Joint Estimation of Channel Responses and Phase Noises in Asynchronous MIMO Systems With Intentional Timing Offset

Abstract

The reception performance of a Multiple-Input-Multiple-Output (MIMO) system suffers from not only the channel fading but also the phase noise. Accurate and efficient estimation algorithms of channel responses and phase noises that enable high-speed wireless communications in MIMO systems are of broad interest. The prior joint estimation schemes of channel responses and phase noises are designed for synchronous MIMO systems, where symbols transmitted from different transmit antennas are strictly synchronized. However, the estimation performance of the prior schemes suffers from the Inter Antenna Interference (IAI), which further limits the reception performance of a MIMO system. In this paper, we propose an asynchronous MIMO system with intentional timing offset. Based on the proposed asynchronous MIMO system, we further design the Joint Estimation of Channel responses and Phase noises using Intentional Timing Offset (JECP-ITO) scheme. We derive the Cramér-Rao Lower Bound (CRLB) of the JECP-ITO scheme in closed form. We provide rigorous theoretical comparisons between the JECP-ITO and the prior scheme in terms of IAI and CRLB. Moreover, we implement the proposed scheme and conduct extensive performance comparisons through simulations.