Error performance analysis of multilevel turbo-code with antenna diversity

A channel coding scheme is analyzed that features parallel concatenated systematic space-time codes with multilevel modulation and multiple transmit/receive antennas. The scheme is referred to as turbo space-time coded modulation (turbo-STCM). It combines the advantages of turbo codes with the diversity of space-time codes. The scheme features full diversity and full rate. We also extend turbo-STCM to the case of large numbers of antennas (>2). Simulation results are provided over the block-fading channel. It is shown that this turbo scheme provides an advantage of 1.1 dB over conventional space-time codes of similar decoding complexity. The analytical union bound of the bit error probability is derived for turbo-STCM over the Rayleigh block-fading channel. The bound makes it possible to express the performance analysis of turbo-STCM in terms of the properties of the constituent space-time codes. The union bound is demonstrated for 8-PSK turbo-STCM with two transmit antennas and one or two receive antennas.