High data rate transmission with 64-DAPSK over fading channel

In this paper a simplified differential amplitude demodulation scheme is proposed for 64-DAPSK (differential amplitude and phase shift keying), which needs less quantity of decision thresholds compared with the conventional schemes. The arithmetic mean threshold (AlMT) scheme is proposed and analyzed with the simplified system in AWGN and flat Rayleigh fading channels. By these proposed schemes, system complexity is reduced considerably, but no performance degradation occurs. In the case of channel coding, the concatenated code consisting of an inner convolutional code and an outer Reed-Solomon code can be applied to 64-DAPSK. Compared with coherent 64-QAM system which employs pilot symbols for channel estimation, 64- DAPSK can achieve the performance close to or even better than that of the former by utilizing the additional redundancy for outer coding, provided that the channel SNR is high enough.