The Improved 4-PSK 4-State Space-Time Trellis Code with Two Transmit Antennas

Space-time coding is a powerful technique to improve the error performance of wireless communications systems by using multiple transmit antenna. In this paper, a new 4-PSK 4-state space-time trellis codes (STTCs) with two transmit antennas for slow fading channels is presented by improving the design parameters of the code. From the simulation results, it is shown that new code is superior to the TSC code and the BBH code by about 0.2 dB at a BER of 10(-4) over slow Rayleigh fading channels, about 0.4 similar to 1.3 dB over slow Rician fading channels. Moreover, it is also shown that new code with Gray mapping can be obtained gains by about 0.1 similar to 0.6 dB while keeping the complexity almost the same as the code with natural mapping.