Semi-Blind Channel Monitoring Mechanisms for Post-Switchover Wireless Microphones

In this paper, we discuss the use of spectrum sensing as a contingency for future wireless microphones (WM). We represent post-switchover operation conditions as a framework where WM sense for signals of digital television (DTV) and TV band devices (TVBD). Using this model, we propose two semi-blind channel monitoring mechanisms that ensure quality of service through fast and fine sensing. To implement such mechanisms, we analyze the pros and cons of five potential detection methods with respect to computational complexity, amount of prior information required for detection, classification ability, and performance under AWGN and frequency-selective fading. Our analysis suggests that methods based on the cyclic prefix (CP) are promising for fast sensing as long as portable TVBD can be detected. With respect to fine sensing, we suggest methods that exploit scattered pilots to improve classification ability and robustness against noise uncertainty, CP length variations, and multipath. The proposed mechanisms incur no performance loss in comparison to fast sensing methods in isolation.