Image Number 3 for United States Patent #5434578.
A system for automatically forming a receive beam being positioned in the direction of a corresponding incoming signal, the system having a known signal corresponding to the incoming signal. The system comprises a plurality, M, of channels, each of the channels collecting the incoming signal and generating a plurality, L, of incoming complex data samples for the incoming signal and a plurality, L, of known complex data samples for the known signal. The system also includes severaly digital beamforming means for forming the receive beam. Each of the digital beamforming means includes means, coupled to the channels, for computing an M by 1 weight vector, W, having several weight elements each corresponding to one of the channels, the computing means including means for solving, for W, the equation, R W=C, where R is an M by M coefficient matrix, an element in the i-th row and the j-th column being an estimate of a value obtained from cross-correlating the incoming complex data sample generated by the i-th channel with the incoming complex data sample of the j-th channel, and where C is an M by 1 constant vector, an element in the i-th row being an estimate of a value obtained from cross-correlating the incoming complex data sample generated by the i-th channel with the known complex data samples. Each of the digital beamforming means further includes multipliers for generating weighted signals, each of the multipliers coupled to a corresponding one of the channels and multiplying one of the weight elements by the incoming complex data samples generated by the corresponding channel, and an adder, coupled to the multipliers, for adding each of the weighted signals.