Optimal Rate Allocation for Distributed Source Coding over Gaussian Multiple Access Channels

We study the problem of joint optimization of Slepian-Wolf (SW) source coding and transmission rates over a Gaussian multiple access channel with the considerations of circuit power consumption and average transmit power constraint. The goal is to maximize the sample rate at the source nodes. We first derive a criterion to determine the optimality of different multiple access schemes such that the highest sample rate can be achieved at the source nodes when SW coding is used. Based on the derived optimality criterion, we propose a rate allocation procedure to determine the jointly optimal SW coding and transmission rates corresponding to orthogonal code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA) and superposition coding with successive interference cancellation (SCSIC) schemes. Several demonstrative numerical examples are provided to show the performance gain of the proposed joint rate allocation scheme.