AU2014253522B2

AU2014253522B2 - Method and device of sending and receiving precoding information

Info

Publication number: AU2014253522B2
Application number: AU2014253522A
Authority: AU
Inventors: Jianguo Wang; Yongxing Zhou
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2010-05-19
Filing date: 2014-10-23
Publication date: 2015-06-18
Anticipated expiration: 2031-05-19
Also published as: AU2014253522C1; AU2014253522A1

Abstract

The present invention discloses a method and a device of sending and receiving precoding information, where the method includes: obtaining, by a terminal, a wideband precoding matrix indicator PMI; separately encoding, by the terminal, an MSB of the wideband PMI or jointly encoding the MSB of the wideband PMI and other information of N bits to obtain encoded information, where the MSB is a part of the wideband PMI, and N is a natural number; and sending, by the terminal, the encoded information to a data sending end. In the embodiments of the present invention, the MSB in the wideband PMI is separately encoded and sent, or the MSB in the wideband PMI and other information of N bits are jointly encoded and sent, which improves reliability of wideband precoding information, and reduces error propagation, thereby further improving the precoding performance.

Description

METHOD AND DEVICE OF SENDING AND RECEIVING PRECODING INFORMATION FIELD OF T HE INVENTION The present application is a divisional application from Australian Patent Application No. 2011255148, the entire disclosure of which is incorporated herein by reference. The present invention relates to the field of coMmuncations technologies, and in particular, to a method and a device of sending and receiving precoding information. BACKGROUND OF THE INVENTION With the continuous development of communications technologies, to improve the performance of data transmission, a data sending end (for example, NodeB (node B) or BS (Base Station, base station) may pre-process data to be sent according to precoding information (for example, PMI (Precoding Matrx Indicator, breeding matrix indicator)) which is fed back by a terminal (for example, U (User Equipment user equipment) or MS (Mobile Station, mobile station)) and a locally prestored codebook, and then send the data to the terminal, so that the data sending process may adapt to a channel state variation, thereby improving the perfomance of the data transmission. Therefore, how to send and receive the precoding information is cruel The existing 3GPP LTE R8 (3rd Generation Partnership Project Long Term Evolution Release 8, 3rd Generation Partnership Project Long Tern Evolution Release 8) system adopts a single codebook, and a preceding matrix of the codebook is indexed by a single PMI (Precoding Matrix Indicator, precoding matrix indicator), and may be periodically and periodically reported respectively through a PUCCH (Physical Uplink Control Channel, physical uplink control channel) and a PUSCH (Physical Uplink Shared Channel, physical uplink shared channel). In the implementation of the present invention, it is found that the prior art at least has the following problem: The wideband preceding matrix indicator PMI easily incurs error propagation. Therefore, it is necessary to further study a reporting mode to improve the system performance. SUMMARY OF THE INVENTION Embodiments of the present invention provide a method and a device of sending and receiving precoding information, so as to improve the system performance.

