Incorporation of linear constraints into the constant modulus algorithm

A linearly constrained version of the constant modulus algorithm (CMA) is developed. It is based on the decomposition property of the generalized sidelobe canceller (GSC) filter structure. When they can be specified, linear constraints are an effective means of incorporating a priori information into the constant modulus algorithm. Exploitation of this knowledge makes the linearly constrained constant modulus (LCCM) approach much less vulnerable to interfering constant-envelope signals, which can cause cancellation of the signal of interest. This is demonstrated in a simulation of the LCCM algorithm in an adaptive array application that includes multipath and constant-modulus interference