Clustering and labeling of orthogonal signals for modulation identification

The increased demands for wireless communications lead to the development of cognitive radio, which realizes an effective utilization of channel resources. A modulation identification takes an important role in cognitive radio. In this paper an identification method is discussed for block orthogonal modulations expressed by general orthogonal modulation. The identification requires a reconstruction of signal-hypercube in a multidimensional space. The clustering and labeling methods are proposed for block orthogonal signals, and are evaluated from the view points of clustering error rate and labeling error rate.