WO2013127339A1

WO2013127339A1 - Method and apparatus for downlink transmission

Info

Publication number: WO2013127339A1
Application number: PCT/CN2013/071941
Authority: WO
Inventors: 朱志球
Original assignee: 电信科学技术研究院
Priority date: 2012-03-02
Filing date: 2013-02-27
Publication date: 2013-09-06
Also published as: CN102595385A; CN102595385B

Abstract

The present invention relates to communications technology. Disclosed are a method and apparatus for downlink transmission. Once a determination is made to use MU-MIMO transmission, a further determination is made, on the basis of channel conditions, to use either single-stream beamforming transmission or dual-stream beamforming transmission, thereby enabling in TM8 support for multi-user single-stream beamforming transmission and multi-user dual-stream beamforming transmission, and better supporting all forms of MIMO under TM8.

Description

The present invention claims the priority of the Chinese patent application filed on March 2, 2012, the Chinese Patent Office, the application number is 201210054242.X, and the invention name is "a downlink transmission method and device". The entire contents are incorporated herein by reference. TECHNICAL FIELD The present invention relates to communications technologies, and in particular, to a downlink transmission method and apparatus. BACKGROUND In order to further enhance downlink multiple input multiple output (MIMO) data transmission capability, a 3rd generation partnership project (3GPP) Long Term Evolution (LTE) system R9 version standard is introduced. Transfer mode 8 ( Transport Mode 8 , ΤΜ 8 ).

In the downlink, when the base station is configured with multiple transmit antennas and transmitters, multiple user equipments can be simultaneously scheduled on the same time-frequency resource by using beamforming or precoding techniques and utilizing the spatial selectivity of the downlink channel. (User's Equipment, UE), improve the frequency band utilization of the system and the number of users supported by the system by means of space division multiplexing.

A dual-stream shaping technology based on dual-port dedicated pilots, TM8, is introduced in LTE R9. According to the standard, TM8 uses antenna ports Port 7 and Port 8 for transmission. The dedicated reference signals of these two ports occupy the same time-frequency resource location, but different orthogonal mask sequences are used to distinguish and pass TM8. The parameter scrambling code identifier (ID) in the downlink control information format 2B (DCI format 2B) is used to initialize the scrambling code. On this basis, the base station can schedule two single-stream transmission UEs to each other on a UE-specific reference signal (UE-specific RS) port to form multi-user MIMO (Multi-user MIMO). , MU-MIMO). The initialization ID is indicated by the scrambling code indicated in the downlink control signaling, and up to four single-flow UEs or two dual-stream UEs can be paired. The MIMO mode supported by the primary mode of the transmission mode 8 is as shown in Table 1. The most typical MIMO transmission mode is the four types shown in Figure la-Id, and the la is SU-MIMO, including single port 7/8. And double-layer transmission, Figure lb is MU-MIMO, scheduling 2 UEs at the same time, and each UE single-layer transmission, Figure lc is MU-MIMO, scheduling 2 UEs simultaneously, double-layer transmission for each UE, Figure Id is MU - MIMO, scheduling 4 UEs simultaneously, each UE single layer transmission. Table 1: TM8 Application Scenario Description

Figure la~ld: Typical MIMO transmission supported by TM8

In contrast, the transmission mode defined by the LTE system in R8 only supports single-user single codeword transmission (such as TM1).

TM2, TM6, TM7), either support only multi-user single codeword transmission (e.g., TM5), or only single-user multi-codeword transmission (e.g., TM3, TM4). Since TM8 can simultaneously realize single-user single codeword, single-user multi-codeword, multi-user single-codeword, multi-user multi-codeword transmission, TM8 puts forward higher requirements for the design of downlink scheduling algorithm.

In the currently disclosed LTE system scheduling algorithm, the basic idea includes the following two steps, namely: firstly performing time domain scheduling according to the data volume of various downlink services of the UE and the quality of service (QoS) requirements, and generating a UE The priority queue; then the frequency domain scheduling is performed for the UEs in the priority queue, and the corresponding frequency domain resources are allocated.

When allocating resources, considering the downlink transmission mode and channel shield of the UE, determine whether to allocate single codeword resources or multi-codeword resources for the currently scheduled UE, and consider whether to use multi-user multiplexing for UEs supporting MU-MIMO. resource of. The current downlink scheduling algorithm of the LTE system can basically meet the requirements of a single downlink transmission mode, but the support for the TM8 needs to be further enhanced.

