A turbo-driven known-modulus blind equalization method

We describe and demonstrate a new turbo-driven blind equalization and decoding method that generates and exploits modulus information obtained initially by using a blind equalizer and a soft-input soft-output decoder. The method is turbo-like in that information is extracted from the equalizer and decoder outputs and then used in subsequent iterations, but it is less computationally complex than true turbo equalization. Compared with existing blind and nonblind turbo methods, the new methods easily accommodate fractionally-spaced equalizers, they can potentially be implemented in a fully blind manner, and they accommodate larger constellations and longer channels.