Asynchronous Detection and Avoidance (DAA) Protocol for Interference Mitigation in Dynamic Spectrum Access

Dynamic spectrum access (DSA) allows opportunistic use of licensed spectral bands by unlicensed radio devices. DSA improves the overall spectral efficiency but could result in interference between licensed and unlicensed radio devices. In this paper, we investigate the detection and avoidance (DAA) technique to mitigate such potential interference. We develop a time-domain asynchronous coordination protocol that provide silent periods for unlicensed devices to detect licensed devices. The protocol does not require any information exchange between the unlicensed devices and thus, is applicable even when the devices are hidden to each other. This new protocol can be used by ultra wide band (UWB) devices to detect and protect WiMax devices within the 3- to 5-GHz bands.