INTER-POINT DATA EXCHANGE IN UL COMP

Abstract

A data exchange method in a Coordinated Multi-Point (CoMP), system, including an assistant point and a converging point. One method comprises selecting a predetermined number of subbands with the best channel quality, and exchanging user data of the selected subbands. Only part of the user data received at the assistant point is transmitted to the converging point. The requirement on the transport network capacity is thus loosened. By transmitting data with the best channel quality, a good enough gain is guaranteed.

Claims

1. A data exchange method for use in an assistant point in a Coordinated Multi-Point (CoMP) system, comprising: selecting a predetermined number N of subbands with the best channel quality, the selected subbands having channel quality better than other subbands of the assistant point; and transmitting user data of the selected N subbands to a converging point.

2. The method according to claim 1, wherein selecting N subbands with the best channel quality further comprises: calculating Resource block quality (RBQ) values of all subbands, and selecting N subbands with the largest N RBQ values as the N subbands with the best channel quality.

3. The method according to claim 1, wherein selecting N subbands with the best channel quality further comprises: calculating Resource block quality (RBQ) values of all subbands, receiving RBQ values of all subbands from the converging point, calculating uplink gains of all subbands based on the RBQ values of the converging point and the RBQ values of the assistant point, and selecting N subbands with the largest uplink gains as the N subbands with the best channel quality.

4. The method according to claim 2, further comprising: transmitting indexes of the selected N subbands to the converging point.

5. The method according to claim 4, wherein the user data and indexes are transmitted in different signaling.

6. The method according to claim 1, wherein selecting N subbands with the best channel quality further comprises: calculating Resource block quality (RBQ) values of all subbands, transmitting the RBQ values of all subbands to the converging point, receiving indexes of N subbands from the converging point, and selecting the N subbands with the received indexes as the N subbands with the best channel quality.

7. The method according to claim 6, wherein the converging point calculates uplink gains of all subbands for a plurality of assistant points based on the RBQ values of the converging point and the RBQ values the respective assistant points, and transmits indexes of N subbands with the largest uplink gains to the respective assistant points.

8. The method according to claim 1, further comprising: pre-processing the user data to obtain soft bits, and wherein the obtained soft bits are transmitted as the user data.

9. The method according to claim 1, further comprising: receiving, from an upper layer component, a notification message indicating the converging point in the CoMP system.

10. The method according to claim 9, further comprising: calculating Resource block quality (RBQ) values of all subbands, transmitting the RBQ values of all subbands to the upper layer component, which sums the RBQ values for a plurality of assistant points, and selects a respective assistant point with a largest summed RBQ value as the converging point.

11. The method according to claim 1, wherein the converging point receives user data from a plurality of assistant points and co-processes the user data from the plurality of assistant points.

12. The method according to claim 1, wherein the converging point is a serving point among a plurality of assistant points in the CoMP system.

13-20. (canceled)

21. An assistant point in a Coordinated Multi-Point (CoMP) system, comprising: at least one communication interface configured for communication, a processor, and a memory storing computer program code thereon which, when running in the processor, causes the assistant point to: select a predetermined number N of subbands with the best channel quality, the selected subbands having channel quality better than other subbands of the assistant point; and wherein the communication interface is configured to transmit user data of the selected N subbands to a converging point.

22. The assistant point according to claim 21, wherein the assistant point is further caused to: calculate Resource block quality (RBQ) values of all subbands, and select N subbands with the largest N RBQ values as the N subbands with the best channel quality, and wherein the communication interface is further configured to transmit indexes of the selected N subbands.

23. The assistant point according to claim 21, wherein the communication interface receives Resource block quality (RBQ) values of all subbands from the converging point, and the assistant point is further caused to: calculate RBQ values of all subbands, and calculate uplink gains of all subbands based on the RBQ values of the converging point and the RBQ values of the assistant point, and select N subbands with the largest uplink gains as the N subbands with the best channel quality, and wherein the communication interface is further configured to transmit indexes of the selected N subbands.

24. The assistant point according to claim 21, wherein the communication interface receives indexes of N subbands from the converging point, and the assistant point is further caused to: calculate Resource block quality (RBQ) values of all subbands, and select the N subbands with the received indexes as the N subbands with the best channel quality, wherein the indexes of N subbands is received in response to transmitting the calculated RBQ values to the converging point.