in one aspect, an embodimem of the present invention provides a method of sending preceding information, vwhich includes: obtainingby a terminala wideband preceding matrix indicator PM; separately encoding, by the terminal, an MSB of the wideband PMI or jointly encoding the MSB of the widehand PMI and other information of N bits to obtain encoded information, where the MSB is a part of the wideband PM and N is a natural number; and sending, by the terminal the encoded information to a data sending end. In one aspect an embodiment of the present invention provides a method of receiving preceding information, which inchdes: receiving, by a data sending end encoded information sent by a terminal; where, the encoded information is information obtained, after the terminal obtains the wideband preceding matri indicator PMI, through separately encoding an MSB of a wideband PMI or jointly encoding the MSB of the wideband PM! and other information ofN bits, where the MSB is a part of the wideband PM and N is a natural number. In another aspect, an embodiment of the present invention provides a device of sending prec oding information, which includes: an information obtaining unit, configured to obtain a wideband precoding matrix indicator PM!: an information encoding unit, configured to separately encode an MSB of the wideband PMI or jointly encode the MSB of the wideband PM! and other information of N bits to obtain encoded information, where the MSB is a part of the videband PMI, and N is a natural number; and an information sending unit, configured to send the information encoded by the information encoding unit to a data sending end. In another aspect, an embodiment of the present invention provides a device of receiving preceding information which includes: an information receiving unit, configured to receive encoded inlbrmation sent by a terminal where, the encoded information is information obtained, after the terminal obtains the wideband precoding matrix indicator PM, through separately encoding an NSB of a wideband PM! or jointly encoding the MSB of the wideband PMI and other information of N bits, where the MSB is a part of the wideband PMI, and N is a natural number. in the embodiments of the present invention, the MSB in the wideband PMI is separately encoded and then sent, or the MSBin the wideband PM! and other information of N bits are jointy encoded and then sentwhich improves reliability of wideband preceding information, and reduces error propagation, thereby further improving the preceding performance. 2 BRIEF DESCRIPTION OF THE DRAWINGS FG. 1 is a schematic flowchart of a method of sendingand receiving pr di at provided by an embodiment of the present invention; FIG. 2 is a schematic diagram of resource mapping of encoded information on a PUSCH provided by an embodiment of the present invention; IG 3 is another schematic diagram of resource mapping of coded iiornation on a PUSCH provided by an embodiment of the present invention; FIG, 4 is a schematic flowchart of another method of sending and receiving preceding information provided by an embodiment of the present invention; FIG. 5 is a schematic structural diagram of a device of sending preceding information provided by an embodiment of the present invention; and FI|. 6 is a schematic structural diagram of a device of receiving precoding information provided by an embodiment of the present inventio DETAILED DESCRIPTION OF THE EMBODIMENTS In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention are described in detail in the following with reference to the accompanying drawings. Referring to FIG, 1, an embodiment of the present invention provides a method of sending preceding information, where a system bandwidth is divided into at least one sub-band. and the method includes the following steps: 101: A terminal obtains a wideband PMI Specifically, the terminal may obtain the wideband PMI according to a preset criterion, and definitely may also obtain the wideband PMI according to other methods in the prior art. In an example where the terminal obtains the wideband PM1 according to the preset criterion, the terminal may calculate the wideband preceding matrix indicator PMI on the basis of a preset criterion 1, which is specifically shown in Equation (1): je=arg max f (w.)I 'W'W where represents a code word in a single codebook C, and represents an objective function of the system bandwidth and a preceding matrix corresponding to the preset criterion 1. It should be noted that, the preset criterion i may be a throughput maxmmization criterion, an objective functin corresponding to the criterion may be a throughput maximization function, and the throughput maximization function may be implemented on the basis of information capacity calculation or on the basis of mutual information or deformation of the mutual information (for example, weighting of mutual information). The embodiment in which the preset criterion I is a capacity maximization criterion is similar to the above embodiment, which is not described in detail here again. Definitely, the target function corresponding to the preset criterion may also be flexibly set according to a practical application condition, which is not specifically restricted here. Alternatively, the terminal calculates the wideband preceding matrix indicator PMI based on a preset criterion 2, which is specifically shown in Equations (2) and (3): .10. = arg max =4.....