Distribution of the Residual Self-Interference Power in In-Band Full-Duplex Wireless Systems

Abstract

This paper derives the distribution of the residual self-interference (SI) power in an analog post-mixer canceler adopted in a wireless in-band full-duplex communication system. We focus on the amount of uncanceled SI power due to SI channel estimation errors. Closed form expressions are provided for the distribution of the residual SI power when Rician and Rayleigh fading SI channels are considered. Moreover, the distribution of the residual SI power is derived for low and high channel gain dynamics, by considering the cases when the SI channel gain is time-invariant and time-variant. While for time-invariant channels the residual SI power is exponentially distributed, for time-variant channels the exponential distribution is not a valid assumption. Instead, the distribution of the residual SI power can be approximated by a product distribution. Several Monte Carlo simulation results show the influence of the channel dynamics on the distribution of the residual SI power. Finally, the accuracy of the theoretical approach is assessed through the comparison of numerical and simulated results, which confirm its effectiveness. INDEX TERMSIn-band full-duplex radio systems, residual self-interference power, stochastic modeling, performance analysis.

Improving the Performance of Spatial Modulation Full-Duplex Relaying System With Hardware Impairment Using Transmit Antenna Selection

“…The termh jR (x j +η t R ) in (5) represents the self-interference originated from FD communication. Due to imperfect hardware and SI channel estimation error, SIC techniques at R may not remove SI completely.…”

Self-interference in Multi-tap Channels for Full-Duplex Wireless Systems

“…Despite of its importance, the characterization of the stochastic properties of the residual SI has received limited attention due to the difficulty of the mathematical modeling process [4][5][6]. In [4], the amount of cancellation and the strength of residual SI are computed considering a single-tap delay channel.…”

“…In [6], the distribution of the residual SI power is also characterized for a single-tap delay channel. In particular, the proposed modeling methodology assumes that the signal takes the same value for a consecutive number of samples, since the carrier frequency (and consequently the sampling frequency) is higher than any frequency component of the input signal.…”

Approximate Distributions of the Residual Self-Interference Power in Multi-Tap Full-Duplex Systems

“…The amount of cancellation and the strength of the residual SI were computed in [3] for a single-tap delay channel. The similarity of the residual SI distribution with known distributions was analysed in [6], and a closed-form approximation was presented in [7]. While [3], [6] and [7] only consider a single-tap delay channel, our work advances the current research in the field by proposing closed-form approximations to the distribution of the residual SI power in multi-tap delay fading channels and assuming hardware impairments.…”

“…The similarity of the residual SI distribution with known distributions was analysed in [6], and a closed-form approximation was presented in [7]. While [3], [6] and [7] only consider a single-tap delay channel, our work advances the current research in the field by proposing closed-form approximations to the distribution of the residual SI power in multi-tap delay fading channels and assuming hardware impairments. The novelty of our work is the assumption of multi-tap delay fading channels and the comparison of two different methods to compute the distribution of the residual SI.…”