Abstract: This application discloses methods an apparatuses for sending and receiving uplink control information in the field of communications technology. In some implementations, a terminal device may receive first downlink control information (DCI) from a network device; determine, based on the received first DCI, that an uplink shared channel scheduled by using the first DCI is used to send only uplink control information (UCI); and send first UCI to the network device through the uplink shared channel scheduled by using the first DCI. In other words, the network device indicates to the terminal device by using DCI so that the terminal device can determine, based on an indication of the network device, whether the uplink shared channel scheduled by using the DCI is used to send only the UCI.

Abstract: This application provides an example communication method and apparatus. The communication method is performed in a communications system, where N antenna ports are configured for the terminal device, N is an integer greater than or equal to 2, the N antenna ports correspond to T antenna port combination modes, each antenna port combination mode corresponds to M antenna ports in the N antenna ports, and each antenna port combination mode set includes at least one antenna port combination mode. The communication method includes receiving, by the network device, first indication information from the terminal device, where the first indication information is used to indicate a first antenna port combination mode set. The method also includes determining, by the network device, K antenna ports in the N antenna ports based on the first antenna port combination mode set and sending, by the network device, second indication information to the terminal device.

Abstract: A method and apparatus for precoding matrix indicator feedback reduce a quantity of bits in the feedback. In the method, a terminal device receive a reference signal from a base station, determines a precoding matrix W in a precoding matrix set corresponding to a rank indication. W satisfies W=W1×W2×W3, W1, W2 and W3 and matrices and respectively corresponding to a first, second and third precoding matrix indicator. None of W1, W2, and W3 is an identity matrix, and the 2M columns in W1 comprise every column in W1×W2. The terminal device transmits the rank indication, the first precoding matrix indicator, the second precoding matrix indicator, and the third precoding matrix indicator to the base station. Therefore, a quantity of to-be-selected vectors is reduced by using a first-stage feedback and a second-stage feedback, thereby reducing calculation complexity of third-stage feedback, and reducing a quantity of bits in the third-stage feedback.

Abstract: This application provides a method for determining a precoding matrix set, so as to avoid a case in which a relatively large quantity of precoding matrices in a precoding matrix set cannot be used, thereby improving system performance. A terminal device receives indication information from a network device, and determines a second precoding matrix set front a first precoding matrix set whose rank is R based on the indication information. Each precoding matrix W in the first precoding matrix set satisfies W=W1×W2, the second precoding matrix set is a proper subset of the first precoding matrix set, and the second precoding matrix set does not include W=W1×W2 that satisfies the specific condition in the first precoding matrix set.

Abstract: This application discloses a precoding matrix index (PMI) reporting method, and related communications apparatus and medium. The method includes: determining an rank indicator (RI) and a PMI, where the PMI is used to determine R precoding matrices W1, . . . , WR. An rth precoding matrix Wr in the R precoding matrices satisfies Wr=W1×W2,r, where an lth row of W2,r is obtained by performing DFT transform on an lth row of a matrix V2,r, and R is indicated by the RI. The PMI includes first indication information and second indication information. The first indication information includes location index information. The location index information is used to indicate Km,r element locations tr,m,1, . . . , tr,m,K?{1, . . . , T} on an mth row of V2,r. The second indication information is used to indicate Km,r complex coefficients a at the element locations tr,m,1, . . . , tr,m,K on the mth row of V2,r. V2,r is determined based on the Km,r element locations and the Km,r complex coefficients.

Abstract: Embodiments of a channel state information (CSI) reporting method and apparatus are disclosed. A method includes: receiving, by a first communications apparatus, reference signals from a second communications apparatus; and performing, by the first communications apparatus, channel measurement based on the reference signals, and sending first CSI to the second communications apparatus in a time unit whose identifier is m, where the first CSI is used to indicate a channel state in a first reference time unit and a channel state in a second reference time unit, where an identifier of the first reference time unit is m?n1, an identifier of the second reference time unit is m?n1?n2, where m, n1, and n2 are integers, and n2 is not equal to 0. This way, matching is improved between CSI applied by a network device and a channel that is at a current moment.

