Minimum Mean Square Error Receiver for Multipath Detection in Non-Orthogonal Multiple Access

Non-orthogonal multiple access (NOMA) is a promising technique for next-generation wireless communications. NOMA witnesses performance degradation due to multi access and multipath interferences in dispersive channel. Therefore, power domain cyclic spread multiple access (PDCSMA), a NOMA variant, has been presented recently to minimize the multipath fading effect. The performance of the PDCSMA is limited due to the noise enhancement during multipath detection. Therefore, this paper proposes a novel minimum mean square error (MMSE) based interference minimization technique for the PDCSMA. The proposed technique acts on received signal matched to each path to minimize multipath interference and the effective noise power due to channel dispersion. Unlike the decorrelator employed in the current PDCSMA, the proposed technique enhances the diversity while suppressing the noise enhancement, which is evident from simulation results.