In this paper, a spectrum sensing algorithm to detect the presence of OFDM based system (DVB-T) with pilot signal insertion is presented. The proposed algorithm makes use of time domain auto-correlation of pilot signals, however is able to differentiate spurious modeled by single tone, unlike existing algorithms which detect spurious as signals rather than noise. Simulation results show that the proposed algorithm achieves performance equal to that of existing algorithms based on autocorrelation of pilot signals. Moreover simulation results show that the proposed algorithm achieves better performance in terms of false alarm rate (<;0.01) than the existing algorithm (>;0.8). This observation indicate that our proposed algorithm is more robust to spurious, without performance loss in probability of detection.