Wideband Frequency-domain Energy Detection In Cognitive Radio

The results of a large number of survey data at home and abroad show that spectrum problem is increasingly serious in the current. As the global informatization degree is increasing day by day, the mobile terminal equipment is gradually popularizated, leading a surge in mobile network and mobile users, so that the demand for spectrum resources has increased dramatically. The implemented method of spectrum division caused idle spectrum resource, so needing to study new method to improve spectrum efficiency by cognitive radio.At present, the existing energy detection in cognitive radio research focuses in the field of narrow-band energy detection, the broadband frequency domain energy detection technology needs further research. This topic has researched spectrum detection problem around with known bandwidth channel and unknown broadband channel, and has carried out broadband frequency domain energy detection algorithm research in cognitive radio.First of all researching the bandwidth of the frequency domain energy detection is known. According to the principle of frequency domain energy detection, refer to the GNU Radio frequency energy detection process, using MATLAB simulated testing process, analyzed frequency domain energy detection performance and the factors affecting the decision threshold.Then researching the broadband frequency domain energy detection. Using the GNU Radio open source software Radio platform based on step-frequency-domain energy detection in order to improve the cognitive radio spectrum sensing performance, realize the broadband frequency domain energy detection with unknown locations and unknown bandwidth.In this method, detailed analysis of the functions and implementation details of its spectrum sensing procedure is performed, and the procedure of multi-step frequency-domain energy detection of GNU Radio for spectrum sensing is simulated, and the spectrum detection performance is obtained. With the simulation results, the factors influencing the decision threshold of per-step energy detection are discussed and the method to determine the decision threshold in per-step is given. The results presented in this paper can be used to set the parameters of GNU Radio for achieving more precise spectrum sensing. The results give the theoretical basis of the GNU Radio system detection threshold setting, and apply to the whole world of broadband frequency domain energy detection.