Combined Multiuser Signal Classification and Blind Equalization

A Multiuser Automatic Modulation Classifier (MAMC) is an important signal processing component of a multi-antenna cognitive radio (CR) receiver that can identify the modulation format employed by multiple users simultaneously. In a typical wireless communication system, transmitted signals are subjected to multipath fading and interference from other users. Multipath fading not only affects symbol detection performance but also affects the performance of the automatic modulation classifier (AMC). A multi-input multi-output (MIMO) blind equalizer is another important component of a multi-antenna CR receiver that improves symbol detection performance by reducing inter symbol interference (ISI) and inter user interference (IUI). In a CR scenario it is preferable to consider the performance of the AMC also while adapting the parameters of the blind equalizer. A n order cumulant based MAMC was recently proposed by the authors. In this paper, we propose a MIMO blind equalizer that improves the performance of both multiuser symbol detection and n order cumulant based MAMC. Computer simulations are provided to illustrate this concept and the proposed algorithm.