Full-duplex Wireless Research Articles

Drone-based mobile full-duplex optical communication

Wireless optical communication plays a vital role in mobile communication networks, and both drones and vehicles are essential mobile communication nodes. Here, image identification technology, gimbal, and full-duplex optical communication systems are integrated to manage the challenging issues of light alignment and target tracking for mobile full-duplex optical communication under the transmission control protocol/internet protocol (TCP/IP) scheme. Both drones and vehicles are equipped with the proposed setup to realize full-duplex wireless optical data transmission at a communication rate of 2 Mbps in both air-to-ground and air-to-air scenarios. By further integrating wireless-fidelity (Wi-Fi) modules, drone-based mobile optical communication systems (MOCSs) can be interconnected with the network via the TCP/IP scheme, and real-time video transmission can be demonstrated. This work provides a feasible route toward a mobile optical communication network (MOCN) for diverse applications.

Movable Antenna-Enabled Co-Frequency Co-Time Full-Duplex Wireless Communication

Movable Antenna-Enabled Co-Frequency Co-Time Full-Duplex Wireless Communication

An experimental study on beamforming architecture and full-duplex wireless across two operational outdoor massive MIMO networks

Full-duplex (FD) wireless communication refers to a communication system in which both ends of a wireless link transmit and receive data simultaneously in the same frequency band. One of the major challenges of FD communication is self-interference (SI), which refers to the interference caused by transmitting elements of a radio to its own receiving elements. Fully digital beamforming is a technique used to conduct beamforming and has been recently repurposed to also reduce SI. However, the cost of fully digital systems dramatically increases with the number of antennas, as each antenna requires an independent Tx-Rx RF chain. Hybrid beamforming systems use a much smaller number of RF chains to feed the same number of antennas, and hence can significantly reduce the deployment cost. In this paper, we aim to quantify the performance gap between these two radio architectures in terms of SI cancellation and system capacity in FD multi-user Multiple Input Multiple Output (MIMO) setups. We first obtained over-the-air channel measurement data on two outdoor massive MIMO deployments over the course of three months. We next study SoftNull and M-HBFD as two state-of-the-art transmit (Tx) beamforming based FD systems, and introduce two new joint transmit-receive (Tx-Rx) beamforming based FD systems named TR-FD2 and TR-HBFD for fully digital and hybrid radio architectures, respectively. We show that the hybrid beamforming systems can achieve 80%–99% of the fully digital systems capacity, depending on the number of users. Our results show that it is possible to get many benefits associated with fully digital massive MIMO systems with a hybrid beamforming architecture at a fraction of the cost.

On the Learning of Digital Self-Interference Cancellation in Full-Duplex Radios

On the Learning of Digital Self-Interference Cancellation in Full-Duplex Radios

Sum Rate Maximization for Multiuser Full-Duplex Wireless Powered Communication Networks

Sum Rate Maximization for Multiuser Full-Duplex Wireless Powered Communication Networks

A Simple Neural Network for Nonlinear Self-Interference Cancellation in Full-Duplex Radios

A Simple Neural Network for Nonlinear Self-Interference Cancellation in Full-Duplex Radios

Fairness-Aware Transmitter Design for OFDMA-Based Full-Duplex Wireless Powered Communication Networks

Fairness-Aware Transmitter Design for OFDMA-Based Full-Duplex Wireless Powered Communication Networks

Factor graph-based deep reinforcement learning for path selection scheme in full-duplex wireless multihop networks

A wireless multihop network (WMN) is set of wirelessly connected nodes without an aid of centralized infrastructure that can forward any packets via intermediate nodes by a multihop fashion. In the WMN, there are still some issues that need to be resolved, like due to any source node may choose an uncertainty path to send their packets through the multihop fashion and this leads to the performance of network capacity can degrade drastically. To solve this problem, in this research, we propose two novel path selection algorithms called SNR-based learning path selection (NLPS) algorithm and SINR-based learning path selection (INLPS) algorithm, which are incorporated with the deep reinforcement learning (DRL) to select the best multihop path from any source node to a destination node with highest end-to-end (E2E) throughput. Besides that, a factor graph (FG) approach and a nested lattice code (NLC) representation are used to reduce the computation time. According to the numerical studies with the NLC is applied, our simulation results reveal that the proposed NLPS and INLPS algorithms can improve the overall average network capacity up to 3.1 times and 10.5 times compared to FG, respectively. However, the overall average computation time are highly increased for NLPS and INLPS, i.e., about 0.627 s and 1.221 s, respectively compared to FG, which is about 0.006 s. In other words, both NLPS and INLPS algorithms can achieve high network capacity and moderate computation time.

