Research On Spectrum Detection Based On Signal Statistic Characteristics

With the growing demand of multimedia communication services, the spectrum resources are scarce. A new technology which improves the utilization rate of the spectrum by twice using the spectrum called Cognitive Radio has been advanced in this paper. Cognitive radio can address the status of spectrum shortage effectively. According to the Raytheon report, the Cognitive Radio technology can increase the spectrum efficiency by 10-20 times.The carry out of the Cognitive Radio wireless communication systems is a complex process. It involves spectrum detection, spectrum decision, spectrum resources management and other key technologies. This paper mainly studies the Cognitive Radio frequency spectrum detection technology, and also proposes a spectrum detection algorithm suiting for WiMAX signal, that is, amended covariance test, bases on several existing spectrum detection algorithm (energy detection, pilot testing, cyclostationary signal detection and covariance test).The paper not only analysises the spectrum detection algorithms which mentioned in the above paragraph but also simulated the detection algorithms using MATLAB. The simulation system bases on IEEE 802.16e protocol standards, The model of the wireless channel is the SUI-3 in Stanford University Interim. To test the spectrum detection algorithm under the influence of noise robustness, the simulation proposes a model for the introduction of noise uncertainty. After the system simulation of spectrum detection algorithm, the probability detection curves of the five spectral detection algorithms have been obtained based on the standatd of IEEE 802.16e. And eventually obtained the comparison of the results of the perfor-mance of this five kinds of spectral detection algorithms. The amended covariance detection improves the probability of detection by 2 dB at least under the condition of the false alarm probability valued 10%. The detection capability improvement of amended covariance detection provides theoretical basis in the application of WiMAX signal detections for Cognitive Radio.