Abstract: This application provides a channel state information transmission method, an access network device, and a terminal device. The method includes: receiving, by an access network device, channel state information CSI reported by a terminal device, where the CSI includes a first precoding matrix indication PMI and a second PMI, and determining, by the access network device, a precoding matrix W based on the first PMI, the second PMI, and a preset codebook, where W meets W=W1×W2, W1 corresponds to the first PMI, W2 corresponds to the second PMI, the second PMI indicates some column vectors of W2 and an amplitude association relationship between the some column vectors of W2 and remaining column vectors of W2, and a quantity of columns of W is greater than 2. According to the method, CSI feedback overheads of the terminal device are effectively reduced.

Abstract: The present disclosure relates to information feedback methods and apparatus. One example method includes receiving signaling from a base station, where the signaling is used to instruct to feed back transmit diversity-based channel state information and sending feedback information to the base station, where the feedback information includes precoding matrix indicator (PMI), the PMI is used to indicate a precoding matrix in a precoding matrix set, and a structure of the precoding matrix is one of two specific structures.

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: Embodiments of this application provide a data transmission method and apparatus. The method includes: sending, by a network device, first information by using first signaling, where the first information is used to indicate a quantity N of transmitted precoding matrix indicators TPMIs in second signaling; and sending, by the network device, resource scheduling information and the N TPMIs by using the second signaling, where the resource scheduling information is used to indicate n scheduled physical resource blocks PRBs of M PRBs included in a communication bandwidth, all or some of the N TPMIs is used to indicate a precoding matrix of the n PRBs.

Abstract: The present invention describes a channel measurement method, including: sending, by a base station, first control information to user equipment UE, where the first control information is used to indicate a measurement reference signal of the UE on a carrier, and the first control information includes at least one first measurement configuration set, and is used to instruct the UE to measure the measurement reference signal based on the at least one first measurement configuration set; sending, by the base station, the measurement reference signal to the UE.

Abstract: Embodiments of this application provide a channel state information transmission method, a terminal device, and a network device.

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 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: 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.

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: 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: 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 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 from 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 provides a channel state information feedback method, user equipment, and a base station. A base station configures N first reference signal resources for UE, and sends the N first reference signal resources to the UE. The UE feeds back the CSI of the M first reference signal resources in a horizontal dimension and the M pieces of first reference signal resource indication information to the base station. This overcomes a disadvantage that only channel state information in a horizontal dimension is fed back in conventional channel estimation.

Abstract: This application provides a wireless communication method, a terminal device, and a network device. The method includes: determining, by a terminal device, a pilot signal corresponding to at least one of a plurality of search sections of a control channel; and detecting, by the terminal device, a control channel candidate in the at least one search section based on a quasi-co-location (QCL) association between the pilot signal corresponding to each search section and the demodulation pilot of the control channel candidate in each search section.

Abstract: The present disclosure relates to information feedback methods and apparatus. One example method includes receiving signaling from a base station, where the signaling is used to instruct to feed back transmit diversity-based channel state information and sending feedback information to the base station, where the feedback information includes precoding matrix indicator (PMI), the PMI is used to indicate a precoding matrix in a precoding matrix set, and a structure of the precoding matrix is one of two specific structures.

Abstract: The present invention provides a method for reporting channel state information. The method includes: receiving, by a base station, a first reference signal sent by user equipment; sending, by the base station, a first parameter set and a second reference signal to the user equipment, where the first parameter set is obtained by the base station by measuring the first reference signal; and receiving, by the base station, a third parameter set sent by the user equipment, where the third parameter set includes a relative value between a parameter in a second parameter set and a parameter in the first parameter set, the second parameter set is obtained by the user equipment by measuring the second reference signal, and the third parameter set and the first parameter set are used by the base station to determine a precoding matrix.

Abstract: Embodiments of the present invention provide a communication method, a base station, and a terminal device. The method includes: transmitting, by a base station, signals to a terminal device by using n port groups, where each of the n port groups includes at least two ports; and receiving, by the base station, s first linear combination coefficient groups transmitted by the terminal device, where each first linear combination coefficient group includes first linear combination coefficients of one of s port groups, at least one first linear combination coefficient group includes at least two non-zero coefficients, the s first linear combination coefficient groups are used to determine a first precoding matrix, the s port groups are included in the n port groups. This can improve channel feedback precision of the terminal device, and further help improve performance of transmission between the base station and the terminal device.

Abstract: The present invention describes a channel measurement method, including: sending, by a base station, first control information to user equipment UE, where the first control information is used to indicate a measurement reference signal of the UE on a carrier, and the first control information includes at least one first measurement configuration set, and is used to instruct the UE to measure the measurement reference signal based on the at least one first measurement configuration set; sending, by the base station, the measurement reference signal to the UE.

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 from 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.