Iterative inter-symbol interference canceling receiver for direct space-time GF(q) LDPC modulation

Abstract

Multiple-input multiple-output (MIMO) wireless communication systems enhance reliability and improve throughput for a given total transmit power. In actual systems, the channel and noise parameters must be estimated to capture the MIMO gains. In this paper, we couple a direct, q-ary Galois field [GF(q)], low-density parity-check (LDPC) space-time coding and modulation scheme with a receiver that iterates between decoding the transmitted symbols, estimating the convolutive MIMO channel with pilots and symbol decisions, and removing inter-symbol interference. The result is a powerful system that outperforms linear space-time equalization and performs within one decibel of a system with perfect channel knowledge and no inter-symbol interference.