Layered Space-time Coding For Mimo Systems Technology

With the rapid development of society, people demand more and more communication and improve the communication system channel capacity and spectrum efficiency, communication researchers have become one of the issues need to be solved, therefore, some researchers proposed a multiple-input multiple-output(MIMO) systems, theoretical analysis can greatly improve the communication system spectrum efficiency. In the MIMO technology, the spatial multiplexing gain help to improve the reliability of communications, space multiplexing and antenna diversity combining, full use of spatial diversity weakens the impact of multipath fading, effectively increase the channel capacity. Among them, the Bell Labs-developed VBLAST(Vertical-Bell Labs Space Time) system as a typical representative of MIMO technology is a hot topic in recent years. Layered space-time technology can take full advantage of multi-path channel characteristics, can improve the spectral efficiency of the new generation of wireless communications technology. However, the system detects a receiver on the VBLAST algorithm has many, but unsatisfactory detection algorithm, there is always less than this and that, therefore, this paper improve the starting performance MIMO technology, a comprehensive system of in-depth VBLAST Research and analysis, include:Firstly common MIMO system model, and then described in detail at the transmitter diagonal layered space-time coding, vertical layered space-time coding, horizontal layered space-time coding techniques, and disadvantages of these three coding techniques by comparing the channel coding at the transmitter, after this select vertical layered space-time coding scheme was coded, and then discussed the transmission wireless channel to establish the actual situation of the potential for channel model,finally, in-depth study of the maximum likelihood detection algorithm ML, minimum mean square error detection algorithm MMSE, zero forcing four space-time detection algorithm for ZF detection algorithm, on this basis, interference cancellation is proposed based on multi-detection algorithm, the more interference cancellation algorithm and the combination of MMSE or ZF algorithm has been improved for better performance, while the simulation analysis.This research work is based upon rigorous theoretical derivation and use of modern simulation technology system simulation matlab, using the commonly used MIMO research assumptions, research on the existing algorithm and proposed algorithm was improved Comprehensive theory of performance comparison, the simulation results are reassuring. As a strong competitive edge in the wireless communication technology, VBLAST has a very good prospect, I hope this research will further in-depth study of VBLAST help.