to the average transmission power calculation unit 113. Here, the delay time given by each buffer is the time from when the main signal is transmitted from the signal processing unit 300 until the transmission level feedback signal corresponding to the main signal reaches the automatic gain correction unit 331. Feedback time. With this delay time, the correction value calculation unit 120 (to be described later) can compare the transmission level related to the main signal at the time of output from the signal processing unit 300 with the transmission level at the end of the antenna 320. .

The average transmission power calculation unit 113 receives the transmission level feedback signal generated by the transmission level monitor circuit 306 and digitized by the AZD conversion unit 307, and the transmission timing of the reference signal delayed by the feedback time by the buffer 111. . The average transmission power calculation unit 113 extracts a feedback value related to the reference signal for the transmission level feedback signal power that is sequentially input based on the transmission timing of the reference signal.

[0041] Average transmission power calculation section 113 calculates an average feedback value by averaging the feedback values related to the extracted reference signal in the reference channel section. The calculated average feedback value corresponds to the average transmission power of the reference signal. The average feedback value is sent to the correction value calculation unit 120. Average transmission power calculator 11 3 corresponds to the average calculating means of the present invention.

Thus, in the present embodiment, the average feedback value is calculated by referring to only the reference signal portion of the feedback signal sent from the transmission level monitor circuit 306. This is because the reference channel is a channel in which data used for demodulating and decoding data in other channels (data channel, etc.) is placed and is often maintained at a constant transmission level. is there. The present invention is not limited to the use of only the reference channel (described later as a modification).

Correction value calculation section 120 compares the expected value of the transmission level feedback signal sent from notch 103 with the average feedback value sent from average transmission power calculation section 113 to calculate a correction value. The correction value calculation unit 120 corresponds to the calculation means, comparison means, and correction means of the present invention.

[0044] Specifically, the correction value calculation unit 120 adds a value obtained by subtracting the average feedback value to the expected value force to the previously calculated correction value, thereby obtaining a new correction value. . The correction value calculated in this way is converted into a power value corresponding to the value and sent to the adding unit 123. For this conversion, the correlation characteristic between the transmission level and the transmission level feedback signal shown in FIG. 16 is used.

The adding unit 121 also subtracts the DZA input power value from the output power set value power, and sends the calculated power value to the adding unit 123. Adder 123 adds the power value sent from adder 121 and the correction value sent from correction value calculator 120, and outputs a TPC signal corresponding to the calculated power value. This output TPC signal is used for gain control of the TPC amplifier 303. Thereafter, the signal whose power has been corrected according to the TPC signal is branched by the coupler 305, and a transmission level feedback signal is generated by the transmission level monitor circuit 306 according to the branched signal and fed back to the signal processing unit 300. Is done. Together with the TPC amplifier 303, the adder 123 corresponds to the correcting means of the present invention.

[Operation Example]

Next, FIGS. 3, 4 and 5 are used for the operation example of the wireless transmission device in the first embodiment. And explain. FIG. 3 is a diagram showing an example of the output power setting value in the first embodiment, FIG. 4 is a diagram showing an example of the DZA input power value of the main signal in the first embodiment, and FIG. It is a data transition figure showing gain correction in one embodiment. As shown in FIGS. 3 and 4, in the present embodiment, the output power set value and the DZA input power value are determined so that the analog gain in the frame is constant in the configuration. In addition, each broken line shown in the vertical axis direction in FIGS. 3 and 4 indicates each channel section of the radio frame format shown in FIG. The data transition shown in Fig. 5 is an example when the update cycle of the analog gain, that is, the update cycle of the TPC signal is set to one frame interval as shown in Fig. 18.

[0047] The signal generation unit 330 outputs the main signal to the DZA conversion unit 301, and sends the DZA input power value of the reference signal arranged in the first reference channel of each frame of the main signal to the addition unit 121. Then, the output power set value of the reference signal is sent to the adding unit 121 and the expected value calculating unit 101, and the output timing of the reference signal is notified to the buffer 111. At this time, 20 (dBm) is sent as the output power setting value for the first reference channel of the leftmost frame in FIG. In addition, 3 (dB) is sent as the DZA input power value for the first reference channel in the leftmost frame in Fig. 4.

