MIMO Self-Coherent OFDM

Self-coherent orthogonal frequency division multiplexing (OFDM) was introduced to wireless communications as a promising physical layer technique due to its complete immunity against phase noise, simple radio frequency (RF) front-end receiver, and good spectral efficiency achievability. In this paper, we propose an Alamouti coded multiple-input multiple-output (MIMO) self-coherent OFDM and analyze its performance in terms of diversity order. We prove theoretically that the system exhibits a diversity loss due to a doubly fading effect experienced by both the RF carrier and OFDM subcarriers. To compensate this loss, we exploit the smart carrier positioning (SCP) technique in conjunction with the proposed system. We present a novel diversity analysis, which proves the system with SCP approaches full diversity. Finally, we show by simulations that the system with SCP outperforms the other known non-coherent OFDM schemes as well as the conventional MIMO-OFDM, when phase noise presents.