Space-Time Turbo Codes: Decorrelation properties and performance analysis for fading channels

This paper studies the decorrelation property of the constituent codes in Space-Time Turbo Codes (STTCs), where different constituent codes are transmitted over different antennas. We show that the time correlation between constituent codes falls of with respect to STTC block length N as 1/√N for large N, and hence goes to zero as N→∞. We then use this result to obtain analytical expressions for the frame error rate (FER) of STTCs in flat fading. The decorrelation property of STTCs helps explain the exceptional performance of STTCs on slowly varying flat fading channels.