Digital Self-Interference Cancellation with Phase Noise Compensation in Full-Duplex OFDM Systems

Increasing demand of high-speed wireless communications, and shortage of available bandwidth necessitate the use of a new generation of communication system capable of utilizing less bandwidth. Deployment of OFDM has let us to reach this aim, however, it still needs to be improved and deal with many obstacles which is required to have a better experience in communicating devices. One of the main challenges in OFDM systems is to solve the issue of the self-interference. Self-Interference happens when the transceiver receives what it is sending, because the transmitter and receiver work in the same frequency. Thus, when it receives the transmitted signal, we should implement an algorithm to remove Self-Interference signal and get the Signal of Interest. This raises another problem, as we wish to just receive the signal from the side, user equipment, the signal’s power is much less than the power of the Self-Interference signal and results in more sophisticated received signal. In this thesis first we studied behavior of OFDM channels in Half-Duplex which there is no Self-Interference. The mutual obstacles which both Half-Duplex and Full-Duplex systems suffer from is Phase Noise, and in full duplex becomes more crucial as we have the effect of the self-interference which results in low gain and high ratio of the noise. This thesis focuses on the compensation of the phase noise in the full duplex system and its effect in cancelling Self-Interference. Half-Duplex system is designed based on recent studies which focus on suppressing the effect of the phase noise, then based on this system, we expanded the system to work in full-duplex mode.