CN116648969A - A communication method and device - Google Patents

Abstract

The present application provides a communication method and device. The communication method includes: the network device sends downlink control information to the terminal device, the downlink control information includes indexes of N precoding matrix subsets, and the terminal device determines at least N precoding matrix subsets from the N precoding matrix subsets according to the downlink control information. coding matrix, and send uplink signals based on at least N precoding matrices, while improving transmission performance, reducing signaling overhead of sub-band precoding indication information and complexity of terminal equipment detecting sub-band precoding indication information.

Description

A communication method and device technical field

The present application relates to the field of wireless communication, and in particular to a communication method and device.

Background technique

In uplink transmission, when both the terminal and the base station are configured with multiple antennas, the base station needs to send precoding information to the terminal through downlink control information (DCI), and the terminal obtains the precoding matrix according to the precoding information, and the precoding matrix is used to transmit The data is mapped to multiple antenna ports, and a physical uplink shared channel (PUSCH) is sent. Precoding makes the transmitted signal more directional, rather than simply radiating around.

The physical uplink shared channel supports a codebook-based transmission mode and a non-codebook-based transmission mode. For the codebook-based transmission mode, the base station selects a precoding matrix in the codebook, and sends a Transmitted Precoding Matrix Indicator (TPMI) to the terminal, and the TPMI corresponds to a precoding matrix. The accuracy of the precoding matrix will affect the demodulation performance of PUSCH. The NR system only supports uplink broadband precoding, that is, the same precoding matrix is used on the scheduled bandwidth. When the frequency selection characteristics of the channel are relatively large, this method will cause system performance loss. If sub-band precoding is used, the base station Sending information to the terminal equipment to indicate the TPMI of each subband will increase the signaling overhead. Therefore, when designing uplink precoding, reducing signaling overhead and improving transmission performance become mutually contradictory aspects.

Contents of the invention

The present invention provides a communication method and device for reducing signaling overhead of sub-band precoding.

In a first aspect, the present application provides a communication method, and the execution subject of the method may be a terminal device, or may be a chip applied in the terminal device. The following description is made by taking the execution subject as a terminal device as an example. The terminal device receives the downlink control information sent by the network device, the downlink control information includes indexes of N precoding matrix subsets, and the N precoding matrix subsets are one of the plurality of precoding matrix subsets divided by the first codebook Or multiple, among the N precoding subsets, at least one precoding matrix subset includes at least two precoding matrices. The terminal device determines at least N precoding matrices in the N precoding matrix subsets, and the terminal device sends uplink signals based on the determined at least N precoding matrices, where N is a positive integer.

In the above implementation manner, the terminal device can respectively select one or more precoding matrices from the N precoding matrix subsets for sending uplink signals, which improves the transmission performance. Moreover, the terminal device receives the indication information of the index of the precoding matrix subset through the downlink control information, since the number of precoding matrix subsets divided by the first codebook may be smaller or much smaller than the precoding matrix contained in the first codebook Therefore, compared with receiving the indication information of the index of the precoding matrix contained in the entire first codebook, receiving the indication information of the index of the precoding matrix subset can reduce the overhead of the downlink control information, thereby helping to reduce the The complexity of end-device detection and the power consumption of the end-device.

In an optional implementation manner, the downlink control information further includes resource indication information for indicating the first downlink reference signal, and the terminal device, based on the first downlink reference signal on the resource indicated by the resource indication information, in the N At least N precoding matrices are determined in the precoding matrix subset.

In the above embodiment, the terminal device determines at least N precoding matrices based on the first downlink reference signal. Since the first downlink reference signal can reflect the channel state of the downlink channel, the terminal device can consider the influence of the channel state and determine the Appropriate precoding matrix to obtain better multi-antenna gain.

In an optional implementation manner, the uplink signal is a physical uplink shared channel PUSCH, the PUSCH occupies M subbands, the downlink control information also includes indication information of M subbands, and at least N precoding matrices are M precoding matrices, Each of the M subbands corresponds to one of the M precoding matrices, where M is a positive integer greater than N. At this time, precoding matrices corresponding to at least two subbands among the M subbands belong to the same precoding matrix subset. The terminal device sends PUSCH on M subbands based on M precoding matrices.

In an optional implementation manner, the uplink signal is a physical uplink shared channel PUSCH, and the PUSCH occupies N subbands, that is, M is equal to N, and the downlink control information also includes indication information of N subbands, and N precoding matrix subsets In one-to-one correspondence with the N subbands, the terminal device sends the PUSCH on the N subbands based on the N precoding matrices.

In an optional implementation manner, the uplink signal is a physical uplink shared channel PUSCH, the PUSCH occupies M subbands, M is greater than N, the downlink control information also includes indication information of M subbands, and N precoding matrix subsets are one Precoding matrix subset, N is 1. Determine the precoding matrix of each subband in the M subbands according to a precoding matrix subset, at least N precoding matrices are M precoding matrices, M subbands and M precoding matrices are in one-to-one correspondence, and the terminal device is based on M precoding matrices transmit PUSCH on M subbands.

In the above method, the downlink control information indicates the index of the precoding matrix subset and the subband indication information, and each subband corresponds to a precoding matrix, for example, it may be the most suitable precoding matrix for the terminal device to send uplink signals, which is beneficial to improve transmission performance.

It should be noted that the M precoding matrices may be completely different M precoding matrices, or may be partly the same precoding matrix, which is not limited in this embodiment of the present invention.

In an optional implementation manner, at least two different precoding matrix subsets among the plurality of precoding matrix subsets correspond to different values of the first codebook parameter, and the first codebook parameter includes a phase. In an optional manner, the plurality of precoding matrix subsets is K, the first codebook contains L precoding matrices, and the precoding matrix included in each precoding matrix subset in the K precoding matrix subsets The index of the matrix satisfies The values of are the same; or, the indexes of the precoding matrices included in each precoding matrix subset satisfy the same value of mod(j,K). Wherein, j is the index of the precoding matrix in the first codebook, is the floor function, is the upper integer function.

In an optional manner, the first codebook is generated based on a discrete Fourier transform matrix, and at least two different precoding matrix subsets among the plurality of precoding matrix subsets correspond to different columns in the discrete Fourier transform matrix vector.

In an optional manner, the downlink control information further includes an index of at least one precoding matrix, and at least one precoding matrix is a precoding matrix that is not expected to be used by the terminal equipment, or is a precoding matrix that is expected to be avoided by the terminal equipment. In an optional manner, the precoding matrix that is not expected to be used by the terminal device is a precoding matrix of an interference channel.

In the above method, when the terminal device determines at least N precoding matrices from the N precoding matrix subsets, it also considers the precoding matrix that the network device does not expect the terminal device to use, so that the terminal device can minimize interference and improve transmission performance

In a second aspect, the present application provides a communication method, and the execution subject of the method may be a network device, or may be a chip applied in the network device. The following description is made by taking the execution subject as an example of a network device. The network device determines N precoding matrix subsets, and the network device sends downlink control information to the terminal device. The downlink control information includes indexes of the N precoding matrix subsets, and the N precoding matrix subsets are divided into the first codebook Among the N precoding matrix subsets, at least one precoding matrix subset includes at least two precoding matrixes.

In the above manner, the network device indicates the indexes of one or more precoding matrix subsets through the downlink control information, since the number of precoding matrix subsets divided by the first codebook may be smaller or much smaller than the precoding matrix subsets contained in the first codebook Therefore, compared with indicating the index of the precoding matrix contained in the first codebook through the downlink control information, the network device indicates the index of the precoding matrix subset through the downlink control information, which can reduce the signal of the downlink control information. order overhead.

In an optional implementation manner, the downlink control information further includes resource indication information for indicating the first downlink reference signal, and the terminal device, based on the first downlink reference signal on the resource indicated by the resource indication information, performs At least N precoding matrices are determined in the coding matrix subset.

In an optional implementation manner, at least N precoding matrices correspond to M subbands, where M is greater than or equal to N, and the network device receives uplink signals on the M subbands.

In an optional implementation manner, the number of at least N precoding matrices is M, and the M precoding matrices are in one-to-one correspondence with the M subbands, and the network device receives uplink signals on the M subbands.

It should be noted that the M precoding matrices may be completely different M precoding matrices, or may be partly the same precoding matrix, which is not limited in this embodiment of the present invention.

In an optional implementation manner, the uplink signal is a physical uplink shared channel PUSCH.

In an optional implementation manner, the N precoding matrix subsets are one precoding matrix subset, where N is 1, and at least N+1 precoding matrixes belong to the same precoding matrix subset.

In an optional implementation manner, at least two different precoding matrix subsets among the plurality of precoding matrix subsets correspond to different values of the first codebook parameter, and the first codebook parameter includes a phase.

In an optional implementation manner, the plurality of precoding matrix subsets is K, the first codebook contains L precoding matrices, and the precoding matrix subsets included in each of the K precoding matrix subsets include The indexing of the encoding matrix satisfies: The values of are the same; or, the indexes of the precoding matrices included in each precoding matrix subset satisfy the same value of mod(j,K). Among them, j is the index of each precoding matrix in the first codebook, is the floor function, is the upper integer function.

