WO2010049007A1 - A method of scheduling data - Google Patents

Abstract

An apparatus for scheduling data for subsequent transmission, wherein data is arranged as discrete elements or aggregations of said elements, having means to puncture discrete or aggregated elements having a first designation into a group of aggregated elements having a second designation. The first designated elements may be pre-assigned to a first destination, and said aggregated groups pre- assigned to a second destination. The apparatus may be a node B of a cellular communication system and the different designations different user equipments.

Description

A METHOD OF SCHEDULING DATA

Field of Invention

The invention relates a method of scheduling data such as in communication systems and has particular but not exclusive application to transmitting data in cellular communication systems.

Background of Invention

A communication system is a facility which facilitates the communication between two or more entities such as communication devices, network entities and other nodes. A communication system may be provided by one more interconnected networks. A communication device can be understood as a device provided with appropriate communication and control capabilities for enabling use thereof for communication with others parties. The communication may comprise, for example, communication of voice, electronic mail (email), text messages, data, multimedia and so on. A communication device typically enables a user of the device to receive and transmit communication via a communication system and can thus be used for accessing various service applications.

In cellular systems a network entity in the form of a base station provides a node for communication with mobile devices in one or more cells. A base station is often referred to as a 'Node B'. There are many different techniques for processing signals for transmission between the base station and the user equipment. Typically the operation of a base station apparatus and other apparatus of an access system required for the communication is controlled by a particular control entity. The control entity is typically interconnected with other control entities of the particular communication network.

A non-limiting example of a type of access architecture is a concept known as the Evolved Universal Terrestrial Radio Access (E-UTRA), which is part of the Third

Generation Partnership Project Long Term Evolution (3GPP LTE) standard. Within the E-UTRA architecture, it is proposed to use Orthogonal Frequency Division Multiple Access (OFDMA) for the downlink (i.e. base station to mobile station) and Single Carrier Frequency Division Multiple Access (SC-FDMA) for the uplink (mobile station to base station). In 3GPP systems it is proposed that, in relation to general control channel structure, there will be a division between control and data, and that both use time domain multiplexing (e.g. a number of OFDM symbols in each TTi (transmission time interval) will carry the control channels for a number of user equipments (e.g. mobile/user equipment UE) for the Physical Downlink Control Channel (PDCCH), and a set of OFDM symbols will carry the shared channel for a number of users (PDSCH).

There are problems for the eNB (evolved node B) scheduler, which will potentially run into a phenomenon called PDCCH blocking, where a UE potentially scheduled for uplink (UL) or downlink (DL) traffic will not be scheduled due to other UEs already having been allocated for the CCE (Control Channel Element) resources that this new UE would be able to receive and decode. The consequence of this is that some UEs might have to be delayed from a scheduling point of view, and have trouble fulfilling their quality of service. Further, from a cell-efficiency point of view a loss of flexibility to schedule users may be disadvantageous.

Aggregation is a known technique where groups of resource elements referred to as CCE's are clustered i.e. concatenated together in groups or blocks of 1 , 2, 4 or 8. .In order to reduce UE decoding complexity, hashing functions are often used. However there still remains the problems of collisions of aggregation possibilities.

Statement of the Invention

According to a first aspect of the invention there is provided a method of scheduling data for subsequent transmission, wherein data is arranged as discrete elements or aggregations of said elements, comprising puncturing discrete or aggregated elements into a group of aggregated elements.

The method may be employed in a cellular communication system. The puncturing may be performed by a node B or a network controller.

The first and second destinations may be different user equipment. In a preferred embodiment the method includes determining the condition of at least two of said links, determining which of said links in a better condition, allocating channel resources to the link in the worse condition and wherein said puncturing being such that elements or aggregated elements associated with the better link are punctured into said aggregated groups which are associated with the worse link.

The data may be control data such as PDCCH data of an E-UTRAN. The data may be control channel elements (CCEs).

The data after puncturing may be transmitted along a single channel.

Preferably the group of aggregated elements into which puncturing occurs comprises 8 or more elements.

According to a second aspect of the invention there is provided an apparatus for scheduling data for subsequent transmission, wherein data is arranged as discrete elements or aggregations of said elements, having means to puncture discrete or aggregated elements into a group of aggregated elements.

In an embodiment the elements or aggregated elements which are punctured into said aggregated groups are pre-assigned to a first destination, and said aggregated groups into which they are punctured are pre-assigned to a second destination.

