THE CONSTANT MODULUS ARRAY FOR COCHANNEL SIGNAL COPY AND DIRECTION FINDING

The constant modulus (CM) array is a blind adaptive beamformer capable of recovering a narrowband signal among several cochannel sources wit hout using a pilot or training signal. It is a conventional weight-and -sum adaptive beamformer whose weights are updated by the constant mod ulus algorithm. An adaptive signal canceller follows the beamformer to remove the captured signal from the array input and to provide an est imate of its direction vector. Based on a Wiener model, we investigate the steady-state properties of the CM array and the signal canceller, For mutually uncorrelated sources and noise, it is shown that the sig nal canceller exactly removes the source captured by the array. Thus, identical stages of the CM array and signal canceller may be used in a multistage system to recover several cochannel sources. Computer simu lations are presented to verify the analytical results and to illustra te the transient behavior of the system.