(2); and where presents a preceding matrix, and is a function of two matrixes and . The matrixes and are indexed fron two codebooks Ci and C2 respectively through wand and are respectively used for indicating a wideband property and a frequency selectivity property of the channel, represents an objective fiction of the system bandwidth and a wideband preceding matrix that are corresponding to the preset criterion 2. (i, represents an objective function of a sub-band i and a precoding matrix that are corresponding to the preset criterion 2, and K is the total number of sub-bands forming the system bandwidth. Here, & is referred to as a wideband preceding matrix indicator, that is, the wideband PMI. It should be noted that the preset Criterion 2 may be a throughput maximization riterion, an objective function corresponding to the criterion may be a throughput maxmizaton function, and the throughput maximization function may be implemented on the basis of information capacity calculation or on the basis of mutual information or deformation of mutual information (for example, weighting of mutual information). Definitely, the target function corresponding to the preset criterion may also be flexibly set according to an actual application condition, which is not specifcally restricted here. Further, after obtaining the wideband PMI, the method may also include the following steps: 4 102: The terminal separately encodes an MSB (Most Significant Bitsst Sit Significant Bit of the wideband PMI, where, Uhe MSB may be a part of the wideband PM!, Specifically, the MSB (Most Significant Bits, Most Significant Bit) of the wideband PMI obtained in step 101 is represented by a, a .aa a, where A is the number of bits of the MSB of the wideband PM I. The terminal may encode the M3SB of the wideband PMI obtained in step 101 through one code (20. A) (referring to 3PP LE TS 36.2|12 V90) where a code word of the code (20, A) is a linear combination of 13 basic sequences, the basic sequence may be expressed as A 1 , i = ,. 19;n = 0, . 12,and specifically may be defined as shown in Table 5-i3.-1 in 3PP LT.E TS 36.212 V9.0.0. Encoded bits may be expressed as and each bi may be expressed as: b k A", mod 2 b,=~(~uVI 1 )niod i019 Defnitely, an applied encoding method may also be flexibly selected according to a practical application condition, which is not specifically restricted here Moreover, it should be noted that, the MSB of the wideband PMi may be a part of the widebard PMI, or may be all bits of the wideband PML When the MSB is a part of the wideband PMIL the MSB being only a part of the wideband PMI is separately encoded and sent, so that the overhead is saved as compared with the case that he entire wideband PMI is separately encoded and sent. in addition, the MSB is used as main component information of the PM!, and even if other component information of the PM! than the MSB, such as an LSB (Least Significant Bits, Least Significant Bit), is not correctly sent, the influence on thesystem performance is small. 103: The terminal sends the encoded information to a data sending end. Specifically the terminal may send the encoded information to the data sending end through a physical uplink control channel PUCCA Furthe, when the encoded information sent through the PUCCI-i, a period same as that of a rank indication RI) may be used; or, the terminal may send the encoded information to the data sending end through a physical uplink shared channel PUSCH, Further the encoded information may be mapped to a position that is on the two sides of a demoduation pilot or reference signal and is adjacem to a PUSCH demodulation pilot or reference signal (Reference Signal, RS) through a channel inerleaver, as shown in FI 2 or FIG. 3, where SO 5 to SI3 represent SC-FDMA symbols in a sub-frame, MSB blocks show positions to which the encoded information is mapped, and RS blocks show positions to which the RS is mapped. Further, when the PUSCH adopts MIMO muliple input multiple output. multiple input nmliple output) multilayer transmission, the encoded information may be mapped to all layers for transmission, 104: The data sending end receives the encoded inflation sent by the terminal. Specifically the data sending end may receive the encoded information sent by the terminal through a physical uplink control channel PUCCH: or, specifically, the data sending end may receive the encoded information sent by the terminal through a physical uplink shared channel PUSCH. Further when the data sending end receives the encoded information sent by te terinal through the physical uplink shared channel BUSCH the encoded information may be mapped to a position that is on the two sides of a demodulation pilot or reference signal and is adjacent to the demodulation pilot or reference signal through a channel interleaver. and received at positions shown by MSBs in F1G. 2 or FIG 3. it should be further noted that, a mapping relationship exists between a precoding matrix indicator PMI and a precoding matrix the mapping relationship enables a distance between preceding matrixes corresponding to two PMis with different most significant bits MSIs to be greater than a distance between precoding matrixes corresponding to two PMIs with different least significant bits SBsand the distance may be defined as a chord distance: d -= 1 A)T B-BA -vihwhere, represents a chord distance between two matrixes A and B with the same dimension, A"! represents conjugate transpose of the matrix A, and Hjrepresents Frobenius norm. Definitely, the distance may also be flexibly defined according to an actual application condition, which is not specifically restricted here. It should be noted that, the MSB of the wideband PM! may be a part of the wideband PMI or the entire wideband PM!, Moreover, it should be noted that, after obtaining the MSB of the wideband PMI, the data sending end may further obtain a reliable wideband or frequency selectivity precoding matrix, together with wideband or frequency selectivity precoding information obtained through other feedback maimers. 