The apparatus may be a node B and the first and second destinations are different user equipments.

In a preferred embodiment it includes means to determine which link to the destinations is in a better condition, means to allocate channel resources to the link in the worse condition, said puncturing means adapted to puncture elements or aggregated elements associated with the better link, into a aggregated groups associated with the worse link.

The data may be control data such as PDCCH data of an E-UTRAN. The data may be control channel elements (CCEs).

In a preferred embodiment the aggregated group comprises 8 or more elements. Summary of Figures

For a better understanding of the present invention and how the same may be carried into effect, reference will now be made by way of example only to the accompanying drawings in which:

Figure 1 shows schematically an LTE system.

Figure 2 shows the system of figure 1 in more detail.

Figure 3 shows a diagram showing various aggregation levels.

Figure 4 shows a flow diagram illustrating one embodiment of the invention.

Figure 5 shows a comparison of performance in a first simulation of two schemes of formatting CCEs for transmission; one of the schemes using puncturing according to an embodiment of the invention.

Figure 6 shows a comparison of performance in a second simulation of two schemes of formatting CCEs for transmission detailed below; one of the schemes using puncturing according to another embodiment of the invention.

Detailed Description of Exemplary Embodiments

Before explaining in detail a few exemplifying embodiments, a brief explanation of wireless access is given with reference to figure 1 which shows a communication system 1 providing wireless communications to a piurafity of communication devices 2. The communication device, for example a mobile user device or equipment, can be used for accessing various services and/or applications provided via the wireless communication system. The communication device can typically access wirelessly a communication system via at least one wireless transmitter and/or receiver node B 3 of an access system. Non-limiting examples of access nodes are a base station of a cellular system, for example a 3G WCDMA Node B, a base station of a wireless local area network (WLAN) and a satellite station of a satellite based communication system, er,

The communications may be arranged in various manners based on an appropriate radio access technology or technologies. The access is provided via radio channels also known as access channels. Each communication device 1 may have one or more radio channels open at the same time. Each communication device may be connected wirelessly to more than one base station 3 or similar entity. Also, a plurality of communication devices may communicate with a base station or simiiar, and/or attempt to access the communication system via the same base station. A plurality of communication devices may also share a channel. For example, to start communications or to connect to a new access system, a plurality of communications devices may attempt to make the initial contact via a single channel, for example via a random access channel (RACH). The attempts to access may be made substantially at the same time.

The base station (eNode B) can be connected to other parts of the communication system via appropriate connections, for one or more appropriate gateway nodes.

The eNodeB 3 has an antenna for communicating with the user equipment via wireless link. The eNodeB has a data processing entity for carrying out various processes. Additionally a memory is provided which stores information which is used by the eNode B. A base station is typically controlled by at least one appropriate controller apparatus, e.g. network controller, generally denoted by 4 and can be provided for managing of the operation of the base station and/or communications via the base station. The controller apparatus is typically provided with memory capacity and at least one data processor. Various functional entities may be provided in the controller by means of the data processing capability. The functional entities provided in the base station controller may provide functions relating to radio resource control, access control, packet data context control, relay control and so forth.

A user device 2 can be used for various tasks such as making and receiving phone calls, for receiving and sending data from and to a data network and for experiencing, for example, multimedia or other content. For example, a communication device may access applications provided via a telephone network and/or a data network, such as applications that are provided based on the Internet Protocol (IP) or any other appropriate protocol. An appropriate mobile communication device may be provided by any device capable of at least sending and/or receiving wireless signals from the access system. Non-limiting examples include a mobile station (MS) such as a mobile phone or a smart phone, a portable computer provided with a wireless interface card or other wireless interface facility, personal data assistant (PDA) provided with wireless communication capabilities, or any combinations of these or the like. The communication device 1 is typically provided with appropriate data processing apparatus.

Figure 2 shows in more detail the system of figure 1 and shows this architecture only to give an example of a possible communication system where the embodiments described below may be provided and that other arrangements and architectures are also possible. For example, the user device may communicate with a different access system. The eNodeB 3 has an antenna 5 for communicating with the user equipment via wireless link. The eNodeB has a data processing entity 6 for carrying out various processes. Such processes may include some embodiments of the invention. Additionally a memory 7 is provided which stores information which is used by the eNode B. It is noted that the embodiments of the invention and functionality may be provided according to some embodiments of the invention by a separate component to the data processing entity. In some embodiments the functionality of the methods according to some embodiments of the invention are carried out by other parts of a system separate from the node B. For example in an embodiment the functionality may be carried out by network controllers.

