Nonlinear decoding based on perturbation codebook for precoded spatial multiplexing systems

Considering the problem of feedback cost and performance loss for precoded spatial multiplexing with limited feedback, an novel nonlinear detection method based on perturbation codebook with limited feedback for precoded vblast is proposed, the corresponding criteria is used for select optimal codeword from the Grassmannian codebook at the receiving according to the channel state information, selecting optimal perturbation codeword, and feedback the Grassmannian preceding word index and perturbation codeword to the transmitter, thereby forming the equivalent channel. At the receiving, recycle and successive mapping from the entire space of constellation points as the first the underlying detection signals at the receiver, in order to maximize the performance of first detection layer, and then using the traditional detection algorithm for the remaining received signal, and determine a set of the optimal detection signal as decoding result based on the maximum likelihood criterion. Simulation results show that the proposed method to ensure system throughput, the cost of the feedback link and BER performance are improved some extent.