Abstract: This application provides a data transmission method, a terminal device, and a network device. The method includes: determining, by a terminal device, reference information indicating a threshold associated with a quantity of resource elements (REs) configured for all or a portion of channel state information (CSI) on an uplink channel; and sending, by the terminal device, the all or the portion of the CSI based on a comparison result of the reference information and a status parameter, wherein the status parameter indicates a quantity of REs occupied by the CSI on the uplink channel.

Abstract: A network device sends K reference signal resources, where K is an integer greater than 0. The network device receives a first random access preamble in a first random access time-frequency resource unit. The network device determines indexes of S reference signal resources and first channel state information CSI of the S reference signal resources based on the first random access preamble and the first random access time-frequency resource unit the S reference signal resources are reference signal resources in the K reference signal resources, and S is an integer greater than 0 and less than or equal to K.

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, . . . , ?{1, . . . , T} on an mth row of V2,r. The second indication information is used to indicate Km,r complex coefficients at the element locations tr,m,1, . . . , 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: This application provides an information transmission method and apparatus. The method includes: receiving, by a terminal device, a plurality of pieces of downlink control information DCI, where each of the plurality of pieces of DCI is used to trigger reporting of one piece of UCI and indicate a physical uplink control channel PUCCH resource carrying the UCI, the UCI includes at least one piece of channel state information CSI and response information, and PUCCH resources indicated by the plurality of pieces of downlink DCI occupy at least one same orthogonal frequency division multiplexing OFDM symbol; and sending, by the terminal device, target UCI on a target PUCCH resource, where the target UCI includes UCI triggered by the plurality of pieces of DCI, and the target PUCCH resource is one of the PUCCH resources indicated by the plurality of pieces of DCI. In this way, aperiodic CSI triggered by DCI can be transmitted on a PUCCH resource.

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: Embodiments of the present invention disclose a link re-establishment method and a device, and relate to the communications field: When detecting that a first downlink beam pair set is invalid, UE sends a first uplink signal to a base station at a moment n by using a first uplink beam pair set through a first uplink channel, where the first uplink signal is used to notify the base station that the first downlink beam pair set is invalid; and the UE detects, at a moment n+k, a first downlink signal sent by the base station by using a second downlink beam pair set through a first downlink channel.

Abstract: Embodiments of this application provide a precoding matrix indication method, a communications apparatus, and a storage medium. A precoding matrix of each of K frequency-domain units satisfies W=W1×W2, and elements in W2 in the K frequency-domain units are represented by P elements that are relatively few. A terminal device reports third indication information, where the third indication information includes first indication information and the second indication information, and the first indication information and the second indication information are independently encoded. The first indication information is used to indicate the P elements, and the second indication information is used to indicate P. Therefore, the terminal device can adjust a quantity of information bits of the second indication information based on a channel condition change, thereby improving precoding matrix reporting efficiency.

Abstract: An interference power measurement method and a device are provided. The method includes: receiving, by a terminal, first signaling that carries first indication information, where the first indication information is used to indicate n first channel state information-reference signal CSI RS resources, and a jth first CSI RS resource is associated with a power parameter Pc,j; and sending, by the terminal, a channel quality indicator CQI, where the CQI is determined based on a total interference power. The total interference power is a linear weighting result of an interference power measured on each of the n first CSI RS resources and an interference power I0 measured on a zero power CSI RS resource. A weighting coefficient of an interference power Ij measured on the jth first CSI RS resource is a function of the power parameter Pc,j, and a weighting coefficient of I0 is a function of 1 - ? j = 1 n ? P c , j .

Abstract: Embodiments of this application provide a precoding matrix indication method, a communications apparatus, and a storage medium. A precoding matrix of each of K frequency-domain units satisfies W=W1×W2, and elements in W2 in the K frequency-domain units are represented by P elements that are relatively few. A terminal device reports third indication information, where the third indication information includes first indication information and the second indication information, and the first indication information and the second indication information are independently encoded. The first indication information is used to indicate the P elements, and the second indication information is used to indicate P. Therefore, the terminal device can adjust a quantity of information bits of the second indication information based on a channel condition change, thereby improving precoding matrix reporting efficiency.