The mobile device may communicate via an appropriate radio interface arrangement of the mobile device. The interface arrangement may be provided for example by means of a radio part 8 and associated antenna arrangement The antenna arrangement may be arranged internally or externally to the mobile device. A mobile device is typically provided with at least one data processing entity 9 and at least one memory 10 for use in tasks it is designed to perform. The data processing and storage entities can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 11. The user may control the operation of the mobile device by means of a suitable user interface such as key pad 12, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 14, a speaker and a microphone are also typically provided. Furthermore, a mobile device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto. A modulator component 13 is also shown.

Some embodiments of this invention are related to the long term evolution (LTE) of 3GPP. In the proposed LTE structure the base station is called eNode B. The physical layer is based on SC FDMA (single carrier division multiple access) for the Uplink and OFDMA (orthogonal frequency division multiple access) for the downlink.

Certain embodiments can be used in a long term evolution (LTE) radio system. The long term evolution (LTE) is a system which provides an evolved radio access system that is connected to a packet data system. Such an access system may be provided, for example, based on architecture that is known from the Evolved Universal Terrestrial Radio Access (E-UTRA) and based on use of the Evolved Universal Terrestrial Radio Access Networks (E-UTRAN) Node Bs (eNBs). An Evolved Universal Terrestrial Radio Access Network (E-UTRAN) consists of E- UTRAN Node Bs (eNBs) which are configured to provide base station and control functionalities. For example, the eNBs nodes can provide independently radio access network features such as user plane radio link control/medium access control/physical layer protocol (RLC/MAC/PHY) and control plane radio resource control (RRC) protocol terminations towards the user devices.

In the proposed LTE structure, the physical layer details are as follows. The generic radio frame for FDD (frequency division duplex) and TDD (time division duplex) has a duration of 10ms and consists of 20 slots with a slot duration of 0.5ms. Two adjacent slots form one sub-frame of length 1 ms

The physical channels defined in the downlink are the Physical Downlink Shared

Channel (PDSCH), the Physical Downlink Control Channel (PDCCH) and the Common Control Physical Channel (CCPCH). The physical channels defined in the uplink are the Physical Uplink Shared Channel (PUSCH) and the Physical Uplink

Control Channel (PUCCH).

Some embodiments of the invention are related to the contro! channel structure in the context of the FDD mode of 3GPP. However, it should be appreciated that embodiments of the invention may also be applied to the TDD mode as well, since the concept of creating control channels for the TDD mode uses similar principies. As discussed, the general control channel structure is such that there wiil be a division between control and data, such that these are using time domain multiplexing (meaning that a number of OFDM symbols in each TTI (transmission time interval) will carry the control channels for a number of UE (PDCCH), and a set of OFDM symbols will carry the shared channel for a number of users (PDSCH)).

To provide robustness towards channel imperfections, the physical downlink controi channel (PDCCH) is often coded prior to transmission. Further, in order to ensure proper coding and transmission, the encoded packet is rate matched to the available capacity on the physical channel. The minimum amount of physical resources that can carry a PDCCH is called a CCE (control channel element). A CCE in proposed future 3GPP systems is set to occupy 36 resource elements, each using QPSK as modulation scheme. This gives 72 channel bits provided by each CCE.

In order to provide sufficient flexibility and coverage for the PDCCH, it is proposed to apply an operation denoted "aggregation", which effectively means that neighbouring CCEs (with limitations) are allowed to be combined; i.e. clumped together to form a block of concatenated CCEs. Aggregation which is used in some embodiments of the invention will now be described. Consider the situation where there is a set of control channel elements (CCEs). These can be used in their base form (which is called aggregation level 1 ). However, for some user equipment that are in worse channel conditions, it is necessary to convey more channel energy/resources. This is provided by concatenating two neighbouring CCEs to form a group will be able to carry a PDCCH at aggregation level 2. For users in even worse conditions, it is possible to use aggregation levels 4 and 8 which concatenate 4 and 8 CCEs. As the rate matcher will adjust the forward error correction code rate to match the available channel capacity, increasing the aggregation level corresponds to lowering the code rate for the PDCCH payload to be transmitted. The PDCCH payload to be transmitted can take the form of different download control information (DCI) formats, as described in 36.212. In general, a lower code rate provides better error correction capabilities for the channel coder, and therefore it will be possible to recover from worse channel propagation conditions.

