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

Residual self-interference (SI) is primarily a key challenge when designing In-Band Full-duplex (IBFDX) wireless systems. Channel estimation errors are one of the major causes of residual SI. Consequently, a deeper understanding of the impact of the channel effects on the residual SI becomes indispensable. In this paper, we investigate the influence of multiple taps on the residual SI power of IBFDX systems. We first formulate the effect of having independent taps on the residual SI power mathematically. The derivations take into account the amount of interference cancellation on each tap by considering phase and amplitude estimation coefficients. We conclude that the increase in the number of taps always leads to an additive effect of the residual power. Such findings are shown mathematically and also reported in different results obtained by simulation. Finally, we compare the distribution of the residual SI power with different known distributions, concluding that Weibull and Gamma distributions are the closest ones in terms of accuracy. In-Band Full-Duplex communication Residual self-interference Independent fading taps channel.authorsversionpublishe

Interference Estimation in Wireless Mobile Random Waypoint Networks

It is well known that the stochastic nature of the interference deeply impacts the performance of emerging and future wireless communication systems. In this work we consider an ad hoc network where the nodes move according to the Random Waypoint mobility model. Assuming a time-varying wireless channel due to slow and fast fading and, considering the dynamic path loss due to the mobility of the nodes, we start by characterizing the interference distribution caused to a receiver by the moving interferers located in a ring. For this purpose, we consider a receiver located at the center of the simulated region. Based on the distribution of the interference’s power, we evaluate different methodologies to estimate the power of the interference in real-time. Results achieved with a Maximum Log-likelihood estimator (MLE) and a Probability Weighted Moments (PWM) estimator are compared. The accuracy of the results achieved with the proposed methodologies in several simulations show that they may used as an effective tool of interference power estimation in future wireless communication systems, exhibiting high accuracy even when the number of samples is low

Familial thyroxine-binding globulin deficiency detected in a pilot screening program for congenital hypothyroidism

During a pilot screening program for congenital hypothyroidism, performed in Italy over a three years period on 38,000 newborns, seven cases (1/5,400) of thyroxine-binding globulin (TBG) deficiency, have been detected. None of these infants was affected by any pathology or had been treated with drugs which could explain TBG deficiency as an acquired condition. Familial studies pointed out that the transmission of the defect is consistent or compatible with X-chromosome linkage