Boosting The Sum Rate in a Three User Noma Network Using Inspired CR-Noma Power Allocation

Abstract

Fifth generation (5G) network which utilizes non-orthogonal multiple access (NOMA) to achieve some of its data requirement and maintain its advantages of low latency, high throughput and spectral efficiency, which needs to be maximized to accommodate more users and enhance network capacity. This research proposes Rayleigh fading ap­proach and inspired cognitive radio (CR-NOMA) power allocation to boost the sum rate in a three-user single carrier (SC-NOMA) system. The adopted model allocates power based on users’ channels condition while guaranteeing the minimum power required by the weakest user. This leads to simulations that involve three users with different channel conditions where their total sum rate is calculated and compared with the sum rate achieved when conventional fixed (F-NOMA) power allocation is used which does not maximize the spectral efficiency in both arrangements. The re­sults revealed that simulation with three users arranged in two different forms that is, two user NOMA system coupled with lone unpaired user communicated using orthogonal multiple access (OMA) and three user SC-NOMA where they both uses F-NOMA power allocation, yields the maximum sum rate of 1.8 x 10-4bps/Hz and 0.3 x 10-4bps/Hz re­spectively. While inspired CR-NOMA power allocation yields a maximum sum rate of 16 bps/Hz for SC-NOMA and 7.5 bps/Hz for typical NOMA-OMA arrangement. The result shows a significant improvement over the existing sys­tem from 5.8% to 47% efficiency despite loading up to three users. Furthermore, the Bit error rate (BER)of SC-NOMA was analyzed using rician fading channels which present decreasing BER from a low of 0.15 to about 0.001 for user 1 and a constant low for user 2 and 3 for inspired CR-NOMA power allocation used in SC-NOMA