In an optional manner, the first codebook is generated based on a discrete Fourier transform matrix, and at least two different precoding matrix subsets among the plurality of precoding matrix subsets correspond to different columns in the discrete Fourier transform matrix vector.

In an optional manner, the downlink control information further includes an index of at least one precoding matrix, and at least one precoding matrix is a precoding matrix that is not expected to be used by the terminal equipment, or is a precoding matrix that is expected to be avoided by the terminal equipment.

In an optional manner, the precoding matrix that is not expected to be used by the terminal device is the precoding matrix of the interference channel.

In the above method, the network device indicates the indexes of the N precoding matrix subsets, and at the same time indicates the precoding matrix that the network device does not expect the terminal device to use, which is beneficial to the terminal device to minimize interference and improve transmission performance.

In a third aspect, a communication device is provided, and the communication device has a function of implementing the behavior in the method example of the first aspect above. The functions described above may be implemented by hardware, or may be implemented by executing corresponding software on the hardware. The hardware or software includes one or more modules corresponding to the above functions. In a possible design, the communication device includes: a receiving unit, the transceiver unit is configured to receive downlink control information, the downlink control information includes indexes of N precoding matrix subsets, N precoding matrix subsets One or more of the plurality of precoding matrix subsets divided into the first codebook, among the N precoding matrix subsets, there is at least one precoding matrix subset including at least two precoding matrices. A processing unit, configured to determine at least N precoding matrices among the N precoding matrix subsets. A sending unit, configured to send uplink signals based on at least N precoding matrices, where N is a positive integer.

These modules can perform the corresponding functions in the method example of the first aspect above. For details, refer to the detailed description in the method example, which will not be repeated here. Meanwhile, regarding the technical effect brought by the third aspect or the corresponding implementation manner, reference may be made to the introduction of the technical effect of the first aspect or the corresponding implementation manner.

In a fourth aspect, a communication device is provided, and the communication device has a function of implementing the behavior in the method example of the second aspect above. The functions described above may be implemented by hardware, or may be implemented by executing corresponding software on the hardware. The hardware or software includes one or more modules corresponding to the above functions. In a possible design, the communication device includes: a processing unit, configured to determine N precoding matrix subsets. A sending unit, configured to send downlink control information, where the downlink control information includes indexes of N precoding matrix subsets, where the N precoding matrix subsets are one or more of the plurality of precoding matrix subsets divided by the first codebook Multiple, among the N precoding matrix subsets, at least one precoding matrix subset includes at least two precoding matrices.

These modules can perform the corresponding functions in the method example of the second aspect above. For details, refer to the detailed description in the method example, and will not repeat them here. Meanwhile, regarding the technical effect brought by the third aspect or the corresponding implementation manner, reference may be made to the introduction of the technical effect of the first aspect or the corresponding implementation manner.

According to a fifth aspect, a communication device is provided. The communication device may be the terminal device in the above method embodiment, or a chip provided in the terminal device, or a larger device including the terminal device. The communication device includes at least one processor, an interface circuit, and optionally, a memory. Wherein, the interface circuit is used to provide the input or output of instructions and/or data for the at least one processor, the memory is used to store computer programs or instructions, at least the processor is coupled with the memory and the interface circuit, when the at least one processor executes the When the above computer program or instruction is used, the communication device is made to execute the method executed by the terminal device in the above method embodiment.

According to a sixth aspect, a communication device is provided. The communication device may be the network device in the above method embodiment, or a chip provided in the network device, or a larger device including the network device. The communication device includes at least one processor, an interface circuit, and optionally, a memory. Wherein, the interface circuit is used to provide the input or output of instructions and/or data for the at least one processor, the memory is used to store computer programs or instructions, at least the processor is coupled with the memory and the interface circuit, when the at least one processor executes the When the above computer program or instruction is used, the communication device is made to execute the method executed by the network device in the above method embodiment.

According to a seventh aspect, a computer program product is provided, and the computer program product includes: computer program code, when the computer program code is executed, the method performed by the terminal device in the above aspects is executed.

In an eighth aspect, a computer program product is provided, and the computer program product includes: computer program code, when the computer program code is executed, the method performed by the network device in the above aspects is executed.

In a ninth aspect, the present application provides a system-on-a-chip, where the system-on-a-chip includes a processor, configured to implement functions of the terminal device in the methods in the foregoing aspects. In a possible design, the chip system further includes a memory, configured to store program instructions and/or data. The system-on-a-chip may consist of chips, or may include chips and other discrete devices.

In a tenth aspect, the present application provides a system-on-a-chip, where the system-on-a-chip includes a processor, configured to implement the functions of the network device in the methods of the foregoing aspects. In a possible design, the chip system further includes a memory, configured to store program instructions and/or data. The system-on-a-chip may consist of chips, or may include chips and other discrete devices.

In an eleventh aspect, the present application provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is run, the methods performed by the terminal device in the above aspects are realized.

In a twelfth aspect, the present application provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed, the method performed by the network device in the above aspects is implemented.

In a thirteenth aspect, a communication system is provided, and the communication system includes the network device and the terminal device mentioned in any one of the above aspects.

Description of drawings

FIG. 1 is a schematic diagram of a possible communication architecture provided by the present application;

FIG. 2 is a schematic flow chart of the communication method provided by the present application;

FIG. 3 is a schematic diagram of the hardware structure of the network device and the terminal device provided by the present application;

Figure 4 is a schematic diagram of a possible device provided by the present application;

Figure 5 is a schematic diagram of a possible device provided by the present application;

FIG. 6 is a schematic structural diagram of a possible communication device provided by the present application;

Detailed ways

The technical solutions in the embodiments of the present application can be applied to various communication systems. For example, a long term evolution (long term evolution, LTE) system, a fifth generation (5th generation, 5G) mobile communication system, and a future mobile communication system.

As shown in FIG. 1 , it is a schematic diagram of a possible network architecture applicable to the embodiment of the present application, including a terminal device 110 and an access network device 120 , and may also include a core network device 130 optionally. The terminal device 110 and the access network device 120 can communicate through the Uu air interface, and the Uu air interface can be understood as a universal interface between the terminal device 110 and the access network device 120 (universal UE to network interface). The transmission of the Uu air interface includes uplink transmission and downlink transmission.

Exemplarily, uplink transmission means that the terminal device 110 sends an uplink signal to the access network device 120 . Wherein, the uplink signal may include one or more of uplink data, uplink control information, or reference signal (Reference Signal, RS). A channel used to transmit an uplink signal is called an uplink channel, and the uplink channel may be a PUSCH or a physical uplink control channel (physical uplink control channel, PUCCH). The PUSCH is used to carry uplink data, and the uplink data may also be referred to as uplink data information. PUSCH can also be used to carry uplink control information. The PUCCH is used to carry uplink control information (uplink control information, UCI) fed back by the terminal equipment. The UCI may include one or more of channel state information (channel state information, CSI), acknowledgment (acknowledgment, ACK), negative acknowledgment (negative acknowledgment, NACK), or scheduling request (scheduling request, SR).

Taking the fifth generation (Fifth generation, 5G) communication system as an example, the core network device 130 includes: an access and mobility management function (access and mobility management function, AMF), a session management function (session management function, SMF), or a user plane function (user plane function, UPF), etc., the access network device 120 is a device with a wireless transceiver function, and is used to communicate with the terminal device 110 . The access network equipment includes but is not limited to a base station (BTS, Node B, eNodeB/eNB, or gNodeB/gNB), a transmission reception point (TRP), a base station in the subsequent evolution of 3GPP, and an access node in a WiFi system , wireless relay nodes, wireless backhaul nodes, etc. The base station may be: a macro base station, a micro base station, a pico base station, a small station, a relay station, and the like. Multiple base stations may support the aforementioned networks of the same access technology, or may support the aforementioned networks of different access technologies. A base station may contain one or more co-sited or non-co-sited transmission and reception points. In the following embodiments, the aforementioned access network devices and core network devices are collectively referred to as network devices relative to terminal devices.

Some nouns or terms used in this application are explained below, and the nouns or terms are also part of the content of the invention.

1. Terminal equipment

A terminal device may be referred to as a terminal for short, and is also called a user equipment (user equipment, UE), which is a device with a wireless transceiver function. Terminal equipment can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; it can also be deployed on water (such as ships, etc.); it can also be deployed in the air (such as aircraft, drones, balloons and satellites, etc.). The terminal device can be a mobile phone, a car, a tablet computer, a smart speaker, a detector, a gas station sensor, a computer with a wireless transceiver function, a virtual reality terminal device, an augmented reality terminal device, a wireless terminal device in industrial control, an unmanned Wireless terminal devices in driving, wireless terminal devices in telemedicine, wireless terminal devices in smart grids, wireless terminal devices in transportation safety, wireless terminal devices in smart cities, or wireless terminal devices in smart homes, etc. Terminal equipment can also be fixed or mobile. The embodiment of the present application does not limit this.

