Research On The Detection Algorithm In Multi-Antenna Systems

The fast increasing demand for high-speed wireless data transmission has posed great challenges for wireless system designation to realize higher throughput wireless communications in radio channels with limited bandwidth. Generally speaking, critical figures of merit for a communication system include high data throughput to its terminals and low bit/frame error rates.In recent years, multiple transmit and receive antennas are more likely to be regarded as a reliable solution in future broadband wireless communication systems, as the capacity of such a multiple-input multiple-output (MIMO) channel increases linearly with the increment of the minimum between the number of transmit and receive antennas in a rich-scattering environment, without increasing the bandwidth or transmitted power. As a simplified version of spatial multiplexing, the Vertical Bell Laboratories Layered Space-Time (V-BLAST) scheme can attain very high spectral efficiency while maintaining relatively low implementation complexity. Many studies have been conducted to achieve better performance or lower implementation complexity.The most classic V-BLAST detection algorithm is the ordered sucsseive interference cancellation detection algorithm, which have the average performance but lower complexity. However, the maximum likelihood detection algorithm can achieve the optimum detection performance while the complexity is extremely high. The paper work is based on these two different algorithms, which are modified to either lower the complexity with little performance loss, or achieve better performance with little complexity increment.Though MIMO system is attractive, this technique requires co-located antenna elements with sufficient antenna spacing. In many practical scenarios, this physical constraint can be easily satisfied in the base station, while not always satisfied in the terminals. In order to overcome this physical constraint issue, a recent approach known as cooperative communications which allows a collection of distributed antennas belonging to different wireless terminals work as relays cooperatively, appears promising. In this paper, we will also investigate the detection algorithm in a distributed multi-antenna system, named cooperative spatial multiplexing systems, which is a extension of the traditional MIMO systems.