Cyclostationary analysis of analog least mean square loop for self-interference cancellation in in-band full-duplex systems

© 2017 IEEE. Analog least mean square (ALMS) loop is a promising mechanism to suppress self-interference (SI) in an in-band full-duplex (IBFD) system. In this letter, a general solution for the weighting error function is derived to investigate the performance of the ALMS loop employed in any IBFD system. The solution is then applied to IBFD systems with single carrier and multicarrier signaling. Due to the cyclostationary property of the transmitted signal, the weighting error function in the multicarrier system varies more significantly than in the single carrier. Therefore, if the ALMS loop can perfectly mimic the SI channel, SI in the single carrier system can be suppressed to a much smaller level than that in the multi-carrier counterpart

Analog Least Mean Square Loop for Self-Interference Cancellation in Generalized Continuous Wave SAR

© 2018 IEEE. Generalized continuous wave synthetic aperture radar (GCW-SAR) is a promising new imaging radar system since it applies the full-duplex (FD) transmission technique to achieve continuous signaling in order to overcome several fundamental limitations of the conventional pulsed SARs. As in any FD wireless communication system, self-interference (SI) is also a key problem which can impact on the GCW-SAR system. In this paper, the analog least mean square (ALMS) loop in the radio frequency domain is adopted to cancel the SI for a GCW-SAR system with periodic chirp signaling. The average residual SI power after the ALMS loop is analyzed theoretically by a stationary analysis. It is found that the ALMS loop not only works with random signals in general FD communication systems, but also works well with the periodic signal in GCW-SAR systems. Simulation results show that over 45 dB SI cancellation can be achieved by the ALMS loop which ensures the proper operation of the GCW-SAR system

Analog Least Mean Square Loop for Self-Interference Cancellation in Generalized Continuous Wave SAR

Generalized continuous wave synthetic aperture radar (GCW-SAR) is a promising new imaging radar system since it applies the full-duplex (FD) transmission technique to achieve continuous signaling in order to overcome several fundamental limitations of the conventional pulsed SARs. As in any FD wireless communication system, self-interference (SI) is also a key problem which can impact on the GCW-SAR system. In this paper, the analog least mean square (ALMS) loop in the radio frequency domain is adopted to cancel the SI for a GCW-SAR system with periodic chirp signaling. The average residual SI power after the ALMS loop is analyzed theoretically by a stationary analysis. It is found that the ALMS loop not only works with random signals in general FD communication systems, but also works well with the periodic signal in GCW-SAR systems. Simulation results show that over 45 dB SI cancellation can be achieved by the ALMS loop which ensures the proper operation of the GCW-SAR system