[0048] Hereinafter, the operation of each functional unit in the automatic gain correction unit 331 that has received such data will be described with reference to FIG. FIG. 5 shows a state in which the data calculated by each function unit in the automatic gain correction unit 331 is controlled and transitioned according to the average feedback value calculated by the average transmission power calculation unit 113 (from the upper part of the figure to the lower part of the figure). Showing the transition). Each section delimited by a dashed line shown in FIG. 5 represents one frame interval (analog gain update cycle) in FIGS.

In addition, the numerical values represented as “DZA input power value” and “output power set value” in FIG. 5 indicate data sent from the signal generation unit 330 as described above, and “expected value”. The numerical value indicated as “” indicates the power value corresponding to the expected value of the transmission level feedback signal calculated by the expected value calculation unit 101, and the numerical value expressed as “correction value” is calculated by the correction value calculation unit 120. The numerical value indicated as “TPC set value” indicates the set power value corresponding to the TPC signal to be output from the adder 123. The numerical value represented as “average transmission power” indicates a power value corresponding to the average feedback value of only the reference signal calculated by the average transmission power calculation unit 113.

In the uppermost part (initial state) shown in FIG. 5, the correction value output from the correction value calculation unit 120 is O (dB) as the initial value. As a result, the TPC signal output from the adder 123 corresponds to a power value (no correction) obtained by subtracting the DZA input power value (3 (dB)) from the output power setting value (20 (dBm)) ( 17 (dB)). A signal whose gain is controlled by the TPC amplification section 303 is transmitted from the antenna by this TPC signal, while a transmission level feedback signal indicating the transmission power of the signal is sequentially fed back to the average transmission power calculation section 113. At this time, the expected value calculation unit 101 calculates the expected value of the transmission level feedback signal as 20 (dBm) based on the output power setting value (20 (dBm)) and is delayed by the buffer 103.

Next, the data state in the second stage from the top in FIG. 5 will be described. At this time, the output power setting value (20 (dBm)) and DZA input power value (+3 (dB)) related to the reference signal placed at the beginning of the second frame from the left in FIGS. Sent to 121. As a result, the adder 121 outputs a power value (17 (dB)).

On the other hand, average transmission power calculation section 113 calculates the average feedback value of the reference signal among the fed back transmission level feedback signals. Here, it is assumed that the power value (average transmission power) corresponding to this average feedback value is calculated as 18 (dBm). The calculated average transmission power is sent to the correction value calculation unit 120.

[0053] Correction value calculation section 120 calculates the expected value (20

(dBm)) and the average transmission power (18 (dBm)). The correction value calculation unit 120 subtracts the average transmission power (18 (d Bm)) from the expected value (20 (dBm)) of the transmission level feedback signal, and further obtains the obtained power value (2 (dB)). It is added to the previous correction value (here, 0 as the initial value) to obtain a new correction value (2 (dB)).

This correction value is added by the adder 123 with the power value (17 (dB)) sent from the adder 121. A TPC signal corresponding to the calculated power value (19 (dB)) is generated and sent to the TPC amplifier 303.

[0055] Thereafter, until the transition to the third stage from the top of FIG. 5 (from the reference frame of the next frame) TPC signal corresponding to the previously calculated power value (19 (dB)) is output during

Next, the data state in the third row from the top in FIG. 5 will be described. At this time, the output power setting value (20 (dBm)) and DZA input power value (+3 (dB)) related to the reference signal placed at the beginning of the third frame from the left in FIGS. 3 and 4 are added. Sent to part 121. As a result, the adder 121 outputs a power value (17 (dB)). At this time, it is assumed that average transmission power calculation section 113 calculates 21 (dBm) as the average transmission power.

[0057] In correction value calculation section 120, a value obtained by subtracting the average transmission power (21 (dBm)) from the expected value (20 (dBm)) of the previously calculated transmission level feedback signal (-1 (dB) ) Is added to the previous correction value (2 (dB)) to obtain the correction value (1 (dB)).

This correction value is added by the adder 123 with the power value (17 (dB)) sent from the adder 121. A TPC signal corresponding to the calculated power value (18 (dB)) is generated and sent to the TPC amplifier 303.

[0059] Finally, the data state at the bottom of FIG. 5 will be described. This is an example when the reference signal of the rightmost frame shown in FIGS. 3 and 4 is input, that is, an example when the output power setting value of the reference signal and the DZA input power value fluctuate. The output power setting value and DZA input power value input to the automatic gain correction unit 331 are 14 (dBm) and +3 (dB), respectively, and the expected value is 14 (dBm). At this time, it is assumed that the average transmission power is calculated as 20 (dBm).