6 In the metho of sedin and rceivig precodig inomaion desribed in th moietOf the present invention, the IMSB in the wideband PMI is separately encoded and sent, which improves reliability of wideband precoding information, and reduces error propagation, thereby further improving the precoding performance Referring to FIG. 4, an embodiment of the present invention provides a method of sending preceding information, where the system wideband is divided into at least one sub-band, and the method includes the following steps: 201: A terminal obtains a wideband IPMI. Specifically, the terminal may obtain the videband PMI according to a preset criteron, and definitely may also obtain the wideband PMI according to other methods in the prior art In an example where the terminal obtains the wideband PMi according to the preset criterion, the terminal may ealculate the wideband preceding matrix indicator PM! on the basis of a preset criterion 1, which is specifically shown in Equation (it Definitely, the target function corresponding to the preset criterion may also be flexibly set according to an actual application condition, which is not specifically restricted here. Alternatively, the terminal calculates the wideband precoding matrix indicator PMi on the basis of a preset criterion 2, which is specifically shown in Equations (2) and (3 Definitely, the target function corresponding to the preset criterion may also be flexibly set accordmg to an actual application conditionhich is not specifically restricted here. Further after obtaining the wideband PMI the method nay also inlude the following steps: 202: The terminal jintly encodes an MSB of the wideband PM and other formation of N bits, where the MSB is a part of the ideband PMi. Specifcally, the MSB (Most Significant Bits, Most Significant Bit) of the wideband PMI obtained in step 201 is represented by A bits, and the other information of N bis may be other bits of the wideband PMI than the MSB, such as a rank indication RI, or acknowledgment (ACINACE) information of a hybrid automatic retransmission request iARQ. The terminal combines the MSB of the wideband PMI! and the other information of N bits into a bit sequence with a length of A+-N. Further, the terminal encodes the bit sequence with the length of A+N through a code (20, A+N), and the encoding may be similar to that in the embodiment shown in FIG. 1. Definitely, an applied encoding method ma' also be flexibly selected according to an actual application condition, which is not specifically restricted here. Moreover, it should be noted that, the MSB of the wideband PM! may be a part of the wideband PMI, or may be all bits of the wideband PMI. 7 20:Tetria sends the encoded ifraint aasniged Specifically, the terminal may send the encoded information to the data sending end through a physical uplink control channel PUCCH. Further, when the encAded infonnation is sent through the PUCCH, a period same as the period of the rank indication (RI) may be used; or, the terminal may send the encoded infonnation to the data sending end through a physical uplink shared channel PUSCH. Further, the encoded information may be mapped to a position that is on the two sides of a PUSCiI demodulation pilot oT reference signal and is adjacent to the demodulation pilot or reference signal (Reference Signal, RS) through a channel interleaver, as shown in FIG. 2 or FIG. 3, where SO to S13 represent SCADMA symbols in a sub-frame, MSB biotks show positions to which the encoded information is mapped and RS blocks show positions to which the RS is mapped. Further, when the PUSCH adopts NIMO (multiple input multiple output, multiple input muliple output) multi-layer transmission, the encoded information may be mapped to all layers for transmission. 204: The data sending end receives the encoded information sent by the terminal. Specifically, dhe data sending end may receive the encoded information sent by the terminal through a physical uplink control channel PUCCH; or, specifically, the data sending end may receive the encoded information sent by the terminal through a physical uplink shared channel PUSCH. Further, when the data sending end receives the encoded information sent by the terminal through the physical uplink shared channel PUSCH, the encoded information may be mapped to a position that is on the two sides of a demodulation pilot or reference signal and is adjacent to the demodulation pilot or reference signal through a channel interleaver, and received at positions shown by MSBs in FIG. 2 or FIG. 3. it should be further noted that, a mapping relationship exists between a preceding matrix indicator PMI and a preceding matrix, the mapping relationship enables a distance between precoding matrixes corresponding to two PMIs with different most significant bits MSBs to be greater than a distance between precoding matrixes corresponding to two PMIs with different least significant bits LSBs, and the distance may be defined as a chord distance, as shown in Equation (5). Definitely, the distance may also be flexibly defined according to an actual application condition, which is not specifically restricted here.

