Distributed reception with coarsely-quantized observation exchanges

This paper considers the problem of jointly decoding binary phase shift keyed (BPSK) messages from a single distant transmitter to a cooperative receive cluster connected by a local area network (LAN). A distributed reception technique is proposed based on the exchange of coarsely-quantized observations among some or all of the nodes in the receive cluster. By taking into account the differences in channel quality across the receive cluster, the quantized information from other nodes in the receive cluster can be appropriately combined with locally unquantized information to form aggregate posterior likelihoods for the received bits. The LAN throughput requirements of this technique are derived as a function of the number of participating nodes in the receive cluster, the forward link code rate, and the quantization parameters. Using information theoretic analysis and simulations of an LDPC coded system in fading channels, numerical results show that the performance penalty (in terms of outage probability and block error rate with respect to ideal receive beamforming) due to coarse quantization is small in the low SNR regimes enabled by cooperative distributed reception.