It has previously been proposed to reduce this as follows. As mentioned four aggregation levels of 1 , 2, 4 and 8 have been proposed. Based on the assumption that each CCE is interleaved sufficiently over the frequency, there is the same average performance of each CCE. This means that a good channel condition UE's control channel information can be transmitted successfully on any single CCE for the same performance. Further, from a packet scheduling point of view, in one scenario, it is not likely that more than 10-12 users will be scheduled at the same time for each link direction.

Aggregation allows that the amount of physical resources remaining available is increased. This will improve the link level performance by a little more than 3 dB due to the added coding available by having more physical channel resources. Aggregation of CCEs is known with the following combination levels {1, 2, 4, and 8}. The aggregation level 8 means that effectively 8 times the original (1 CCE) resources are available. Given the fact that the user information payload (DCI - downlink control information) is kept the same, this increasing of aggregation levels corresponds to lowering the effective code rate, and thereby improving the coverage.

The main problem of a UE such as a mobile searching for its resource assignment {either downlink allocation or an uplink resource grant) is that the UE does not know which CCE (or set of aggregated CCEs) it should observe. If there are no restrictions on which positions to observe, the UE would be doing approximately 500 blind decoding attempts each time it would potentially receive a PDCCH for dynamic scheduling Recently, work has been done into defining ways which would reduce the overall decoding complexity burden on a UE it needs to do searching for a PDCCH. The outcome of this is presented in TS 36.213 v. 8.3.0, section 9.1.1 where it is described at which aggregation levels each UE should be searching for its allocation. In general, the UE would be looking (in the UE specific search space) for 6 possibilities at aggregation level 1 , 6 possibilities at aggregation level 2, 2 possibilities at aggregation level 4, and 2 possibilities at level 8.

Seen from a UE decoding complexity perspective, the decision in TS36.213 on the hashing functions provides significant decoding complexity restrictions, such that the UE processing power and battery power consumption is maintained at a sufficiently low level. However, there is a potential problem of blocking between aggregation levels. This situation of blocking arises when the eNB first schedules two poor condition UEs at aggregation leve! 8 - in one example this would be at offsest 0 and offset 8, such that all CCEs with indices 0 to 15 are reserved and used for these two UE, and following this, the eNB subsequently tries to schedule a third UE with very good channel conditions using aggregation levels. One such situation is outlined in figure 3 below, where it is seen that the search space at aggregation level 1 for this third UE ranges from index 0 to indexS. There is no way that this UE can be scheduled, as ail the possible CCEs have already been reserved/used for the first two UEs being scheduled. The above example is merely to be considered as an example, and when considering more than 3 UEs, the outlined situation will happen with higher probability. In order to show some of the problems that exist with the current hashing functions, the hashing functions will ideally provide a full scattering of the possible starting points at each aggregation level. This might lead to the situation as given in figure 3, where all the possible positions at aggregation level 1 collide with a single aggregation level 8 possibility. Four different aggregation levels are shown as indicated, and the start points are indicated by arrows. Further, this aggregation level 1 user collides or overlaps with 2 possibilities at aggregation leve! 4. This leaves less room for the eNB scheduler to shift the resources around for iow aggregation level users when high aggregation level users have been scheduled. The eNB will primarily base its decision on the aggregation level to use upon the channel quality indication received from the UE. However, the UE will not know the actual decision on which aggregation level to use, so it will have to search the all possible aggregation levels for allocations.

One embodiment of the invention uses puncturing as a solution to the problem. In one embodiment of the invention puncturing of UE PDCCH allocations (e.g. in node

Bs at higher aggregation levels) is performed to allow for good condition UEs. A good condition Ue is having good cannel propagation conditions, meaning that it will typically be located close to the eNB, while the poor condition UEs will typically be located at the cell edgefor transmission. The term "puncturing" means that data (e.g. CCE's) destined for a particular user, (destination or use) are over-laid into a block of data (e.g. aggregation of 8 CCE's) destined for a different user, (destination or use).

in one example, it may be that a link A to UE (A) is in a good condition and a link B to a poor condition UE (B), which both would like to use the same region of CCEs. In this context the region of CCEs is defined as the set of CCEs which are being reserved for or used for the worst condition UE. At aggregation level 8, the region of CCEs spans 8 CCEs for scheduling resources, for example in the down link. According to an embodiment of the invention CCE resources are firstly allocated to the link with the bad condition UE (user B). Then CCEs associated with the user A are be punctured into the CCEs originally assigned to user B. This means that the decoding for user B will become worse, as one CCE is containing some PDCCH information which is intended for a different UE. However, it has been determined this will only pose a smal! degradation. Advantageously, at the same time however it allows the opportunity for user A to be scheduled for traffic. Although user B only gets 7/8 of the CCE resources, a degradation of less than 1 dB occurs One of the main benefits of this embodiment of the invention is that the PDCCH capacity is potentially boosted even when we have some poor condition UEs for scheduling.