It should be noted that, the MSB of the wideband PMI may be a part of the wideband PMI, or may be all bits of the wideband PMI Moreover, it should be noted that, after obtaining the MSB of the wideband PMI, the data sending end may further obtain a reliable wideband or frequency selectivity precoding matrix, together with wideband or frequency selectivity preceding information obtained through other feedback manner s. in the method of sending and receiving precoding information described in the embodiment of the present invention, the NISB in the wideband PMI and other information of N bits are jointly encoded and sent, which improves reliability of wideband preceding information, and reduces error propagation. thereby further improving the precoding performance. Referring to FIG. 5, corresponding to the above method embodiments, an embodiment of the present invention provides a device of sending precoding information. The device is applicable to a system in which bandwidth is divided into at least one sub-band, and includes: An information obtaining unit 301 is configured to obtain a wideband precoding matrix indicator PM!. Specifically, a terminal may obtain the wideband PMI according to a preset criterion, and definitely may also obtan the wideband PMI according to other methods in the prior art. In an example where the terminal obtains the wideband PM! according to the preset criterion the information obtaining unit calculates the wideband preceding matrix indicator PM! on the basis of a preset criterion I which is specifically shown in Equation (I). Alternatively, the information obtang unit calculates the wideband precodmg matnx indicator PMI on the basis of a preset criterion 2, which is specifically shown in Equations (2) and Definitely, the target function corresponding to the preset criterion may also be flexibly set according to an actual application condition, which is not specifically restricted here, An information encoding unit 302 is configured to separately encode an MSB of the wideband PM! or jointly encode the NSB of the wideband PMI and other information of N bits to obtain encoded information, where the NSB is a part of the wideband PMi and N is a natural number. An information sending unit 303 is configured to send the information encoded by the information encoding unit to a data sending end. The device of sending precoding information in the embodiment of the present invention may be specifically a terminal In the device of sending preceding information described in the emibodiment of the present invention, the MSB in the wideband PMI is separately encoded and sent, or the MSB in the 9 wideband PMi and other information of N bits are jointly encoded and sent, which improves reliability of wideband preceding information, and reduces err propagation, thereby further improving the preceding performance Referring to FIG. 6 corresponding to the above method embodiments, an embodiment of the present invention provides a device of receiving precoding information. The device is applicable to a system in which bandwidth is divided into at least one sub-and, and includes: An information receiving unit 601 is configured to recAive encoded information sent by a terminal I ere, the encoded information is information obtained, afer the terminal obtains the wideband precoding matrix indicator PMI through separately encoding an MSB of a wideband PMI or jointly encoding the MSB of the wideband PMI and other information of N bits, where the MSB is a part of the wideband PMI, and N is a natural number. In the device of receiving precoding information described in the embodiment ofthe present invention, the information sent by the terminal after separately encoding the MSB in the wideband PMI or jointly encoding the MSB in the wideband PMI and other information of N bits is received, which improves reliability of widehand precoding information, and reduces error propagation, thereby further improving the preceding performance. The data sending end in the above embodiments may be a NodeB (node B). a BS (Base Station, base station), a home base station, or a relay station; and the terminal in the above embodiments may be a LIE (User Equipment, user equipment) or an MS (Mobile Station, mobile station. All or a part of the content in the technical solutions according to the embodiments of the present invention may be implemented through software programming. The software program is stored in a readable storage medium, such as a hard disk, an optical disk or a floppy disk in a computer, The above descriptions are merely exemplary embodiments of the present inention, but are not intended to limit the present invention. Any modification, equivalent replacement, or improvement made without departing from the principle of the present invention should fail withi the protection scope of the present invention. to

