Adjustable Minimum Variance Distortionless Restriction Beamforming for Cognitive Radio Networks

In this work, a distributed beamforming scheme performed by a network of cognitive transmitters is proposed that can achieve a desired beampattern (BP) toward second-user-equipment receiver (SUE RX), while keeping its interference toward primary-user-equipment receiver (PUE RX) bounded. Specifically, the proposed solution extends the concept of minimum variance distortionless restriction (MVDR) beamforming to derive a more flexible method that can adjust BP with powers toward SUE RXs and PUE RXs under their thresholds. The numerical results exhibited at the end exemplify the possible BPs obtained by varying the key parameters, and show its performance gains achievable.