Abstract:
Embodiments of the present invention provide a method for feeding back channel state information, a user equipment, and abase station, to improve feedback precision of channel state information. The method includes: receiving a reference signal sent by a base station; selecting a precoding matrix W from a codebook according to the reference signal, where a column vector of the precoding matrix W may be expressed as α[V ejϕv]T, v=[1 ejθ]; and sending a precoding matrix indicator PMI to the base station, where the PMI is corresponding to the selected precoding matrix W. The present invention may further improve quantization precision and achieve balance between overheads and the quantization precision. The base station performs precoding on a sent signal according to a fed back precoding matrix indicator, which can improve precoding precision, thereby improving a data transmission rate and system throughput.
Abstract:
The present invention provides a codebook configuration method and user equipment. The UE receives a reference signal that is of an antenna whose quantity of antenna ports is X and that is sent by a base station and configuration information of a codebook subset restriction for the quantity X of antenna ports, where the configuration information of the codebook subset restriction for the quantity X of antenna ports includes first configuration information and second configuration information; determines, according to the configuration information of the codebook subset restriction for the quantity X of antenna ports, a precoding matrix on which channel measurement and feedback need to be performed; and obtains, by means of measurement according to the reference signal, the precoding matrix on which channel measurement and feedback need to be performed and that is of antenna ports.
Abstract:
The present invention discloses a channel state information CSI reporting method and apparatus, and a base station antenna. In the method, at least one precoding matrix is selected from a codebook based on a reference signal sent by a base station, and CSI is sent to the base station. The CSI includes at least one selected precoding matrix indicator PMI, and the PMI is corresponding to the selected at least one precoding matrix. At least one precoding matrix W included in the codebook may be expressed as W=W1W2, where is a Kronecker product, and at least one of W1 or W2 is an antenna selection matrix. Therefore, in embodiments of the present invention, the base station can select, according to the at least one precoding matrix that is fed back, one or more antenna ports to send a signal.
Abstract:
In a 3D MIMO scenario with 16 antenna ports, antenna ports can be extended in different directions because of different configuration manners of the antenna ports. An apparatus and method where different antenna port counting manners are determined in different configurations are provided, so that in different configurations, a matrix whose dimension is 8 and a matrix whose dimension is 2 are determined in a precoding codebook, and a value of a PMI is fed back to indicate a precoding matrix.
Abstract:
A method and an apparatus for measuring and feeding back channel information are disclosed. In an embodiment the method includes receiving, by a first network device, a reference signal and measuring the reference signal to obtain a measurement result. The method further includes selecting a first codebook from a first codebook set according to the measurement result, wherein the first codebook set comprises at least two first codebooks, a sub-vector Wx of each first codebook is formed by a zero vector and a non-zero vector, wherein the vectors forming the Wx correspond to different groups of antenna ports, and sending a codebook index to a second network device, wherein the codebook index corresponds to the first codebook selected from the first codebook set.
Abstract:
In a 3D MIMO scenario with 16 antenna ports, antenna ports can be extended in different directions because of different configuration manners of the antenna ports. An apparatus and method where different antenna port counting manners are determined in different configurations are provided, so that in different configurations, a matrix whose dimension is 8 and a matrix whose dimension is 2 are determined in a precoding codebook, and a value of a PMI is fed back to indicate a precoding matrix.
Abstract:
Embodiments provide a method for generating a random access channel ZC sequence, and an apparatus. A method for generating a random access channel ZC sequence includes: generating, by a base station, notification signaling, where the notification signaling instructs user equipment UE to generate a random access ZC sequence by using a second restricted set in a random access set; and sending, by the base station, the notification signaling to the UE, so that the UE generates the random access ZC sequence by using the second restricted set, where the random access set includes an unrestricted set, a first restricted set, and the second restricted set; and the second restricted set is a random access set that the UE needs to use when a Doppler frequency shift of the UE is greater than or equal to a first predetermined value.
Abstract:
The present invention discloses a method for transmitting a 4-antenna precoding matrix, a user equipment, and a base station. The method includes determining a rank used for indicating the number of transmission layers, determining a first precoding matrix in a codebook set corresponding to the rank, determining a first PMI and a second PMI used for indicating the first precoding matrix, and sending the first PMI and the second PMI used for indicating the first precoding matrix to a base station.
Abstract:
The present invention discloses a method for transmitting a 4-antenna precoding matrix, a user equipment, and a base station. The method includes determining a rank used for indicating the number of transmission layers, determining a first precoding matrix in a codebook set corresponding to the rank, determining a first PMI and a second PMI used for indicating the first precoding matrix, and sending the first PMI and the second PMI used for indicating the first precoding matrix to a base station.
Abstract:
This application discloses a sequence generating method and apparatus, and relates to the field of communications technologies, to resolve a problem that a PAPR of a DMRS symbol is higher than that of a data symbol. An initialization factor of a first sequence is obtained, where the initialization factor is associated with a first parameter, and the first sequence is generated based on the initialization factor. In addition, the first parameter is a port number, or the first parameter is a code division multiplexing CDM group identity.