Claims

1. A method, comprising: encoding, by a terminal, jointly at least one bit but not all bits of a wideband precoding matrix indicator (PMI) with a rank indication (RI) to obtain encoded information, wherein the at least one bit of the wideband PMI jointly encoded with the RI contains no least significant bit (LSB) of the wideband PMI; and sending, by the terminal, the encoded information to a data sending end.

2. The method according to claim 1, wherein: the sending, by the terminal, the encoded information to the data sending end comprises: sending, by the terminal, the encoded information through a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH).

3 The method according to claim 2, wherein when the terminal sends the encoded information through the physical uplink shared channel (PUSCH), the encoded information is mapped to a position that is on the two sides of a demodulation pilot or reference signal and is adjacent to the demodulation pilot or reference signal through a channel interleaver.

4. The method according to claim 2, wherein when the PUSCH adopts multiple input multiple output (MIMO) multi-layer transmission, the encoded information is mapped to all layers for transmission.

5. The method according to any one of claims 1 to 4, wherein the data sending end is a base station or a node B.

6. A method, comprising: receiving, by a data sending end, encoded information from a terminal; and decoding, by the data sending end, the received encoded information, wherein the received encoded information is formed by jointly encoding at least one bit but not all bits of a wideband precoding matrix indication (PMI) with a rank indication (RI), and the at least one bit of the wideband PMI jointly encoded with the RI contains no least significant bit (LSB) of the wideband PMI.

7. The method according to claim 6, wherein: the receiving, by the data sending end, the encoded information comprises: receiving, by the data sending end, the encoded information through a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). 11

8. The method according to claim 7, wherein: when the data sending end receives the encoded information through the physical uplink shared channel (PUSCH), the encoded information is mapped to a position that is on the two sides of a demodulation pilot or reference signal and is adjacent to the demodulation pilot or reference signal through a channel interleaver.

9. The method according to claim 7, wherein when the PUSCH adopts multiple input multiple output (MIMO) multi-layer transmission, the encoded information is mapped to all layers for transmission.

10. The method according to any one of claims 6 to 9, wherein the data sending end is a base station or a node B.

11. A terminal device, comprising: an information encoding unit, configured to jointly encode at least one bit but not all bits of a wideband precoding matrix indicator (PMI) with a rank indication (RI) to obtain encoded information, wherein the at least one bit of the wideband PMI jointly encoded with the RI contains no least significant bit (LSB) of the wideband PMI; and an information sending unit, configured to send the encoded information to a data sending end.

12. The terminal device according to claim 11, wherein the encoded information is sent through a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH).

13. The terminal device according to claim 12, wherein the encoded information is sent through the physical uplink shared channel (PUSCH) and the encoded information is mapped to a resource position that is on two sides of a demodulation pilot or reference signal and is adjacent to the demodulation pilot or reference signal through a channel interleaver.

14. The terminal device according to claim 12, wherein a mapping relationship exists between a PMI and a precoding matrix and the mapping relationship enables a distance between precoding matrixes corresponding to two PMIs with different most significant bits (MSBs) to be greater than a distance between precoding matrixes corresponding to two PMIs with different LSBs.

15. The terminal device according to any one of claims 11 to 14, wherein the data sending end is a base station or a node B.

16. A network device, comprising: an information receiving unit, configured to receive encoded information from a terminal; and a decoding unit, configured to decode the encoded information, wherein the received encoded information is formed by jointly encoding at least one bit but not all bits of a wideband precoding matrix indicator (PMI) with a rank indication (RI), and the at least 12 one bit of the wideband PMI jointly encoded with the RI contains no least significant bit (LSB) of the wideband PMI.

17. The network device according to claim 16, the encoded information is received through a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH).

18. The network device according to claim 17, wherein the encoded information is received through the physical uplink shared channel (PUSCH) and the encoded information is mapped to a resource position that is on two sides of a demodulation pilot or reference signal and is adjacent to the demodulation pilot or reference signal through a channel interleaver.

19. The network device according to claim 17, wherein the PUSCH adopts multiple input multiple output (MIMO) multi-layer transmission, and the encoded information is mapped to all layers for transmission.

20. The network device according to any one of claims 16 to 19, wherein the network device is a base station or a node B. 13