BLER and AoI Analysis of Multiantenna NOMA-FD Relay Systems for Short-Packet Communications

In this paper mathematically studies utilizing finite block length in a full-duplex (FD) relay network with multiple antennas and non-orthogonal multiple access (NOMA). Specifically, the block error rate (BLER) and age-of-information (AoI) of the investigated system with residual self-interference and imperfect successive interference cancellation are derived. Moreover, the power allocation coefficient is optimized to minimize the average BLER and the influences of various parameters on system's performance are examined. We enhance the BLER and AoI performance by employing the maximal-ratio combining and maximal-ratio transmission techniques at multiple antennas of source and destination nodes. Simulation results validate our analytical frameworks. Numerical results indicate that employing multi-antennas for a NOMA system with FD relay gives exceptionally low average BLER that fulfils the targets of high reliability and latency of the wireless systems. Furthermore, the optimal AoI of the investigated system can be achieved by selecting a suitable block length. In particular, the minimum AoI is obtained when SNR = 10 dB and the block length is 300. Also, the average BLER and average AoI of the considered NOMA-FD system outperform conventional orthogonal multiple access and half-duplex (HD) systems. Especially when the block length is less than 250, the AoI of the FD system is reduced by 90% compared to that of the HD system.