Because the MIMO mode supported by the TM8 is flexible and can achieve fast switching between single-user/multi-user and single-stream/dual-stream, the existing scheduling algorithms do not fully consider the various MIMO modes supported by the TM8, so the TM8 cannot be fully utilized. The transmission capability, the current downlink scheduling algorithm can only support partial MIMO methods on the TM8 process, such as single-user single-stream (single codeword) and single-user dual-stream (multi-codeword), which is very supportive for multi-user single-stream. Poor, and does not support multi-user dual stream transmission. SUMMARY OF THE INVENTION Embodiments of the present invention provide a downlink transmission method and apparatus to better support various MIMO modes under the TM8. A downlink transmission method includes:

Determining activation of multi-user multiple input multiple output MU-MIMO transmission;

Determining a single stream shaping transmission or a dual stream shaping transmission according to channel conditions;

Time domain resource allocation and frequency domain resource allocation for user equipment;

Downlink data transmission is performed through the allocated resources.

A downlink transmission device includes:

a multi-user transmission determining unit, configured to determine an activated multi-user multiple-input multi-output MU-MIMO transmission; a dual-stream transmission determining unit, configured to determine, according to a channel condition, a single-stream shaped transmission or a dual-stream shaped transmission; the resource allocation unit, Performing time domain resource allocation and frequency domain resource allocation for user equipment;

a data transmission unit, configured to perform downlink data transmission by the allocated resources.

The embodiment of the present invention provides a downlink transmission method and apparatus. After determining the MU-MIMO transmission mode, it is further determined whether to use a single-stream or dual-stream transmission according to a channel condition, thereby implementing multi-user support on the TM8. Single-stream transmission and multi-user dual-stream transmission, better support various MIMO modes under TM8. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a schematic diagram of a MIMO mode supported by a transmission mode 8 in the prior art;

2 is a flowchart of a downlink transmission method according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a downlink transmission apparatus according to an embodiment of the present invention. The embodiments of the present invention provide a downlink transmission method and apparatus. After determining to use the MU-MIMO transmission mode, further determining whether to use single-stream or dual-stream shaping according to channel conditions, thereby implementing on the TM8. Support multi-user single-stream transmission and multi-user dual-stream transmission, better support various MIMO modes under TM8.

As shown in FIG. 2, the downlink transmission method provided by the embodiment of the present invention includes:

Step S201, determining to activate the MU-MIMO transmission; Step S202: Determine, according to the channel condition, a single stream shaping transmission or a dual stream shaping transmission;

Step S203: Perform time domain resource allocation and frequency domain resource allocation for the UE.

Step S204: Perform downlink data transmission by using the allocated resources.

Since after determining the activation of the MU-MIMO mode, the single-stream shaping transmission or the dual-stream shaping transmission in the transmission mode is further determined according to the channel condition, so that more comprehensive support is provided for various MIMO modes under the TM8.

In step S201, determining to activate the MU-MIMO transmission may be based on a Physical Downlink Control Channel (PDSCH) resource utilization rate, a Physical Downlink Shared Channel (PDCCH) resource utilization rate, and a PDSCH sum. The resource-limited condition of the PDCCH is used to determine the activated MU-MIMO transmission. Specifically, the step S201 specifically includes:

Determining that the PDSCH resource utilization is greater than the set first threshold in the statistical period, the PDCCH resource utilization in the statistical period is less than the set second threshold, and the number of times the downlink scheduling PDSCH resource is limited in the statistical period minus the downlink scheduling in the counting period When the difference between the times of the PDCCH resource limitation is greater than the third threshold, the current cell downlink MU-MIMO transmission is activated, and the downlink scheduling PDSCH resource limitation refers to partial UE failure due to insufficient physical resource block (PRB) resources. In the case of scheduling, the downlink scheduling PDCCH resource limitation refers to a situation in which the UE is not scheduled due to unsuccessful PDCCH resource allocation.

Specifically, the statistical duration ⁷ ^ -MHi can be set first, and periodic statistics and judgments are started. After the statistical duration has been set, the preset statistical duration can be used when the subsequent MU-MIMO transmission is activated. No longer reset

In the statistical period ^Tdl — ^Mu — ^Stat , the PRB resource usage of each downlink subframe PDSCH of the current cell is counted, and the CCE resource usage of the PDCCH of each downlink subframe of the current cell is counted, and the statistical period ^Tdl — ^Mu — ^Stat internal downlink scheduling is determined. The number of PDSCH resource-limited times ^N PDSCH—and the number of times the downlink dynamic scheduling PDCCH resource is limited in the statistical period N PDCCH _ run_ out .

When the statistical period arrives, the PDSCH resource utilization rate ^{77 in the} statistical period and the resource utilization rate of the PDCCH "CCE H are calculated, and then the downlink MU-MIMO activation determination is performed:

If "PRB-PDSCH > TH _dMuMIMO - _pDSCH , and CCE PDCCH < dlMuMIMO _ PDCCH , and

^N PDSCH _ mn_out - ^N PDCCH — run — out > ^TH body t , then activate downlink MU-MIMO transmission for the current cell, and instruct the physical layer to perform related measurement;

Otherwise, the current cell does not use downlink MU-MIMO transmission.

