Protocol analysis of signal detection for deriving minimum isolation distance for frequency recycling under WLAN

The cognitive radio (CR) system is powerful technique for significantly improving the frequency spectrum efficiency. This paper clarifies the minimum distance of the two independent wireless LAN (WLAN) systems for suppressing the mutual interference, where the WLAN system is one of CR systems. We use the two real-time spectrum analyzers for the simultaneous detection of the emitted signals from the two systems. As a result, we detect not only the packet access timing of two systems but also the length of packet. Therefore, the protocol of WLAN system is recognized, so the minimum distance of two systems for spectrum sharing is estimated.