NEW COMPUTER GENERATED-SCMA CODEBOOK WITH MAXIMIZED EUCLIDIAN DISTANCE FOR 5G

Abstract

Sparse code multiple access (SCMA) is one of the Non-Orthogonal Multiple Access (NOMA) that attracts many researchers for its promising future uses in 5G systems. In this paper, a Computer Generated-Sparse Code Multiple Access (CG-SCMA) is proposed. CG-SCMA generates a complex SCMA codebook that maximizes the Minimum Euclidian Distance (MinED) of 16-point star-QAM. This codebook is generated using computer program to specify the most appropriate values for this constellation. Then Trellis Coded Modulation (TCM) is used to divide the constellation into four sub constellations to maximize MinED.  The new codebook reaches MinED for four sub constellations {3.46, 2.16, 2.16, 3.46} and achieves increment over SCMA codebook based 16-point star-QAM by 10.1%. The multiplexer and de-multiplexer for proposed codebook and traditional SCAM codebook is implemented using netFPGA-1G-CML Kintex-7. it can speed up the process by 597.6 times over MATLAB simulator and decreasing BER compared to open literature codebooks.