25. The assistant point according to claim 21, which is further caused to: pre-process the user data to obtain soft bits, and wherein the obtained soft bits are transmitted as the user data.

26. The assistant point according to claim 21, wherein the communication interface receives, from a upper layer component, a notification message indicating the converging point in the CoMP system.

27. A data exchange method for use in a converging point in a Coordinated Multi-Point (CoMP) system, comprising: calculating Resource block quality (RBQ) values of all subbands, transmitting the RBQ values to a plurality of assistant points, and receiving user data of a predetermined number N of subbands and indexes of the N subbands from respective assistant points used for multiple reception, so as to co-process the user data, wherein the N subbands are selected by the respective assistant points by using the RBQ values of the converging points and RBQ values of the respective assistant points to calculate uplink gains of all subbands and selecting N subbands with the largest uplink gains.

28. A data exchange method for use in a converging point in a Coordinated Multi-Point (CoMP) system comprising: calculating Resource block quality (RBQ) values of all subbands, receiving RBQ values from a plurality of assistant points used for multiple reception, calculating uplink gains of all subbands based on the RBQ values of the converging points and RBQ values of respective assistant points, and selecting a predetermined number N of subbands with the largest uplink gains, transmitting indexes of the selected N subbands to the respective assistant points, and receiving user data of the selected N subbands from the respective assistant points.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The foregoing and other features of this disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

[0036] FIG. 1 shows a CoMP scenario.

[0037] FIG. 2 shows an UL processing procedure in a CoMP scenario.

[0038] FIG. 3 illustrates a flowchart of a data exchange method according to an embodiment of the disclosure.

[0039] FIG. 4 illustrates a sequence of a data exchange procedure according to an embodiment of the disclosure.

[0040] FIG. 5 illustrates a sequence of a data exchange procedure according to another embodiment of the disclosure.

[0041] FIG. 6 illustrates a sequence of a data exchange procedure according to still another embodiment of the disclosure.

[0042] FIG. 7 illustrates a block diagram of an assistant point according to an embodiment of the disclosure.

[0043] FIG. 8 illustrates a block diagram of an assistant point according to another embodiment of the disclosure.

[0044] FIG. 9 is a schematic view of an arrangement which may be used in the assistant point shown in FIG. 8 according to an embodiment of the disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

[0045] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of claimed subject matter. However, it will be understood by those skilled in the art that claimed subject matter may be practiced without these specific details. In other instances, well-known methods, procedures, components and/or circuits have not been described in detail.

[0046] In the disclosure, the user data to be exchanged for further co-processing are selected at assistant points or a converging point, to match the inter-point transport network capacity and meanwhile guarantee a good UL CoMP gain.

[0047] FIG. 3 illustrates a flowchart of a data exchange method 300 according to an embodiment of the disclosure. The method 300 occurs at an assistant point. As shown, firstly, the assistant point receives user data from a user (e.g., a UE) at step S301. At step S302, the assistant point selects subbands to be transmitted. In order to guarantee the UL gain, the assistant point selects those subbands with the best channel quality. That is, the selected subbands have a channel quality better than any of the other subbands of the assistant point. The number of selected subbands, N, is predetermined according to the current transport network status, such as the network capacity. Then at step S303, the assistant point transmits user data of the selected subbands to the converging point. In case that the converging point is not aware of the indexes of the selected subbands, the assistant point also transmits the indexes of the selected subbands to the converging point. The transmission of the user data and of the indexes may be performed by the same signalling, or by different signalling.

[0048] FIG. 4 illustrates a sequence of a data exchange procedure according to an embodiment of the disclosure. FIG. 4 is shown by taking the scenario shown in FIG. 1 as an example. It is obvious that the number of assistant points in the system is not limited to two. There may be more or less assistant points in the system. Each assistant point, after having received user data from the UE 140, calculates RBQ (Resource block quality) values of all subbands, and selects N subbands with the largest N RBQ values. According to the deployment, the N subbands selected by the assistant point 120 may be different from those selected by the assistant point 130. The assistant points 120 and 130 then each transmit the user data of the selected N subbands to the converging point 110. The assistant points 120 and 130 also transmit the indexes of the selected N subbands to the converging point 110. The converging point 110 co-processes the user data received from respective assistant points 120 and 130 and from the UE 140.

