Null-steering beamforming in uncertain environment

In this paper, we study a transmit null-steering beamforming problem for wireless sensor networks in uncertain communication environment. Given a desired receiver direction, the system requires to avoid the unknown eavesdroppers as well. In this case, we adjust both the sensors distribution and phase offsets such that beamforming is achieved at the desired direction, and meanwhile the communication of all the other directions is suppressed, which substantially reduces the risk of information theft by eavesdroppers. The Particle Swarm Optimization (PSO) algorithm is used to solve this constraint problem.