In the embodiment of the present application, the device for realizing the function of the terminal may be a terminal device; it may also be a device capable of supporting the terminal device to realize the function, such as a chip system, and the device may be installed in the terminal device. In the embodiment of the present application, the system-on-a-chip may be composed of chips, or may include chips and other discrete devices. In the technical solution provided by the embodiment of the present application, the technical solution provided by the embodiment of the present application is described by taking the terminal device as an example for realizing the function of the terminal device.

2. Network equipment

The network device may be an access network device, and the access network device may also be called a radio access network (radio access network, RAN) device or a base station, and is a device that provides a wireless communication function for a terminal device. Access network devices include, but are not limited to: 5G next-generation node B (generation nodeB, gNB), evolved node B (evolved node B, eNB), baseband unit (baseband unit, BBU), transceiver point (transmitting and receiving point (TRP), transmitting point (transmitting point, TP), an access network device in a future mobile communication system or an access point in a WiFi system, etc. The access network device may also be a wireless controller, a centralized unit (centralized unit, CU), and/or a distributed unit (distributed unit, DU) in a cloud radio access network (cloud radio access network, CRAN) scenario, or a network The device may be a relay station, a vehicle-mounted device, and a network device in a future evolved PLMN network.

A terminal device can communicate with multiple access network devices of different technologies, for example, a terminal device can communicate with an access network device supporting long term evolution (LTE), and can also communicate with an access network device supporting 5G , and can also communicate with access network devices supporting LTE and access network devices supporting 5G at the same time. The embodiment of this application is not limited.

In the embodiment of the present application, the device for realizing the function of the network device may be a network device; it may also be a device capable of supporting the network device to realize the function, such as a chip system, and the device may be installed in the network device. In the technical solution provided by the embodiment of the present application, the technical solution provided by the embodiment of the present application is described by taking the network device as an example for realizing the function of the network device.

3. Uplink (UL) communication and downlink (DL) communication

In the wireless communication system, according to the different types of sending nodes and receiving nodes, communication can be divided into different types. Generally, sending information from a network device to a terminal device is called downlink (DL) communication, and sending information from a terminal device to a network device is called uplink (UL) communication. In the fourth generation (4G) and 5G wireless communication systems - the new radio access technology (NR) system, the uplink communication can obtain the channel status through the sounding reference signal (SRS) Information (Channel state information, CSI) measurement, downlink communication can obtain channel state information through a channel state information reference signal (CSI-reference signal, CSI-RS).

4. Time-frequency resource granularity

The time-frequency resource may also be referred to as resource for short, and the time-frequency resource granularity may also be referred to as resource granularity for short. In the NR system, the resource granularity of uplink scheduling supports two types, or in other words, there are two types of time-frequency resource allocation in NR, which are resource group (resource block group, RBG)-based allocation types (also known as resource allocation 0 , resource allocation 0,) and resource block (resource block, RB)-based allocation type (also known as resource allocation 1, resource allocation 1). Each RB includes 12 resource elements (resource element, RE) in the frequency domain, that is, 12 subcarriers. Each RBG includes one or more RBs, and the number of RBs included in each RBG is also referred to as the size of the RBG. In this application, the size of each RBG may be related to a bandwidth part (Bandwidth Part, BWP). For example, when the number of RBs included in the bandwidth part BWP is different, the number of RBs included in each RBG is also different. Optionally, the size of each RBG may not be related to the BWP, and the size of each RBG may be indicated by high-layer signaling.

Five, sub-band

One subband includes one or more RBs in the frequency domain, or one subband may include one or more RBGs in the frequency domain. Since each RBG also includes multiple RBs, the size of the subband may be the same as or different from that of the RBG. For example, assuming that a bandwidth part BWP includes 10 RBs, and two consecutive RBs are divided into subbands, they can be divided into 5 subbands. Optionally, the division of the subbands may be based on the scheduling bandwidth, and the scheduling bandwidth is less than or equal to the size of the bandwidth part BWP. The scheduling bandwidth is the bandwidth corresponding to the actual frequency domain resource occupied by the terminal device sending the PUSCH at a certain moment (for example, a certain time slot (slot)). A subband in the embodiment of the present invention may be an RBG occupied by the PUSCH, or may be an RB occupied by the PUSCH.

6. Frequency selective gain and beamforming gain

Frequency selection gain means that the network device calculates the priority of each subband according to the Channel Quality Indicator (CQI) or SINR of each subband, and schedules each subband according to the subband of each terminal device. Scheduling is performed according to the priority of each terminal device, so that each terminal device performs signal transmission on the sub-band with the best channel quality.

For beamforming gain, the terminal device weights the uplink signal to form a narrow beam aimed at the network device, or understood as a directional beam, which directs energy to the target network device, which is beneficial to improve the received signal strength.

7. Channel reciprocity

Generally, when a terminal device can directly derive uplink channel information from downlink channel information, or a network device can directly derive downlink channel information from uplink channel information, it can be considered that the communication system has the feature of channel reciprocity.

8. Codebook

One codebook consists of multiple precoding matrices. Taking the transmit antenna port of the terminal device as an example with 2 antenna ports, Table 1 and Table 2 give examples of the codebook when the terminal device transmits one stream and two streams, where each precoding matrix in the codebook corresponds to an index value, Or call it TPMI index.

Table 1

Table 1 is an example of the codebook when the transmit antenna port of the terminal device is 2 and the rank is 1. In Table 1, there are six kinds of precoding matrices, and the corresponding TPMI index values are 0 to 5 respectively.

Table 2

Table 2 shows the codebook when the terminal transmit antenna port is 2 and the rank is 2. There are three kinds of precoding matrices, and the corresponding TPMI index values are 0 to 2 respectively.

Wherein, in Table 1 and Table 2, W is a precoding matrix or vector. After the precoding matrix is determined, the terminal device maps the PUSCH data to each antenna port through the precoding matrix. For example, the terminal device can map the PUSCH data to the antenna port through the process of formula (1-1):

y ^(υ-1) (i) is the data before precoding, v is the layer index, is the precoded data, that is, the data corresponding to the antenna port p _ρ-1 . For single-layer transmission with two antennas, that is, p _ρ-1 is 2 and v is 1. If it is single-antenna transmission, W defaults to 1, which is equivalent to no precoding.

By measuring the SRS, the network device can obtain the channel state information of the uplink channel and select a precoding matrix. For example, it may be the most suitable precoding matrix for the current uplink channel, and send the TPMI of the precoding matrix to the terminal device. In an example of selecting a precoding matrix, the network device may select an optimal precoding matrix for uplink PUSCH transmission based on a capacity maximization criterion. After the network device determines the TPMI, it needs to send the TPMI to the terminal device before the terminal device sends the uplink data, so as to inform the terminal device which precoding matrix to use to send the uplink data. For example, taking the codebook of the transmission layer as an example, assuming that the terminal device is k, in the channel from the terminal device to the network device, the power on the mth frequency domain resource is p _k,m , and the mth frequency domain resource The signal to interference plus noise ratio (Signal to Interference plus Noise Ratio, SINR) on is γ _k,m . The channel on the mth frequency domain resource of the terminal device k is an H _k,m matrix. SINR is defined as:

Where g _k,m are weight coefficients on the receiving antenna of the network device, and w _k is the precoding matrix of the terminal device k. For example, using the matched filtering method to solve, g _k,m =(H _k,m w _k ) ^H can be obtained, I _k,m is the interference covariance matrix between cells, and σ ² is the noise power. An alternative selection criterion is to select the precoding matrix by the capacity maximization criterion:

Where Φ is a set of precoding matrices. When the same precoding matrix is used on each frequency domain resource of the terminal device, w _k has nothing to do with the frequency domain resource index.

In the embodiment of the present invention, in the codebook-based transmission mode, the network device and the terminal device can use the same codebook. Precoding matrices in different codebooks may also be different. In the embodiment of the present invention, some existing candidate codebooks may be used, and in addition, some new codebooks may also be used. For example, a codebook generated based on structured antenna grouping or a codebook generated based on discrete Fourier transform (DFT).

In one embodiment, a codebook generated based on structured antenna grouping is used. This embodiment may divide the codebook into subsets of precoding matrices based on phase. Furthermore, in the codebook generated based on structured antenna grouping, since each precoding matrix corresponds to one phase value or multiple phase values, the embodiment of the present invention divides the precoding matrix included in the codebook based on the phase corresponding to the precoding matrix The coding matrix is divided into various subsets to form multiple precoding matrix subsets. For example, for a codebook with 8 antenna ports, if A ₁ is a precoding matrix with 8 antenna ports and a rank of 1, the codebook is generated as follows:

Among them, θ, ε, δ, and φ are different phases. Since each phase can have multiple values, this phase can also be understood as a phase variable. B, D, E, F∈{exp(jθ)}, p is the number of rows of A ₁ matrix, q is the number of columns, N ₁ , N ₁ , N ₃ , and N ₄ are quantization factors, which can control the accuracy of the codebook. The larger the value of the quantization factor, the more optional phase More, the accuracy of the precoding matrix in the codebook is also higher. The quantization factor can be configured through radio resource control (Radio Resource Control, RRC) signaling, and can also be configured through a media access control control element (Media Access Control Control Element, MAC CE). For the case of non-8-antenna ports, for example, 2-antenna or 4-antenna ports, this method is still applicable, except that the magnitude of the phase may be different.

