Separation of cochannel signals using the parametric constant modulus algorithm

In an earlier paper, Rao and Kumaresan (see Proc. of the 29-th Asilomar Conf. on Sig., Sys., and Comp., 1995) proposed a new algorithm, called the parametric constant modulus algorithm (PCMA) to demodulate noiseless, synthetic as well as real-world, cochannel FM signals. They extend the PCMA to develop two new procedures. The first one addresses the problem of reserving two closely spaced noisy sinewaves (from a short data record). The second algorithm is applied to estimate the phase parameters of two superimposed noisy chirp signals; both algorithm´s performance are compared with the Cramer-Rao bounds. The techniques described are of interest in wireless/military communications in the context of carrier frequency and Doppler estimation