Bezout Equalizer for MIMO Systems
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. However, the inevitable ISI (Inter-Symbol-Interference) and ICI (Inter-Channel-Interference) need to be addressed in order to fully explore the advantage of the MIMO systems. We have developed the Bezout equalizer to combat the both interferences through a simple array of linear FIR filters. We air to use this approach to enhance the receiver design and improve the performance.
Background & Objective: Recently, MIMO techniques attracted lots of attention. One technique, which theoretically achieves channel capacity in MIMO systems, is called BLAST. The original Blast used a cyclic association of data streams, called layers, with transmit antennas, thereby producing an “averaged†channel which is the same for all layers. Difficulties in the realization of the original Blast led to a modified architecture where each layer is associated with a certain transmit antenna. However, in order to achieve the full capacity of the MIMO channel, long data blocks, powerful channel coding, and perfect detection of each layer are required. In addition, in practical systems, the problem of error propagation limits the performance.
Technical Discussion: This work provides a system and method that designs an optimum Bezout space-time equalizer based on estimated MIMO channel characteristics, combines Bezout space-time equalizers with sequential detection and decoding techniques, and processes the input sequences via a layered and pipeline architecture. With a sequential space-time equalizer, an input data stream with a highest signal-to-noise ratio (SNR)is recovered first. Then previously detected transmitting streams are used to reduce interference in subsequent detected input stream. The sequential equalization and detection reduces the number of unknown input streams. The, "excess dimensionality" offered by the increasing asymmetry between the transmitted and received signal space provides the necessary flexibility that improves the capacity of the system.
Outside Collaborations: This project is performed in collaboration with Princeton University.
Contact: Jinyun Zhang
Technology Area: Digital Communications
Modification Date: September 12, 2007
