OFDM-MIMO Communication Systems In A Rayleigh Faded Environment With Imperfect Channel Estimates

摘要

This paper presents the performance of mobile orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) communication systems with imperfect knowledge of the channel matrix. MIMO systems typically require a channel matrix, which can be determined initially from a training sequence. However, mobile communication systems exhibit a time-varying channel matrix and have time and frequency selective fades which result in performance degradation of the MIMO system. Channel tracking methods can be used to estimate the time-varying channel matrix but cannot in practice be error free. This paper presents results of V-BLAST (Vertical Bell Laboratories Layered Space-Time) MIMO simulations using the Geometric Wide-band Time-varying Channel Model (GWTCM) with Rayleigh faded environments and imperfect channel matrix knowledge. Flat fading is assumed for each OFDM subcarrier. OFDM-MIMO architectures such as OFDM coupled with V-BLAST can be easily implemented by exploiting the built-in and flexible multi-channel architectures of advanced Software Defined Radios (SDR).