JP2019512910A - Precoding processing method, user equipment, and base station - Google Patents

Abstract

The present invention discloses a precoding processing method, user equipment and a base station. In the procedure of this method, a first user equipment (UE) presets a precoding parameter set including a plurality of candidate precoding parameters, and the first UE receives a reference signal transmitted from a base station. The channel state is estimated based on the reference signal, and a plurality of feedback target precoding parameters are selected from the precoding parameter set based on the channel state, and precoding is performed for the plurality of feedback target precoding parameters. Generating the coding indicator and feeding back the precoding indicator to the base station.

Description

  The present application relates to mobile communication technology, and more particularly, to a precoding processing method, user equipment, and a base station.

  In a wireless communication system, when a base station performs precoding processing, it is usually necessary to feed back one precoding matrix indicator (PMI) from a user equipment (UE). Thereby, the base station determines the precoding matrix to be used for the UE based on the PMI fed back from the UE.

  In multi-user transmission, the scheme to feed back the PMI from the UEs described above applies to orthogonal transmission systems, ie, the PMIs assigned to different UEs are different.

  The embodiment of the present application is made in view of the above, provides a precoding processing method, and aims to improve the accuracy of downlink scheduling. Correspondingly, system throughput and user throughput can also be improved to some extent.

The embodiment of the present application is realized as follows.
A method of precoding processing, wherein a first user equipment (UE) presets a precoding parameter set including a plurality of candidate precoding parameters, and the first UE transmits a reference signal transmitted from a base station. Receiving, estimating a channel state based on the reference signal, selecting a plurality of feedback target precoding parameters from the precoding parameter set based on the channel state, and selecting the plurality of feedback target precoding parameters. Generating a precoding indicator for the coding parameters and feeding back the precoding indicator to the base station.

  A channel condition based on the reference signal, which is a user equipment, a setting module for presetting a precoding parameter set including a plurality of candidate precoding parameters, a reception module for receiving a reference signal transmitted from a base station, and , And a selection module for selecting a plurality of feedback target precoding parameters from the precoding parameter set based on the channel state, and a plurality of feedback target precoding parameters. And a feedback module for feeding back the precoding indicator to the base station.

  A base station configured to preset a precoding parameter set including a plurality of candidate precoding parameters, and transmitting a reference signal to a first user equipment (UE), whereby the first UE is configured to: A channel state is estimated based on the received reference signal, and a plurality of feedback target precoding parameters are selected from the precoding parameter set based on the channel state, and the plurality of feedback target precoding parameters are selected. A transmitting module for generating a precoding indicator, a receiving module for receiving the precoding indicator fed back from the first UE, the precoding indicator and the precoding Based on the meter set, and a precoding module for determining precoding parameters for precoding the data of the first UE.

  As understood from the solution described above, according to the precoding processing method, user equipment and base station in the mobile communication system provided in the embodiment of the present application, a plurality of precoding indicators fed back from the UE to the base station are used. The feedback target precoding parameters can be indicated to improve the accuracy of precoding matrix feedback. Furthermore, the base station schedules multiple users based on precoding indicators fed back from each UE, and multiple combinations of user pairing to achieve multi-user orthogonal and / or non-orthogonal transmission. It is possible to make decisions, increase multi-user gain, and improve system throughput and user throughput.

FIG. 7 is a schematic diagram of a flow of a precoding processing method in some embodiments of the present application. It is a schematic diagram of the flow of the precoding processing method in another one part Example of this application. FIG. 10 is an application scenario diagram of a precoding processing method in some embodiments of the present application. FIG. 6 is a signaling diagram of a precoding method in accordance with some embodiments of the present application. FIG. 5 is a schematic diagram of a configuration of user equipment in some embodiments of the present application. FIG. 6 is a schematic diagram of a configuration of a base station in some embodiments of the present application.

  In order to make the object, means of solution, and merits of the present invention clearer, the present invention will be described in more detail by way of examples with reference to the drawings.

  In multi-user transmission, the scheme to feed back the PMI from the UEs described above applies to orthogonal transmission systems, ie, the PMIs assigned to different UEs are different. In a non-orthogonal transmission system where multiple UEs use the same PMI, for example, non-orthogonal multiple access (NOMA), a scheme in which only one PMI is fed back from each UE is determined by the base station from each UE It is disadvantageous to select the same PMI for two or more UEs based on the feedback of and it may not be possible to determine the same PMI that simultaneously fulfills the best performance of multiple UEs. Therefore, the decrease in the effectiveness of the PMI feedback by the UE may affect the accuracy of the downlink scheduling by the base station, and the frequency utilization efficiency of some UEs may also decrease.