For the codebook generated based on DFT, taking the case of 8 antenna ports as an example, the structure of the precoding matrix of this method can be expressed as:

Where v _{t, m} is the precoding matrix formed in the same polarization direction, which is composed of DFT matrix, and θ is the phase offset in different polarization directions. This method is also applicable to cases where the number of antenna ports is not 8, for example, codebook generation when the number of antenna ports is 2, 4, or 16.

Since the precoding matrix in the codebook is divided into multiple precoding matrix subsets, in this case, the codebook can also be understood as a codebook set.

The selection of the precoding matrix will affect the demodulation performance of the PUSCH, and an inappropriate precoding matrix will lead to a decrease in the demodulation performance of the PUSCH. Therefore, the larger the codebook, the greater the number of precoding matrices in the codebook, and the more precoding matrices to choose from. Therefore, the accuracy of the precoding matrix is also higher, but at this time the indication information indicating TPMI The signaling overhead is also greater.

For example, if the codebook includes 256 precoding matrices, 8 bits are required to indicate the precoding matrix index. Based on this situation, if indicated by the subband, assuming that there are M subbands, and each subband can select the precoding matrix in the codebook, 8*M bits are required to indicate a precoding matrix index corresponding to each subband, Assuming M=40, 320 bits are required. If the 320 bits are directly carried by DCI, on the one hand, the DCI occupies more control channel resources, which will cause congestion of the control channel and lower reliability; on the other hand, the number of bits carried by the DCI exceeds the DCI used for downlink scheduling. The size will increase the number of blind detection of terminal equipment.

At present, when designing the precoding matrix, only the bandwidth-based precoding matrix is considered, that is, the same precoding matrix is used on all scheduling resources allocated by the terminal equipment. This method is suitable for the situation where the channel in the frequency domain is relatively flat and the channel changes little. When the channel fluctuates greatly in the frequency domain, the bandwidth-based precoding matrix may not be able to match the channel change, which is not conducive to obtaining frequency selection gain and beamforming gain. In addition, when pairing multiple terminal devices, since different terminal devices can be paired on different frequency domain resource blocks, if a bandwidth-based precoding matrix is used, it is not conducive to suppressing interference between paired terminal devices.

In one embodiment of the present application, a communication method is provided for enabling an uplink sub-band level precoding matrix while reducing signaling overhead. Referring to Fig. 2, it is a flowchart of the method. In the following introduction, take this method applied to the schematic diagram of the network architecture shown in FIG. 1 as an example.

For ease of introduction, in the following, it is taken that the method is executed by a network device and a terminal device as an example. This is because the embodiment of the present application takes the network architecture shown in FIG. 1 as an example. Therefore, the network devices described below are, for example, access network devices in the network architecture shown in FIG. 1 , and the terminal devices described below may be terminal devices in the network architecture shown in FIG. 1 .

Referring to FIG. 2 , it is a schematic flowchart of a communication method provided in this application. The method mainly includes S21 to S25.

S21: The terminal device sends an SRS to the network device, and correspondingly, the network device receives the SRS sent by the terminal device.

Specifically, the terminal device sends an SRS to the network device on the SRS resource configured by the network device, and correspondingly, the network device receives the SRS on the SRS resource configured by it, measures an uplink channel, and obtains channel state information.

S22: The network device determines N precoding matrix subsets.

Specifically, the network device determines N precoding matrix subsets according to the state information of the uplink channel and the scheduling bandwidth obtained through SRS measurement. Wherein, the N precoding matrix subsets are one or more of the plurality of precoding matrix subsets divided by the first codebook, and among the N precoding matrix subsets, there is at least one precoding matrix subset including at least two precoding matrix subsets. encoding matrix. The N precoding matrix subsets determined by the network device may be N different precoding matrix subsets, or may include two or more identical precoding matrix subsets. For example, the network device determines five Precoding matrix subsets, where there are two precoding matrix subsets that are the same precoding matrix subset. This is because the scheduling bandwidth can include multiple subbands. When the network device determines the N precoding matrix subsets, it considers the channel state information on each subband and determines the precoding matrix subset based on each subband. When , there may be two or more subbands in the scheduling bandwidth applicable to the same precoding matrix subset.

The first codebook may be one of the existing candidate codebooks, a codebook generated based on structured antenna grouping, a codebook generated based on DFT transformation, or a codebook generated in other ways. Since the first codebook contains multiple precoding matrices, the first codebook can be divided into multiple precoding matrix subsets, and each precoding matrix subset contains several precoding matrices. Of course, there may also be one or more Only one precoding matrix is included in the subset of precoding matrices. When N is greater than 1, the multiple precoding matrices in the first codebook are divided into different precoding matrix subsets. The N precoding matrix subsets may include one or more precoding matrix subsets in the multiple precoding matrix subsets divided by the first codebook, and may also include All the precoding matrix subsets, at this time, can be understood as N precoding matrix subsets, that is, the first codebook itself. Since each precoding subset also includes one or more precoding matrices, at this time, if each precoding matrix subset is regarded as a codebook, the first codebook can be understood as a codebook set.

In an optional manner, the first codebook includes at least one first codebook parameter, and among the plurality of precoding matrix subsets divided by the first codebook, at least two different precoding matrix subsets correspond to the first codebook Different values of parameters, the codebook parameters include phase. Optionally, the multiple precoding matrices in the first codebook are divided into multiple precoding matrix subsets by phase. The phase may be a phase offset between antennas or antenna ports. Since each phase can correspond to different values, the phase can also be understood as a phase variable. For example, when the first codebook is a codebook generated based on structured antenna grouping, the codebook generated based on structured antenna grouping may have multiple phase variables. A precoding matrix subset may be constructed by fixing values of one or more phases and traversing values of one or more remaining phases. The value of each phase is determined based on the quantization factor, and the value of the quantization factor is the maximum number of selectable values for each phase. The quantization factor may be a predefined value, or may be indicated by indication information, and the indication information indicating the quantization factor may be carried in RRC signaling, or carried in MAC CE, or carried in RRC signaling and MAC CE. Based on this division method, the precoding matrix in the first codebook can be divided into multiple precoding matrix subsets. After the precoding matrix subset division is determined, in order to indicate different subsets, each subset needs to be The number of the subset can also be understood as the index of each precoding matrix subset. Different state values of one or more bits of an indication field may be used to indicate different precoding matrix subsets, and each state value represents a precoding matrix subset. For example, if the codebook generated based on structured antenna grouping has 4 phases, namely θ, ε, δ, φ, and the values of θ, ε, δ are fixed, by traversing the possible values of φ to construct a subset of precoding matrices, where each possible value of φ corresponds to a precoding matrix. Further, the quantization factors of phase θ, ε, δ, φ are N ₁ , N ₁ , N ₃ , N ₄ respectively, that is, θ, ε, δ, φ have N ₁ , N ₁ , N ₃ , N ₄ different values, and Table 3 shows a manner in which the first codebook is divided into multiple precoding matrix subsets.

table 3

In Table 3, there are four phase variables θ, ε, δ, φ, respectively the first phase to the fourth phase, and the values of the quantization factors N ₁ , N ₁ , N ₃ , N ₄ corresponding to each phase variable are equal to is 4, corresponding to 64 kinds of precoding matrix subsets. For each subset, the three phases are fixed values, and the different values of the remaining phase correspond to multiple precoding matrices in the subset. For example, the subset number 1, the first phase, the second phase, and the third phase are all fixed values, and the N ₄ values of the fourth phase correspond to the N ₄ precoding matrices in the precoding matrix subset numbered 1 . Optionally, for the 64 precoding matrix subsets, different precoding matrix subsets may be indicated by using different state values of a 6-bit indication field of the indication information.

When generating the codebook, in order to reduce overhead, there may be two phases that are equal. For example, for the above four phase variables, if two phase variables are equal, at this time, it is equivalent to only three phases. Or it can be understood that only three phases are variable at this time, that is, a precoding matrix subset can be determined only by phase values of three phases. For example, there are four phases θ, ε, δ, φ, which are the first phase to the fourth phase respectively. Take the second phase and the third phase as an example, that is, ε and δ are the same. At this time, only two phases need to be fixed. Phase values, and a precoding matrix subset can be constructed by traversing the value of the remaining phase. Table 4 shows an example in which the first codebook is divided into multiple precoding matrix subsets when there are 4 phases and two phases are equal.