This procedure is illustrated in figure 4 which shows a flowchart showing an embodiment of the invention. Reference is made to the figure which illustrates a method according to an embodiment of the present invention. The typical scheduling procedure would be such that the eNB schedule UEs according to their relative priorities. And when the resources starts being allocated for UEs, we have the possibility to puncture aggregation level 8 UEs allocations (provided that they have sufficiently good channel conditions (even that they are in relative poor conditions)) to make room for this additional UE. Additionally, the opposite situation could also be envisioned - that is, a good condition UE has already been scheduled and assigned CCE resources, and subsequently a poor condition UE is intended for scheduling. Given that the channel conditions for this UE allows for puncturing, even that

8 CCEs are required, we can perform puncturing of this poor condition UE to put the allocation information "around" the already scheduled UE.

In step S1 , a base station (e.g. eNode B) determines the condition of link A between node B and User Equipment A. At the next step S2 the condition of the link B between base station and User Equipment B is determined by the base station. At step S3 the base stations determines which of the links is in a worse condition. This condition of the links can vary due to many causes and be determined in several ways. At step S4 resources are allocated initially and to the link which is in the worse condition. At step S5, aggregated CCE's are selected from this link to which resources have been allocated. In step S6, CCE's from the link which has the better condition are punctured into the aggregated CCE's selected at step S5. Finally at Step S7 punctured data is sent in the downlink to the User Equipments A and B. It should noted that the example of figure 4 is schematic to show a basic embodiment of the invention. Where the eNodeB serves a large number of UE's, the NodeB will determine the quality of links for all or most of these. It should be appreciated that a plurality of schemes for ordering or prioritising those links can be included into embodiments of the invention. It should also be appreciated that other parts of the system may perform the above task. The network controller may also perform this task in further embodiments of the invention, as weil as any appropriate node in a communication system including gateways and the like.

Reference will now be made to particular embodiments of the invention to illustrate simple possibilities of implementing an embodiment of the invention and comparing result in simulations. Two simulated performances were run, each comparing two cases, one without puncturing, the other with puncturing according to an embodiment of the scheme.

Simulation 1 was run for comparison purposes for two cases detailed below.

Case 1 used a scheme which used an aggregation of 8 CCE's (i.e. an aggregation level of 8) for user B. A representation of the allocation of CCEs to a user B how the how the CCE's would be mapped is show below:

Case i B B B B B B B B X X X X X X X X X X X X...

where B represents a CCE for user B, whilst X just represents dummy data representing CCE's for another user being scheduled

Below is a simple representation for case 2 where a single user B is allocated initially the first eight CCEs, but one of these is punctured by user A according to one embodiment of the invention; one of the CCE's is reallocated with data for user A . This is represented as below:

Case 2 B B A B B B B B X X X X X X X X X X X X... (where B=8 CCE for user 'B', A=ICCE for user ¹A', while X is just dummy data representing other users being scheduled.

Simulations were run for comparison purposes for both cases using 3GPP TU channel profile. The CCE's for both user A and user B were transmitted using the same transmit power.

Simulation 2.

This simulation is similar to the above one above but compared aggregation scheme where 4 CCEs were aggregated together. It compares results for simulations run for cases 3 and 4 listed below.

Case 3 is an un-punctured scheme which used an aggregation of 4 CCE's for user B (i.e. has a level 4 aggregation scheme):

Case 3 B B B B X X X X X X X X X X X

In case 4, the scheme of case 3 above was punctured with one CCE with data for user A:

Case 4 B B A B X X X X X X X X

Results

Figure 5 shows simulation results comparing case 1 and case 2 and thus shows the effect of puncturing of the aggregation level 8 PDCCH by a single aggregation level

1 PDCCH. Case 1 is the non-punctured performance, while case 2 represents the performance of the punctured PDCCH. The figures show the SNR-BLER mapping curve, (signal to noise ratio against block error rate). The figure shows that the poor condition UE using the puncturing scheme would experience a BLER performance which is approximately 1.4 dB worse than in the case that it is not punctured.