  FIG. 1 is a schematic diagram of a flow of a precoding processing method in some embodiments of the present application. This method is used for the first UE and includes the following steps.

  In step 101, a precoding parameter set including a plurality of candidate precoding parameters is preset.

In this step, the precoding parameter set includes G candidate precoding parameters, where G> M ² , G is a positive integer, and M is the total number of antennas of the base station. The precoding parameter set may be one codebook, and candidate precoding parameters may be represented by a precoding matrix.

ここで、ｍ＝０，１，・・・，Ｍ−１であり、ｍ＝０，１，・・・，Ｍ−１である。例えば、Ｍ＝２、Ｇ＝５である場合、プリコーディングパラメータ集合には、５つのプリコーディング行列が含まれる。即ち、

ここで、Ｇの値によって、プリコーディングパラメータ集合内の候補プリコーディングパラメータの個数が決められる。第１のＵＥは、Ｇの具体的な数値を設定することにより、プリコーディングパラメータ集合の大きさを制御することができる。Ｇが大きければ、プリコーディングパラメータ集合内の選択可能なプリコーディング行列の個数が多くなる。 For example, the element P _g (m, n) of the m-th row and the n-th column of the g-th candidate precoding matrix P _g (g = 0, 1,..., G-1) is It may be done.

Here, m = 0, 1, ..., M-1, and m = 0, 1, ..., M-1. For example, if M = 2 and G = 5, the precoding parameter set includes five precoding matrices. That is,

Here, the value of G determines the number of candidate precoding parameters in the precoding parameter set. The first UE can control the size of the precoding parameter set by setting a specific value of G. If G is large, the number of selectable precoding matrices in the precoding parameter set increases.

  In step 102, a reference signal transmitted from a base station is received, and channel conditions are estimated based on the reference signal.

  The first UE may estimate channel state information (CSI) based on the received reference signal (RS). For example, in a long-term evolution (LTE) system, the first UE receives the CSI-RS signal transmitted from the base station, and estimates the CSI represented by matrix H among them.

  In step 103, based on the channel condition, a plurality of feedback target precoding parameters are selected from among the precoding parameter set, and precoding indicators are generated for the plurality of feedback target precoding parameters.

  In this step, the first UE selects L feedback target precoding parameters from among a set of precoding parameters set in advance based on the channel condition of the own station, that is, based on the CSI matrix. The L precoding matrices are selected from the G precoding matrices. This selection may be made by the following two methods.

Scheme 1: Selection Based on Performance Indicators In some embodiments, for each candidate precoding matrix P _g , a capacity performance indicator is calculated based on the candidate precoding matrix and the CSI matrix H of the first UE. Thereafter, all capacity performance indicators are arranged in descending order, and L candidate precoding matrices corresponding to the L capacity performance indicators to be maximum are selected according to the capacity performance indicators arranged in the descending order, It is assumed to be a feedback target precoding parameter.
Here, the specific method of calculating the capacity performance indicator may be referred to the calculation method in the LTE system, and the description thereof will be omitted here.

Scheme 2: Selection Based on Quantization In some embodiments, for each candidate precoding matrix P _g , the deviation between the candidate precoding matrix and the CSI matrix H of the first UE is calculated. The deviations of all candidate precoding matrices are arranged in ascending order, and L candidate precoding matrices corresponding to the L least deviations are selected according to the arranged deviations in ascending order, and a plurality of feedback target precoding matrices are selected. Let it be a coding parameter.

In some embodiments, before calculating the deviation between each candidate precoding matrix and the CSI matrix, singular value decomposition is performed on the CSI matrix H to calculate the right singular matrix, as shown in Equation 3 below. Get V

  Also, the value of L may be preset to a fixed value by the first UE, eg, L = 3, or determined by the first UE in a capacity ratio manner, or the base The station may send downlink control signaling to inform the first UE of the value of L.

  In one embodiment, determining L on a volumetric basis specifically includes the following steps:

In step 1031, a sum of first SINRs is calculated based on all candidate precoding matrices P _g and CSI matrix H, that is, G based on G candidate precoding matrices P _g and CSI matrix H. The first SINR values are calculated and their sum is calculated to obtain the first SINR sum.

