Performance evaluation of RS encoded TCM-8PSK in the presence of interference [satellite communication]

The effects of adjacent channel interference (ACI) and cochannel interference (CCI) on a Reed-Solomon/trellis coded modulation (RS/TCM) concatenated system with quadrature phase-shift keying (QPSK) as the interference source are examined. All results are obtained using direct simulation by computer. The system is examined in both an AWGN (additive white Gaussian noise) channel and a Rician fading channel, assuming an L-band carrier. The inner code of the RS/TCM system is rate 2/3, 4-state TCM and the outer code is a rate 56/63 RS code. It is shown that in all cases the gain of the RS/TCM system (over QPSK) increases as the interference increases. Specifically, for the fading channel with a bit error rate of 10^-4, RS/TCM showed a gain of about 10.5 dB under ACI with a channel separation of 2.0/T_s, where T_s is the symbol duration, and an SIR (signal to interference ratio) of -2 dB. For CCI, the gain was about 6.5 dB with an SIR of 5 dB