Its towel:

The PDSCH resource is restricted. In the downlink scheduling process, the PDSCH has no PRB resources that can be allocated.

The UE does not get scheduled;

The PDCCH resource limitation refers to a situation in which the UE is not scheduled due to unsuccessful PDCCH resource allocation in the uplink and downlink scheduling processes; The PDSCH channel resource utilization rate ⁷⁷ - TM ^{5Cff is} defined as: the ratio of the number of PRBs actually used by the _PDSCH channel in period ⁷ to the total number of resources available during the period;

The PDCCH channel resource utilization is defined as: the ratio of the number of Control Channel Elements (CCEs) actually used by the pQCCH channel to the total number of available CCE resources during the period;

The parameter TH ^dlMu TH _dlMu and ^^ "ί are pre-set threshold values, and the specific values may be given by the network capacity plan. In step S202, according to the information reported by the UE and/or the base station according to the channel reciprocity The obtained channel information is subjected to single- and dual-stream adaptive decision. For the UE of ΤΜ8, there are two options for reporting the channel quality indicator (CQI) information of the UE: codebook-based reporting and non-codebook-based Reporting, at this time, step S202 specifically includes:

For the UE that reports the CQI information in the non-codebook mode, the channel information measured according to the Sounding Reference Signal (SRS) is decomposed into the current UE to determine the single stream shaping transmission or the dual stream shaping transmission.

For the UE that reports the CQI information in the codebook mode, according to the rank information indication reported by the UE ( Rank Indicator,

RI) combines the feedback information of the historical data transmission to determine whether the current UE uses a single stream shaping transmission or a dual stream shaping transmission.

Since the single/dual stream adaptive decision can be performed by those skilled in the art according to the prior art, the embodiment of the present invention will not be described in detail.

In step S203, the time domain resource allocation and the frequency domain resource allocation are performed for the UE, which specifically includes:

Performing time domain scheduling according to the data volume and QoS requirements of various downlink services of the UE, generating a priority queue of the UE; performing frequency domain scheduling for the UEs in the priority queue in turn, and allocating corresponding frequency domain resources.

Specifically, the frequency domain scheduling is performed on the UEs in the priority queues, and when the corresponding frequency domain resources are allocated, the MU-MIMO function may be determined whether the MU-MIMO function is currently activated. The conditions (ie, the above-mentioned channel conditions) and other factors are selected whether to use single-stream or dual-stream transmission. If MU-MIMO has been activated, the UE configured as TM8 in the system performs data transmission according to the following scheme: According to the priority queue order, for each UE in the priority queue, the resource list that is not allocated to any UE in the subframe is determined as a single-user available PRB resource list, and a single-user available PRB resource list set is formed, which will already be In the resource list allocated to other UEs, the resource list whose number of used data layers is less than or equal to the preset number of layers is determined as a multi-user available PRB resource list, and a multi-user available PRB resource list set is formed;

When there is a single-user available PRB resource list whose data bearer capability meets the current UE data transmission requirement, the single-user available PRB resource list whose data bearer capability meets the current UE data transmission requirement is allocated to the current UE, and the modulation and coding policy MCS information is determined. ; Otherwise, when there is no single-user available PRB resource list with data bearer capability meeting the current UE data transmission requirements:

A single-user available PRB resource list with the largest data carrying capacity in the PRB resource list set; the current UE is paired with each primary user in the multi-user available PRB resource list set, and the matching resource is allocated;

When there is a resource list of the paired primary user whose data bearer capability meets the current UE data transmission requirement, the resource list of the paired primary user whose data bearer capability meets the current UE data transmission requirement is allocated to the current UE, and the modulation and coding policy MCS information is determined;

When there is no resource list of the paired primary user whose data carrying capacity meets the current UE data transmission requirement, the multi-user available PRB resource list with the largest data carrying capacity in the resource list of the primary user paired with the current UE and the temporarily stored single user are compared. A list of available single-user PRB resources with the largest data carrying capacity in the PRB resource list set is selected, and a resource list with a large data carrying capability is selected and allocated to the current UE, and the modulation and coding policy MCS information is determined.

