Tam Çift Yönlü Haberleşme Sistemleri için Analog Özgirişim Giderme Teknikleri

Abstract

Currently, with the development of the communication systems, the demand for high speeds and spectrum is increasing. In order to satisfiy this demand, Full Duplex Communication Systems are being studied. It doubles the spectrum efficiency because they work at the same time and the same frequency. However, since the communication is done at the same time and frequency, the strong tranmit signal leakage the receiver path. This leakage is called self interference and it prevents Full Duplex Communication. In order to have healthy communication, this self interference must be cancelled. This cancellation is done in three different areas such as propagation domain, analog domain and digital domain. In this thesis, self interference cancellation is emphasized in propagation and analog domain. First of all, different configurations are implemented in the propagation area. According to the isolation and characteristics in this area, self interference has been cancelled in the analog domain. In the analog domain cancellation, self interference is imitated and removed from the receiving line. In the studies analog domain, using the adaptive filter infrastucture, firstly self interference cancellation was studied therotically, then this self interference cancellation was realized by designing card. According to the spectum results obtained from this card, approximately 60 dB self interference cancellation has been achivied at 10 MHz bandwidth. Error Vector Magnitude analysis was carried out in order to examine the effect of this self Interference cancellation on communication systems. According to this analysis, -55 dBm receiving sensitivity performance was measured while transmitting 0 dBm.