[0049] In LTE, a number of subbands, i.e., physical resource blocks, are allocated for a scheduled UE to transmit data, which are numbered as M. The channel quality may be represented by the signal to interference and noise ratio (SINR) value. On a point, the SINR on each subband of the UE can be obtained after channel/interference estimation and equalization. The SINR values are converted to a RBQ value of this subband,and the RBQ value of the i.sup.th subband on the j.sup.th point is denoted as

RBQ.sub.i.sup.(j)=K log(1+SINR.sub.i.sup.(j))   (1)

[0050] where K is the number of subcarriers in a subband.

[0051] The UL CoMP gain from multiple points with exchanging and integration on the j.sub.l.sup.th point for the i.sup.th subband is defined as

[00001]$\begin{array}{cc}{g}^{\left(j_l\right)}\left(i\right)=\frac{\underset{j=0,j\ne j_l}{\overset{J-1}{.Math.}}.Math.{\mathrm{RBQ}}_i^{\left(j\right)}}{{\mathrm{RBQ}}_i^{\left(j_l\right)}}& \left(2\right)\end{array}$

[0052] where J is the number of points used for multiple receptions in uplink in the CoMP system.

[0053] Each assistant point may obtain the RBQ values of all subbands as above, and selects N subbands with the largest N RBQ values as the N subbands with the best channel quality.

[0054] The disclosure is not limited to the RBQ and uplink gains calculation as above, and any other appropriate criteria that can represent the channel quality are applicable. For example, the SINR value may be used instead of the RBQ.

[0055] FIG. 5 illustrates a sequence of a data exchange procedure according to another embodiment of the disclosure. FIG. 5 is shown by taking the scenario shown in FIG. 1 as an example. It is obvious that the number of assistant points in the system is not limited to two. There may be more or less assistant points in the system.

[0056] Each point, including the assistant points 120 and 130, and the converging point 110, after having received user data from the UE 140, calculates RBQ values of all subbands themselves. The converging point 110 then transmits its RBQ values of all subbands to each assistant point. The assistant points 120 and 130 then calculate uplink gains of all subbands based on the RBQ values of the converging point and its own RBQ values, by for example, equation (2) above. The assistant points 120 and 130 each select N subbands with the largest uplink gains as the N subbands with the best channel quality. The assistant points 120 and 130 then transmit the user data of the selected N subbands to the converging point 110. The assistant points 120 and 130 also transmit the indexes of the selected N subbands to the converging point 110. The converging point 110 co-processes the user data received from respective assistant points 120 and 130 and from the UE 140.

[0057] FIG. 6 illustrates a sequence of a data exchange procedure according to still another embodiment of the disclosure. FIG. 6 is shown by taking the scenario shown in FIG. 1 as an example. It is obvious that the number of assistant points in the system is not limited to two. There may be more or less assistant points in the system.

[0058] Each point, including the assistant points 120 and 130, and the converging point 110, after having received user data from the UE 140, calculates RBQ values of all subbands. Each of the assistant points 120 and 130 transmits its RBQ values of all subbands to the converging point 110, which calculates uplink gains of all subbands based on the RBQ values of the assistant points and its own RBQ values, by for example, equation (2) above. The converging point 110 selects N subbands with the largest uplink gains as the N subbands with the best channel quality, and informs each assistant point of indexes of the N subbands. The assistant points 120 and 130 then select N subbands according to the indexes received from the converging point 110, and transmit the user data of the selected N subbands to the converging point 110. Finally, the converging point 110 co-processes the user data received from respective assistant points 120 and 130 and from the UE 140.

[0059] In the data exchange procedure sequences shown in FIGS. 4-6, it is illustrated that each point may pre-process the user data received from the UE 140. As shown in Table 1, soft-bit pre-processing may reduce the requirement on transport capacity while maintaining an acceptable UL gain. Accordingly, each point may convert the user data received from the UE 140 into soft bits, and then transmit soft bits of the selected subbands for co-processing. Certainly, the disclosure is also applicable to any other pre-processing option, such as the raw data in time or frequency domain without pre-processing. That is, the user data exchanged between converging node and assistant nodes may be the raw data received from the UE.

