Joint Effects of Imperfect CSI and SIC on NOMA Based Satellite-Terrestrial Systems

Abstract

This paper investigates a satellite-terrestrial system employing the non-orthogonal multiple access (NOMA) scheme over Shadowed-Rician fading channels. The effects of both imperfect channel state information (CSI) and imperfect successive interference cancellation (SIC) on the NOMA based satellite-terrestrial system are taken into account. First, the outage performance of the proposed system is evaluated, and the closed-form expressions for the exact and asymptotic outage probabilities are obtained. Next, the expressions of the ergodic sum rate and system throughput are derived in the presence of channel estimation errors and residual interference. Moreover, we analyze the impacts of different residual interference levels on the energy efficiency. Finally, the numerical simulation results are conducted to verify the correctness of theoretical analysis and the advantages of the proposed NOMA scheme. At medium-high SNR region, the NOMA users are capable of outperforming orthogonal multiple access (OMA) users in terms of outage behaviors and system throughput with imperfect CSI and imperfect SIC. The ergodic sum rate decreases as the level of residual interference increases, and is even lower than that of OMA once goes beyond a certain value. Additionally, the energy efficiency of NOMA scheme is sensitive to the imperfect SIC.INDEX TERMS Satellite-terrestrial system, non-orthogonal multiple access (NOMA), imperfect CSI, imperfect SIC.

NOMA-Based Integrated Satellite Terrestrial Networks With Relay Selection and Imperfect SIC

“…The NOMA-based ISTNs is a hot research topic, and we will expand our research on more benchmark problems in this field in our future work. In addition to OP and EC performance, delay is also an important indicator in the SatCom networks, and the performance analysis of system delay under satellites with different orbit could be adopted to satisfy the delay requirements of 5G and B5G networks [34], [46]. Moreover, the optimal power allocation scheme is another critical research hotspot [30], which can best improve the spectrum efficiency and meet the QoS requirements of different users.…”

“…The authors of [42] derived the closed-form expressions of OP and ergodic sum rate (ESR) for a FD cooperative NOMA relay system with imperfect SIC, and compared the performance with the OMA scheme. At present, only a small amount of literature has analyzed the application of imperfect SIC in the NOMA-based SatCom networks [44]- [46]. The authors of [44] researched the outage performance of the imperfect SIC in a NOMA-based hybrid satellite-terrestrial relay network.…”

“…The authors of [44] researched the outage performance of the imperfect SIC in a NOMA-based hybrid satellite-terrestrial relay network. In [45], [46], the authors introduced an independent residual interference parameter to represent imperfect SIC in the NOMA-based SatCom networks.…”

“…The delay for the GEO is a little larger, however, the advantages of the GEO can fill this shortage for its wide coverage, high reliability, etc. 2 The two-user situation based on NOMA is assumed in our paper for the simplification in the analysis of the system performance and has been recognized by the Third Generation Partnership Project (3GPP) [33], [46], which is the basis of our future research with multi-user scenario. 3 The single antenna is assumed for both the satellite and terrestrial devices to balance the system complexity, cost and system performance [20], which will be extended to multi-antenna situations in our future work.…”

Bit Error Rate Analysis of NOMA-OFDM in 5G Systems With Non-Linear HPA With Memory

“…In downlink NOMA scenarios, all the individual information signals are superimposed on a single signal transmitted by the base station (BS) to the equipment users. For the decoding processes, most research works consider using successive interference cancellation (SIC) techniques in receiving devices to separate signals in the power domain for each user [12][13][14]. Studies in the literature indicate that a key parameter for good NOMA performance is the correct power allocation per user [4,15].…”