Global convergence of a single-axis constant modulus algorithm

We propose a modification to the constant modulus criterion for real valued sources processed with a complex valued receiver. Our modification is called single-axis constant modulus criterion (SA-CM) because it operates solely on the real component of the complex equalizer output. We show that under idealized conditions, a finite length, baud-spaced, complex valued equalizer minimizing the SA-CM criterion admits only desirable global minima settings that are ISI-free. A single-axis receiver architecture is compared to other receiver architectures for real valued sources and staggered modulation schemes. Simulation examples using vestigial sideband (VSB) signaling verify our methods.