Efficient decoding methods in MIMO systems

A typical MIMO system utilizes multiple antennas to transmit simultaneously several independent data streams to the receiver end. As a result of this inter-stream interference is said to occur since the reception of each stream at the receiver will be disturbed not only by noise but from the interference of other streams as well. In order to successfully detect and decode the received signal, joint detection and decoding can be employed to separate and recover the transmitted data in the best possible manner. This approach has huge complexity which grows exponentially as the number of antennas increases, thus prohibiting its implementation in a real time system. For real time implementation computationally effective methods are sought after but which often does not necessarily yield the best performance thus incurring a performance-complexity trade-off. The current research in this area has led to the development of both linear and non-linear techniques most of which are computationally intensive and complex. This paper discusses low complexity methods which are suitable for real time applications.