[0060] In the correction value calculation unit 120, a value (0) obtained by subtracting the average transmission power (20 (dBm)) from the expected value (20 (dBm)) of the transmission level feedback signal calculated previously is the previous value. The correction value (l (dB)) is added to obtain the correction value (l (dB)). This correction value is added by the adder 123 with the power value (11 (dB)) sent from the adder 121. A TPC signal corresponding to the power value (12 (dB)) calculated in this way is generated and sent to the TPC amplifier 303.

The operation and effect of the wireless transmission device in the first embodiment described above will be described below. In the wireless transmission device according to the first embodiment, the automatic gain correction device adjusts the transmission level (power or voltage) of the signal transmitted from the antenna 320 to an appropriate power level. The function is executed.

[0062] The signal level to be transmitted from the antenna 320 is also detected by the transmission level monitor circuit 306, and a transmission level feedback signal indicating the transmission level is fed back to the signal processing unit 300. The signal processing unit 300 calculates an average feedback value obtained by averaging the transmission level feedback signals related to the reference signal, and determines a transmission power correction value based on the average feedback value related to the reference signal. In this determination, a new correction value is obtained by using the difference between the expected value of the transmission level feedback signal corresponding to the output power setting value, which is the expected value of the transmission level of the signal at the antenna end, and the average feedback value of the reference signal as a change amount. It is determined. Thereafter, the TPC signal reflecting this correction value is sent to the TPC amplifying unit 303, and the transmission level of the main signal is adjusted according to this TPC signal.

As described above, in the automatic gain correction function in the first embodiment, the average transmission power of only the reference signal transmitted at a constant transmission power among the transmission signals is calculated, and the transmission power is calculated based on the average transmission power. The correction value is determined, and the transmission level of the main signal is adjusted based on the correction value.

[0064] As a result, even in a system in which transmission power is varied within a frame as shown in Figs. 3 and 4, a section (reference channel) in which transmission power is kept constant in a section shorter than one frame time. Since the correction value is determined based on the detected transmission power, automatic gain correction can be appropriately operated even when the transmission power fluctuates in other channels.

[0065] [Second Embodiment]

Next, a radio transmission apparatus according to the second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram illustrating a functional configuration example of the signal processing unit in the second embodiment. The wireless transmission device in the second embodiment is obtained by modifying the automatic gain correction unit 331 of the signal processing unit 300 in the first embodiment. Other than the modified automatic gain correction unit 331 is the same as that of the first embodiment, and thus the description thereof is omitted here.

In the automatic gain correction unit 331 in the first embodiment, the expected value calculation unit 101 expects the transmission level feedback signal based on the output power setting value related to the reference signal. The expected value calculation unit 101 in the second embodiment calculates the expected value based on the power value obtained by adding the output power setting value and the DZA input power value with respect to the reference signal. At this time, the adding unit 123 adds the output power setting value and the correction value sent from the correction value calculating unit 120, and generates a TPC signal corresponding to the obtained power value.

[Operation example]

Hereinafter, an operation example of each functional unit of the automatic gain correction unit 331 in the second embodiment will be described with reference to FIGS. FIG. 7 is a diagram showing an example of the output power setting value in the second embodiment, FIG. 8 is a diagram showing an example of the DZA input power value of the main signal in the second embodiment, and FIG. It is a data transition diagram showing gain correction in two embodiments. Each broken line shown in the vertical axis direction in FIGS. 7 and 8 indicates a section of each channel in the radio frame format shown in FIG. The data transition shown in FIG. 9 is an example when the analog gain update cycle, that is, the TPC signal update cycle is set to one frame interval as shown in FIG. FIG. 9 shows a state of transition controlled (transition from the upper part of the figure to the lower part of the figure) according to the average feedback value calculated by the average transmission power calculation unit 113. The meanings of the numerical values in FIG. 9 are the same as those in FIG.

[0068] In the uppermost part (initial state) shown in FIG. 9, the DZA input power value (+3 (dB)) and the output power setting value (1) for the reference signal placed at the beginning of the leftmost frame in FIGS. 7 (dBm)) is input to the automatic gain correction unit 331. Also, the correction value output from the correction value calculation unit 120 is 0 (dB) as an initial value.

