Second-order LMS based wireless channel tracking: implementation under imperfect carrier synchronization

• Published in: Signal processing 2003, Vol.83 (1), p.199-212
• Main Authors: Xue, Yisheng, Zhu, Xuelong
• Format: Article
• Language: English
• Subjects: Applied sciences; Carrier synchronization; Detection, estimation, filtering, equalization, prediction; Digital phase-locked loop; Exact sciences and technology; Extended Kalman filter; Information, signal and communications theory; Second-order LMS algorithm; Signal and communications theory; Signal, noise; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Wireless channel tracking
• ISSN: 0165-1684; 1872-7557
• DOI: 10.1016/S0165-1684(02)00392-4

In this paper, we are concerned with the implementation of second-order LMS (SOLMS) based wireless channel tracking under imperfect carrier synchronization. First, we present a performance analysis of the SOLMS based wireless channel tracking in the presence of carrier-frequency offset. With this analysis, we study how carrier-frequency offset affects the performance of the SOLMS based tracking designed under perfect carrier synchronization. Our studies show that only when high quality oscillators are employed can we take the carrier-frequency offset as part of the fading channel gain and perform adaptive wireless channel tracking directly. Then, under the framework of extended Kalman filtering, we propose an adaptive joint wireless channel tracking and carrier-frequency offset compensation method that can be simplified to a SOLMS based channel tracking with an incorporated second-order digital phase-locked loop. Monte-Carlo simulations under an IS-136 like environment are performed to support the theoretical analysis and to demonstrate the performance of the proposed method.