[0060] In the system, the converging point may be known to all the points in the system. In an embodiment, it is a serving point. In another embodiment, it is decided by an upper layer component, such as a RNC (Radio Network Controller) in LTE. All points in the system transmit RBQ values of all subbands to the upper layer component, which sums the RBQ values for respective points and selects a point with the largest summed RBQ value as the converging point. The upper layer component may inform the points of the determined converging point by a notification message.

[0061] The soft bit means the post-processed data after demodulation with soft outputs. It is always regarded as a log-likelihood ratio (LLR), which quantifies the different probability level for a bit to be ‘0’ or ‘1’. These soft bits are fed into a Turbo decoder to be decoded.

[0062] The methods and procedures according to the disclosure described above may be performed by any suitable components or other means capable of performing the corresponding functions of the methods and procedures. For example, the methods and procedures may be performed at any assistant point illustrated in FIG. 7 and at a converging point (not shown).

[0063] FIG. 7 illustrates a block diagram of an assistant point 7000 according to another embodiment of the disclosure. As shown, the assistant point 7000 comprises a data determination unit 7100, a transmitter 7200, and a receiver 7300. The data determination unit 7100 is configured to select a predetermined number N of subbands with the best channel quality. The transmitter 7200 is configued to transmit user data of the selected N subbands to the converging point.

[0064] In an embodiment, such as for the assistant poitns 120 and 130 in FIG. 4, the data determination unit 7100 may comprise a calculatior 7110 configured to calculate RBQ values of all subbands, and a selector 7120 configured to select N subbands with the largest N RBQ values as the N subbands with the best channel quality, as shown in FIG. 7.

[0065] In an embodiment, such as for the assistant points 120 and 130 in FIG. 5, the receiver 7300 receives RBQ values of all subbands from the converging point 110. The calculator 7100 calculates RBQ values of all subbands, and calculates uplink gains of all subbands based on the RBQ values of the converging point and its own RBQ values. The selector 7120 selects N subbands with the laregst uplink gains, and the transmitter 7200 transmits user data of the selected N subbands to the converging point 110. The transmitter 7200 also transmits indexes of the selected N subbands, so that the converging point knows from which subbands the received data user are.

[0066] In an embodiment, such as for the assistant points 120 and 130 in FIG. 6, the transmitter 7200 transmits the calculated RBQ values to the converging point 110, which decides the N subbands of the best channel quality. In response to the transmission of the transmitter, the receiver 7300 receives indexes of N subbands from the converging point. The selector 7120 selects N subbands according to the received indexes, and the transmiter 7200 then transmits user data of the selected N subbands to the converging point.

[0067] The converging point shall be known to the assistant points. For example, the converging point may be the serving point in the system. As an alternative, the converging point in the system may be decided by an upper layer component, such as a RNC (Radio Network Controller) in a LTE. The transmitter 7200 of each assistant point transmits RBQ values of all subbands to the upper layer component. The upper layer component sums the RBQ values for respective points, and selects a point with the largest summed RBQ value as the converging point. The upper layer component may inform the point of the determined converging point by a notification message. The receiver 7300 of each assistant point receives the notification message indicating the converging point, and thereby knows the converging point that is responsible for co-processing.

[0068] FIG. 8 illustrates a block diagram of assistant point 8000 according to an embodiment of the disclosure. The part of assistant point 8000 which is most affected by the adaptation to the method and procedure described herein, e.g., the method shown in FIG. 3 and the procedure shown in FIGS. 4-6, is illustrated as an arrangement 8001, surrounded by a dashed line. Assistant point 8000 may be any kind of points, depending on in which type of communication system it is operable. Assistant point 8000 and arrangement 8001 are further configured to communicate with other entities via a communication interface 8002 which may be regarded as part of the arrangement 8001. The communication interface 8002 comprises means for wireless communication or wired communication with other devices or nodes, such as UE and the converging point. The arrangement 8001 or Assistant point 8000 may further comprise other functional units 8004, such as functional units providing regular functions, and may further comprise one or more storage units or memories 8003 for storing computer program code and other information thereon. The arrangement 8001 could be implemented, e.g., by one or more of: a processor or a micro processor capable of executing computer program code and adequate software and memory for storing of the software, a Programmable Logic Device (PLD) or other electronic component(s) or processing circuitry configured to perform the actions described above, and illustrated, e.g., in FIGS. 3-6. The arrangement part of Assistant point 8000 may be implemented as shown in FIG. 8. In particular, the arrangement 8001 comprises a data determination unit 8100, a transmitter 8200 and a receiver 8300. The function of data determination unit 8100, transmitter 8200 and receiver 8300 in the arrangement 8001 is the same as that of data determination unit 7100, transmitter 7200 and receiver 7300 in the assistant point 7000 shown in FIG. 7, and the detailed description is omitted herein for simplicity.

