Speech transmission using DPCM coding, partial response continuous phase modulation and diversity

This paper considers the performance of a speech transmission scheme with application to cellular digital mobile radio systems. The source coder is embedded DPCM and modulation scheme belongs to a class of Partial Response Continuous Phase Modulation Both quantizing noise and transmission errors contribute to the overall mean squared error. The performance measure is audio signal to noise ratio. It is seen that in a fading environment space diversity is very effective in bringing down the threshold of channel signal to noise ratio to maintain the required audio signal to noise ratio. The number of channels the system can support is evaluated under various conditions.