In step 1032, according to the predetermined order, L candidate precoding matrices are selected from the codebook, and based on the L candidate precoding matrices and CSI matrix H, the sum of the second SINRs is selected. The values of L second SINRs are calculated based on L candidate precoding matrices P _g and CSI matrix H, and their sums are calculated to obtain the sum of the second SINRs.
Here, for the predetermined arrangement order, L candidate precoding matrices may be selected from the G candidate precoding matrices by a scanning method.

In step 1033, if the ratio of the sum of the second SINRs to the sum of the first SINRs is larger than a predetermined threshold, L candidate precoding matrices are used as a plurality of feedback target precoding parameters. For example, this predetermined threshold is 60%.
Here, steps 1032 and 1033 are iterative processes, and for each of L candidate precoding matrices, calculate the ratio of the sum of the second SINR and the sum of the first SINR, and this ratio is a predetermined threshold value. If it is, the iteration ends.

At step 104, the precoding indicator is fed back to the base station.
The precoding indicator is indexed in the candidate precoding set of each of the L candidate precoding matrices. Whether the first UE feeds back the precoding indicator to the base station is semi-statically configured by higher layer signaling (eg, radio resource control (RRC) signaling) or at the base station by downlink control signaling It may be set dynamically.

  From the received signaling, knowing that it is necessary to feed back, the first UE feeds back the precoding indicator to the base station on the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH). It is also good.

  In this embodiment, the first UE selects a plurality of feedback target precoding parameters from among a set of precoding parameters based on channel conditions, and uses precoding indicators for the plurality of feedback target precoding parameters. To feed back to the base station. Compared to a scheme that feeds back only one PMI, it improves the accuracy of feedback of precoding matrix by the UE. This allows the base station to provide multiple combinations of user pairings during multi-user scheduling, increasing multi-user gain and improving system throughput and user throughput.

Also, in the LTE system, the codebook of precoding matrix in case of two antennas includes four codebook vectors, ie, four candidate precoding matrices, and the codebook of precoding matrix in case of four antennas is , 16 codebook vectors, ie 16 candidate precoding matrices. In this embodiment, the precoding parameter set includes G number of candidate precoding parameter, a G> M ^2. As can be seen from here, the number of candidate precoding matrices increases. This allows the UE to more accurately select a precoding matrix to match with based on CSI, and can improve precoding gain.

  FIG. 2 is a schematic diagram of a flow of a precoding processing method in another embodiment of the present application. This method is used by a base station and includes the following steps.

In step 201, a precoding parameter set including a plurality of candidate precoding parameters is preset.
The setting method of this step is the same as that of step 101, and the description thereof is omitted here.

  In step 202, by transmitting a reference signal to the first UE, the first UE estimates channel conditions based on the received reference signals, and among the precoding parameter sets based on the channel conditions , Select a plurality of feedback target precoding parameters, and generate precoding indicators for the plurality of feedback target precoding parameters.

  In step 203, the precoding indicator fed back from the first UE is received.

  In step 204, precoding parameters for precoding data of the first UE are determined based on the precoding indicator and the precoding parameter set.

  The base station receives the precoding indicator fed back from each UE. The precoding indicator is indexed for each of the L precoding matrices selected by the UE. The base station performs scheduling based on the precoding indicator of each UE to determine the multi-antenna transmission mode of the first UE and the precoding parameters to use. Here, the multi-antenna transmission mode includes the following four types.

(1) Single-User Multi-Input Multiple-Output (SU-MIMO) Transmission The base station schedules only one UE in a certain resource block. As shown in FIG. 3, the first UE is UE1, the base station and UE1 each have two antennas, and the base station uses these two antennas to transmit UE1 and SU- Perform MIMO transmission. In this case, the base station learns L precoding matrices from the precoding indicator fed back from UE1, selects the best precoding matrix among them, and selects the data of the first UE. Precoding and transmitting precoded data to the first UE.

  Since the base station can know the CSI of the UE from the uplink reference signal, selecting one precoding matrix to be the best is determined by the method based on the performance indicator in step 103 or the method based on quantization. You may choose.

(2) NOMA transmission The base station determines the second UE that uses the same space resource as the first UE, and selects one common pre-coding indicator from among the first UE and the second UE precoding indicator. The coding parameter is searched for as a first precoding parameter, and the first precoding parameter is used to precode data of the first UE and the second UE. Here, the second UE may include one or more UEs.

