Performance Of Full-duplex System Research Articles

Effect of Doppler Shift on the Performance of Full-Duplex Systems

Effect of Doppler Shift on the Performance of Full-Duplex Systems

Linear Transceiver Design for Full-Duplex MIMO Relay Systems: A Non-Iterative Approach

Full-duplex (FD) multiple-input multiple-output relaying can significantly increase the spectral efficiency of cooperative systems. As known, the loop interference (LI) is a main factor affecting the performance of FD systems. The joint source/relay precoding has been considered a promising technique to reduce the influence of LI. Unfortunately, existing methods are developed as iterative, which is not desirable from the implementation point of view. In this letter, we propose a novel design to solve the problem. The proposed scheme not only gives closed-form solutions but avoids iterative operations. Simulation results show that our design can provide comparable performance to iterative schemes; meanwhile the required computational complexity is lower.

Bidirectional Full-Duplex Systems in a Multispectrum Environment

Our investigation focuses on the performance of full-duplex systems where both nodes simultaneously exchange their signals using a single spectrum for two-way communication. To maximize the achievable sum rate (ASR) for full-duplex systems in multispectrum environments, we address a new selection strategy that considers the channel state of both nodes. The ASR for a multispectral bidirectional full-duplex (M-BFD) system is obtained using the proposed selection strategy and compared with conventional multispectral bidirectional half-duplex (M-BHD) systems. We derive the ASR as closed-form expressions and quantify the effect of selection diversity on the ASRs for M-BFD and M-BHD systems. In addition, we present practical-case Monte Carlo simulation results by considering the effects of self-interference (SI) and channel correlation. The numerical results show that the ASR gain for M-BFD is larger than that for M-BHD.

On Phase Noise Suppression in Full-Duplex Systems

Oscillator phase noise has been shown to be one of the main performance limiting factors in full-duplex systems. In this paper, we consider the problem of self-interference cancellation with phase noise suppression in full-duplex systems. The feasibility of performing phase noise suppression in full-duplex systems in terms of both complexity and achieved gain is analytically and experimentally investigated. First, the effect of phase noise on full-duplex systems and the possibility of performing phase noise suppression are studied. Two different phase noise suppression techniques with a detailed complexity analysis are then proposed. For each suppression technique, both free-running and phase locked loop based oscillators are considered. Due to the fact that full-duplex system performance highly depends on hardware impairments, experimental analysis is essential for reliable results. In this paper, the performance of the proposed techniques is experimentally investigated in a typical indoor environment. The experimental results are shown to confirm the results obtained from numerical simulations on two different experimental research platforms. At the end, the tradeoff between the required complexity and the gain achieved using phase noise suppression is discussed.

Rate Gain Region and Design Tradeoffs for Full-Duplex Wireless Communications

In this paper, we analytically study the regime in which practical full-duplex systems can achieve larger rates than an equivalent half-duplex systems. The key challenge in practical full-duplex systems is uncancelled self-interference signal, which is caused by a combination of hardware and implementation imperfections. Thus, we first present a signal model which captures the effect of significant impairments such as oscillator phase noise, low-noise amplifier noise figure, mixer noise, and analog-to-digital converter quantization noise. Using the detailed signal model, we study the rate gain region, which is defined as the region of received signal-of-interest strength where full-duplex systems outperform half-duplex systems in terms of achievable rate. The rate gain region is derived as a piece-wise linear approximation in log-domain, and numerical results show that the approximation closely matches the exact region. Our analysis shows that when phase noise dominates mixer and quantization noise, full-duplex systems can use either active analog cancellation or base-band digital cancellation to achieve near-identical rate gain regions. Finally, as a design example, we numerically investigate the full-duplex system performance and rate gain region in typical indoor environments for practical wireless applications.