The complex bootstrap algorithm for blind separation of QAM multiuser CDMA signals

The bootstrap separator for multiuser signals is principally composed of cancelers, each one using the output of the other cancelers to facilitate control of its adaptive weight. In fact, such a structure performs as a "signal separator" rather than an interference canceler. Since for its separation there is no need for a reference signal las in LMS cancelers), it is sometimes justifiably called a "Blind Separator". However, for its operation the bootstrap separator requires a signal distinguisher termed "discriminator". The algorithm was used in the past in applications such as dually polarized satellite communications and microwave terrestrial links. It was particularly reported for multiuser CDMA signal separating, with the signum function as discriminator. Especially for QAM signals, complex presentation is important. Therefore, we will concentrate in this report on what we call the "Complex Bootstrap Algorithm". It is an extension to the previously reported bootstrap structure of [5]. We will examine its performance and emphasize the hardware saving in its implementation, and the ease of using it in simulation.