Abstract: Channel state information (CSI) sending methods, apparatuses, and systems are disclosed. In an implementation, a method comprises: receiving, by a network device from a terminal device, channel state information (CSI) comprising a rank indicator (RI), indication information, and a second precoding matrix indicator (PMI2); determining, by the network device, the RI and the indication information from the CSI; determining, by the network device, the PMI2 based on the RI and the indication information; and determining, by the network device, a precoding matrix W based on the RI and the PMI2, wherein W satisfies W=W1×W2, W is an Nt by L matrix, W1 is an Nt by 2I matrix, W2 is a 2I by L matrix, L is a rank indicated by the RI, Nt is greater than or equal to L, and I is an integer greater than or equal to 1.

Abstract: This application provides a channel state information feedback method and an apparatus. The method includes: generating first frequency domain indication information and M1 pieces of first precoding indication information, where the first frequency domain indication information is used to indicate L1 frequency domain subbands in T frequency domain subbands, the T frequency domain subbands are a system bandwidth or a part of the system bandwidth, 1?L1<T, the T frequency domain subbands are in a one-to-one correspondence with T precoding matrices, and a precoding matrix wk corresponding to a kth frequency domain subband satisfies: Wk=W1×W2k, where w1 represents a matrix with Nt rows and R columns, and W2k represents a matrix with R rows and S columns; and w1 represents a matrix with Nt rows and R columns, and W2k represents a matrix with R rows and S columns.

Abstract: One example method includes determining, by a terminal device, that at least two physical uplink control channel (PUCCH) resources collide in a time unit n, where n is an integer, and the at least two PUCCH resources include a first resource configured for first uplink control information (UCI) and a second resource configured for second UCI; and determining, by the terminal device, the first resource and a third resource in the time unit n, where the third resource is one of M PUCCH resources, the first resource and the third resource do not include a same orthogonal frequency division multiplexing (OFDM) symbol in time domain, and M is a positive integer greater than or equal to 1, and the first resource is used to carry a part or all of the first UCI, and the third resource is used to carry a part or all of the second UCI.

Abstract: Embodiments of this application disclose a terminal device capability transmission method, apparatus, and system. A terminal device reports, to a network device, capability information used to indicate a channel state information CSI reporting capability of the terminal device. The capability information is associated with a quantity, supported by the terminal device in a time-domain unit, of ports of pilots used for CSI measurement, and is used to enable the network device receiving the capability information to learn the CSI reporting capability of the terminal device, thereby determining a CSI measurement configuration of the terminal device.

Abstract: A bit field indication manner is provided. A first field is determined, where the first field includes T1 bits, at least one of the T1 bits indicates at least two elements {bi0, bi1, . . . , bik} in a set B, the at least one bit further indicates at least one element {?j0, ?j1, . . . , ?jh} in a set ?, and at least one element in {bi0, bi1, . . . , bik} and at least one element in {?j0, ?j1, . . . , ?jh} are used to form a preceding matrix, where the set B={b0, b1, L, bT2?1}, an element in the set B is a vector with a length of N/4, the set ?={?0, ?1, . . . , ?S?1}, an element in ? is a complex number of a unit amplitude.

Abstract: A channel state information sending method, a channel state information receiving method, and a device are disclosed, to reduce resource overheads required when a terminal device feeds back CSI to a network device in a scenario of a high precision codebook-based precoding matrix. The method includes: determining, by a terminal device, a precoding matrix W; sending, by the terminal device, a signal including CSI to a network device; obtaining, by the network device, an RI and indication information based on the signal including the CSI; obtaining, by the network device, a PMI2 based on the RI and the indication information; and determining, by the network device, the precoding matrix W based on the rank indicator RI and the second precoding matrix indicator PMI2.

Abstract: This application provides a channel state information feedback method and an apparatus. The method includes: generating first frequency domain indication information and M1 pieces of first precoding indication information, where the first frequency domain indication information is used to indicate L1 frequency domain subbands in T frequency domain subbands, the T frequency domain subbands are a system bandwidth or a part of the system bandwidth, 1?L1<T, the T frequency domain subbands are in a one-to-one correspondence with T precoding matrices, and a precoding matrix wk corresponding to a kth frequency domain subband satisfies: Wk=W1×W2k, where w1 represents a matrix with Nt rows and R columns, and W2k represents a matrix with R rows and S columns; and w1 represents a matrix with Nt rows and R columns, and W2k represents a matrix with R rows and S columns.