Deep learning based detection of signal of interest of uplink NOMA multi-users in NOMA In-band Full-duplex Radio communication

The research focuses on investigating the symbol error rate (SER) performance of the Non Orthogonal Multiple Access (NOMA) In-band Full-duplex Radio communication system, which is considered a promising technology for 5G/6G. This system facilitates simultaneous transmission and reception of data over the same resource block for multiple users via power domain multiplexing. However, the system faces a significant challenge in the form of self-interference signal (SI). The SI signal transmitted from the NOMA In-band full-duplex radio transmitting antenna is also received by its own receiving antenna. It limits perfect successive interference cancellation (SIC) for channel estimation and signal detection of the signal of interest (SoI) from uplink NOMA multi-users at the receiver of NOMA In-band Full-duplex radio. Furthermore the SER performance is significantly degraded due to various SI and SoI channel imperfections. To address this, a three-phase-based efficient approach has been proposed for simultaneous non-linear SI cancellation and detection of the SoI from uplink NOMA two users under aforementioned SI and SoI channel imperfections. The approach uses the Least Square-SIC Estimator, Minimum Mean Square Error-SIC Estimator, and deep learning (DL) methods. The reported 4 dB SNR gain compared to least square-SIC/minimum mean square error SIC and DNN-based methods demonstrate the robustness of the proposed DL-aided approach against various SI and SoI channel imperfections for NOMA In-band Full-duplex Radio communication.

Dual-polarization MZM-based photonic nonlinear analog self-interference cancellation for in-band full-duplex radios

In this paper, we propose a dual-polarization Mach-Zehnder modulator-based photonic nonlinear analog self-interference cancellation (SIC) technique for in-band full duplex (IBFD) systems. By using the proposed technique, an arbitrary 4th order nonlinear transfer function can be generated, meaning the performance limitation caused by the nonlinearity of the analog SIC circuit can be overcome by imitating the nonlinear transfer function of the analog SIC circuit before cancellation. This paper also presents a performance analysis through simulations and the results of a proof-of-concept demonstration. In the experiment, the proposed nonlinear SIC technique could achieve 29 dB cancellation over 500 MHz bandwidth centered at 1.25 GHz frequency along various degree of distortion caused by nonlinearity. In addition, the performance enhancements achieved by the proposed technique are evaluated in terms of error vector magnitudes (EVMs) and constellations of the signal-of-interest (SOI) in the simulation which is based on the experimental SIC results. More than 3 dB of SOI power gain could be obtained in evaluated EVM performances.

Energy-Efficiency Optimization With Model Convexification for Wireless Ad Hoc Networks With Multi-Packet Reception Capability

Energy efficiency is a significant requirement of resource management and design optimization in information networks. In this work, we propose an iterative fractional programming framework embedded with a distributed primal-dual extra-gradient projection algorithm, which addresses a wide class of the energy-efficiency optimization problems in wireless ad hoc networks with full-duplex radios and multi-packet reception capability. Specifically, we propose a model convexification mechanism by joining an affine transformation and an exponential transformation into the nonlinear fractional programming, which enables us to deal with the challenge arising from the complexity and non-convex structure of the original problem. With the model convexification, we can map the non-convex power control space into a convex space and equivalently derive a sequence of convex subproblems, which relaxes the convexity assumption widely adopted in the existing literature. We further propose a distributed primal-dual algorithm based on extra-gradient projection to solve the convex subproblem at each iteration of the fractional programming. The convergence of the proposed iterative fractional programming and the distributed optimization method is theoretically proven. Numerical results also verify the proposed method and demonstrate its superior performance over other representative distributed and centralized schemes in terms of achieving global energy efficiency.

HITLinQ: Improving path capacity through hybrid information-theoretic link scheduling in multi-hop wireless networks

By taking advantage of full-duplex radios, a one-sided interference channel model in the case of co-directional transmission on two links having a common node is introduced. Analysis of this model shows that asymmetric increase of transmitter power or decrease of distance will change the path capacity. When the signal noise ratio is high in this channel, using full-duplex radios for simultaneous co-directional transmission will worsen the path capacity, while direct transmission is better. On this basis, a scheduling strategy, called the hybrid information-theoretic link scheduling (HITLinQ) algorithm, which combines self-interference and inter-link interference management with link reconstruction, is proposed. The simulation results show that HITLinQ can provide capacity of not less than several baseline algorithms on a long multi-hop path under given setting.

