Outage analysis of SWIPT‐based full‐duplex cognitive NOMA downlink system over Nakagami‐m fading channels

Abstract

Summary Cognitive nonorthogonal multiple access (NOMA) technique allows multiple users to share the same time and same frequency resources to fulfil the reliability and spectral efficiency requirements of 5G communication standards. In this paper, simultaneous wireless information and power transfer (SWIPT)–based full‐duplex cognitive NOMA downlink system is proposed. In this system, secondary source (SS) serves as a relay to far primary user as there is no direct link from the primary source. NOMA technique is used at SS to transmit information to far primary user and secondary user. The time switching mechanism is adopted at SS for harvesting energy and information decoding. Analytical closed‐form expressions are derived for the outage probabilities of both primary and secondary users. Outage analysis is carried out in Nakagami‐ m fading environment in the presence of self‐interference at SS. In addition to that, the optimal harvesting time to maximize the instantaneous throughput of the far primary user is also derived. Numerical results are plotted to validate the derived expressions. It is inferred that the outage probability of the proposed system depends on the fading environment, harvesting parameters, and self‐interference at SS.

Outage analysis of cognitive non‐orthogonal multiple access downlink system with secondary source selection in Nakagami‐m fading environment

“…It infers that, the outage performance of PU 1 monotonically decrease as SNR increases and saturates around 20 dB with acceptable BER of 10 −2 . Compared to Sashiganth et al, 29 the outage performance of PU 2 and SU degrades worse and attains saturation due to the presence of interference constraint λ at SS transmission. Moreover the outage performance of PU 2 and SU can be improved by increasing L and λ .…”

“…The outage probabilities of PU 1 , PU 2 , and SU are shown in Figure 3. Here, the outage probability performance is analyzed and compared with Sashiganth et al 29 The curves are plotted based on Equations , (), and (). It infers that, the outage performance of PU 1 monotonically decrease as SNR increases and saturates around 20 dB with acceptable BER of 10 −2 .…”

“…Comparisons of outage performance of P U 1 , P U 2 , and S U in the presence of interference constraint λ and noise with 29 ( , )…”

“…In Sashiganth et al 29 we have proposed a SWIPT based full‐duplex Cognitive‐NOMA downlink system to provide connection between Far Primary User (FPU) and primary source (base station). The system performance was improved by finding the optimal harvesting time coefficient.…”

Adaptive multiple access assists multiple users over multiple‐input‐multiple‐output non‐orthogonal multiple access wireless networks

“…[27][28][29] In NOMA network, two commonly distribution models are Rayleigh distribution and Nakagami-m distribution. [30][31][32][33] Note that the Nakagami-m distribution, where the coefficient m = 1, becomes the Rayleigh distribution. The authors have confirmed that the system performance is improved by increasing the Nakagami-m coefficient.…”