Quick Change Detection In Multiple Channels Based On WLAN

Quick change detection in multiple channels is the technology that is employed bycognitive user to search spectrum hole to access as fast as possible. In this paper quickchange detection in multiple channels is mainly studied and its performance is verifiedin WLAN (Wireless Local Access Network). First of all, the development backgroundand status of cognitive radio and quick change detection in multiple channels isintroduced. Then the channel model for dynamic spectrum access and quick changedetection in single channel is introduced. And the algorithm for quick change detectionin multiple channels based on minimizing access delay is studied in detail. Theperformance of the algorithm is evaluated by simulation experiments in terms of accessdelay and handoff times. Simulation results indicate that the performance can beimproved significantly compared the case of multiple channels to single channel, andthe algorithm of multi-channel with memory to that without memory. And then themathematical model for multiple channels based on exponential distribution isestablished to improve the applicability of quick change detection in multiple channelswith memory. Finally, the channel model and the algorithm based on multiple channelsare verified by using the data collected from the WLAN through USRP (UniversalSoftware Radio Peripheral) and the algorithm is realized.