Specifically, when allocating resources for each UE in the priority queue, it is first necessary to determine a candidate PRB resource list set:

For the PRB resource that is not allocated to any UE in the current subframe, it is placed in the resource set S 1 , and the resources in S 1 are sorted according to the CQI on each PRB from high to low, and according to the downlink control information of the current UE. The resource allocation type supported by the Downlink control information (DCI) format determines the availability of the resource, generates a candidate PRB resource list set by using the available resources, and identifies the corresponding resource list as a single-user available PRB resource list, and the corresponding resource list set identifier. A collection of PRB resource lists available for a single user.

For PRB resources that have been allocated to UEs in other TM8 modes, if the number of data layers that have been used is less than or equal to MaxAllowedLayer (pre-set parameters, which are used to control the maximum number of data layers that can be used under TM8, this parameter can be based on the device. Supported complexity settings, typically 4 or 2), form a list of thousands of resources according to the resource allocation result of the primary user (assuming that the i-th candidate PRB resource list is ^^, the number of PRBs contained therein is N _p∞rmgPRB ( i, ), and the resource list is identified as a multi-user available PR resource list, and the corresponding resource list set identifier is a multi-user available PRB resource list set.

The resource allocation types supported by various DCI formats are shown in Table 2:

Table 2: Resource allocation types supported by various DCI formats

The DCI format supported by the TM8 includes: DCI format 1A DCI format 2B. Various resource allocation classes Under the type, the availability of resources is judged as follows:

For Type 0, the PRB is available only when all PRBs in the Resource Block Group (RBG) to which the PRB belongs are available.

For Type 1, the selected PRB must be in the same addressing space;

For Type 2, the selected PRB must meet the requirements of the Virtual Resource Block (VRB) continuity.

The availability of resources under various resource allocation types is well known to those skilled in the art and will not be described in detail herein.

When the resources are allocated to the current UE, if the single-user available resource list set is not empty, the resources are sequentially selected in the single-user available resource list set to perform resource allocation, and the data carrying capacity of the allocated resources is calculated; The data bearer capability can meet the data transmission requirements of the current UE to be scheduled, and then select the resource in the allocated single-user resource list as the resource used by the UE in the downlink data transmission process, and determine the modulation coding scheme (Modulation Code Scheme). , MCS) and other information, and determine the end of this resource allocation;

If the data carrying capacity of the allocated resource cannot meet the data transmission requirement of the currently scheduled UE, the current single user resource allocation result is temporarily stored, and the multi-user resource allocation is continued.

In the multi-user resource allocation, if the multi-user available PRB resource list set is not empty, the information of each primary UE on the resource list is obtained for each resource list in the multi-user available PRB resource list set, and the UE and each are performed. The resource matching decision of the MU-MIMO of the primary UE completes the selection of the paired resource list.

If there are multiple primary UEs on a certain resource list, when performing UE pairing decision, it is necessary to ensure that the paired UE and any primary UE satisfy the condition of MU-MIMO pairing transmission; if there is a paired UE and any one of the primary UEs If the identifier of the unsuccessful pairing is returned when the UE pairing decision module is invoked on the resource list, the current UE fails to pair on the resource list, and the current UE cannot use the resources in the PRB resource list of the multi-user available.

If the multi-user resource allocation result is not empty, the data bearer capability of the allocated multi-user resource is calculated: if the data bearer capability of the allocated resource can meet the data transmission requirement of the currently scheduled UE, the allocated multi-user available PRB is selected. The resource in the resource list is used as the resource used by the UE in the current downlink data transmission process, and the MCS and other information are determined to determine the end of the current resource allocation;

If the data carrying capacity of the multi-user resource cannot meet the data transmission requirement of the UE, the temporary single-user resource allocation result is obtained, and compared with the multi-user resource allocation result, and one of the data carrying capacity is selected as the final resource. The result is assigned, and information such as MCS is determined at the same time to determine the end of the current resource allocation.

According to the above resource allocation idea, the UE of the TM8 can flexibly implement resource allocation of single/multi-user MIMO, and can flexibly implement various MIMO transmission modes in Table 1.

At present, when multi-user pairing is performed, the spatial characteristics of the channel are not fully utilized. For the beamforming of TM8, there is room for further optimization of the pairing algorithm. The current multi-user paired transmission is only used in frequency domain scheduling. It is considered that the pairing criterion only considers the wireless channel transmission status of the master/slave user of the paired transmission, and therefore cannot fully utilize the resources: for example, assume that UE1 and UE2 satisfy the capability of MU-MIMO transmission according to the condition of the wireless channel, and assume that UE1 is The primary user who has already allocated the resource, but the amount of data that UE1 needs to transmit is large, and the number of resources required is large, and the number of resources required by UE2 is small. When pairing transmission, considering the performance of data demodulation, UE1 and UE2 uses the same resources, so this paired transmission cannot fully utilize the system's wireless resources.

