Beamforming design for interference cancellation in fifth generation new radio system

Abstract

This study proposes a hybrid beamforming (HBF) architecture for interference mitigation design aimed at improving interference cancellation in fifth-generation new radio (5G-NR) systems. The proposed architecture employs interference suppression at two processing level: the linear eigen zero forcing (EZF) method is applied at the base station (BS) to mitigate inter-user interference (IUI), while the nonlinear successive interference cancellation (SIC) is implemented at each user terminal to cancel intra-user interference. Although EZF is linear, meaning it doesn’t require iterative or cumulative operations, its operations are complex and rely on matrix inversion. On the other hand, SIC is a non-linear algorithm, meaning it requires many sequential iterative operations, which increases the probability of cumulative errors. Therefore, using EZF as the first stage makes the signals to be processed in SIC less overlapping, thus reducing cumulative errors, especially under varying channel conditions. The single to interference and noise ratio (SINR) reached a value of 11.9 dB. This is based on the simulation scenarios that were tested. and a channel quality indicator (CQI) value of 10. Moreover, the proposed scheme provides a spectral efficiency of 36 bit/s/Hz at 100 MHz bandwidth and -20 dB signal-to-noise ratio (SNR), achieving performance approaches the performance of a fully digital interference-free system under the considered simulation conditions. while maintaining practical computational complexity.