  In the example as shown in FIG. 3, the first UE is UE1, the second UE is UE2, and the base station decides to schedule UE1 and UE2 simultaneously on the same spatial resource, The powers allocated to UE1 and UE2 are different. This is the so-called NOMA transmission. However, from the point of view of transmission between the base station and UE1, it still belongs to SU-MIMO transmission. Similarly, transmissions between the base station and UE 2 also belong to SU-MIMO transmissions.

  In this case, the base station knows a set of precoding matrices corresponding to UE1 from the precoding indicator fed back from UE1, and uses the precoding indicator fed back from UE2 to another set of precoding matrices corresponding to UE2. Know the coding matrix Each of these two sets of precoding matrices includes L precoding matrices. Thereafter, the base station selects the same precoding matrix from among these two sets of precoding matrices, and uses it as a precoding matrix to be used for NOMA transmission, precoding data of UE1 and UE2, and precoding The latter data is transmitted to UE1 and UE2, respectively.

  Here, selecting the same precoding matrix satisfies that the sum of the capacity performance indicator of the first UE and the second UE is maximized, or the capacity performance indicator of the first UE is the best. Meet the second UE's capacity performance indicator is second best, or satisfy the first UE's performance indicator second best and the second UE's performance indicator is best You may follow the principle. Here, the capacity performance indicator may be any one of throughput, SINR, and FER.

(3) Multi-user multi-input multi-output (MU-MIMO) transmission A third UE that uses a different spatial resource from the first UE is determined, and the first UE among the precoding indicators of the third UE is determined. The second precoding parameter different from the precoding parameter is searched for, and the second precoding parameter is used to precode data of the third UE. Here, the third UE may include one or more UEs.

  In the example as shown in FIG. 3, the third UE is UE3 and the base station decides to schedule UE1 and UE3 on two different spatial resources, respectively. In this case, the base station determines two different precoding matrices based on the precoding indicator fed back from UE1 and the precoding indicator fed back from UE3, respectively, to precode data of UE1 and UE3. Each uses and transmits data after precoding to UE1 and UE3, respectively.

(4) NOMA + MU-MIMO transmission The base station determines a second UE that uses the same space resource as the first UE and a third UE that uses a different space resource than the first UE. Among the precoding indicators of the UE and the second UE, one common precoding parameter is searched as the first precoding parameter, and the first precoding parameter is selected from the precoding indicators of the third UE. Searching for a second precoding parameter different from the first one and using the first precoding parameter to precode data of the first UE and the second UE, and using the second precoding parameter Precode data of 3 UEs.

  As described above, in FIG. 3, the base station schedules UE1, UE2, and UE3 simultaneously, where it transmits in the NOMA scheme between UE1 and UE2, and between MU1, UE2, UE2, and UE3. Transmit in the MIMO scheme. Since each UE has fed back multiple precoding matrices, the base station satisfies the use of the same precoding matrix for NOMA in such composite transmission, and is paired with MU-MIMO Other precoding matrices to use for the UE can be determined, improving multi-user multiplexing gain and increasing system throughput and user throughput.

  FIG. 4 is a signaling diagram of a precoding method in accordance with some embodiments of the present application. Referring to FIG. 4, the method includes the following steps.

At step 400, the base station and the first UE respectively pre-configure a precoding parameter set.
The base station and the first UE perform configuration in a similar manner, eg, the method in step 101. Here, the precoding parameter set includes a plurality of candidate precoding parameters.

  In step 401, the base station transmits downlink control signaling to notify the first UE to feed back a precoding indicator indicating multiple precoding matrices.

  For example, the base station sets an indication bit in the physical downlink control channel (PDCCH). When the UE receives this indication bit, it knows from this indication bit whether it is necessary to feed back the precoding indicator. This configuration may be a dynamic configuration, and the UE performs selection of multiple precoding matrices only after receiving this indication bit. For example, the base station statistics block error rate (BLER) based on the result of downlink hybrid automatic repeat request (HARQ), and when the BLER is larger than a predetermined threshold, sets an indication bit in PDCCH. It is also good.

  At step 402, the base station transmits a reference signal to the first UE.

  In step 403, the first UE estimates channel conditions based on the received reference signal, and selects a plurality of feedback target precoding parameters from among a set of precoding parameters based on the channel conditions, A precoding indicator is generated for a plurality of feedback target precoding parameters.

  At step 404, the first UE feeds back the precoding indicator to the base station.

  In step 405, the base station determines a precoding parameter for precoding data of the first UE based on the precoding indicator and the precoding parameter set, and, based on the determined precoding parameter, Precode data of 1 UE.