The embodiment of the present invention further provides a pairing mode. For each two UEs that are paired, it is determined that the spectrum efficiency of the two UEs is greater than a preset absolute spectral efficiency threshold, and the spectrum efficiency difference between the two UEs is smaller than the foregoing. Setting the spectral efficiency difference threshold, and determining that the configuration of the two UEs is less than a preset correlation matching threshold, determining that the current two UEs are capable of pairing, otherwise determining that the current two UEs cannot be paired .

Specifically, it is determined whether a plurality of users can use the same PRB resource for data transmission according to channel information of the user or the like. In addition, in the pairing algorithm, service level matching can also be performed according to characteristics such as service type.

In the resource allocation process, each UE performs resource allocation in order of priority. In the resource allocation process, if MU-MIMO resources are needed, a pairing attempt is performed on the corresponding resource block. That is, the resources of the respective transport layers that perform MU transmission on the same physical resource are allocated in order, rather than being allocated at the same time. In this manner of resource allocation, there is a primary and secondary point between UEs performing MU-MIMO transmission, wherein a UE that has determined that the resource is occupied in a Transmission Timing Interval (TTI) is called a primary. UE (in one TTI, multiple primary UEs may exist simultaneously on the same resource), and a UE attempting to perform MU-MIMO paired transmission is referred to as a paired UE.

When pairing, the channel information is first considered, including channel shield information and channel state information. According to the candidate PRB resource list i output by the frequency domain scheduling module (assuming that the number of PRBs in the resource list is ^N S ^{PRB (I >} , the number is the number of resource blocks allocated to the primary UE), the two UEs currently attempting to pair are searched. The stored CQI information of each PRB is a later spectral efficiency information that comprehensively considers the latest CQI report and CQI correction, and the CQI reconstruction result.

The channel shield information may be, but is not limited to, spectral efficiency; the channel state information may be, but is not limited to, a form vector correlation.

For each UE (assuming the primary UE and the paired UE are UE1 and UE2 respectively), respectively, based on the spectrum efficiency information of the UE on the above resources, the average spectral efficiency ^e ff H 0) on the selected resource is obtained,

effpDSCH _ UE\ ) - T 7 7 ^e ffpDSC

pairingPRB v/ . M Σ H _ UE\ _ PRB effpDSCH _UE2 (0 - ~Tj 7 " . ^ effpDSCH _UE2_ PRB (^)

pairingPRB v / N The decision of spectral efficiency after fitting: If effpDSCH UEI (0- ^e ffpi < dlUePairEffDiffTH, ^PDSCH mi (0 > dlUePairEflFTH, and ^^ ^{Cff Mi2} ( ^Z )> dlUePairEffrH, then further matching can be performed; otherwise, it is determined that the current two UEs do not meet the pairing requirement, wherein the spectrum efficiency difference threshold dlUePairEffDiffTH, absolute spectral efficiency threshold dlUePairEffTH is a preset threshold value, which can be determined by link simulation;

If the paired UE is determined by fitting the spectral efficiency, the angle of arrival (AoA) obtained by estimating the SRS by the two UEs is obtained, and the correlation is calculated: assuming that AoA of UE1 is AoA of UE2,

^ For the number of transmit antennas, for the antenna spacing, calculate the shape vector of UE n:

¥ _ vec _n = exp - 2π - [ΐ : N _t ] - d - sin {θ _η )) / ^βϊ

Then the correlation of the shape vectors of the two UEs is:

If ^ < (111^?& 01⁄2£^11, the channel conditions of the current two UEs meet the requirements of the paired transmission; otherwise, it is determined that the channel conditions of the current two UEs do not satisfy the requirements of the paired transmission, where the shape vector correlation The threshold dlUePairCoeflfTH is a preset threshold and can be determined by link simulation.

After the pairing is successful, the allocation of the paired resources is further performed. The process of allocating the paired resources specifically includes: when the resource conditions of the primary UE satisfying the pairing requirement, the number of available resources is greater than or equal to the number of resources required by the paired UE. In the resource list, in the resource list that the number of available resources is greater than or equal to the number of resources required by the paired UE, the resource list with the smallest difference between the number of available resources minus the number of resources required for the paired UE is allocated to the paired UE.

When there is no resource list in which the number of available resources is greater than or equal to the number of resources required by the paired UE in the resource list of the primary UE in which the channel conditions satisfy the pairing requirement, the difference between the number of resources required to select the paired UE minus the number of available resources is the smallest. The resource list allocates resources for the paired UE.

