Performance comparison of two differential chip detection schemes of DSSS systems

Direct-sequence spread-spectrum (DSSS) with differential chip detection (DCD) schemes, chip model 1 and chip model 2, have been proposed in reference of A. Cavallini et al. (1997) and Q. Shi et al. (2002), respectively. The performances of these two DCD schemes have been studied via simulations in reference to M.M.K. Howlader and H, Chang (2003). In this paper, we derive the decision variables of these two DCD over additive white Gaussian noise (AWGN) and Rayleigh fading channel, and our results show that the noise variance in chip model 2 is twice of that in chip model 1.