Summary
The 2018 International Symposium on Information Theory and Its Applications　(ISITA2018)
2018
Session Number:Mo-PM-1-3
Session:
Number:Mo-PM-1-3.2
Sparse Multiple Access and Code Design with Near Channel Capacity Performance
Akira Osamura, Guanghui Song, Jun Cheng, Kui Cai,
pp.139-143
Publication Date:2018/10/18
Online ISSN:2188-5079
DOI:10.34385/proc.55.Mo-PM-1-3.2
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Summary:
For the problem of multiple users simultaneously communicating with a single receiver, a sparse multiple access scheme is proposed. Each user employs a low-density paritycheck (LDPC) code. To mitigate multi-user interference, the codeword of each user is randomly punctured and the punctured bits are replaced by idle slots. That is, only a small random set of users are active at each time. The restriction of number of concurrent users significantly reduces the multi-user decoding complexity. Moreover, this puncture facilitates an efficient message-passing decoding over a sparse graph. With a joint optimization of the degree distribution of the LDPC code and the column weight distribution of the puncture matrix, capacityapproaching performance is achieved.