Ergodic Capacity of NOMA-Based Multi-Antenna LMS Systems with Imperfect Limitations

Abstract

With the rapid development of land mobile satellite (LMS) systems, large scale sensors and devices are willing to request wireless services, which is a challenge to the quality of service requirement and spectrum resources utilization on onboard LMS systems. Under this situation, the non-orthogonal multiple access (NOMA) is regarded as a promising technology for improving spectrum efficiency of LMS systems. In this paper, we analyze the ergodic capacity (EC) of NOMA-based multi-antenna LMS systems in the presence of imperfect limitations, i.e., channel estimation errors, imperfect successive interference cancellation, and co-channel interference. By considering multiple antennas at the satellite and terrestrial sensor users, the closed-form expression for EC of the NOMA-based LMS systems with imperfect limitations is obtained. Monte Carlo simulations are provided to verify theoretical results and reveal the influence of key parameters on system performance.

Ergodic Capacity for NOMA-Enabled ISATNs with Transmit Antenna Selection and Imperfect CSI and SIC

“…The previous paper of us [30] is the first in open technical papers that investigated the joint effect of imperfect CSI and SIC on the performance of land mobile satellite system. Different from [30], in this paper, a HAP which works as an aerial half-duplex decode-and-forward (DF) relay is employed in the system and the TAS scheme is adopted at the transmitter of HAP. Try the authors' best knowledge, there is no prior work that analyzed the ergodic capacity (EC) for NOMA-enabled ISATNs with TAS scheme and imperfections.…”

“…Moreover, HAP uses N r receive antennas and N t transmit antennas to form a uniform planar array (UPA), which can improve array gain. In addition, the terrestrial destinations are assumed to be small devices, such as IoT sensors, whose structures can only deploy single antenna [30,32].…”

“…In the signal decoding under NOMA scheme, imperfect SIC is considered for weak performance of receiver [33]. Therefore, when the receiver decodes the signal x 2 with less power, the residual signal x 1 which does not completely eliminate is viewed as interference [30]. At the same time, considering CEEs, the signal-to-interference-plus-noise ratio (SINR) of different signals at aerial relay is denoted, correspondingly, as…”

“…EC is a key merit to analyze the performance of the considered ISATN. The EC of the ISATN defines the time average of the capacity on the satellite to aerial link and aerial to users' links [30]. Due to the ISATN consists two phases, the overall EC can be denoted as…”

“…By substituting (30) and (32) into S 1 , with the aid of [ [36], Eq.2.24.3.1] and [ [36], Eq.8.2.2.14], S 1 can be expressed as…”