Specifically, in the current TTI scheduling, the number of resource blocks required by the paired UE and the number of resource blocks allocated in the current TTI of the primary UE are determined:

First, according to the paired UE (assumed to be UE2), the average spectrum year in each candidate PRB resource list that satisfies the pairing condition (assuming that the i-th candidate PRB resource list is ^LIST PRB, and the number of PRBs included therein is ^{Ν ΡΚΒ} ( ^Ζ )) ^e ff _P诵Λι, and the amount of data that the paired UE needs to transmit in the current subframe, and determining the number of PRBs required by the UE in each candidate PRB resource list by the table lookup ^NpRB — ^UE2 ( ^Z );

Then, the selection of the paired resource list is performed. If there is at least one candidate resource list satisfying the pairing transmission requirement, the number of resources is satisfied: _GPRB ^) ^{≥ N} _PRB - _UE 2 ⁽ j) , then all the candidate resources satisfying the above conditions In the list, select ^^"^ ² ^) - ^^ - ^ ² ( ⁷ ) the smallest resource list q as the resource for the final pairing transmission, and one or more primary users on the resource list q are the primary users of the paired transmission.

Otherwise, select ^ - ⁷ ) ^_ ^. The "^^^" minimum resource list q is used as the resource for the final pairing transmission, and one or more primary users on the resource list q are the primary users of the paired transmission. The following describes the selection of the resource list by using a specific example: Assume that the resource list L1, L2, and L3 are allocated to UE1, UE2, and UE3 in this subframe, and now consider to allocate MU-MIMO resources for UE4; assume that UE4 is in resource list L1, L2. The number of PRBs included in the list of LI, L2, and L3 and the number of PRBs required by the UE4 in each resource list are as shown in Table 3, and the UEs, UE2, and UE3 respectively satisfy the channel condition matching criteria in the solution. :

Table 3: UE4 Resource Allocation Statistics

For the data listed in the example 1 in Table 3, according to the resource allocation principle, L3 cannot meet the requirements of UE4, L1 and L2 can meet the requirements of UE4, and 5-4<8-6, so the resource list L1 should be selected as the MU. - MIMO's pairing resource list, ie UE4 performs MU-MIMO paired transmission with UE 1 on resource list L1.

For the data listed in Example 2 in Table 3, according to the resource allocation principle, each resource list cannot meet the requirements of UE4, and the number of resources in L3 is the smallest compared with the required number of UE4, so resource list L3 should be selected as MU-MIMO. The paired resource list, that is, UE4 performs MU-MIMO transmission with UE3 on resource list L3.

The embodiment of the present invention further provides a downlink transmission device, as shown in FIG. 3, including:

a multi-user transmission determining unit 301, configured to determine an activated multi-user multiple-input multiple-output MU-MIMO transmission; a dual-stream transmission determining unit 302, configured to determine, according to a channel condition, a single-stream shaped transmission or a dual-stream shaped transmission; 303. Perform time domain resource allocation and frequency domain resource allocation for user equipment.

The data transmission unit 304 is configured to perform downlink data transmission by using the allocated resources.

The multi-user transmission determining unit 301 is specifically configured to:

The activated MU-MIMO transmission is determined according to the physical downlink shared channel PDSCH resource utilization, the physical downlink control channel PDCCH resource utilization, and the resource limited condition of the PDSCH and the PDCCH.

Specifically, the multi-user transmission determining unit 301 is specifically configured to:

Determining that the PDSCH resource utilization is greater than the set first threshold in the statistical period, the PDCCH resource utilization in the statistical period is less than the set second threshold, and the number of times the downlink scheduling PDSCH resource is limited in the statistical period minus the downlink scheduling in the counting period When the difference between the number of times the PDCCH resource is limited is greater than the third threshold, the current cell downlink is activated. MU-MIMO transmission, the downlink scheduling PDSCH resource limitation refers to a situation in which some UEs are not scheduled due to insufficient PRB resources. The downlink scheduling PDCCH resource limitation refers to a situation in which the UE is not scheduled due to unsuccessful PDCCH resource allocation.

The dual stream transmission determining unit 302 is specifically configured to:

For the UE that uses the C艮I information in the non-codebook mode, the channel information measured according to the sounding reference signal SRS is decomposed into the current UE to determine the single stream shaping transmission or the dual stream shaping transmission.

The UE that reports the CQI information in the codebook mode indicates that the RI combines the feedback information of the historical data transmission with the rank information reported by the UE to determine whether the current UE uses the single stream shaping transmission or the dual stream shaping transmission.

