This paper proposes novel techniques to improve the ADPCM voice signal transmission quality of TDMA-TDD systems in fading environments. The proposed scheme employs an improved error detection technique with a PCM signal differential detection and a cyclic redundancy code. Erroneous PCM bursts are replaced by error-free bursts. Hardware simulation results show that these techniques significantly improve ADPCM voice transmission quality in the fading environments typical of personal communication systems. The developed techniques enhance ADPCM voice transmission quality for cost -effective personal communication systems.