Hybrid SR ARQ scheme using two dimensional trellis coded modulation and code combining for AWGN channel

Abstract

In this paper, we evaluate the weight spectra of the rate 2/3, 4-state two dimensional trellis coded modulation (2D-TCM). Using the weight spectra and the code combining technique, the throughput of hybrid selective repeat automatic repeat request (SIR ARQ) scheme is obtained over additive white Gaussian noise (AWGN) channel. Numerical results show that the proposed scheme yields better throughput efficiency than the scheme using the rate 2/3, 4-state symmetric TCM at the values of E-s/N-0 up to 10 dB. The throughput of the proposed scheme is also investigated for noisy feedback channel and for finite receiver buffer, respectively. It is observed that the throughput decreases significantly when the feedback channel error probability is very high. It is also observed that the throughput of the proposed scheme with finite receiver buffer decreases under bad channel conditions because of the buffer overflow.