CMA-Based Channel Estimation for Space-Time Block Coding Transmission Systems
Wireless Personal Communications: An International Journal
IEEE Transactions on Signal Processing
Blind equalization technique for cross correlation constant modulus algorithm (CC-CMA)
WSEAS Transactions on Signal Processing
A class of channels resulting in ill-convergence for CMA in decision feedback equalizers
IEEE Transactions on Signal Processing
Hi-index | 754.84 |
The Godard (1980) 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 the 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 the 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. The MSE bounds on CM receiver performance are derived and shown to be tight in simulations. The analysis shows that, while in some cases the CM receiver performs almost as well as the (nonblind) Wiener receiver, it is also possible that, due to its blind nature, the CM receiver may perform considerably worse than a (nonblind) Wiener receiver