Abstract: This application provides a data transmission method, terminal device, and network device. The method includes: sending, by a terminal device, at least one precoded reference signal on at least one reference signal resource corresponding to a first PRG, where different precoding matrixes are used for different reference signals, and the first PRG is a PRG used to transmit a reference signal; receiving, by the terminal device, resource indication information, where the resource indication information indicates a reference signal resource that is corresponding to a second PRG and that is in the at least one reference signal resource, and the second PRG is a PRG used to transmit a physical uplink shared channel (PUSCH); and sending, by the terminal device, a precoded PUSCH on the second PRG based on the resource indication information, where a precoding matrix used for the PUSCH is a precoding matrix used for a reference signal sent on the reference signal resource corresponding to the second PRG.

Abstract: Methods, base station, and receiving device are provided to advance a decoding time of a second codeword. The method performed by a base station includes obtaining a demodulation pilot pattern (DPP) in a transmission time unit, the DPP includes a first DPP of a first codeword and a second DPP of a second codeword; the first DPP indicates a time-frequency resource of each OFDM symbol in a first set, and the second DPP indicates a time-frequency resource of each OFDM symbol in a second set; and an MCS indication value of the first codeword is greater than an MCS indication value of the second codeword; and mapping a pilot signal to a time-frequency resource based on the DPP, and sending the pilot signal, a transmission time of a first OFDM symbol in the first set is before a transmission time of a first OFDM symbol in the second set.

Abstract: Embodiments of this application provide a channel state information transmission method, a terminal device, and a network device. The method includes: sending, by a terminal device, a first reference signal through a first antenna port set, where the first antenna port set includes n antenna ports; receiving, by the terminal device, a second reference signal through a second antenna port set, where the second antenna port set includes N antenna ports, and the first antenna port set is a proper subset of the second.

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, . . . , ?{1, . . . , T} on an mth row of V2,r. The second indication information is used to indicate Km,r complex coefficients at the element locations tr,m,1, . . . , 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 this application provide a precoding matrix indication method, a communications apparatus, and a storage medium. A precoding matrix of each of K frequency-domain units satisfies W=W1×W2, and elements in W2 in the K frequency-domain units are represented by P elements that are relatively few. A terminal device reports third indication information, where the third indication information includes first indication information and the second indication information, and the first indication information and the second indication information are independently encoded. The first indication information is used to indicate the P elements, and the second indication information is used to indicate P. Therefore, the terminal device can adjust a quantity of information bits of the second indication information based on a channel condition change, thereby improving precoding matrix reporting efficiency.

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: This application provides a channel state information reporting method and apparatus. The method includes: A terminal device receives M pieces of downlink control information, where first downlink control information in the M pieces of downlink control information indicates a first channel state information configuration, the first channel state information configuration is associated with a first channel state information interference measurement CSI-IM resource group, and the first CSI-IM resource group includes N1 CSI-IM resources, where M and N1 are positive integers, and N1 is greater than 1; and the terminal device measures a target CSI-IM resource, and reports channel state information, where the target CSI-IM resource is determined by the terminal device from the N1 CSI-IM resources based on M, and a quantity of target CSI-IM resources is less than N1.

Abstract: A channel state information reporting method and apparatus are described. The method can include a terminal device obtaining first indication information and sending the first indication information to a network device. The network device receives the first indication information, where the first indication information indicates a differential value between channel state information of a first antenna port set and channel state information of a second antenna port set. The first antenna port set includes x antenna ports of the terminal device, the second antenna port set includes m antenna ports of the terminal device, and the first antenna port set is different from the second antenna port set. The channel state information reporting method and apparatus in embodiments of this application help improve accuracy of channel state information obtained by a network device, and improve data transmission performance.

Abstract: Embodiments of the present invention disclose a signal receiving method, a signal transmission method, and a device, and relate to the communications field, so as to resolve a problem that a supported quantity of UEs that perform orthogonal code division multiplexing through cyclic shifts is relatively small when a frequency deviation between a center frequency for receiving a signal by UE and a center frequency for transmitting a signal by a base station is greater than a subcarrier spacing used for communication between the base station and the UE. The embodiments of the present invention are used in a signal transmission process.

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,rand 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,Kmj?{1, . . . , T} on an mth row of V2,r. The second indication information is used to indicate Km,r complex coefficients ar,m,tr,mj at the element locations tr,m,1, . . . , tr,m,kmj on the mth row of V2,r. V2,r is determined based on the Km,r element locations and the Km,r complex coefficients.