Performance Analysis of In-Band-Full-Duplex Multi-Cell Wideband IAB Networks

TL;DR

This work analyzes multi-cell wideband mmWave IBFD IAB networks using stochastic geometry, with wired gNBs modeled by MHCPP to reflect practical deployment and reduce backhaul wiring costs. The authors derive association probabilities, SINR coverage, capacity with outage, and ergodic capacity by leveraging a composite Gamma-Lognormal distribution to capture Nakagami-M fading and lognormal shadowing, and they account for sidelobe and ADC noise to avoid underestimating interference and noise. Key contributions include a tractable analytical framework for IBFD performance in non-Poisson gNB layouts, a comparison against HD benchmarks, and insights into how biasing, RSI, ADC resolution, and MHCPP hard-core distance shape network performance. The results show that with proper IAB-to-gNB biasing and effective self-interference cancellation, IBFD offers substantial capacity gains, and MHCPP deployment enhances ergodic capacity relative to PPP, highlighting practical deployment and design considerations for next-generation IAB networks.

Abstract

This paper analyzes the performance of the 3rd Generation Partnership Project (3GPP)-inspired multi-cell wideband single-hop backhaul millimeter-wave-in-band-full-duplex (IBFD)-integrated access and backhaul (IAB) networks by using stochastic geometry. We model the wired-connected Next Generation NodeBs (gNBs) as the Matérn hard-core point process (MHCPP) to meet the real-world deployment requirement and reduce the cost caused by wired connection in the network. We first derive association probabilities that reflect how likely the typical user-equipment is served by a gNB or an IAB-node based on the maximum long-term averaged biased-received-desired-signal power criteria. Further, by leveraging the composite Gamma-Lognormal distribution, we derive the closed-form signal to interference plus noise ratio coverage, capacity with outage, and ergodic capacity of the network. In order to avoid underestimating the noise, we consider the sidelobe gain on inter-cell interference links and the analog to digital converter quantization noise. Compared with the half-duplex transmission, numerical results show an enhanced capacity with outage and ergodic capacity provided by IBFD under successful self-interference cancellation. We also study how the power bias and density ratio of the IAB-node to gNB, and the hard-core distance can affect system performances.

Figures (5)

• Figure 1: (a) Illustration of a multi-cell single-hop backhaul mmWave-IBFD-IAB network. (b) A realized mmWave-IBFD-IAB network. $R_0=1000$m, $\lambda_\mathrm{m}=1\times10^{-5}/\text{m}^2$, $\lambda_\mathrm{s}=4\times10^{-5}/\text{m}^2$, $\lambda_\mathrm{u}=2\times10^{-4}/\text{m}^2$, $\xi=100$m.
• Figure 2: Verification of theoretical results for (a) association probabilities and (b) $\mathrm{SINR}$ coverage v.s. bias ratio $\tfrac{T_\mathrm{s}}{T_\mathrm{m}}$ at $\mathrm{SINR}$ threshold $\tau=0,5,10$ dB.
• Figure 3: Single-hop backhaul mmWave-IBFD-IAB networks capacity with outage at a minimum received $\mathrm{SINR}=0$ dB (i.e., $\tau_\mathrm{min}=0$ dB) in terms of $\tfrac{T_\mathrm{s}}{T_\mathrm{m}}=0,10,20$ dB (a) v.s. different values of RSI factors; (b) v.s. different values of ADC quantization bits.
• Figure 4: Single-hop backhaul mmWave-IBFD-IAB networks ergodic capacity in terms of $\tfrac{\lambda_\mathrm{s}}{\lambda_\mathrm{m}}=4,6,8$ (${\lambda_\mathrm{m}}=1\times10^{-5}/\mathrm{m}^2$) (a) v.s. different RSI factor; (b) v.s. different hard-core distance.
• Figure 5: Ergodic capacity comparison for different links per subcarrier in terms of single path and multi-path scenario.