Performance Analysis of Filtered OFDM Based Downlink and Uplink NOMA System over Nakagami-m Fading Channel

Abstract

Efficient consumption of available resources and fulfillment of increasing demands are the two main challenges which are addressed by exploring advanced multiple access schemes along with efficient modulation techniques. To this end, non-orthogonal multiple access (NOMA) is discussed as a promising scheme for future 5G traffic. NOMA enables the users to share same resource block, permitting certain level of interference. In this paper, we propose filtered OFDM (F-OFDM) as a transmission waveform for NOMA systems, as it offers all the advantages of OFDM with the additional provision of sub-band filtering to satisfy the diverse services of the users. We examine F-OFDM in both downlink and uplink NOMA systems. Error-related performances of both downlink and uplink F-OFDM NOMA systems are analyzed and compared with conventional OFDM NOMA system over Nakagami-m fading channel. The results show that the error performance of F-OFDM NOMA is better than that of OFDM NOMA. An improvement of about 2 dB and 1 dB in bit error rate is achieved in downlink and uplink F-OFDM NOMA, respectively. Monte Carlo simulations are conducted for different values of fading parameter m, supporting the obtained analytical results

NOMA-NR-FOFDM Performance Enhancement-Based Sub-band Filtering

“…5 (a-b) over AWGN and Rayleigh fading channels respectively. As compared with the results get in [14], the full-band-based filtering scenario provides almost the same error floor with a benefit of approximately 11dB SNR, while the subband-based filtering scenario achieves almost the same error floor with a benefit of approximately 17dB SNR. The BER better performance of the proposed system as compared with ref [14] is due to SINR gain through employing the 5G frame structure.…”

“…Table .1 displays the simulation parameters of the proposed system considering two scenarios. Since the work in [14] considered combining NOMA technique and fullband based F-OFDM, equivalent parameters are considered in scenario-I for performance comparison. As in [14], Binary Phase Shift Keying (BPSK) modulation is used for FU while Quadrature Phase Shift Keying (QPSK) is used for NU due to channel conditions.…”

“…In [14], the authors combined the NOMA technique with FOFDM for both uplink and downlink transmissions. The system was evaluated using PSD, and BER for AWGN, Rayleigh, and Nakagami-m fading channels.…”

“…While [15] & [16] included a breakdown of all the candidate waveforms for the 5G system, the authors recommended FOFDM as the best waveform among all contenders. The authors in [14] considered NOMA multiple access with FOFDM-based fullband filtering. All the mentioned literature made their analysis without considering the flexibility of the 5G frame structure.…”

Unified Performance Analysis of Near and Far User in Downlink NOMA System over η - μ Fading Channel

“…Moreover, the various technical aspects of NOMA have been widely discussed. In [8] and [9], the authors have analyzed different modulation techniques for improving the performance of NOMA system. In [10], the authors have shown that NOMA has superior energy efficiency performance in comparison with conventional orthogonal multiple access.…”