Research Of The MIMO System Combining STBC And VBLAST

Multiple Input Multiple Output (MIMO) is an important breakthrough in the wireless mobile communication. It is the crucial technology in the new generation mobile communication system, which made people develop more effective technology of coding, modem, and signal process to improve quality and spectrum efficiency. Space-time coding technology is a good scheme. This technique is mainly designed to combat fading by combining the technique of channel coding and antenna diversity, hence increasing the capacity of wireless communications systems. Space-time coding combines signal processing with coding techniques appropriate to multiple transmit antenna and provides significant gain. It is a new solution to satisfy high data-rate of wireless communication in the future.Space-time coding includes space-time trellis coding (STTC), layered space-time coding (LSTC) and space-time block coding (STBC). In general, STTC has more gain of diversity and coding, but higher code and decode complexity and it is difficult to apply. LSTC has high spread using but the performance is not good against fading. STBC is good against fading and lower complexity of the receiver structure. But when the number of the transmitting antennas is ration, the complexity of decoding will go up in index.We investigate the novel MIMO system combining STBC with VBLAST in the paper. The mostly study as follows:(1) We work over the basic concept, the channel model and the present researching the civil and international situation of the MIMO system. And it is analyzed and deduced the MIMO system channel capacity in slow fading even Rayleigh information channel, introduced the factors affecting MIMO system capacity.(2) We lucubrated the basic concept, principle and cassette of the important technique of space-time code -diversity. Especially, we study the separation and combination of multi-path signal in the multi-path fading environment and the transmit diversity based on the transmitters.(3) After we lucubrated the sort algorithm and the code and decode of STBC andVBLAST in Rayleigh fading channel, we put forward a MIMO system model combining STBC and VBLAST, deduced the adjudicated statistical expression of the MIMO system's STBC and VBLAST, which combing STBC and VBLAST, applying sorted QR decomposition (SQRD) at the receivers.(4) We used MATLAB for simulating. And we compare the simulation outcome of the issued system with VBLAST's and the system's combining STBC with VBLAST, which are based on traditional algorithm.