Self-Interference Cancellation in Full Duplex Radios and LTE-Unlicensed.

摘要

All the commercial radios are half duplex in a sense that they are unable to transmit and receive at the same time on the same frequency. A full duplex radio simultaneously transmits and receives at that same time and on the same frequency thus doubling the throughput of the existing systems. One of the fundamental challenges in enabling full duplex is the cancellation of the self-interference that is caused by device's own transmitter. Considering the high level of the self-interference at the receiver front end, it is necessary to cancel out the interference in the analog domain to avoid the ADC saturation. As one of the major focus of this thesis, all the existing methods, algorithms and accomplishments in enabling full duplex have been summarized. A novel method for interference cancellation using cables, power splitters and step attenuators has been implemented on the actual hardware and its performance evaluation and limitations have been summarized.;Currently deployed cellular networks use bands which have been licensed and approved by the FCC. With the developments in cellular standards Rel-10 LTE advanced which supports carrier aggregation has been established where a multiple carriers are aggregated to provide a larger bandwidth. As cellular operators explore the possibility of extending the carrier aggregation to the unlicensed spectrum in the 5GHz, current developments in creating a friendly ecosystem in unlicensed bands have been summarized which form the basis of Rel-13 LTE- Licensed Assisted Access.