  In this paper, a closed-form solution minimizing the Godard or Constant
Modulus (CM) cost function under the practical conditions of finite SNR and
finite equalizer length is derived. While previous work has been reported by
Zeng et al., IEEE Trans. Information Theory. 1998, to establish the link
between the constant modulus and Wiener receivers, we show that under the
Gaussian approximation of intersymbol interference at the output of the
equalizer, the CM finite-length receiver is equivalent to the nonblind MMSE
equalizer up to a complex gain factor. Some simulation results are provided to
support the Gaussian approximation assumption.
