The Multidimensional TCM With Applications To Space-Time Coding

Trellis-Coded Modulation with multidimensional constellations (MD-TCM) is a bandwidth efficient transmission scheme that can achieve high coding gain compared to conventional two-dimensional schemes. The MD-TCM has the virtues of phase rotation invariant, lower complexity of decoding, and noninteger number of spectral efficiency.Space-time Coding based on Multiple Input Multiply Output (MIMO) technique, is a new coding and signal processing technique in high-speed wireless communications. Space-time coding, which introduces temporal and spatial correlation into signals transmitted, can dramatically increase the channel capacity and spectral efficiency of a wireless system without occupying more bandwidth. So it is considered as a key for the future wireless communication systems.In this paper, we mainly study the performance of space-time coding that based on MD-TCM for Rayleigh-fading channel. First, the design, encoding and decoding principles of MD-TCM is introduced and the performance evaluation between it and 2D-TCM is conducted by simulation.Then this paper proposes a model of serially concatenated system, i.e. concatenated TCM with LDPC, to make MD-TCM applicable to Rayleigh-fading channel. The concatenated system combines the highlighting of LDPC with against burst errors effectively and TCM with high bandwidth efficient. Simulation results demonstrate that LDPC can significantly improve the performance of TCM. Moreover, the phenomenon that LDPC-TCM compared with LDPC modulation systems has no superiority in performance is surveyed and underlying attributes are educed. After introducing the basic idea of space-time block and layered space-time codes briefly, MD-TCM is applied to these two space-time coding techniques, from the perspectives of spatial diversity and multiplexing, to achieve coding and diversity gain simultaneously. Finally, taking factors mentioned above into consideration, a layered STBC system based on MDTCM is designed, in which iterative signal processing is introduced in the VA. This system that realizes the tradeoff between performance and efficiency ideally, achieves lower complexity and better performance, is practical.