Power Domain NOMA Design Based on MBER Criterion

Non-orthogonal multiple access (NOMA) has been gaining notable attention in the context of next generation communication system. The key primary benefit includes the higher spectrum efficiency compared to its various orthogonal counterparts. In this treatise, we consider a power NOMA design based on the minimum bit error ratio (MBER) criterion. Inspiration has been drawn from the MBER based works, which show a considerable performance improvement in terms of bit error ratio (BER) for a system. In this work, we have considered a single-input single-output (SISO) system with quadrature phase shift keying (QPSK) signal constellation. The numerical results demonstrate an overall BER improvement compared to the existing schemes, albeit, the scheme attracts large computational complexity. Traditionally, NOMA increases the spectral efficiency compared to its orthogonal counterpart. Nevertheless, our proposed solution will still hold this feature along with a better BER performance, though its spectral efficiency will be less compared to the traditional sum-rate based power NOMA.