[0069] Thereby, the TPC signal output from the adding unit 123 becomes (17 (dBm)) corresponding to the output power setting value (17 (dBm)). A signal whose gain is controlled by the TPC amplification unit 303 is transmitted from the antenna by the TPC signal, while a transmission level feedback signal corresponding to the transmission power of the signal is sequentially fed back to the average transmission power calculation unit 3. Ru

. At this time, the expected value calculation unit 101 determines the expected value of the transmission level feedback signal based on the added power value of the output power setting value (17 (dBm)) and the DZA input power value (+3 (dB)). Calculated as 20 (dBm) and delayed by the buffer 103.

Next, the data state in the second row from the top in FIG. 9 will be described. At this time, The DZA input power value (+3 (dB)) and the output power setting value (17 (dBm)) related to the reference signal arranged at the head of the second frame from the left are input to the automatic gain correction unit 331.

[0071] Average transmission power calculation section 113 calculates the average feedback value of the reference signal among the fed back transmission level feedback signals. Here, it is assumed that the power value (average transmission power) corresponding to this average feedback value is calculated as 18 (dBm). The calculated average transmission power is sent to the correction value calculation unit 120.

[0072] Correction value calculation section 120 calculates the expected value (20

(dBm)) and the average transmission power (18 (dBm)). The correction value calculation unit 120 subtracts the average transmission power (18 (d Bm)) from the expected value (20 (dBm)) of the transmission level feedback signal, and further obtains the obtained power value (2 (dB)). It is added to the previous correction value (here, 0 as the initial value) to obtain a new correction value (+2 (dB)). This correction value is added to the output power setting value (17 (dBm)) by the adding unit 123. A TPC signal corresponding to the power value (19 (dB)) calculated in this way is generated and sent to the TPC amplifier 303.

[0073] Thereafter, until the transition to the third stage from the top of Fig. 9 (interval until the reference channel of the next frame), the TPC corresponding to the previously calculated TPC setting value (19 (dB)) A signal is output.

Next, the data state in the third row from the top in FIG. 9 will be described. At this time, the DZA input power value (+3 (dB)) and output power setting value (17 (dBm)) related to the reference signal placed at the beginning of the third frame from the left in Figs. Input to correction unit 331. At this time, it is assumed that average transmission power calculation section 113 calculates 21 (dBm) as the transmission average power.

In correction value calculation section 120, a value obtained by subtracting the average transmission power (21 (dBm)) from the expected value (20 (dBm)) of the transmission level feedback signal calculated previously (−1 (dB) ) Is added to the previous correction value (2 (dB)) to obtain the correction value (+ l (dB)). This correction value is added to the output power set value (17 (dBm)) by the adding unit 123. A TPC signal corresponding to the power value (18 (dB)) calculated in this way is generated and sent to the TPC amplifier 303.

[0076] Finally, the data state at the bottom of FIG. 9 will be described. This is shown in Figures 7 and 8. In this example, the reference signal of the rightmost frame is input, that is, the output power setting value of the reference signal fluctuates. That is, the output power setting value and DZA input power value input to the automatic gain correction unit 331 are 11 (dBm) and +3 (dB), respectively, and the expected value is 14 (dBm). At this time, it is assumed that the average transmission power is calculated as 20 (dBm).

[0077] In the correction value calculation unit 120, a value (0) obtained by subtracting the average transmission power (20 (dBm)) from the expected value (20 (dBm)) of the transmission level feedback signal calculated previously is the previous value. The correction value (l (dB)) is added to obtain the correction value (+ l (dB)). This correction value is added to the output power set value (11 (dBm)) by the adding unit 123. A TPC signal corresponding to the power value (12 (dB)) calculated in this way is generated and sent to the TPC amplifier 303.

In the wireless transmission device in the second embodiment, in the automatic gain correction function, the TPC signal is generated based on the power value obtained by correcting the output power set value by the correction value calculated by the correction value calculation unit 120; The expected value calculation unit 101 is different from the first embodiment in that the expected value calculation unit 101 calculates the expected value of the transmission level feedback signal corresponding to the added value of the output power setting value and the DZA input power value.

However, in the wireless transmission device in the second embodiment, similarly to the first embodiment, a transmission power correction value is determined based on the average transmission power of only the reference signal, and the main value is determined based on the correction value. Since the signal transmission level is adjusted, automatic gain correction can be appropriately operated even when the transmission power is varied within the frame.

