Transceiver design framework for multiuser MIMO-OFDM broadcast systems with channel gram matrix feedback

摘要

This work considers a multiple-input multipleoutputud(MIMO) orthogonal frequency division multiplexingudbased multiuser broadcast system with precoding at the transmitterudand feedback of channel state information. A generaludframework is presented for the transceiver design, and also forudthe design of the feedback link based on the quantization of theudusers’ MIMO channel Gram matrices. The proposed design ofudthe feedback link exploits the correlation of the channel responseudin the frequency domain due to the finite length of the channeludtime impulse responses to outperform other schemes based onudfeedback of the per carrier frequency responses. The transceiveruddesign framework is based on a unitary linear transformationudapplied at the receivers which allows the computation of equivalentudtriangular channel response matrices at the transmitter.udAn analytic study of the error propagation due to the channeludquantization in the feedback link and the computation of theudequivalent triangular channel matrices is also performed. Basedudon the previous concepts, all the usual transceiver design criteriaudcan be applied within this framework, and the particular caseudof a space-frequency precoder for robust mean square errorudminimization is derived as an example. Finally, the benefitsudof the proposed strategy are evaluated by means of numericaludsimulations and compared to other existing techniques.