This marginal loss is relatively low. It is smali enough in its effect on the user B such that it allows resources to be effectively "stolen" by hijacking some CCE's from UEs at higher aggregation levels, provided that the power margin for the poor condition UE is sufficiently large. The reason for the 1.4 dB loss compared to the expected 0.6 dB loss comes from the fact that the data fields of the received packet are polluted by information for destined for another UE. BLER is the block error ratio, which is a ratio between the number of failed packet receptions to the total number of packets, and in general this term is used to express the performance of transmission over a radio channel.

Figure 6 shows corresponding results for similarly run simulations for cases 3 and 4 i.e. elements punctured into blocks of a lower aggregation level As can be seen the penalty for puncturing is much larger, as the UE decoding reaches an irreducible error floor, which causes the performance loss to become almost 10 dB for a PDCCH BLER of 10%.

The results show that for larger aggregation fevels, puncturing according to embodiments of the invention allow resources to be freed up in return for an acceptable reduction in performance. The scheme is preferably applied to aggregation levels 8 UEs or more. In case the puncturing UE PDCCH information is towered in power, the decoding performance is correspondingly better. The invention improves the PDCCH capacity in terms of number of UEs scheduled for scenarios where there are more transmit power than CCE resource available.

Some embodiments including the ones illustrated by way of example are such that data are sent to different destinations, e.g. in the downlink from a Node B to mobile (UE) A and mobile (UE) B. Embodiments of the invention are not limited to this but can also be applied to scenarios where data are of two types are sent to the same destination or user equipment but may have a different purpose or use. For example data sent to a User Equipment may be designated "audio" or "visual" data; such data is destined to be received by the User Equipment e.g. mobile or PC). However the data at the end terminal are processed in a different manner; e.g. for audio or visual presentation, in the exam . In one embodiment of the invention audio data (elements) may be punctured into visual data or vice versa. The type of puncturing scheme in such embodiments of the invention may depend on the quality or other requirements or processing ability appropriate for the two or more types of data. It should be noted that figure 1 shows only an example of a possible communication system to which embodiments of the invention can be incorporated into and that other arrangements and systems can also incorporate embodiments of the invention.

The invention is not limited to cellular communication systems but can be applied to any system where data is scheduled for transmission with different designations e.g. to various destinations or uses. It is also applicable to various types of network not limited to Local Area Networks (LANS), Wireless LANs (WLANS), Internet etc. Functionality may be provided rather than in Node B in network elements, gateways or any suitable node or element. It should be appreciated that although the preferred embodiments of the invention have been described in the context of the LTE proposals, embodiments of the present invention may be used within the framework provided by any other standard whether it has proposed or has yet to be evolved. Embodiments of the invention may also be used in scenarios where there is no standardized framework. Accordingly references to an eNode B should be considered to be equally applicable to a base station or a control entity.

The embodiments of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any blocks of the logic flow as in the figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions.

The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims.

Claims

1. A method of scheduling data for subsequent transmission, wherein data is arranged as discrete elements or aggregations of said elements, comprising puncturing discrete or aggregated elements into a group of aggregated elements.

2. A method of scheduling data as claimed in claim 1 wherein said elements are of substantially the same size.

3. A method of scheduling data as claimed in claims 1 or 2 where said method is employed in a communication system.

4. A method as claimed in claims 1 , 2 or 3 wherein the elements or aggregated elements which are punctured into said groups are pre-assigned to a first destination and said groups into which they are punctured are pre-assigned to a second destination.

5. A method as claimed in claims 1 to 4 which is employed in a cellular communication system

6. A method as claimed in claim 5 wherein said puncturing is performed by a node B.

7. A method as claimed in claim 5 wherein said puncturing is performed by a network controller.

8. A method as claimed in claims 3 to 7 wherein said first and second destinations are different user equipment.

9. A method as claimed in claims 1 to 8 wherein said data is transmitted to at least two equipments via at least two corresponding links.

10. A method as claimed in claim 9 including determining the condition of at least two of said links, determining which of said Jinks in a better condition, allocating channel resources to the link in the worse condition and wherein said puncturing being such that elements or aggregated elements associated with the better link are punctured into said aggregated groups which are associated with the worse link.