Table 4

As shown in Table 4, the values of N ₁ , N ₁ , N ₃ , and N ₄ are all 4, and there are three variable phases θ, ε, δ, which are the first phase, the second phase and the fourth phase , at this time, it can be understood that the first phase is the same as the third phase, and it can also be understood that the second phase is the same as the third phase. For the 3 variable phases, it is only necessary to fix the values of 2 of the phase variables, and traverse the value of the remaining 1 phase to determine a precoding matrix in a subset of precoding matrices. For example, the subset number is 1, the first phase and the second phase are fixed, and the 4 different values of the fourth phase correspond to 4 precoding matrices in the precoding matrix subset, 3 phases, and the quantization factor of each phase is 4. There are 16 kinds of precoding matrix subsets in total. At this time, different status values of the 4-bit indication field can be used to indicate different precoding matrix subsets.

For example, there is only one variable phase, and the precoding matrix subset corresponding to this one phase can be expressed as the following table 5:

table 5

In Table 5, θ is the above-mentioned phase, and a precoding matrix subset can be constructed by traversing different values of θ.

For example, there are two variable phases, and a precoding matrix subset can be constructed by fixing the value of one phase and traversing the value of the other phase. Refer to Table 6 for a possible example:

Table 6

In Table 6, θ and ε are the first phase and the second phase respectively, the value of the first phase θ is fixed at θ _x , and a precoding matrix subset can be constructed by traversing different values of the second phase ε.

The above description of the phase and quantization factor is only exemplary, and the value of the phase and the magnitude of the quantization factor may also be in other forms, which are not limited in this application. At the same time, in the above example, a precoding matrix subset is constructed by traversing the value of one phase and fixing the value of the remaining phase. In practical applications, it is also possible to traverse two or more phase values and fix the remaining phase. The method of taking the phase value constructs a precoding matrix subset, which is not limited in this application.

In yet another optional manner, the first codebook contains L precoding matrices, each of the L precoding matrices corresponds to an index value of a precoding matrix, and the L precoding matrices Divided into K precoding matrix subsets, each precoding matrix subset contains one or more precoding matrices, and for each precoding matrix subset, the index value of the precoding matrix it contains satisfies The value of is the same, or the index value of the precoding matrix contained in it satisfies the same value of mod(j, K), where j is the index of the precoding matrix, is the floor function, is the upper integer function. For convenience of description, the following relational expression 1 is used to represent the index of the precoding matrix in each precoding matrix subset satisfying have the same value, and use relational expression 2 to represent that the index of the precoding matrix in each precoding matrix subset satisfies the value of mod(j, K) being the same.

Example 1, when L is equal to 28 and K is equal to 4, the first codebook contains 28 precoding matrices, the index values of the precoding matrices corresponding to the 28 precoding matrices are 0 to 27, and are divided into 4 precoding matrices Encoding a subset of matrices. When the index value of the precoding matrix in each precoding matrix subset satisfies relational expression 1, optionally, index value 0 to index value 6, index value 7 to index value 13, index value 14 to 20, index value 21 to The precoding matrix with an index value of 27 belongs to the first to fourth precoding matrix subsets: for the first precoding matrix subset, the index value of the precoding matrix contained in it is substituted into the value of the first relation. 0; for the second precoding matrix subset, the index value of the precoding matrix contained in it is substituted into relation 1, and the value is 1; for the third precoding matrix subset, the index of the precoding matrix contained in it is The value substituted into relational expression 1 is 2; for the fourth precoding matrix subset, the index value of the precoding matrix contained in it is substituted into relational expression 1, and the value is 3.

Example 2, when L is equal to 28 and K is equal to 4, the first codebook contains 28 precoding matrices, the index values of the precoding matrices corresponding to the 28 precoding matrices are 0 to 27, and are divided into 4 precoding matrices Encoding a subset of matrices. When the index values of the precoding matrices in each precoding matrix subset satisfy the same values substituted into relational expression 2, it can be understood that several precoding matrices with index values at equal intervals form a precoding matrix subset. Precoding matrices with index values of 0, 4, 8, 12, 16, 20, and 24 belong to the same precoding matrix subset, or called the first precoding matrix subset; index values are 1, 5, 9, and 13 , 17, 21, and 25 precoding matrices belong to the same precoding matrix subset, or called the second precoding matrix subset; precoding matrices with index values of 2, 6, 10, 14, 18, 22, and 26 Belong to the same precoding matrix subset, or called the third precoding matrix subset; precoding matrices with index values 3, 7, 11, 15, 19, 23, 27 belong to the same precoding matrix subset, or called It is the fourth precoding matrix subset.

Relational expression 1 can also be expressed in another way, that is, when the first codebook is divided into multiple precoding matrix subsets, it can be divided by multiple precoding matrices with adjacent index values, that is, each The precoding matrix subset includes multiple precoding matrices with adjacent index values. Relational expression 2 can also be expressed in another way, that is, when the first codebook is divided into multiple precoding matrix subsets, the multiple precoding matrices can be divided by index values at equal intervals, that is, Each precoding matrix subset includes multiple precoding matrices with index values at equal intervals.

It should be noted that when L is divisible by K, the number of precoding matrices contained in different precoding matrix subsets in the first codebook is the same; when L cannot be divisible by K, the different The number of precoding matrices included in the precoding matrix subset may be different, and further, there may be only one precoding matrix in a certain precoding matrix subset, which is not limited in this application.

In another optional manner, if the first codebook is a codebook generated based on DFT, at least two different precoding matrix subsets in the plurality of precoding matrix subsets in the first codebook correspond to DFT transformation matrix different column vectors, that is, multiple precoding matrices in the first codebook are divided into multiple precoding matrix subsets by using at least one column vector in the DFT transformation matrix. The column vectors in the DFT transformation matrices corresponding to different precoding matrix subsets are different.

For example, for a codebook generated based on DFT, the matrix generated by this method can be expressed as: in, u _m can be understood as a column in the DFT matrix, where N ₁ and N ₂ are the number of antenna ports in the horizontal and vertical dimensions, respectively, and O ₁ and O ₂ are the oversampling factors in the horizontal and vertical dimensions, respectively. In this codebook generation method, it mainly includes the selected vertical position and beam in the horizontal dimension, as well as the phase offset in different polarization directions. When constructing the precoding matrix subset, it is necessary to determine the values of t and m in v _{t, m} Index and phase θ, where each value of t corresponds to a beam in the horizontal direction, and each value of m corresponds to a beam in the vertical direction.

For the precoding matrix subset division based on the codebook generated by DFT, an optional precoding matrix subset construction method can be expressed as: Given a certain t and m, θ is variable. For example, when t and m take 1, θ takes Another optional method for constructing a precoding matrix subset can be expressed as: grouping the values of t and m, and each group of t, m and θ can form a precoding matrix set. For example, the beams corresponding to indexes t, t+O ₁ , m, m+O ₂ are divided into a group, and the indexes are t+1, t+1+O ₁ , m+1, m+1+O ₂ The corresponding beams are divided into one group, and so on. In addition, the grouping method in this example assumes that m>1, t>1, O ₁ >1, O ₂ >1. When the above parameters take other values, the grouping method may be different.

S23: The network device sends downlink control information to the terminal device, where the downlink control information includes indexes of N precoding matrix subsets. Correspondingly, the terminal device receives downlink control information.

Specifically, the downlink control information includes indexes of N precoding matrix subsets. Optionally, the downlink control information may further include resource indication information of a first downlink reference signal, and the first downlink reference signal may be channel state Reference signal CSI-RS. The indexes of the N precoding matrix subsets may all be indexes of different precoding matrix subsets. For example, the downlink control information indicates the indexes of 5 precoding matrix subsets, and the 5 index values are 1 and 2 respectively. , 3, 4, 5. The same index of the precoding matrix subset may also exist, that is, the same index value may exist in the indexes of the N precoding matrix subsets. For example, the downlink control information indicates the indexes of the five precoding matrix subsets, and the index values can be 1, 1, 2, 3, and 4 respectively, that is, at this time, there are two precoding matrixes in the five precoding matrix subsets The subsets are the same precoding matrix subsets.

S24: The terminal device determines at least N precoding matrices in the N precoding matrix subsets.

Specifically, the terminal device receives the downlink control information, and determines at least N precoding matrices according to the indexes of the N precoding matrix subsets indicated by the downlink control information. When the downlink control information also includes resource indication information of the first downlink reference signal, the terminal device determines at least N precoding matrix subset indexes and the first reference signal on the resource indication information indicated by the downlink control information. precoding matrix. The resource corresponding to the resource indication information of the first reference signal may be a time-domain resource, a frequency-domain resource or a time-frequency resource.

S25: The terminal device sends uplink signals based on at least N precoding matrices, where N is a positive integer.

