Wyner-Ziv nested lattice coding for single-cell multicast service delivery

This paper addresses the problem of physical-layer multicasting over single-cell point-to-multipoint communication. We consider a base station that needs to convey a common information to a group of users. We propose a Wyner-Ziv coder (WZC) based on doubly nested lattice quantization. In our scheme, we use the base layer generated by a standard coder as the decoder side information. Then, WZC is performed for enhancing the quality of the transmitted message. With the proposed layered coding, two enhancement messages will be generated, the first for all users and the second for only a subgroup of users with the best channel conditions. We optimize the scheme parameters in order to maximize the multicast rate and minimize the reconstruction distortion at all users. The efficiency of the proposed scheme is confirmed by the rate-distortion performance results that show significant decrease of the decoded signal distortion, compared to the basic multicasting scheme.