A feasible high capacity wireless network architecture with MIMO precoding

In this paper, we consider the application of Tomlinson-Harashima precoding (THP) in the downlink of a wireless network with multiple-input-multiple-output (MIMO) capabilities. Applying precoding enables point-to-multipoint transmission strategy to be implemented in such a way that at each transmission slot, a subset of mobile stations can be selected to receive data packets over parallel subchannels formed by precoding. Although THP is a suboptimal MIMO transmission strategy, in this paper, we show that scheduling gain available in a point-to-multipoint networking environment with THP is enough to compensate the capacity loss due to suboptimality of THP alone. We compare the achievable capacities of THP, conventional MIMO spatial multiplexing (V-BLAST) and information theoretic MIMO capacity bound to show the advantages of precoding, particularly THP, when point-to-multipoint transmissions are allowed. We present a feasible network architecture with a scheduling approach, where multiple antennas are deployed on the access point and mobile stations remain with single antennas.