Specifically, the terminal device determines at least N precoding matrices, and sends uplink signals based on the at least N precoding matrices. Optionally, the uplink signal is a physical shared uplink channel PUSCH, and the PUSCH occupies multiple subbands. For multiple subbands, each subband includes at least one RB or RBG, and the bandwidth of each subband is smaller than the bandwidth part BWP. When each subband includes an RBG, the size of each subband is the same as the size of the RBG. At this time, since the number of RBs contained in each BBG is related to the bandwidth part BWP, it can also be understood that the size of each subband is related to the bandwidth part BWP related. When each sub-band includes multiple RBGs, the number of RBGs included in each sub-band may be indicated by indication information. At this time, it can also be understood that the size of each sub-band is independently configured and has nothing to do with the size of the bandwidth part WBP. The indication information may be carried in DCI, in RRC signaling, or in MAC CE, or in RRC signaling and MCA CE, which is not limited in this application.

If the PUSCH occupies M subbands, each subband corresponds to a precoding matrix, and the precoding matrices on different subbands may be the same or different. Further, the precoding matrices on different subbands may belong to the same The precoding matrix subsets may also belong to different precoding matrix subsets, that is, M is a positive integer greater than or equal to N.

Example 1, the number of precoding matrix subsets indicated by the downlink control information is N, and the N precoding matrix subsets are different. The terminal device sends PUSCH to occupy M subbands, and M is equal to N. At this time, the precoding matrices corresponding to different subbands belong to different precoding matrix subsets, that is, M precoding matrix subsets correspond to M subbands one-to-one Further, when the precoding matrices in the M precoding matrix subsets are different, the M different precoding matrices determined by the terminal device correspond to the M subbands one-to-one.

Example 2, the number of precoding matrix subsets indicated by the downlink control information is N, where the N precoding matrix subsets include n different precoding matrix subsets in total, and N is greater than n. The terminal device sends PUSCH to occupy M subbands, and M is greater than n. At this time, among the M subbands, there are at least two subbands corresponding to the same precoding matrix subsets. Further, the precoding matrices corresponding to the at least two subbands can be The same precoding matrices in the same precoding matrix subset may also be different precoding matrices.

Example 3, the number of precoding matrix subsets indicated by the downlink control information is 1, that is, N is equal to 1, and the terminal device sends PUSCH to occupy M subbands, and M is greater than N. At this time, M subbands correspond to one precoding matrix sub-set Further, the precoding matrices corresponding to the M subbands may all be different, or there may be at least two subbands corresponding to the same precoding matrix.

The correspondence between the above N precoding matrix subsets and multiple subbands is only exemplary. In this application, for multiple subbands, based on the principle of capacity maximization, each subband can correspond to one of the N precoding matrix subsets. For any precoding matrix in any precoding matrix subset, the precoding matrices corresponding to different subbands can be the same or different, and the precoding matrices on different subbands can belong to the same precoding matrix subset or can belong to Different subsets of precoding matrices. It avoids that when the terminal equipment can only use one precoding matrix to send uplink signals on the M subbands, the one precoding matrix may not be able to match the decrease in frequency selection gain and beamforming gain caused by channel changes. At the same time, the network device indicates part of the precoding matrix information to the terminal device, which can reduce the signaling overhead of subband-level precoding, reduce the complexity of terminal device detection, and improve transmission performance.

In addition, in an embodiment, the above-mentioned downlink control information is also used to indicate the index of at least one precoding matrix, and the precoding matrix corresponding to the at least one precoding matrix index is a precoding matrix that the network device does not expect the terminal device to use, or it is understood that The precoding matrix that the network device expects the terminal device to avoid using. Optionally, the precoding matrix corresponding to the at least one precoding matrix index may be a precoding matrix of an interference channel, and further optionally, the interference channel may be an interference channel of the bandwidth part BWP. For example, the network device indicates the precoding matrix of the interference channel to the terminal device, and the terminal device determines at least N precoding matrices among the N precoding matrix subsets according to the downlink control information, considering the precoding matrix of the interference channel, the terminal device will Among the N precoding matrix subsets, select the precoding matrix with the lowest possible correlation with the precoding matrix of the interference channel to avoid the influence of the interference channel, so that the terminal device can better transmit uplink signals and improve communication quality .

It should be noted that this application uses the downlink control information as an example to indicate information. In practical applications, the content indicated by the downlink control information in this application can be carried in DCI, and can also be carried in RRC signaling or MAC CE. Alternatively, the content indicated by the downlink control information requested by itself may also be jointly indicated by RRC signaling and MAC CE, which is not limited in this application.

FIG. 3 is a schematic diagram of the hardware structure of the network device and the terminal device provided by the present application.

The terminal device 130 includes at least one processor 301 , at least one memory 302 , and at least one transceiver 303 . Optionally, the terminal device 130 may further include an output device 304 and an input device 305 .

The processor 301, the memory 302 and the transceiver 303 are connected through a bus. The processor 301 may be a general-purpose central processing unit (Central Processing Unit, CPU), a microprocessor, an application-specific integrated circuit (Application-Specific Integrated Circuit, ASIC), or one or more devices used to control the execution of the program program of this application. integrated circuit. The processor 301 may also include multiple CPUs, and the processor 301 may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, or processing cores for processing data such as computer program instructions.

The memory 302 may be a read-only memory (Read-Only Memory, ROM) or other types of static storage devices that can store static information and instructions, a random access memory (Random Access Memory, RAM) or other types that can store information and instructions It can also be an electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, EEPROM), a compact disc (Compact Disc Read-Only Memory, CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or can be used to carry or store desired program code in the form of instructions or data structures and can be programmed by a computer Any other medium accessed, but not limited to. The memory 302 may exist independently, and is connected to the processor 301 through a bus. The memory 302 can also be integrated with the processor 301 . Wherein, the memory 302 is used to store the application program code for executing the solution of the present application, and the execution is controlled by the processor 301 . The processor 301 is configured to execute the computer program code stored in the memory 302, so as to implement the coordinated transmission method described in the embodiment of the present application.

The transceiver 303 can use any device such as a transceiver for communicating with other devices or communication networks, such as Ethernet, radio access network (Radio Access Network, RAN), wireless local area network (Wireless Local Area Networks, WLAN), etc. . The transceiver 303 includes a transmitter Tx and a receiver Rx.

Output device 304 is in communication with processor 301 and can display information in a variety of ways. For example, the output device 304 may be a liquid crystal display (Liquid Crystal Display, LCD), a light emitting diode (Light Emitting Diode, LED) display device, a cathode ray tube (Cathode Ray Tube, CRT) display device, or a projector (projector) wait. The input device 305 communicates with the processor 301 and can receive user input in various ways. For example, the input device 305 may be a mouse, a keyboard, a touch screen device, or a sensing device, among others.

The network device 120 includes at least one processor 201 , at least one memory 202 , at least one transceiver 203 and at least one network interface 204 . The processor 201, the memory 202, the transceiver 203 and the network interface 204 are connected through a bus. Among them, the network interface 204 is used to connect with the core network equipment through a link (for example, S1 interface), or connect with the network interface of other access network equipment (not shown in the figure) through a wired or wireless link (for example, X2 interface). ), which is not specifically limited in this embodiment of the present application. In addition, for related descriptions of the processor 201, the memory 202, and the transceiver 203, reference may be made to the description of the processor 301, the memory 302, and the transceiver 303 in the terminal device 130, and details are not repeated here.

FIG. 4 is a schematic structural diagram of a possible communication device provided by the present application. The communication device 400 can implement the functions of the network device in the above method embodiments, and therefore can also realize the beneficial effects of the above method embodiments. In the embodiment of the present application, the communication device may be the access network device 120 shown in FIG. 1 , or may be a module (such as a chip) applied to the access network device. The communication device 400 includes a transceiver unit 401 and a processing unit 402 .

Specifically, the processing unit 402 is configured to determine N precoding matrix subsets, the N precoding matrix subsets are one or more of the multiple precoding matrix subsets divided by the first codebook, and the N precoding matrix subsets In the set, there is at least one precoding matrix subset including at least two precoding matrices. The transceiver unit 401 is configured to send downlink control information to the terminal device, where the downlink control information includes indexes of N precoding matrix subsets. Optionally, the transceiver unit 401 is also configured to receive an uplink signal sent by a terminal device, the uplink signal occupies M subbands, the downlink control information also includes indication information of the M subbands, and the M subbands correspond to N precoding matrices. For a specific description, reference may be made to the description in the foregoing method embodiments.

FIG. 5 is a schematic structural diagram of a possible communication device provided by an embodiment of the present application. The communication device 500 can realize the functions of the terminal device in the above method embodiments, and therefore can also realize the beneficial effects of the above method embodiments. In the embodiment of the present application, the communication device may be the terminal device 110 shown in FIG. 1 , or may be a module (such as a chip) applied to the terminal device. The communication device 500 includes a transceiver module 501 and a processing module 502 .

Specifically, the transceiver module 501 is configured to receive downlink control information from the network device, the downlink control information includes indexes of N precoding matrix subsets, and the N precoding matrix subsets are multiple precoding matrix partitions divided by the first codebook. One or more of the coding matrix subsets, among the N precoding matrix subsets, at least one precoding matrix subset includes at least two precoding matrices. The processing module 502 is configured to determine at least N precoding matrices among the N precoding matrix subsets. The transceiver module 501 is also configured to send uplink signals to network devices based on at least N precoding matrices.