  In step 406, the base station transmits pre-coded data to the first UE.

  FIG. 5 is a schematic diagram of a configuration of a first UE 500 in some embodiments of the present application. The first UE 500 is received by a setting module 510 which presets a precoding parameter set including a plurality of candidate precoding parameters, a receiving module 520 which receives a reference signal transmitted from a base station, and a receiving module 520 From among the precoding parameter sets set by the setting module 510 based on the estimation module 530 that estimates the channel state based on the selected reference signal and the channel conditions estimated by the estimation module 530, a plurality of feedback target pre A selection module 540 for selecting a coding parameter, a generation module 550 for generating a precoding indicator for a plurality of feedback target precoding parameters selected by the selection module 540, a generation module It includes a feedback module 560 feeds back the precoding indicators generated by Yuru 550 to the base station.

In some embodiments, the precoding parameter set includes G candidate precoding parameters, where G> M ² and M is the total number of antennas at the base station.

によって、ｇ番目の候補プリコーディング行列Ｐ_ｇを算出して、候補プリコーディングパラメータとし、ここで、ｇ＝０，１，・・・，Ｇ−１であり、ｍ＝０，１，・・・，Ｍ−１であり、ｎ＝０，１，・・・，Ｍ−１であり、Ｐ_ｇ（ｍ，ｎ）は候補プリコーディング行列Ｐ_ｇのｍ行目ｎ列目の要素を表す。 In some embodiments, configuration module 510 may

, Calculate the g th candidate precoding matrix P _g to be candidate precoding parameters, where g = 0, 1,..., G−1, m = 0, 1,. , M−1, n = 0, 1,..., M−1, and P _g (m, n) represents an element of the m th row and the n th column of the candidate precoding matrix P _g .

  In some embodiments, the selection module 540 calculates, for each candidate precoding parameter, a capacity performance indicator based on the candidate precoding parameter and the channel condition, and the capacity performance indicator of all candidate precoding parameters. According to the capacity performance index arranged in descending order and arranged in descending order, L candidate precoding parameters corresponding to L capacity performance indices to be maximum are selected as a plurality of feedback target precoding parameters, Where L is the total number of feedback target precoding parameters.

  In some embodiments, for each candidate precoding parameter, the selection module 540 calculates the deviation between the candidate precoding parameter and the channel state, and arranges the deviations of all candidate precoding parameters in ascending order, the ascending order The L candidate precoding parameters corresponding to the least L deviations are selected according to the deviations ordered in to be a plurality of feedback object precoding parameters, where L is the feedback object precoding parameters The total number of

  In some embodiments, the selection module 540 calculates a first signal to interference plus noise ratio (SINR) for each candidate precoding parameter and the channel condition, respectively, and selects the first of all candidate precoding parameters. The first sum of SINRs is calculated based on the SINRs of L, and L candidate precoding parameters are selected from the precoding parameter set according to a predetermined order of alignment, and the L candidate precoding parameters are calculated. Then, L second SINRs are respectively calculated based on each of the candidate precoding parameters and the channel condition, and based on L second SINRs of the L candidate precoding parameters, The sum of the second SINRs is calculated, and the sum of the second SINRs and the first SI If the ratio of the sum of R is greater than a predetermined threshold value, the L number of candidate precoding parameter to the plurality of feedback target precoding parameter.

  In some embodiments, the receiving module 520 further receives pre-coded first UE data transmitted from the base station, wherein the base station receives the first UE data with the first UE. Determine a second UE using the same spatial resource, and determine one common precoding parameter as a first precoding parameter based on the first UE and the second UE precoding indicator; Precoding data of the first UE and the second UE using the first precoding parameter.

  In some embodiments, the receiving module 520 further receives the pre-coded first UE data transmitted from the base station, where different spatial resources from the first UE are used. And determining a second precoding parameter different from the first precoding parameter based on the third UE precoding indicator, and using the second precoding parameter. And precode data of the third UE.

  FIG. 6 is a schematic diagram of a configuration of a base station 600 in some embodiments of the present application. The base station 600 sets a precoding parameter set including a plurality of candidate precoding parameters in advance, and transmits a reference signal to the first user equipment (UE) so that the first UE can: Channel state is estimated based on the received reference signal, and a plurality of feedback target precoding parameters are selected from among a set of precoding parameters based on the channel state, and the plurality of feedback target precoding parameters are selected. Transmitting module 620 configured to generate a precoding indicator, receiving module 630 receiving the precoding indicator fed back from the first UE, and the precoding indicator received by receiving module 630 Based on the precoding parameter set that has been set by the setting module 610 includes a precoding module 640 the data of the first UE determines the precoding parameters for precoding, the.

