A Multiple Access Scheme for Non-Coherent SIMO Communications

In this paper, we introduce a multiple access scheme for non-coherent single-input multiple-output (SIMO) communications. We first define an individual codebook for each user as the image of a non-coherent single-user codebook of smaller dimension through a bijective mapping. We investigate the available options at the decoder, including linear equalization in the absence of reference symbols, and joint multi-user decoding. In particular, we propose greedy decoders that exploit the structure of the encoder mappings to separate the signals of different users, denoise, and decode each signal as in the single-user case. Numerical results show that our scheme outperforms the time-division multiple access and the pilot-based coherent approach.