Fast Adaptive Beamforming with Smart Antenna for Radio Frequency Repeater

We present a fast adaptive beamforming null algorithm with smart antenna for Radio Frequency Repeater (RFR). The smart antenna system is realized by a Direction Of Arrival (DOA) Estimator, whose output is used by an adaptive beamforming algorithm to shape a suitable radiation pattern of the equivalent antenna; so that the co-channel interference due to retransmitting antenna can be reduced. The proposed adaptive beamforming algorithm, which has been proved by formulaic analysis and simulation, has a lower computation complexity yet better performance.