Optionally, the downlink control information further includes resource indication information indicating the first downlink reference signal, and the terminal device determines at least N precoding matrices.

The uplink signal is PUSCH, and the PUSCH occupies M subbands. The M subbands correspond to N precoding matrix subsets. Among the M subbands, each subband corresponds to a precoding matrix, and different subbands correspond to different precoding matrices. The matrix subset can correspond to different precoding matrices in the same precoding matrix subset, and can also correspond to the same precoding matrix in the same precoding matrix subset:

Example 1, M is equal to N, M subbands correspond to N different precoding matrix subsets one-to-one, and M subbands correspond to N precoding matrices in the N precoding matrix subsets one to one.

Example 2, M is greater than N, and M subbands correspond to N different precoding subsets, that is, there are two or more subbands corresponding to the same precoding subset. At this time, the precoding matrices corresponding to two or more subbands corresponding to the same precoding matrix subset may be the same or different.

Example 3, N is equal to 1, and M subbands are in one-to-one correspondence with M precoding matrices in a precoding subset. The M precoding matrices can be M different precoding matrices, or there can be two or two The same precoding matrix as above.

For a more detailed description of the above-mentioned transceiver unit 401, transceiver module 501, processing unit 402, and processing module 502, reference may be made to relevant descriptions in the above-mentioned method embodiments, and no further description is given here. The hardware element of the above-mentioned transceiver unit 401 or the transceiver module 501 may be a transceiver, and the hardware element of the processing unit 402 or the processing module 502 may be a processor.

FIG. 6 is a schematic structural diagram of a possible communication device provided by the present application. The communication device 600 includes a processor 601 and an interface circuit 602 . The processor 601 and the interface circuit 602 may be connected through a bus 603 . It can be understood that the interface circuit 602 is a transceiver or an input/output interface. Optionally, the communication device 600 may further include a memory for storing instructions executed by the processor 601 or storing input data required by the processor 601 to execute the instructions or storing data generated after the processor 601 executes the instructions.

When the communication device 600 is used to implement the methods in the above method embodiments, the processor 601 is used to execute the functions of the processing unit 402 or the processing module 502, and the interface circuit 602 is used to execute the functions of the transceiver unit 401 or the transceiver module 501.

When the communication device 600 is a chip applied to a terminal device, the terminal device chip implements the functions of the terminal device in the above method embodiment. The terminal device chip receives information from other modules in the terminal device (such as radio frequency modules or antennas), and the information is sent to the terminal device by the network device; or, the terminal device chip sends information to other modules in the terminal device (such as radio frequency modules or antenna) to send information, which is sent by the terminal device to the network device.

When the communication device 600 is a chip applied to a network device, the network device chip implements the functions of the network device in the above method embodiments. The network device chip receives information from other modules in the network device (such as radio frequency modules or antennas), and the information is sent to the network device by the terminal device; or, the network device chip sends information to other modules in the network device (such as radio frequency modules or antenna) to send information, which is sent by the network device to the terminal device.

It can be understood that the processor in the embodiments of the present application may be a central processing unit (central processing unit, CPU), and may also be other general-purpose processors, digital signal processors (digital signal processor, DSP), application specific integrated circuits (application specific integrated circuit, ASIC), field programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. A general-purpose processor can be a microprocessor, or any conventional processor.

In this embodiment of the present application, a terminal device or a network device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (central processing unit, CPU), a memory management unit (memory management unit, MMU), and memory (also called main memory). The operating system may be any one or more computer operating systems that implement business processing through processes, for example, Linux operating system, Unix operating system, Android operating system, iOS operating system, or windows operating system. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. Moreover, the embodiment of the present application does not specifically limit the specific structure of the execution subject of the method provided by the embodiment of the present application, as long as the program that records the code of the method provided by the embodiment of the present application can be run to provide the method according to the embodiment of the present application. For example, the execution subject of the method provided by the embodiment of the present application may be a terminal device or a network device, or a functional module in a terminal device or a network device that can call a program and execute the program.

Additionally, various aspects or features of the present application may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used in this application covers a computer program accessible from any computer readable device, carrier or media. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, or tapes, etc.), optical disks (e.g., compact discs (compact discs, CDs), digital versatile discs (digital versatile discs, DVDs), etc.), smart cards and flash memory devices (eg, erasable programmable read-only memory (EPROM), card, stick or key drives, etc.). Additionally, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing and/or carrying instructions and/or data.

It should be noted that the memory of the systems and methods described herein is intended to include, but not be limited to, these and any other suitable types of memory.

The present application also provides a computer program product, the computer program product includes: computer program code, when the computer program code is run on the computer, the computer is made to execute any method described above by the terminal device or the network device Methods.

The present application also provides a computer-readable storage medium, the computer-readable storage medium stores program codes, and when the program codes are run on a computer, the computer is made to execute the method performed by the network device or the terminal device in the foregoing method embodiments. Methods.

The present application also provides a system, which includes at least one terminal device and at least one network device.

In the above embodiments, all or part of them may be implemented by software, hardware, firmware or any combination thereof. When implemented using software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on the computer, the processes or functions according to the embodiments of the present application will be generated in whole or in part. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website, computer, server or data center Transmission to another website site, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device such as a server or a data center integrated with one or more available media. The available medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a high-density digital video disc (digital video disc, DVD)), or a semiconductor medium (for example, a solid state disk (solid state disc, SSD)) etc.

The terms "component", "module", "system" and the like are used in this specification to refer to a computer-related entity, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, or a computer. By way of illustration, both an application running on a computing device and the computing device can be components. One or more components can reside within a process or thread of execution and a component can be localized on one computer or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. A component may, for example, pass a local or remote processes to communicate.

It should be understood that references to "an embodiment" throughout this specification mean that a particular feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the present application. Thus, the various embodiments throughout the specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

It should be understood that in this embodiment of the application, the numbers "first", "second"... are only used to distinguish different objects, such as different network devices, and do not limit the scope of the embodiment of this application. Examples are not limited to this.

It should also be understood that in this application, "when", "if" and "if" all mean that the network element will make corresponding processing under certain objective circumstances, and it is not a limited time, and it does not require the network element to There must be an action of judgment during implementation, and it does not mean that there are other restrictions.

It should also be understood that in this application, "at least one" means one or more, and "multiple" means two or more.

It should also be understood that in each embodiment of the present application, "A corresponds to B" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean determining B only according to A, and B may also be determined according to A and/or other information.

It should also be understood that the term "and/or" in this article is only an association relationship describing associated objects, indicating that there may be three relationships, for example, A and/or B may indicate: A exists alone, and A and B exist simultaneously. B, there are three situations of B alone. In addition, the character "/" in this article generally indicates that the contextual objects are an "or" relationship.

The meaning of the expression similar to "the item includes one or more of the following: A, B, and C" appearing in this application, unless otherwise specified, usually means that the item can be any of the following: A; B ;C;A and B;A and C;B and C;A,B and C;A and A;A,A and A;A,A and B;A,A and C,A,B and B;A , C and C; B and B, B, B and B, B, B and C, C and C; C, C and C, and other combinations of A, B and C. The above is an example of the three elements of A, B and C to illustrate the optional items of the project. When the expression is "the project includes at least one of the following: A, B, ..., and X", it is in the expression When there are more elements, then the applicable entries for this item can also be obtained according to the aforementioned rules.

It can be understood that in the embodiment of the present application, the terminal device and/or the network device may perform some or all of the steps in the embodiment of the present application, these steps or operations are only examples, and the embodiment of the present application may also perform other operations or various Operational deformation. In addition, each step may be performed in a different order presented in the embodiment of the present application, and it may not be necessary to perform all operations in the embodiment of the present application.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.

If the functions described above are realized in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory ROM, random access memory RAM, magnetic disk or optical disk, and other media capable of storing program codes.