In some embodiments, the precoding parameter set includes G candidate precoding parameters, where G> M ² and M is the total number of antennas at the base station.

によって、ｇ番目の候補プリコーディング行列Ｐ_ｇを算出して、候補プリコーディングパラメータとし、ここで、ｇ＝０，１，・・・，Ｇ−１であり、ｍ＝０，１，・・・，Ｍ−１であり、ｎ＝０，１，・・・，Ｍ−１であり、Ｐ_ｇ（ｍ，ｎ）は候補プリコーディング行列Ｐ_ｇのｍ行目ｎ列目の要素を表す。 In some embodiments, configuration module 610 may

, Calculate the g th candidate precoding matrix P _g to be candidate precoding parameters, where g = 0, 1,..., G−1, m = 0, 1,. , M−1, n = 0, 1,..., M−1, and P _g (m, n) represents an element of the m th row and the n th column of the candidate precoding matrix P _g .

  In some embodiments, the precoding module 640 determines a second UE that uses the same spatial resources as the first UE, and among the first UE and second UE precoding indicators, One common precoding parameter is searched as a first precoding parameter, and data of the first UE and the second UE is precoded using the first precoding parameter.

  In some embodiments, the precoding module 640 determines a third UE that uses a different spatial resource than the first UE and, among the third UE precoding indicators, a first precoding parameter. And precoding data of the third UE using the second precoding parameters.

  In some embodiments, the base station 600 controls packet error rate statistics based on the result of the downlink hybrid automatic retransmission request, and transmits control instructions to the transmitting module if the packet error rate is greater than a predetermined threshold. It further comprises a module 650, and the transmission module 620 further transmits downlink control signaling according to the control command transmitted from the control module 650 to notify the first UE to feed back the precoding indicator.

  According to the precoding processing method provided in the embodiments of the present application, the UE transmits a plurality of feedback target precoding parameters to the base station via the precoding indicator to improve the accuracy of precoding feedback. The base station can then provide multiple combinations of user pairings during multi-user scheduling, increasing multi-user gain and improving system throughput and user throughput.

  As should be understood by those skilled in the art, the function of each processing means in the user equipment and base station of the embodiment of the present application can be understood with reference to the related description of the embodiment regarding the method described above, and the implementation of the present application Each processing means in the example user equipment and base station can be realized by executing the software that implements the method in the example of the present application in the user equipment and the base station.

  It should be understood that, in some embodiments provided herein, the disclosed apparatus and method may be implemented in another manner. The embodiments of the device described above are merely schematic. For example, the division of the means is only a logical division of functions, and may be another division scheme in actual implementation. For example, multiple modules or assemblies may be combined, incorporated into another system, or some configurations may be ignored or not performed. Also, the coupling or direct coupling or communication connection of each component shown or described may be through some interface, and the indirect coupling or communication connection of a device or module may be electrical , Mechanical or other forms.

  As can be understood by those skilled in the art, all or part of the steps for realizing the embodiments of the above method may be performed by instructing the relevant hardware by a program. The aforementioned program may be stored in a computer readable storage medium. In executing the program, steps are carried out which include an embodiment of the above method. The above-described storage media include various media capable of storing program codes, such as mobile storage devices, read-only memories (ROMs), random access memories (RAMs), magnetic disks and optical disks. .

  The above is only a preferred embodiment of the present application, and does not limit the protection scope of the present application. All modifications, equivalent replacements, improvements and the like made within the spirit and principle of the present application should be included within the protection scope of the present application.

500 First UE
510 configuration module 520 reception module 530 estimation module 540 selection module 550 generation module 560 feedback module 600 base station 610 configuration module 620 transmission module 630 reception module 640 precoding module 650 control module

At step 104, the precoding indicator is fed back to the base station.
The precoding indicator is indexed in the precoding parameter set of each of the L candidate precoding matrices. Whether the first UE feeds back the precoding indicator to the base station is semi-statically configured by higher layer signaling (eg, radio resource control (RRC) signaling) or at the base station by downlink control signaling It may be set dynamically.

In some embodiments, the receiving module 520 is further operable to receive a first UE for data after precoding transmitted from the base station, wherein said base station, said first UE Determining a third UE using different spatial resources, and determining a second precoding parameter different from the first precoding parameter based on the third UE precoding indicator; The data of the third UE is precoded using precoding parameters.

