Kimberley Brynn King
Digitally-Assisted RF-Analog Self-Interference Cancellation For Wideband Full-Duplex Radios
This thesis presents a new approach to cancel Self-Interference in full-duplex radios. By augmenting minimum complexity RF-analog interference cancellation hardware that uses a radio frequency (RF) vector multiplier with the flexibility and effectiveness of a digital rational function finite impulse response filter, the proposed approach allowed for excellent cancellation performance over a wide modulation bandwidth. The parameters of the proposed rational function finite impulse response filter are identified using a deterministic and single iteration algorithm. This algorithm is devised by exploiting a simplified baseband equivalent behaviour model of the front-end of the full-duplex radio. The hardware proof-of-concept prototype, built using off-the-shelf RF-analog circuits, demonstrated a self-interference cancellation of minimum 50~dB, and 40~dB for various digitally modulated test signals with modulation bandwidths of 20~MHz and 40-120~MHz respectively.