[0080] [Third embodiment]

Next, a radio transmission apparatus according to the third embodiment of the present invention will be described with reference to FIG. FIG. 10 is a diagram illustrating a functional configuration example of the signal processing unit in the third embodiment. The wireless transmission device in the third embodiment is obtained by further modifying the automatic gain correction unit 331 in the second embodiment. Since components other than the modified automatic gain correction unit 331 are the same as those in the first embodiment and the second embodiment, description thereof is omitted here.

[0081] In the automatic gain correction unit 331 in the first embodiment and the second embodiment, the reference The correction value of the transmission power was determined by comparing the average transmission power fed back for the signal with the expected value of the transmission level of the reference signal.

[0082] In automatic gain correction section 331 in the third embodiment, a transmission power correction value is determined based on a power value calculated by a predetermined weighted average for a predetermined section regardless of the channel configuration in the frame. Is done. Hereinafter, a functional unit different from the second embodiment in the automatic gain correction unit 331 in the third embodiment will be described.

The expected value calculation unit 101 receives the output power setting value and the DZA input power value from the signal generation unit 330. At this time, it is assumed that the DZA input power value received by the expected value calculation unit 101 changes as shown in FIG. FIG. 11 is a graph showing an example of the DZA input power value of the main signal. In addition, the expected value calculation unit 101 receives a predetermined timing notification from the signal generation unit 330 together with the above-described data. The vertical broken lines in the graph of FIG. 11 indicate the time for receiving the timing notification. This may indicate each channel section or may indicate other timing.

[0084] Expected value calculation section 101 calculates the weighted average depending on the DZA input power value and its transmission time in a predetermined time (between time T1 and time T7 shown in FIG. 11) according to the timing notification. The expected value is calculated by adding the output power value to the output power setting value.

Hereinafter, in the example of FIG. 11, an example of calculating expected values from time T1 to time T7 will be described. As for the output power setting value, a constant 20 (dBm) is input, and the time interval of timing notification is constant. The expected value calculation unit 101 receives the timing notification and the DZA input power value at the following times.

[0086] Timing T1: DZ A input power value (0 (dB))

Timing T2: DZ A input power value (6 (dB))

Timing T3: DZ A input power value (6 (dB))

Timing T4: DZA input power value (3 (dB))

Timing T5: DZ A input power value (3 (dB))

Timing T6: DZ A input power value (3 (dB)) As a result, the expected value calculation unit 101 calculates the expected value V based on the weighted average between the timing notification at time T1 and the timing notification at time T7 as follows. At this time, the timing interval (1: T1) is weighted with respect to the DZ A input power value (O (dB)), and the timing interval (2: T2 and T3) with respect to the DZA input power value (one 6 (dB)). ) Is weighted, and the timing interval (3: （4—Τ7) is weighted to the DZA input power value (-3 (dB)). The calculated expected value is delayed by the buffer 103 and then sent to the correction value calculating unit 120.

[0087] V = +20 (dBm) + 10 * log {(10 ° ¹⁰ * l + l 0 " ^{6 10} * 2 + 10" ^{3 10} * 3) / (1 + 2 + 3)} = + 17 ( dBm)

The average transmission power calculation unit 113 averages the sequentially input transmission level feedback signals within a predetermined time (between time T1 and time T7 shown in FIG. 11) according to the timing notification. Calculate the value. The calculated average feedback value is sent to the correction value calculation unit 120. Thus, in the third embodiment, the average feedback value is calculated with reference to the signal within a predetermined time among the feedback signals sent from the transmission level monitor circuit 306.

In the wireless transmission device in the third embodiment, in the automatic gain correction function, an expected value obtained by weighted average of the DZA input power value and its transmission time within a predetermined time and the average of the transmission level feedback signal within the predetermined time Correct the transmit power correction value by comparing it with the feedback value. This is to perform weighting calculation processing so as to be able to cope with fluctuations in transmission power within a predetermined time.

Thus, according to the wireless transmission device in the third embodiment, automatic gain correction can be appropriately operated even in a configuration in which transmission power is varied within a frame. Further, according to the wireless transmission device in the third embodiment, an appropriate transmission power correction value can be calculated from data within a predetermined time regardless of the channel configuration in the frame, etc. Design becomes possible.