Contention With Collision Detection in Wireless Full-Duplex Networks

Contention With Collision Detection in Wireless Full-Duplex Networks

2 × 2 MIMO In-Band Full Duplex Radio Front-End With Two-Stage Passive Suppression and Four Three-Tap RF Cancellers

2 × 2 MIMO In-Band Full Duplex Radio Front-End With Two-Stage Passive Suppression and Four Three-Tap RF Cancellers

Machine Learning-Based Self-Interference Cancellation for Full-Duplex Radio: Approaches, Open Challenges, and Future Research Directions

Machine Learning-Based Self-Interference Cancellation for Full-Duplex Radio: Approaches, Open Challenges, and Future Research Directions

Novel Cancellation Techniques and Throughput Analysis for 6G Full-Duplex Wireless System

Recent researches show that it is possible to achieve full-duplex system if the self-interference signal could be cancelled completely for 6G research. The majority of the overall self-interference cancellation is contributed by passive cancellation. The lowest complexity cancellation technique is digital cancellation. Therefore, this paper presents a novel passive cancellation technique based on multi-path effect and a novel digital cancellation method considering nonlinearity factor in full-duplex system. Therein, for passive cancellation method, theoretical analysis is presented and practical experiments show that it can achieve about 50 dB only in 10-cm space. For digital cancellation method, a model based on practical platform is given and it can achieve about 30 dB under high transmit power. In addition, two relay schemes based on full-duplex for two-way relay channel called FD-DF (full-duplex decode-and-forward) and FD-AF (full-duplex amplify-and-forward) are presented. Two proposed schemes can nearly double the system throughputs especially in high signal-to-noise radio regions compared with traditional AF scheme.

A Balanced Distributed Cascode Power Amplifier With an Integrated Chebyshev Load Balancer for Full-Duplex Wireless Operation

A Balanced Distributed Cascode Power Amplifier With an Integrated Chebyshev Load Balancer for Full-Duplex Wireless Operation

OSAT Production Testing of 5G, Power Discretes & 3D packaged ICs

The presentation will be segmented into three. OSAT production testing challenges of three vital product families that are important to our semiconductor industry will be showcased in each segment. The first segment will describe the products and impacts to RF production testing of both Sub-8GHz carrier frequency range and the mmWave frequency range of operation. The second segment will explore emerging MOSFET technologies that enable faster switching rates and higher voltage and current topologies. The third segment will describe the challenges of production test content for 3D-stacked advanced packages. 5G RF has enabled mmWave carrier frequencies, small cell deployment, massive MIMO (Multiple In, Multiple Out), beam forming, and full duplex wireless transmission and reception operations. These features require new production test methodologies. There is an astronomical rise in battery powered applications like toys, consumer goods, automotive and trains. Power path turn on/off with MOSFETs is in the critical path. The technology has advanced from the traditional Si to GaN and SiC based products that have a smaller size and allow for higher application efficiencies. Test specifications and limits are improving and production testing methods are evolving to account for these changes. Advanced packaging has enabled the path to integrate chiplets within a single package. Heterogeneous Integration (HI) is a powerful design innovation that allows tighter integration and, in some cases, improved signal and power performance at the system level. Production test methodologies are being streamlined to make test a competitive advantage for our customers.

Self-Interference Cancellation Techniques for In-Band Full-Duplex Wireless Communication Systems: A Review

In-Band Full-Duplex (IBFD) systems have the capability of simultaneously transmitting and receiving signals through the channel and require the same resources as half-duplex systems. Unfortunately, IBFD systems have self-interference (SI) issues that prevent the system from gaining double throughput with respect to half-duplex systems. Therefore, the IBFD system will be more reliable if SI is mitigated more. This contribution will look at SI cancellation in wireless radio and underwater acoustic systems. The reviewed documents cover all types of SI cancellations, including passive, analog, and digital cancellations. In a practical full-duplex system, the SI cancellation for all domains must cancel the SI below the receiver noise floor.

Power Optimization of Cell-Free Massive MIMO With Full-Duplex and Low-Resolution ADCs

This paper analyzes the spectral/energy efficiency (SE/EE) of a full-duplex (FD) cell-free (CF) massive multiple-input multiple-output (mMIMO) over Rician fading channels. Due to the FD radios, the access points (APs) suffer from self-interference (SI) and inter-AP interference (IAI) while the downlink (DL) users’ signals are corrupted by the uplink (UL) users’ transmissions. We consider the case, where low-resolution analog-to-digital converters (ADCs) are utilized at the APs and DL users, which introduces the quantization noise (QN). The combined effects of Rician κ-factor, residual SI/IAI, UL-to-DL interference, multi-user interference, and QN on the UL/DL SEs are characterized. The UL SE is degraded by the increase in DL power, whereas the growth in UL power deteriorates the DL SE. The effects of the residual SI/IAI and UL-to-DL interference are worsened by the low-resolution ADCs. We optimize the UL/DL transmit powers to maximize the overall sum SE of the network. It is observed that the proposed power allocation algorithm brings substantial sum SE gain. A trade-off analysis between the EE and SE, as a function of the ADCs’ resolution, shows that the entire envelope of the operating region of FD CF mMIMO is enhanced in Rician channels.