Abstract: Embodiments of the present disclosure disclose a method and an apparatus for determining a precoding matrix, which relate to the field of communications technologies and may improve throughput of a MIMO system and optimize overall system performance, including: determining a rank constraint of a jth transmitting end, where j=1, 2, . . . , K, and K is the total number of transmitting ends in a MIMO system; iteratively calculating an optimal precoding matrix of the jth transmitting end according to a channel matrix from the jth transmitting end to a jth receiving end, an autocorrelation matrix of interference and noise of the jth receiving end, and the rank constraint of the jth transmitting end, where the optimal precoding matrix maximizes channel capacity of a link from the jth transmitting end to the jth receiving end under a circumstance that precoding matrices of other transmitting ends do not change.

Abstract: A channel information feedback method, an information processing method, a mobile station, a base station, and a MIMO system are disclosed by embodiments of the present invention. Through the foregoing technical solutions, different numbers of channel information feedback bits are allocated for different channels dynamically, and the feedback gain is made better use of.

Abstract: A method, a system, a Base Station (BS) and a mobile terminal device for collaborative communication are disclosed, so as to multiplex open-loop and closed-loop users and improve a utilization rate of system frequency spectrum. The method includes receiving CSI sent by a user, in which the CSI is CSI of an LOS signal of the user that is obtained by eliminating CSI of a multi-path signal. The method then obtains CSI of a closed-loop user having a channel that is orthogonal to a channel of the user, and performs pre-coding calculations by using the CSI of the LOS signal of the user and the CSI of the closed-loop user. Communication data is then sent to the user by using the result of the pre-coding calculation.

Abstract: A channel information feedback method, an information processing method, a mobile station, a base station, and a MIMO system are disclosed by embodiments of the present invention. Through the foregoing technical solutions, different numbers of channel information feedback bits are allocated for different channels dynamically, and the feedback gain is made better use of.