BER Performance of SCMA with Large Codebooks

The paper studies the bit error rate (BER) performance of sparse code multiple access systems with codebooks of different dimensions. SCMA is considered as a code-domain non-orthogonal multiple access technique for spectrally efficient transmission, high reliability, and massive connectivity in 6G wireless networks. The paper briefly describes a scalable codebook construction method based on the synthesis of sparse matrices of a prescribed dimension. The comparison is carried out for the 3GPP TDL-A multipath channel model. Simulation results show that large codebooks provide a lower bit error rate than independently reused small codebooks. In the high signal-to-noise ratio region, the BER gain reaches about two orders of magnitude.