[0090] [First modification in the above-described embodiment]

In the wireless transmission devices according to the first embodiment and the second embodiment described above, the average transmission power calculation unit 113 transmits data related to the reference signal among the transmission level feedback signals. Instead of the force reference signal that was used to calculate the average feedback value using only the control signal, only the control signal placed in the control channel may be used, or a combination of both may be used. May be. In the radio transmitting apparatus in such a first modification, a radio frame as shown in FIG. 12 is used. FIG. 12 is a diagram showing a radio frame format composed of a reference channel, a control channel, and a data channel.

[0091] When only the control channel is used instead of the reference channel, the signal generation unit 330 sends the generated main signal to the DZA conversion unit 301, and sets the transmission timing of the control signal of the main signal. The automatic gain correction unit 331 may be notified.

Thus, average transmission power calculation section 113 extracts the feedback value related to the control signal for the transmission level feedback signal power that is sequentially input at the transmission timing of this control signal. If the feedback value for the extracted control signal is averaged over the control channel interval, the average feedback value corresponding to the average transmission power of the control signal should be calculated.

Similarly, a reference signal and a control signal may be used in combination. In this case, the signal generation unit 330 may notify the automatic gain correction unit 331 of the transmission timing of the reference signal and the control signal of the main signal. Then, the correction value is corrected by calculating the expected value and the average feedback value within the time of the combination.

[Second Modification of the above-described Embodiment]

In the wireless transmission device described above, correction value calculation section 120 changes the difference between the expected value of the transmission level feedback signal calculated by expected value calculation section 101 and the average feedback value sent from average transmission power calculation section 113 as it is. A new correction value was calculated by adding it to the previously calculated correction value as an amount, but a predetermined change amount corresponding to the difference value may be determined in advance.

[0095] For example, when the expected value of the transmission level feedback signal is larger than the average feedback value, the amount of change is set to 0.5 (dB), and the expected value of the transmission level feedback signal is averaged. When the feedback value is smaller, the change amount is set to 10.5 (dB), and when the expected value of the transmission level feed knock signal is the same as the average feedback value, the change amount is set to O (dB). Decide as follows. Such a definition may be held in advance by the correction value calculation unit 120. Hereinafter, this definition table held by the correction value calculation unit 120 is referred to as a correction value change amount table. FIG. 14 is a data transition diagram showing gain correction in the third modification.

[0096] It is assumed that the upper force in FIG. 14 is also calculated as 18 (dBm) by the average transmission power calculation unit 113 in the second-stage data state. The correction value calculation unit 120 receives the expected value (20 (dBm)) of the transmission level feedback signal calculated earlier and the average transmission power (18 (d Bm)), and compares them. The correction value calculation unit 120 determines that the expected value (20 (dBm)) of the transmission level feedback signal is larger than the average transmission power (18 (dBm))! / The amount of change in the correction value corresponding to this is determined as 0.5 (dB). The correction value calculation unit 120 calculates the change amount to the previous correction value (here, 0 as an initial value) to obtain a new correction value (0.5 (dB)). This correction value is added by the adder 123 with the power value (17 (dB)) sent from the adder 121. A TPC signal corresponding to the power value (17.5 (dB)) calculated in this way is generated and sent to the TPC amplifier 303.

Next, it is assumed that 21 (dBm) is calculated as the transmission average power in the data state in the third row from the top in FIG. The correction value calculation unit 120 determines that the expected value (20 (dBm)) of the transmission level feedback signal is smaller than the average transmission power (21 (dBm)), and the correction value change amount table power is determined accordingly. Determine the amount of change in the correction value—0.5 (dB). The correction value calculation unit 120 adds the amount of change to the previous correction value (0.5 (dB)) to obtain a new correction value (0). As a result, a TPC signal output from the adder 123 is generated as a TPC signal corresponding to the power value (17 (dB)) (no correction) sent from the adder 121 and sent to the TPC amplifier 303. .

[0098] Finally, it is assumed that the average transmission power is calculated as 20 (dBm) in the lowermost data state in FIG. The correction value calculation unit 120 determines that the expected value (20 (dBm)) of the transmission level feedback signal calculated previously and the average transmission power (20 (dBm)) are the same value, and the correction value Change amount table power Change amount 0 (no change) is determined accordingly. The Since it has been determined that there is no change amount, the correction value calculation unit 120 uses the previous correction value (0) as the new correction value (0).

