Hybrid Full-/Half-Duplex System Analysis in Heterogeneous Wireless Networks (1411.4848v2)

Abstract: Full-duplex (FD) radio has been introduced for bidirectional communications on the same temporal and spectral resources so as to maximize spectral efficiency. In this paper, motivated by the recent advances in FD radios, we provide a foundation for hybrid-duplex heterogeneous networks (HDHNs), composed of multi-tier networks with a mixture of access points (APs), operating either in bidirectional FD mode or downlink half-duplex (HD) mode. Specifically, we characterize the net- work interference from FD-mode cells, and derive the HDHN throughput by accounting for AP spatial density, self-interference cancellation (IC) capability, and transmission power of APs and users. By quantifying the HDHN throughput, we present the effect of network parameters and the self-IC capability on the HDHN throughput, and show the superiority of FD mode for larger AP densities (i.e., larger network interference and shorter communication distance) or higher self-IC capability. Furthermore, our results show operating all APs in FD or HD achieves higher throughput compared to the mixture of two mode APs in each tier network, and introducing hybrid-duplex for different tier networks improves the heterogenous network throughput.

• The paper presents a framework integrating full- and half-duplex modes to enhance spectral efficiency, showing FD benefits under high AP density and strong self-interference cancellation.
• It employs a Poisson point process model to characterize network and self-interference impacts in K-tier wireless systems.
• The results indicate that strategic FD and HD mode deployment can significantly improve throughput, paving the way for optimized next-generation wireless networks.

Analysis of Hybrid Full-/Half-Duplex Systems in Heterogeneous Wireless Networks

This paper provides a comprehensive analysis of hybrid full-duplex (FD) and half-duplex (HD) communication modes in heterogeneous wireless networks. The research leverages recent advances in FD radio technology to propose a framework that integrates both duplex modes, aiming to enhance the spectral efficiency and throughput of future cellular networks. The paper intricately models network interference, self-interference, AP spatial density, and transmission power, presenting a thorough examination of hybrid-duplex heterogeneous networks (HDHN).

Network Model and Interference Characterization

The authors outline a network composed of K-tier wireless systems, where access points (APs) operate either in FD or HD mode. FD radio allows simultaneous transmission and reception, potentially doubling spectral efficiency, but introduces self-interference challenges. HD mode traditionally isolates transmission and reception to mitigate such issues. The paper characterizes interference from FD-mode cells using a Poisson point process (PPP) framework and explores the role of spatial AP distribution and its impact on communication efficiency.

Throughput Analysis and Results

The key contribution is the derivation of the HDHN throughput, defined as the average data rate per unit area that is successfully transmitted and received in the network. The analysis considers several parameters, including AP spatial density and self-interference cancellation (IC) capabilities, revealing complex trade-offs between network interference and duplex mode selection. The research finds that FD is generally more advantageous under conditions of high AP density or strong self-IC capabilities, corroborated by simulation results.

The paper meticulously calculates the successful transmission probabilities and presents scenarios where FD mode leads to superior network throughput compared to HD. Notably, it suggests that under perfect self-interference cancellation, operating all APs in FD mode optimizes the throughput, as the added capability of bidirectional communication outweighs the potential interference drawbacks.

Practical and Theoretical Implications

This paper’s implications are significant for the design and optimization of next-generation wireless networks. It provides a foundation for considering diverse duplex modes across different network tiers to maximize throughput. The findings suggest strategic deployment of FD and HD modes can lead to substantial improvements in network performance, particularly in dense urban environments.

Theoretically, the research enriches the understanding of duplex mode interaction with network interference, highlighting the necessity for advanced self-interference mitigation techniques in future FD implementations. It opens pathways for further exploration into adaptive duplex mode switching, refined interference management, and enhanced multi-antenna FD systems.

Future Directions

Future work could explore multi-antenna FD systems, examining how MIMO configurations alter the interference landscape and throughput dynamics in HDHN. There is also potential for exploring adaptive transmission power control and advanced interference cancellation methods to further optimize FD operation in heterogeneous networks.

In summary, this paper presents a robust analysis of hybrid-duplex systems, offering valuable insights into optimizing wireless network performance through strategic duplex mode deployment. By quantifying the interactions between network parameters and interference, it sets the stage for further advancements in the field of wireless communications.