Mobile Communication System Blast Space-time Codec Technology Research

Space-time coding, which based on multi-antenna at the transmitter, is a new coding/signal processing technique applied to wireless communication systems .It can increase system capacity and data rates through different mechanisms, without spreading the system bandwidth and increasing the transmit power. Space-time coding technology is the combination of channel coding with antenna diversity techniques and this enormously increases the wireless communication system capacity as well as diversity advantage and coding gain. Furthermore, its spectrum efficiency significantly exceeds that of conventional single-antenna systems. Since the advance of space-time coding there has been extensive research aiming at improving the performance of the original space-time-code(STC) designs and it is very likely to be used in next-generation(4G) mobile communication systems. Nevertheless we must systematically understand its principle and put forward some practical coding/decoding algorithms in order to adopt it in already-in-used and next-generation wireless networks.So in this paper we first overview the development of the mobile communication systems and explicate the R&D (research and development) trends of next-generation mobile communication systems; Then we analysis and compare channel characteristics in time-domain,frequency-domain and spatial-domain followed by discussions on two schemes for transmitting digital multiple-beam,with highlight on digital beam-forming(DBF).Thirdly ,we analysis the transmit diversity and receive diversity techniques with focusing on conclusion of and classification for transmit diversity techniques that connected tightly with the space-time coding .At the end of this paper we study space-time block coding criteria and coding/decoding methods with Alamouti scheme as an example ,then we extend all these to the case of multiple transmitting antennas (more than 2);we also review several encoding methods for Layered Space-Time codes with emphasising on following decoding schemes for V-BLAST:maximum-likelihood detection(ML),minimum-mean-squared-error(MMSE) technique , zero-forcing (ZF) algorithm,successive cancellation(SUC) and ordered successive cancellation(OSUC),etc.Simulation results prove some conclusions of this paper, which also explains the feasibility of STC's application to future mobile communication systems to enhance system capacity and/or spectrum efficiency.