On the Design of PolarSK-SCMA Codebooks

In this paper, the concepts of polarization shift keying (PolarSK) and sparse code multiple access (SCMA) are integrated to reap their advantages for massive machine type communication (mMTC). In the proposed PolarSK-SCMA scheme, the available degree of freedom in the polarization domain is employed to convey the bits information, leading to improved spectrum efficiency. We devote to enhanced codebook design for the proposed PolarSK-SCMA. The design criterion of the mother constellation (MC) is first derived in PolarSK modulation scheme. Then, a codebook design scheme is introduced by taking into account the product distance of the MC and the product distance of the superimposed constellation over the PolarSK-SCMA scheme. Finally, simulation results are presented for various scenarios to illustrate the performance improvements of the proposed PolarSK-SCMA codebooks.