The resource allocation unit 303 is specifically used to:

The resource allocation unit 303 sequentially performs frequency domain scheduling for the UEs in the priority queue, and allocates corresponding frequency domain resources, including:

According to the priority queue order, for each UE in the priority queue, the resource list that is not allocated to any UE in the subframe is determined as a single-user available PRB resource list, and a single-user available PRB resource list set is formed, which will already be In the resource list allocated to other UEs, the resource list whose number of used data layers is less than or equal to the preset number of layers is determined as a multi-user available PRB resource list, and a multi-user available PRB resource list set is formed;

When there is a single-user available PRB resource list whose data bearer capability meets the current UE data transmission requirement, the single-user available PRB resource list whose data bearer capability meets the current UE data transmission requirement is allocated to the current UE, and the modulation and coding policy MCS information is determined. ;

When there is no single-user available PRB resource list whose data bearer capability meets the current UE data transmission requirement: Temporary single-user available PRB resource list set The single-user available PRB resource list with the largest data carrying capacity in the PRB resource list set;

Pairing the current UE with each primary user in the multi-user available PRB resource list set, and performing allocation of the paired resources;

When there is no resource list of the paired primary user whose data carrying capacity meets the current UE data transmission requirement, the multi-user available PRB resource list with the largest data carrying capacity in the resource list of the primary user paired with the current UE and the temporarily stored single user are compared. A resource list with a large data bearer capability can be allocated to the current UE, and a modulation coding policy MCS information is determined, by using a PRB resource list with the largest data bearer capability in the PRB resource list set. The resource allocation unit 303 matches the current UE with each primary user in the multi-user available PRB resource list set. Yes, specifically:

For every two UEs that are paired, it is determined that the spectrum efficiency of the two UEs is greater than a preset absolute spectral efficiency threshold, and the spectral efficiency difference between the two UEs is less than a preset spectral efficiency difference threshold, and two When the mapping vector correlation of the UEs is less than the preset correlation matching threshold, it is determined that the current two UEs can be paired, otherwise it is determined that the current two UEs cannot be paired.

The resource allocation unit 303 performs allocation of the pairing resources, and specifically includes:

When there is a resource list in which the number of available resources is greater than or equal to the number of resources required by the paired UE in the resource list of the primary UE in which the channel conditions satisfy the pairing requirement, the resource list in which the number of available resources is greater than or equal to the number of resources required by the paired UE The resource list with the smallest difference between the number of available resources minus the number of resources required for the paired UE is allocated to the paired UE;

The data transmission unit 304 performs downlink data transmission, and specifically includes:

And determining, according to the current resource allocation, the UE, the time-frequency resource allocated to the UE, and the corresponding modulation and coding policy MCS information, performing downlink data transmission for the UE.

The embodiment of the present invention provides a downlink transmission method and apparatus. After determining the MU-MIMO transmission mode, it is further determined whether to use a single-stream or dual-stream transmission according to a channel condition, thereby implementing multi-user support on the TM8. Single-stream transmission and multi-user dual-stream transmission, better support various MIMO modes under TM8.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the present invention can be embodied in the form of a computer program product embodied on one or more computer-usable storage interfaces (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each process and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory include instructions. The manufacturing device, the instruction device implements the functions specified in one or more blocks of a flow or a flow and/or a block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

Although the preferred embodiment of the invention has been described, it will be apparent to those of ordinary skill in the art that <RTIgt; Therefore, the appended claims are intended to be construed as including the preferred embodiments and the modifications

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims

Rights request

A downlink transmission method, comprising:

Performing time domain resource allocation and frequency domain resource allocation for the user equipment UE;

Downlink data transmission is performed through the allocated resources.

2. The method according to claim 1, wherein the determining to activate the MU-MIMO transmission comprises:

The method of claim 2, wherein the determining to activate the MU-MIMO transmission comprises:

Determining that the PDSCH resource utilization is greater than the set first threshold in the statistical period, the PDCCH resource utilization in the statistical period is less than the set second threshold, and the number of times the downlink scheduling PDSCH resource is limited in the statistical period minus the downlink scheduling in the counting period When the difference between the number of times the PDCCH resource is limited is greater than the third threshold, the current cell downlink MU-MIMO transmission is activated, and the downlink scheduling PDSCH resource limitation refers to a situation in which some UEs are not scheduled due to insufficient physical resource block PRB resources. The downlink scheduling PDCCH resource limitation refers to a situation in which the UE cannot obtain scheduling due to unsuccessful PDCCH resource allocation.

The method according to claim 1, wherein the determining, by the channel condition, the single-stream shaping transmission or the dual-stream shaping transmission comprises:

For the UE that reports the channel guard quantity indicating CQI information in the non-codebook manner, the channel information measured according to the sounding reference signal SRS is decomposed into the current UE to determine the single stream shaping transmission or the dual stream shaping transmission; The UE that reports the CQI information in the codebook manner, according to the rank information reported by the UE, indicates that the RI combines the feedback information of the historical data transmission to determine whether the current UE uses the single stream shaping transmission or the dual stream shaping transmission.

