MIMO-OFDM channel feedback based on distributed compressive sensing: A new perspective

The availability of channel state information (CSI) at the transmitter is crucial to multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems to suppress interference with precoding techniques. In a MIMO-OFDM frequency division duplex (FDD) system, the amount of CSI required by the transmitter increases linear with the number of subcarriers, and therefore becomes prohibitive for a large bandwidth configuration. Conventional schemes based on broadband analog CSI feedback can reduce the overhead, but has limitations to achieve higher spectral efficiency and feedback robustness. In this paper we first propose a novel broadband analog CSI feedback framework for MIMO-OFDM systems based on the distributed compressive sensing (DCS) theory. Then, we further optimize this framework to maximize its feedback benefits. By exploiting the sparse common support (joint sparsity) inherent in MIMO channels and taking advantage of the high efficiency of DCS in encoding original MIMO channels, the proposed framework is capable of significantly reducing the overhead and enhancing the robustness. The numerical results validate the effectiveness of the proposed scheme.