Relationships Between the Constant Modulus and Wiener Receivers

— The Godard or the constant modulus algorithm (CMA) is an effective technique for blind receiver design in communications. However, due to the complexity of the Constant Modulus (CM) cost function, the performance of CM receivers has primarily been evaluated using simulations. Theoretical analysis is typically based on either the noiseless case or approximations of the cost function. The following question, while resolvable numerically for a specific example, remains unanswered in a generic manner: In the presence of channel noise, where are the CM local minima and what are their mean-squared errors (MSE)? In this paper, a geometrical approach is presented that relates CM to Wiener (or minimum MSE) receivers. Given the MSE and the intersymbol/user interference of a Wiener receiver, a sufficient condition is given for the existence of a CM local minimum in the neighborhood of the Wiener receiver. MSE bounds on CM receiver performance are derived and shown to be tight in simulations...

• Type: Journal
• Year: 1998
• Where: TIT
• Authors: Hanks H. Zeng, Lang Tong, C. Richard Johnson Jr.
• Keywords: Cm Receiver, Constant Modulus, TIT 1998, Wiener Receiver