The method according to claim 1, wherein the performing time domain resource allocation and frequency domain resource allocation for the UE includes:

Generating a priority queue of the UE according to the data volume of the downlink services of the UE and the QoS requirement of the service shield QoS requirement;

The frequency domain scheduling is performed for the UEs in the priority queue, and the corresponding frequency domain resources are allocated.

The method according to claim 5, wherein the performing the frequency domain scheduling by the UEs in the priority queues and allocating the corresponding frequency domain resources, specifically: According to the priority queue order, for each UE in the priority queue, the resource list that is not allocated to any UE in the subframe is determined as a single-user available PRB resource list, and a single-user available PRB resource list set is formed, which will already be In the resource list allocated to other UEs, the resource list whose number of used data layers is less than or equal to the preset number of layers is determined as a multi-user available PRB resource list, and a multi-user available PRB resource list set is formed;

When there is no single-user available PRB resource list whose data bearer capability meets the current UE data transmission requirement: a single-user available PRB resource list with the largest data bearer capability in the PRB resource list set; the current UE and the multi-user available PRB Each primary user in the resource list set is paired and assigned resources are allocated;

When there is a resource list of the paired primary user whose data bearer capability meets the current UE data transmission requirement, the resource list of the paired primary user whose data bearer capability meets the current UE data transmission requirement is allocated to the current UE, and the modulation and coding policy MCS is determined. Information

The method according to claim 6, wherein the pairing the current UE with each primary user in the multi-user available PRB resource list set includes:

The method according to claim 6, wherein the performing the allocation of the pairing resources comprises: in the resource list of the primary UE in which the channel conditions satisfy the pairing requirement, the number of available resources is greater than or equal to the paired UE. When the resource list of the required number of resources is used, in the resource list in which the number of available resources is greater than or equal to the number of resources required by the paired UE, the resource list with the smallest difference between the number of available resources minus the number of resources required for the paired UE is Pairing UEs to allocate resources;

9. A downlink transmission device, comprising: a multi-user transmission determining unit, configured to determine an activated multi-user multiple-input multi-output MU-MIMO transmission; a dual-stream transmission determining unit, configured to determine, according to a channel condition, a single-stream shaped transmission or a dual-stream shaped transmission; the resource allocation unit, Performing time domain resource allocation and frequency domain resource allocation for user equipment;

The apparatus according to claim 9, wherein the multi-user transmission determining unit is specifically configured to: according to a physical downlink shared channel PDSCH resource utilization, a physical downlink control channel PDCCH resource utilization, and resources of a PDSCH and a PDCCH The restricted case determines to activate the MU-MIMO transmission.

The apparatus according to claim 10, wherein the multi-user transmission determining unit is specifically configured to: determine that a PDSCH resource utilization rate in the statistical period is greater than a set first threshold, and a PDCCH resource utilization ratio in the statistical period is less than The second threshold is set, and the number of times the downlink scheduling PDSCH resource is limited in the statistical period minus the number of times the downlink scheduling PDCCH resource is limited in the counting period is greater than the third threshold, and the current cell downlink is activated.

MU-MIMO transmission, the downlink scheduling PDSCH resource limitation refers to a situation in which some UEs are not scheduled due to insufficient PRB resources, and the downlink scheduling PDCCH resource limitation refers to unsuccessful allocation of PDCCH resources.

The UE does not get scheduled.

The apparatus according to claim 9, wherein the dual stream transmission determining unit is specifically configured to: measure, according to the sounding reference signal SRS, the UE that reports the channel shield quantity indicating CQI information by using a non-codebook manner The channel information is decomposed into eigenvalues to determine whether the current UE uses single stream shaping transmission or dual stream shaping transmission;

The device according to claim 9, wherein the resource allocation unit is configured to: perform time domain scheduling according to data types and QoS requirements of various downlink services of the UE, and generate a priority queue of the UE; The UE in the priority queue performs frequency domain scheduling and allocates corresponding frequency domain resources.

The device according to claim 13, wherein the resource allocation unit performs frequency domain scheduling for the UEs in the priority queue, and allocates corresponding frequency domain resources, which specifically includes:

When there is no single-user available PRB resource list whose data carrying capacity meets the current UE data transmission requirement: a temporary single-user available PRB resource list set has the largest single-user available PRB resource list in the PRB resource list set; Pairing the current UE with each primary user in the multi-user available PRB resource list set, and performing allocation of the paired resources;

The device according to claim 14, wherein the resource allocation unit pairs the current UE with each primary user in the PRB resource list set of the multi-user, including:

The device according to claim 14, wherein the resource allocation unit performs the allocation of the pairing resources, and specifically includes: