The Next-generation Wireless Communications System Space-time Trellis Code Technology Research

With the fast development of mobile communication and emerging services, the demands for the limited frequency resource are booming. To develop highly efficient coding, modulation and signal processing technologies is becoming the most necessary measure to realize these demands. 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 and it is very likely to be used in next-generation mobile communication systems.This thesis focuses on the space-time trellis code which will be used in next-generation mobile communication system. The main contents are as follows: 1) we analyze the channel capacity of MIMO from the aspect of information theory based on the quasistatic flat fading channel; 2) we research the design criteria for Rayleigh STTC which is the base for the design of the STTC; 3) based on the delay diversity and STTC of N=2, we put forward a method for the design of STTC which can avoid designing special STTC by hand. And this method can design the STTC which can adapt to any number of transmit antennas and any modulation, so it is a general method. 4) On the case of large number of transmit antennas, the search space of STTC is very great, and even if we have searched for the valid codes, the decode is also very complex. So we put forward an orthogonal method which can be used to design the STTC with large number of transmit antennas and avoid the complicated search for the code. The experiment has proved this method is very practical.