Performance of High-Mobility MIMO Communications with Doppler Diversity

TL;DR

This paper analyzes the performance of high-mobility MIMO systems leveraging Doppler diversity, deriving asymptotic sum rate expressions and exploring the effects of system parameters on performance.

Contribution

It introduces a comprehensive analysis of MIMO systems with Doppler diversity using random matrix theory and derives conditions for optimal diversity and coding gain.

Findings

Asymptotic sum rate expressions for MIMO with Doppler diversity are derived.

Maximum Doppler diversity order is achieved under specific conditions as SNR and repetition number increase.

System performance is significantly influenced by channel parameters and configuration choices.

Abstract

A rapid change of channels in high-speed mobile communications will lead to difficulties in channel estimation and tracking but can also provide Doppler diversity. In this paper, the performance of a multiple-input multiple-output system with pilot-assisted repetition coding and spatial multiplexing is studied. With minimum mean square error (MMSE) channel estimation, an equivalent channel model and the corresponding system model are presented. Based on random matrix theory, asymptotic expressions of the normalized achievable sum rate of the linear receivers, such as the maximal ratio combining (MRC) receiver, MMSE receiver and MRC-like receiver, are derived. In addition, according to the symbol error rate of the MRC-like receiver, the maximum normalized Doppler diversity order and the minimum coding gain loss can be achieved when the repetition number and signal-to-noise ratio tend to infinity, and the corresponding conditions are derived. Based on the theoretical results, the impacts of different system configurations and channel parameters on the system performance are demonstrated.