Abstract: The present disclosure provide a method and an apparatus for transmitting channel state information. A terminal device receives a reference signal from a network device, obtains a precoding matrix based on the reference signal. The terminal device determines first amplitude information and second amplitude information of the precoding matrix. The first amplitude information is used to indicate amplitude quantization information of a wideband, and the second amplitude information is used to indicate amplitude quantization information of N subbands of the wideband. The terminal device sends the first amplitude information and the second amplitude information to the network device.

Abstract: This application discloses a data transmission solution. A terminal device generates channel state information and data for transmission in a data channel. The transmit power of the data channel is determined based on the number of bits used to transmit the data and the number of bits used to transmit the channel state information. The solution of this application reduces bit error probability and improves data decoding accuracy.

Abstract: Embodiments provide a channel state information reporting method, including: determining, by a terminal, R first precoding matrix indicators PMIs of M first reference signal resources, and determining a channel quality indicator CQI based on the R first PMIs, where M and R are integers greater than or equal to 1; and reporting, by the terminal, channel state information, where the channel state information includes the R first PMIs and N CQIs.

Abstract: Embodiments of the present invention disclose a channel quality index measurement method and apparatus. The method includes: determining, by a base station, a target CSI-RS on each of time-frequency resources corresponding to resource numbers of a terminal, where the target CSI-RS is a precoded CSI-RS, and the time-frequency resource is a resource element used to transmit the CSI-RS or the target CSI-RS; sending, by the base station, the target CSI-RS on each of the time-frequency resources corresponding to the resource numbers to the terminal on the time-frequency resource; sending, by the base station to the terminal, indication information used to indicate the resource numbers of the terminal; and receiving, by the base station, a CQI that is sent by the terminal and that is used to indicate channel quality.

Abstract: The invention discloses a beamforming method for polarized antenna array consisting of a plurality of antenna elements, applied to single layer beamforming or dual layer beamforming, which includes the steps: determining (201) first beamforming weights for phase compensation among the antenna elements within each polarization direction; determining (202) second beamforming weights for phase compensation between equivalent channels of two polarization directions; and calculating (203) hybrid beamforming weights as product of the first beamforming weights and the second beamforming weights. A beamforming apparatus for polarized antenna array is also provided in the invention as well as a radio communication device and a system thereof With the invention, the single-layer and dual-layer beamforming weights are determined for the cross-polarized antenna array without requiring full channel knowledge or the aid of PMI. Computation complexity is lowered and full power amplifier utilization can be achieved.

Abstract: A method in the embodiments of this application includes: generating, by a terminal device, first information, where the first information includes parameters q, m1, m2, . . . , mL, and indication information of a vector V; q is an integer, and q<Q; Q is an integer, and Q>1; 0?ml?N?1, and 1?l?L; L>1, N, L, and l are integers, and N is a quantity of subbands in a frequency domain bandwidth; and the vector V includes L elements and satisfies V=Fq×C, where C is a vector formed by N elements c1, . . . , cN, C=[c1 c2 . . . cN]T, ck is used to indicate channel state information on a kth frequency domain subband, ck is a complex number, a modulus of ck is |ck|?1, and 1?k?N; and sending, by the terminal device, the first information to a network device.

Abstract: A bit field indication manner is provided. A first field is determined, where the first field includes T1 bits, at least one of the T1 bits indicates at least two elements {bi0, bi1, . . . , bik} in a set B, the at least one bit further indicates at least one element {?j0, ?j1, . . . , ?jh} in a set ?, and at least one element in {bi0, bi1, . . . , bik} and at least one element in {?j0, ?j1, . . . , ?jh} are used to form a precoding matrix, where the set B={b0, b1, . . . , bT2?1}, an element in the set B is a vector with a length of N/4, the set ?={?0, ?1, . . . , ?S?1}, an element in ? is a complex number of a unit amplitude.