Claims (23)

It is a precoding processing method, and
The first user equipment (UE) presets a precoding parameter set including a plurality of candidate precoding parameters,
The first UE receives a reference signal transmitted from a base station, and estimates channel conditions based on the reference signal,
A plurality of feedback target precoding parameters are selected from the precoding parameter set based on the channel state, and a precoding indicator is generated for the plurality of feedback target precoding parameters,
Feeding back the precoding indicator to the base station;
A method characterized by comprising. The precoding parameter set includes G candidate precoding parameters, where G> M ² , G is a positive integer, and M is a total number of antennas of the base station. The method of claim 1. Setting the precoding parameter set in advance is:

Calculating the g th candidate precoding matrix P _{g according} to
Here, g = 0, 1, ..., G-1, m = 0, 1, ..., M-1, and n = 0, 1, ..., M-1. , P _g (m, n) represent the elements of the m th row and the n th column of the candidate precoding matrix P _g ,
A method according to claim 2, characterized in that. Selecting a plurality of feedback target precoding parameters from the precoding parameter set based on the channel state may include:
For each candidate precoding parameter, calculate a capacity performance indicator based on the candidate precoding parameter and the channel condition,
Order the capacity performance indicators of all candidate precoding parameters in descending order, and select L candidate precoding parameters corresponding to the L capacity performance indicators to be maximized according to the capacity performance indicators arranged in the descending order , And the plurality of feedback target precoding parameters,
The method according to claim 1, wherein L is a total number of feedback target precoding parameters.   The method according to claim 4, wherein the capacity performance indicator is any one of throughput, signal to interference and noise ratio, and frame error rate. Selecting a plurality of feedback target precoding parameters from the precoding parameter set based on the channel state may include:
The deviation between the candidate precoding parameter and the channel state is calculated for each candidate precoding parameter,
The deviations of all candidate precoding parameters are arranged in ascending order, and L candidate precoding parameters corresponding to the L least deviations are selected according to the arranged deviations in ascending order, and the plurality of feedback targets are selected. Including precoding parameters, and
The method according to claim 1, wherein L is a total number of feedback target precoding parameters. Selecting a plurality of feedback target precoding parameters from the precoding parameter set based on the channel state may include:
A first signal to interference and noise ratio (SINR) is calculated for each candidate precoding parameter and each of the channel conditions, and the sum of the first SINR based on the first SINR of all candidate precoding parameters Calculate
According to the predetermined arrangement order, L candidate precoding parameters are selected from the precoding parameter set, and for each of the L candidate precoding parameters, each of the candidate precoding parameters is based on the channel condition. Calculating the L second SINRs, and calculating the sum of the second SINRs based on the L second SINRs of the L candidate precoding parameters;
Setting the L candidate precoding parameters as the plurality of feedback target precoding parameters if a ratio of the second SINR sum to the first SINR sum is larger than a predetermined threshold;
A method according to claim 1, characterized in that.   Receiving the precoded data of the first UE transmitted from the base station, wherein the base station determines a second UE that uses the same spatial resources as the first UE; A common precoding parameter is determined as a first precoding parameter based on the first UE and the second UE precoding indicator, and the first precoding parameter is used to determine the first precoding parameter. The method according to any of the preceding claims, further comprising: precoding data of a UE of the UE and the second UE.   Receiving pre-coded data of the first UE transmitted from the base station, determining a third UE using a different spatial resource than the first UE, and Determining a second precoding parameter different from the first precoding parameter based on a precoding indicator, and precoding data of the third UE using the second precoding parameter; The method of claim 8, further comprising: A user equipment that is a first user equipment (UE), and
A setting module for presetting a precoding parameter set including a plurality of candidate precoding parameters;
A receiving module for receiving a reference signal transmitted from a base station;
An estimation module that estimates channel conditions based on the reference signal;
A selection module for selecting a plurality of feedback target precoding parameters from the precoding parameter set based on the channel state;
A generation module that generates a precoding indicator for the plurality of feedback target precoding parameters;
A feedback module for feeding back the precoding indicator to the base station. The precoding parameter set includes G candidate precoding parameters, where G> M ² , G is a positive integer, and M is the total number of antennas at the base station. The user equipment according to claim 10. The setting module is

