A spectrum sensing prototype for Japanese digital television signals

Both spectrum regulators and standardization organizations are making efforts to realize licensed exempt utilization of TV white space (TVWS). One of major concerns in the usage of TVWS is the potential interference imposed by a TV band device (TVBD) to primary users (PU) in TV bands. Spectrum sensing is used as one important solution for protection of PU. In this work, we aim at developing a real-time sensing prototype that fulfills FCC regulation requirement for sensing only TVBD. To overcome the sensing challenges arising from adjacent channel interference (ACI) in real sensing world, a partial bandwidth based feature detection (PB-FD) method is proposed, which can be used to detect many types of OFDM based signals. When the PB-FD is applied to detect DTV signals of Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) standard, it is specified to detect the centre segment of ISDB-T spectrum. In this paper, we present the sensing algorithm and its simulation results, major system features and performance of the sensing prototype. Hardware performance test for sensing ISDB-T signals under ACI is performed. A sensing performance of above 0.9 detection probability with a false alarm probability of 0.01 is achieved for signal level ≥-114dBm/6MHz, with a sensing time equals to 0.6 second for sensing one channel.