An iterative siso strategy for mimo fading channels

Abstract

We propose a low complexity superposition cod- ing approach to maximize the throughput of MIMO quasi-static fading channels. The MIMO channel is transformed to SISO channels using MMSE and an iterative decoding approach is pro- posed. The throughput of the proposed coding and decoding strategy may be less than the maximum possible. I. INTRODUCTION We investigate how to improve the throughput of Multiple Input Multiple Output (MIMO) quasi-static fading channels, which can be viewed as a broadcast channel. The Single Input Single Out- put (SISO) case can be viewed as a degraded Gaussian broadcast channel whose capacity region is known. An infinite level superposi- tion coding is investigated by Shamai ( 13 to maximize throughput for Rayleigh fading channels. For practical implementation, we investi- gated the optimal finite level superposition coding strategy (2). How- ever, the MIMO broadcast channel capacity region is only known for some special cases with complex coding strategy. In this paper, we provide a suboptimal superposition SISO coding strategy and MMSE decoding strategy for MIMO quasi-static fading channels. The decoding for our proposed system takes an interesting iterative fashion. The decoding dynamics and the convergence can be visualized by a chart similar to EXIT charts used in turbo coding research. We then pose the optimization problem for the proposed coding and decoding strategy.