Design and Analysis of In-Band Full-Duplex Private 5G Networks Using FR2 Band

This paper studies a solution for efficient industrial Internet of things (IIoT) communications through an in-band full-duplex (IBFD) enabled private 5G network in frequency range 2 (FR2) band (
$\geq 24.250$
GHz), where ultra-reliable low-latency communications (URLLC) and enhanced mobile broadband (eMBB) devices can be simultaneously served. Large-scale antenna array and RF beamforming are applied, and a self-interference cancellation (SIC) scheme is proposed under such architecture. Particularly, the proposed RF cancellation scheme addressed two key issues of extending current technologies to wideband operations in FR2 band: limited operational bandwidth and the requirement for a large number of cancellers. Then, a frequency domain-based digital canceller is proposed to process with the residual self-interference (RSI) with short processing latency. A game theoretic user allocation algorithm is proposed to minimise co-channel interference (CCI) in a heterogeneous environment. Given a typical IIoT scenario, the performance of such IBFD private 5G network is evaluated in terms of bit error rate (BER) and spectral efficiency (SE) through simulations and analysed based on numerical results and theoretical calculations. It is demonstrated that the latency of uplink eMBB devices can be reduced by 54% through IBFD radios, and the latency of downlink URLLC devices can be reduced to 0.5 ms with the help of flexible numerology, mini-slot, and self-contained sub-frames introduced in 5G NR. IBFD radios can enhance the SE by 92% compared to HD radios with our SIC and user allocation policy. The high SE in conjunction with abundant resources in FR2 band provides multi-Gbps peak data rates, high reliability, and massive connectivity.