11. A method as claimed in claims 1 to 9 wherein said data is control data.

12. A method as claimed in claim 10 wherein said data is PDCCH data of an E- UTRAN.

13. A method as claimed in claims 1 to 11 wherein the data after puncturing is transmitted along a single channel.

14. A method as claimed in any preceding claim wherein said group of aggregated elements into which puncturing occurs comprises 8 or more elements.

15. A method as claimed in any preceding claim wherein said elements are control channel elements (CCEs).

16. A method as claimed in claim 14 wherein a single element is punctured into an aggregated block of 8 elements.

17. A method of receiving and decoding data wherein data is arranged as discrete elements or aggregations of said elements, wherein discrete or aggregated elements have been punctured into a group of aggregated elements.

18. A method as claimed in claim 17 wherein the elements or aggregated elements which are punctured into said aggregated groups are pre-assigned to a first destination and said aggregated groups into which they are punctured are pre- assigned to a second destination.

19. A method as claimed in claims 17 or 18 which is employed in a cellular communication system.

20. A method as claimed in claims 17 to 19 wherein said first and second destinations are different user equipment.

21. A method as claimed in claim 17 to 20 wherein said data is control data.

22. A method as claimed in claim 21 wherein said data is PDCCH data of an E- UTRAN.

23. A method as claimed in ciaim 17 to 22 wherein the data after puncturing is transmitted along a single channel.

24. A method as claimed 17 to 23 wherein said aggregated groups comprise 8 or more elements.

25. A method as claimed in claim 17 to 24 wherein said elements are control channel elements (CCEs).

26. A computer readable medium comprising a computer program thereon, said computer program performing the method of any of claims 1 to 25.

27. An apparatus for scheduling data for subsequent transmission, wherein data is arranged as discrete elements or aggregations of said elements, having means to puncture discrete or aggregated elements into a group of aggregated elements.

28. An apparatus as claimed in claim 28 wherein the elements or aggregated elements which are punctured into said aggregated groups are pre-assigned to a first destination, and said aggregated groups into which they are punctured are pre-assigned to a second destination.

29. An apparatus as claimed in any of claims 27 or 28 which is part of a cellular communication system.

30. An apparatus as claimed in claim 29 which is a node B.

31. An apparatus as claimed in any of claims 28 to 30 wherein said first and second destinations are different user equipments.

32. An apparatus as claimed in claim 31 wherein said data is transmitted to the at least two equipments via at least two corresponding links.

33. An apparatus as claimed in claims 32 including means to determine which link to the destinations is in a better condition, means to allocate channel resources to the link in the worse condition, said puncturing means adapted to puncture elements or aggregated elements associated with the better link, into a aggregated groups associated with the worse link.

34. An apparatus as claimed in claim 30 which is a node B of an Evolved Universal

Terrestrial Radio Access Network.

35. An apparatus as claimed in claims 27 to 34 wherein said data is control data.

36. An apparatus as claimed in claim 35 wherein said data is PDCCH data of an E- UTRAN.

37. An apparatus as claimed in claims 27 to 36 wherein the data after puncturing is transmitted along a single channel.

38. An apparatus as claimed in claims 27 to 37 wherein said aggregated group comprises 8 or more elements.

39. An apparatus as claimed in claims 27 to 39 wherein said elements are control channel elements (CCEs)

40. An apparatus as claimed in any of claims 27 to 39 wherein said data is hashed data.

41. An apparatus as claimed in any of claims 27 to 40 wherein the puncturing means punctures a single element into an aggregated group of 8 elements or more.

42. An apparatus for receiving and decoding data wherein data is arranged as discrete elements or aggregations of said elements, wherein discrete or aggregated elements have been punctured into a group of aggregated elements.

43. An apparatus as claimed in claims 42 wherein the elements or aggregated elements which are punctured into said aggregated groups are pre-assigned to a first destination and said aggregated groups blocks into which they are punctured are pre-assigned to a second destination.

44. An apparatus as claimed in claims 42 or 43 which is a user equipment of a cellular communication system.

45. An apparatus as claimed in claims 42 to 44 wherein said first and second destinations are different user equipment.

46. An apparatus as claimed in claims 42 to 45 wherein said data is control data.

47. An apparatus as claimed in claim 46 wherein said data is PDCCH data of an E- UTRAN.

48. An apparatus as claimed in claims to 42 to 47 wherein said elements are control channel elements (CCEs).