, Calculate the g-th candidate precoding matrix P _g to be the candidate precoding parameters, where g = 0, 1,..., G−1, m = 0, 1,. , M−1, n = 0, 1,..., M−1, and P _g (m, n) represents an element of the m th row and the n th column of the candidate precoding matrix P _g , The user equipment according to claim 11, characterized in that:   The selection module calculates, for each candidate precoding parameter, a capacity performance index based on the candidate precoding parameter and the channel condition, and arranges the capacity performance index of all candidate precoding parameters in descending order. The L candidate precoding parameters corresponding to the largest L capacity performance indices are selected according to the capacity performance index ordered in, to be the plurality of feedback target precoding parameters, where L is The user equipment according to claim 10, which is a total number of feedback target precoding parameters.   The selection module calculates, for each candidate precoding parameter, the deviation between the candidate precoding parameter and the channel state, arranges the deviations of all candidate precoding parameters in ascending order, and sets the deviations in ascending order. Therefore, L candidate precoding parameters corresponding to L least deviations are selected as the plurality of feedback target precoding parameters, where L is the total number of feedback target precoding parameters, 11. The user equipment according to claim 10, characterized in that:   The selection module calculates a first signal to interference and noise ratio (SINR) for each candidate precoding parameter and the channel condition respectively, and based on the first SINR of all candidate precoding parameters, A sum of SINRs of 1 is calculated, and L candidate precoding parameters are selected from the precoding parameter set according to a predetermined order of arrangement, and each candidate precoding parameter is selected for each of the L candidate precoding parameters. L second SINRs are calculated based on each of the coding parameters and the channel condition, and the second SINR sum is calculated based on L second SINRs of the L candidate precoding parameters. Calculating the ratio of the sum of the second SINR to the sum of the first SINR If greater than the threshold value, the user equipment according to any one of claims 10 to 14 wherein the L-number of candidate precoding parameter of the plurality of feedback target precoding parameter, characterized in that.   The receiving module further receives the precoded data of the first UE transmitted from the base station, wherein the base station uses the same space resource as the first UE. Of UEs, and based on the precoding indicators of the first UE and the second UE, determine one common precoding parameter as a first precoding parameter, the first precoding parameter The user equipment according to claim 10, further comprising: precoding data of the first UE and the second UE using.   The receiving module further receives the precoded data of the first UE transmitted from the base station, where it determines a third UE that uses a different spatial resource than the first UE. Determining a second precoding parameter different from the first precoding parameter based on the third UE precoding indicator, and using the second precoding parameter to determine the third UE's The user equipment according to claim 16, characterized in that it precodes data. A base station,
A setting module for presetting a precoding parameter set including a plurality of candidate precoding parameters;
By transmitting a reference signal to a first user equipment (UE), the first UE estimates channel conditions based on the received reference signals, and based on the channel conditions the precoding parameters A transmitting module for selecting a plurality of feedback target precoding parameters from the set and generating a precoding indicator for the plurality of feedback target precoding parameters;
A receiving module for receiving the precoding indicator fed back from the first UE;
A precoding module that determines precoding parameters for precoding data of the first UE based on the precoding indicator and the precoding parameter set;
A base station comprising: The precoding parameter set includes G candidate precoding parameters, where G> M ² , G is a positive integer, and M is a total number of antennas of the base station. The base station according to claim 18. The setting module is

, Calculate the g-th candidate precoding matrix P _g to be the candidate precoding parameters, where g = 0, 1,..., G−1, m = 0, 1,. , M−1, n = 0, 1,..., M−1, and P _g (m, n) represents an element of the m th row and the n th column of the candidate precoding matrix P _g , The base station according to claim 19, characterized in that:   The precoding module determines a second UE that uses the same spatial resource as the first UE, and selects one common precoding indicator from among the first UE and the second UE precoding indicator. 19. The method according to claim 18, wherein a coding parameter is searched as a first precoding parameter, and data of the first UE and the second UE is precoded using the first precoding parameter. Base station described.   The precoding module determines a third UE using a spatial resource different from the first UE, and a second UE different from the first precoding parameter among precoding indicators of the third UE. The base station according to claim 18, wherein precoding parameters of the third UE are searched for, and data of the third UE is precoded using the second precoding parameters. A control module is further provided that statistics a packet error rate based on the result of the downlink hybrid automatic retransmission request, and transmits a control command to the transmission module if the packet error rate is greater than a predetermined threshold.
The transmission module further transmits downlink control signaling according to the control command to notify the first UE to feed back the precoding indicator.
The base station according to any one of claims 18 to 22, characterized in that:

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