Performance analysis of CMA adaptive array for QAM signals
Kentaro Nishimori, Nobuyoshi Kikuma, Naoki Inagaki · Electronics and Communications in Japan (Part I Communications) · 1997
Recently, land mobile communication has advanced significantly. In order to carry out transmission at higher speeds than ever, the problem of frequency-selective fading due to multipath propagation must be addressed. As a remedy, the use of an adaptive array is investigated. Of these adaptive arrays, the CMA adaptive array is known to have excellent interference suppression characteristics. The CMA was originally conceived for constant-modulus signals. However, from the point of view of efficient frequency use, the characteristics of the CMA for signals of nonsteady modulus such as 16 QAM signals have been recognized and operating examples have been reported. However, to date no discussion has been reported as to the excellent operation of the CMA for QAM signals. In this paper, by using the two-wave model, an operation analysis (multipath suppression and convergence) of the CMA for QAM signals is carried out theoretically. Also, computer simulation is carried out to verify the validity of the theoretical analysis. © 1997 Scripta Technica, Inc. Electron Comm Jpn Pt 1, 80(11): 11–21, 1997