[0069] It should be noted that Assistant Point 8000 of FIG. 8 may include more or fewer elements than shown, in various arrangements, and each component may be implemeted in hardware, software or combination thereof.

[0070] FIG. 9 is a schematic view of arrangement 9000 which may be used in Assistant Point 8000. Comprised in the arrangement 9000 are here a processing unit or processor 9006, e.g., with a Digital Signal Processor (DSP). The processing unit 9006 may be a single unit or a plurality of units to perform different actions of the method and procedures described herein. The arrangement 9000 may also comprise an input unit 9002 for receiving signals from other entities, and an output unit 9004 for providing signal(s) to other entities. The input unit and the output unit may be arranged as an integrated entity or as illustrated in the example of FIG. 9.

[0071] Furthermore, the arrangement 9000 comprises at least one computer program product 9008 in the form of a non-volatile or volatile memory, e.g., an Electrically Erasable Programmable Read-Only Memory (EEPROM), a flash memory and a hard drive. The computer program product 9008 comprises a computer program 9010, which comprises code/computer readable instructions, which when executed by the processing unit 9006 in the arrangement 9000 causes the arrangement 9000 and/or Assistant Point 8000 in which it is comprised to perform the actions, e.g., of the procedures described earlier in conjunction with FIGS. 3-6.

[0072] The computer prorgam 9010 may be configured as a computer program code structured in computer program modules 9010A-9010C.

[0073] In an exemplifying embodiment, the code in the computer program of the arrangement 9000 includes a data determination module 9010A for selecting a predetermined number N of subbands with the best channel quality. The code in the computer program 9010 may further include a transmitting module 9010B for transmitting user data of the selected subbands.

[0074] According to an embodiment, the code in the computer program 9010 may further include a receiving module 9010C for receiving RBQ values of all subbands from the converging point. The data determination modules 9010A calculates RBQ values of all subbands, calculates uplink gains of all subbands based on the RBQ values of the converging point and its own RBQ values, and selects N subbands with the laregst uplink gains.

[0075] The foregoing description of implementations provides illustration and description, but is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Modifications and variations are possible in light of the above teachings, or may be acquired from practice of the disclosure. For example, while blocks have been described with regard to FIGS. 3-6 in a specific order, the order of the blocks may be modified in other implementations consistent with the principles of the disclosure. Further, non-dependent blocks may be performed in parallel.

[0076] Aspects of the disclosure may also be implemented in methods and/or computer program products. Accordingly, the disclosure may be embodied in hardware and/or in hardware/software (including firmware, resident software, microcode, etc.). Furthermore, the disclosure may take the form of a computer program product on a computer-usable or computer-readable storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system. The actual software code or specialized control hardware used to implement embodiments described herein is not limiting of the disclosure. Thus, the operation and behaviour of the aspects were described without reference to the specific software code—it being understood that those skilled in the art will be able to design software and control hardware to implement the aspects based on the description herein.

[0077] Furthermore, certain portions of the disclosure may be implemented as “logic” that performs one or more functions. This logic may include hardware, such as an application specific integrated circuit or field programmable gate array or a combination of hardware and software.

[0078] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps, components or groups but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0079] No element, act, or instruction used in the disclosure should be construed as critical or essential to the disclosure unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.

[0080] The foregoing description gives only the embodiments of the present disclosure and is not intended to limit the present disclosure in any way. Thus, any modification, substitution, improvement or like made within the spirit and principle of the present disclosure should be encompassed by the scope of the present disclosure.