Layered bezout space-time equalizers for mimo

MIMO (Multiple-Input-Multiple-Output) techniques are viewed by many as having the potential to greatly increase wireless system capacity with multiple antennas in both the transmitter and the receiver end. Bezout equalization offers an effective tool to combat the inevitable ISI (Inter-Symbol-Interference) and ICI (Inter-Channel-Interference) in MIMO systems through a simple array of linear FIR filters. In this paper, we propose a Layered Bezout Space-Time (LaBest) equalizer for MIMO systems, which represents a combination of Bezout equalization and the layered detection technique originated from BLAST. With successively cancelling the interferences generated by those already detected transmitting streams, the layered architecture gradually reduce the number of unknown inputs of the MIMO system. Then the "excess dimensionality" offered by the increasing asymmetricity between the transmitted and received signal space provides the necessary flexibility that allows the improvement of capacity. The LaBest equalizer can effectively cope with the ISI problems, and thus is applicable to 3G/4G broadband wireless communications, where frequency-selective fading can no longer be ignored. Another unique feature of LaBest is the introduction of two additional design parameters: equalizer order and equalization delay, which have critical roles on equalization performance. The optimal design of equalizer parameters and layered detection order is also addressed. Simulation results demonstrate substantial enhancement of SNR performance by using the LaBest equalizer as compared with the parallel Bezout equalizers.