A Pattern Shaping Approach for Distributed Collaborative Beamforming

Collaborative transmit beamforming using coherent distributed arrays is a method by which multiple wireless nodes synchronize their transmissions in order to synthesize a virtual antenna array. Assuming a high degree of inter-node synchronization in frequency, phase, and location, wireless transmitters can synthesize a beam with a power gain of N2 towards any arbitrary direction. Using a planar model, we examine the use of global optimization algorithms to add additional beams or nulls to the transmit pattern of a distributed array. Using simulations, we show that adjusting the positions of array nodes can reliably create multiple side beams or nulls in desired azimuth locations. Simulated annealing and pattern search optimization methods are explored for both beam forming and nulling and are compared across the average side beam intensity, node displacement, and algorithm running time.