The above is only a specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application. Should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims (34)

1. A method of communication, the method comprising:

   receiving downlink control information from network equipment, wherein the downlink control information comprises indexes of N precoding matrix subsets, the N precoding matrix subsets are one or more of a plurality of precoding matrix subsets divided by a first codebook, and at least one precoding matrix subset in the N precoding matrix subsets comprises at least two precoding matrices;

   determining at least N precoding matrices from the N precoding matrix subsets;

   and transmitting uplink signals based on the at least N precoding matrixes, wherein N is a positive integer.
2. The method of claim 1, wherein the downlink control information further comprises: resource indication information for indicating the first downlink reference signal;

   The determining at least N precoding matrices among the N precoding matrices includes: and determining at least N precoding matrixes in the N precoding matrix subsets based on the first downlink reference signals on the resources indicated by the resource indication information.
3. The method of claim 1 or 2, wherein the uplink signal is a physical uplink shared channel PUSCH, the PUSCH occupies N subbands, the downlink control information further includes indication information of the N subbands, the at least N precoding matrices are N, the N precoding matrix subsets are in one-to-one correspondence with the N subbands, and the N precoding matrices are in one-to-one correspondence with the N subbands;

   the transmitting uplink signals based on the N precoding matrices includes: and transmitting the PUSCH on the N sub-bands based on the N precoding matrixes.
4. The method of claim 1 or 2, wherein the uplink signal is a physical uplink shared channel PUSCH, the N precoding matrix subsets are one precoding matrix subset, and the PUSCH occupies M subbands;

   the determining at least N precoding matrices in the N precoding matrix subsets includes: determining M precoding matrixes in the precoding matrix subset, wherein the M precoding matrixes are in one-to-one correspondence with the M sub-bands;

   The transmitting uplink signals based on the N precoding matrices includes: and transmitting the PUSCH on the M sub-bands based on the M precoding matrices.
5. The method of any of claims 1-4, wherein at least two different ones of the plurality of precoding matrix subsets correspond to different values of the first codebook parameter, the first codebook parameter comprising a phase.
6. The method of any of claims 1-4, wherein the plurality of precoding matrix subsets is K, the first codebook contains L precoding matrices, and an index of a precoding matrix included in each of the plurality of precoding matrix subsets satisfies:or mod (j, K), where j is the index of each precoding matrix in the first codebook,in order to lower the round-down function,is a top-rounding function.
7. The method of any of claims 1-4, wherein the first codebook is generated based on a discrete fourier transform matrix, at least two different ones of the plurality of precoding matrix subsets corresponding to different column vectors in the discrete fourier transform matrix.
8. The method of any one of claims 1-7, wherein the downlink control information further comprises: and an index of at least one precoding matrix, the at least one precoding matrix being a precoding matrix not intended for the terminal equipment.
9. A method of communication, the method comprising:

   determining N precoding matrix subsets;

   and sending downlink control information to the terminal equipment, wherein the downlink control information comprises indexes of N precoding matrix subsets, the N precoding matrix subsets are one or more of a plurality of precoding matrix subsets divided by a first codebook, and at least one precoding matrix subset in the N precoding matrix subsets comprises at least two precoding matrices.
10. The method of claim 9, wherein the downlink control information further comprises: and the resource indication information is used for indicating a first downlink reference signal, and the downlink reference signal is used for determining at least N precoding matrixes in the N precoding matrix subsets by the terminal equipment.
11. The method of claim 9 or 10, wherein the at least N precoding matrices correspond to M subbands, M being greater than or equal to N, the method further comprising: and receiving uplink signals on the M sub-bands, wherein the uplink signals are Physical Uplink Shared Channels (PUSCHs).
12. The method according to claim 10 or 11, wherein the at least N precoding matrices belong to M different subsets of precoding matrices or the at least N precoding matrices belong to the same subset of precoding matrices.
13. The method according to any of claims 9-12, wherein at least two different ones of the plurality of precoding matrix subsets correspond to different values of the first codebook parameter, the first codebook parameter comprising a phase.
14. The method according to any of claims 9-12, wherein the plurality of precoding matrix subsets is K, the first codebook contains L precoding matrices, and each precoding matrix subset in the plurality of precoding matrix subsets includes a precoding matrix satisfying:or mod (j, K), where j is the index of each precoding matrix in the first codebook,in order to lower the round-down function,is a top-rounding function.
15. The method of any of claims 9-12, wherein the first codebook is generated based on a discrete fourier transform matrix, at least two different ones of the plurality of precoding matrix subsets corresponding to different column vectors in the discrete fourier transform matrix.
16. The method of any one of claims 9-15, wherein the downlink control information further comprises: and an index of at least one precoding matrix, the at least one precoding matrix being a precoding matrix not intended for the terminal equipment.
17. A communication device, the device comprising:

    a receiving unit, configured to receive downlink control information from a network device, where the downlink control information includes indexes of N precoding matrix subsets, where the N precoding matrix subsets are one or more of a plurality of precoding matrix subsets divided by a first codebook, and at least one precoding matrix subset of the N precoding matrix subsets includes at least two precoding matrices;

    a processing unit, configured to determine at least N precoding matrices from the N precoding matrix subsets;

    and the sending unit is used for sending the uplink signals based on the at least N precoding matrixes, wherein N is a positive integer.
18. The communications apparatus of claim 17, wherein the downlink control information further comprises: resource indication information for indicating the first downlink reference signal;

    the determining at least N precoding matrices among the N precoding matrices includes: and determining at least N precoding matrixes in the N precoding matrix subsets based on the first downlink reference signals on the resources indicated by the resource indication information.
19. The communications apparatus of claim 17 or 18, wherein the uplink signal is a physical uplink shared channel, PUSCH, the PUSCH occupies N subbands, the downlink control information further includes indication information for the N subbands, the N precoding matrix subsets are in one-to-one correspondence with the N subbands, and the N precoding matrices are in one-to-one correspondence with the N subbands;

    the transmitting uplink signals based on the N precoding matrices includes: and transmitting the PUSCH on the N sub-bands based on the N precoding matrixes.
20. The communications apparatus of claim 17 or 18, wherein the uplink signal is a physical uplink shared channel, PUSCH, the N precoding matrix subsets are one precoding matrix subset, and the PUSCH occupies M subbands;

    the determining at least N precoding matrices in the N precoding matrix subsets includes: determining M precoding matrixes in the precoding matrix subset, wherein the M precoding matrixes are in one-to-one correspondence with the M sub-bands;

    the transmitting uplink signals based on the N precoding matrices includes: and transmitting the PUSCH on the M sub-bands based on the M precoding matrices.
21. The communications apparatus of any of claims 17-20, wherein at least two different ones of the plurality of precoding matrix subsets correspond to different values of the first codebook parameter, the first codebook parameter comprising a phase.
22. The communications apparatus of any one of claims 17-20, wherein the plurality of precoding matrix subsets is K, the first codebook comprises L precoding matrices, and each precoding matrix subset of the plurality of precoding matrix subsets includes a precoding matrix that satisfies:or mod (j, K), where j is the index of each precoding matrix in the first codebook,in order to lower the round-down function,is a top-rounding function.
23. The communications apparatus of any of claims 17-20, wherein the first codebook is generated based on a discrete fourier transform matrix, at least two different ones of the plurality of precoding matrix subsets corresponding to different column vectors in the discrete fourier transform matrix.
24. The communication apparatus according to any one of claims 17-23, wherein the downlink control information further comprises: and an index of at least one precoding matrix, the at least one precoding matrix being a precoding matrix not intended for the terminal equipment.
25. A communication device, the communication device comprising:

    a processing unit, configured to determine N precoding matrix subsets;

    a sending unit, configured to send downlink control information to a terminal device, where the downlink control information includes indexes of N precoding matrix subsets, where the N precoding matrix subsets are one or more of a plurality of precoding matrix subsets divided by a first codebook, and at least one precoding matrix subset of the N precoding matrix subsets includes at least two precoding matrices.
26. The communications apparatus of claim 25, wherein the downlink control information further comprises: and the resource indication information is used for indicating a first downlink reference signal, and the downlink reference signal is used for determining at least N precoding matrixes in the N precoding matrix subsets by the terminal equipment.
27. The communications apparatus of claim 25 or 26, wherein the at least N precoding matrices are in one-to-one correspondence with at least N subbands, the communications apparatus further comprising: and the receiving unit is used for receiving uplink signals on the at least N sub-bands, wherein the uplink signals are Physical Uplink Shared Channels (PUSCHs).
28. The communications apparatus of claim 26 or 27, wherein the at least N precoding matrices belong to M different subsets of precoding matrices or the at least N precoding matrices belong to the same subset of precoding matrices.
29. The communications apparatus of any of claims 25-28, wherein at least two different ones of the plurality of precoding matrix subsets correspond to different values of the first codebook parameter, the first codebook parameter comprising a phase.
30. The communications apparatus of any one of claims 25-28, wherein the plurality of precoding matrix subsets is K, the first codebook comprises L precoding matrices, and each precoding matrix subset of the plurality of precoding matrix subsets comprises a precoding matrix that satisfies:or mod (j, K), where j is the index of each precoding matrix in the first codebook,in order to lower the round-down function,is a top-rounding function.
31. The communications apparatus of any of claims 25-28, wherein the first codebook is generated based on a discrete fourier transform matrix, at least two different ones of the plurality of precoding matrix subsets corresponding to different column vectors in the discrete fourier transform matrix.
32. The method of any one of claims 25-31, wherein the downlink control information further comprises: and an index of at least one precoding matrix, the at least one precoding matrix being a precoding matrix not intended for the terminal equipment.
33. A communication device, comprising: at least one processor and interface circuitry to provide input or output of instructions and/or data to the at least one processor, which when executed causes the apparatus to implement the method of any of claims 1-8 or 9-16.
34. A computer readable storage medium comprising a program or instructions which, when run on a computer, performs the method of any of claims 1-8 or claims 9-16.