A Feature-Domain Channel Acquisition Scheme for MIMO-OFDM

Abstract

This paper studies the channel acquisition problem in multi-input-multi-output orthogonal frequency division multiplexing networks based on channel statistical information, aiming at mitigating the interference caused by users sharing the same resource blocks and the same pilot signal in massive access. A novel feature domain is established for wireless channels by approximating the channel into a linear combination of statistical subchannels, so as to reduce the number of parameters to be estimated as well as enhance the accuracy of channel acquisition. In order to estimate the multipliers of subchannels in the linear combination, a zero-forcing-based and a minimum-mean-square-error-based iterative algorithms are proposed to optimize the transceiver matrices for feature-domain channel acquisition. Simulation results show that the proposed schemes achieve a more accurate acquisition of the channels than the existing channel acquisition methods when a considerable number of users share the same resource blocks, demonstrating the effectiveness of the proposed feature-domain channel acquisition methods for massive access.