Note that the definition in the correction value change amount table held by the correction value calculation unit 120 is not limited to the above example. In addition to the above example, for example, the expected value of the transmission level feedback signal is also obtained by subtracting the average feedback value (difference value) greater than the upper limit value (l (dB)). )), The difference value is smaller than the lower limit value (-1 (dB)), V, and the amount of change (-1 (dB)), the difference value is less than the upper limit value (+1 (dB)) and If the value is lower than the lower limit (1 1 (dB)), it may be defined that there is no change. The amount of change, the upper limit value, and the lower limit value in this example may be variable values according to the circuits constituting the device.

[Supplementary items in the above embodiment]

The average transmission power calculation unit 113 in the above-described embodiment receives a reference signal transmission timing, and extracts the feedback value related to the reference signal from the transmission level feedback signal sequentially input according to the timing shown in FIG. In this way, even if CP (Cyclic Prefix) is added in the reference channel, it is possible to cope with it.

[0101] In other words, since the CP is realized by copying a part of the end of the time-axis signal and adding it to the head of the symbol, the signal after the CP is added can be any time point within the CP time. Even if the original symbol time length is extracted, a substantially similar average feedback value can be calculated. For example, even if the average transmission power calculation unit 113 averages the feedback value in the time interval (1), (2), and (3) shown in FIG. Can be calculated. FIG. 13 is a diagram showing an average feedback value calculation interval.

As described above, the average feedback value production section in the average transmission power calculation unit 113 does not need to be strictly adjusted, and can be realized with a simple circuit configuration.

Claims

The scope of the claims

[1] A wireless transmission device that transmits by changing the transmission level of a transmission signal,

Detecting means for detecting a transmission level of the transmission signal;

Calculating means for calculating a gain correction value using a transmission level of a section in which an expected value of the transmission level is constant among transmission levels detected by the detecting means;

A wireless transmission apparatus comprising: correction means for performing gain correction of the transmission signal based on the gain correction value.

[2] When the transmission signal is multiplexed with a plurality of channels as a section where the expected value of the transmission level is constant, the calculation means is at least one of a reference channel and a control channel among the plurality of channels. The wireless transmission device according to claim 1, wherein a section is used.

[3] The calculation means includes:

An average calculating means for calculating an average transmission level in a section where the expected value of the transmission level is constant;

Holding means for holding an average expected value of transmission levels in a section where the expected value of the transmission level is constant;

A comparison means for obtaining a difference between the average transmission level and the average expected value; a correction means for correcting the gain correction value using the difference obtained by the comparison means as a change amount;

The wireless transmission device according to claim 1, comprising:

4. The radio transmitting apparatus according to claim 3, wherein the correction means uses a predetermined correction value corresponding to the difference obtained by the comparison means as the change amount.

5. The radio transmission apparatus according to claim 3, wherein the average calculation means uses a symbol time as a section for calculating the average transmission level.

[6] A wireless transmission device that transmits by changing the transmission level of a transmission signal,

Detecting means for detecting a transmission level of the transmission signal;

Average calculating means for calculating an average transmission level of a predetermined section of the transmission level detected by the detecting means; Expected value calculating means for calculating an expected value of the transmission level by a weighted average based on the transmission power value and the transmission time in the predetermined section;

Calculating means for calculating a gain correction value using the average transmission level and an expected value of the transmission level;

[7] In a transmission power control method in a wireless transmission device that transmits by changing the transmission level of a transmission signal,

A detection step of detecting a transmission level of the transmission signal;

A calculating step of calculating a gain correction value using a transmission level in a section in which an expected value of the transmission level is constant among the detected transmission levels;

A transmission power control method comprising: a gain correction step of performing gain correction of the transmission signal based on the gain correction value.

[8] In the calculation step, when the transmission signal is multiplexed with a plurality of channels as a section where the expected value of the transmission level is constant, at least one of the reference channel and the control channel among the plurality of channels is used. The transmission power control method according to claim 7, wherein a section is used.

[9] The calculation step includes:

An average calculating step for calculating an average transmission level in a section where the expected value of the transmission level is constant;

A holding step for holding an average expected value of the transmission level in a section in which the expected value of the transmission level is constant;

A comparison step for obtaining a difference between the average transmission level and the average expected value; and a correction step for correcting the gain correction value using the difference obtained by the comparison step as a change amount;

The transmission power control method according to claim 8, comprising:

10. The transmission power control method according to claim 9, wherein the correction step uses a predetermined correction value corresponding to the difference obtained in the comparison step as the amount of change. 10. The transmission power control method according to claim 9, wherein the average calculation step uses a symbol time as a section for calculating the average transmission level.