A dual-threshold energy detection method based on historical perception information

Abstract

The invention discloses a double-threshold energy detection method based on historical perception information, which uses the energy detection method to estimate the probability that the state of the authorized user's occupation of the authorized frequency band changes or does not change between adjacent perception frames, according to the theory of false alarm probability Value and these two probabilities set the high threshold and low threshold that meet the target false alarm probability constraints; then perform spectrum detection, if the energy statistics value of the current sensing frame is greater than the high threshold, it is determined that the authorized user occupies the authorized frequency band in the current sensing frame , otherwise, according to the high threshold and low threshold, use the energy statistics of the current sensing frame and historical sensing frames to make a second judgment on the state of the authorized user occupying the authorized frequency band; the advantage is that it can not only meet the constraints of the target false alarm probability, but also A higher detection probability is obtained, the spectrum detection performance is effectively improved, and at the same time, the implementation complexity is low, the detection real-time performance is better, and the occupied system bandwidth is also small.

Description

technical field [0001] The invention relates to a frequency spectrum detection technology in a cognitive radio system, in particular to a dual-threshold energy detection method based on historical perception information. Background technique [0002] With the rapid development of wireless communication technology, people's demand for spectrum is increasing. At present, most countries and regions still use a static spectrum allocation method, that is, a specific frequency band is assigned to a specific user, and other users are not allowed to use it. Therefore, the spectrum utilization rate of the wireless communication system is not high. To this end, a cognitive radio (Cognitive Radio, CR) technology has been proposed. Under the premise of not excessively interfering with the communication of authorized users, cognitive users can improve the spectrum utilization efficiency of wireless communication systems by using idle frequency bands. [0003] As a key technology in cogn...

AI Technical Summary

Problems solved by technology

Although the improved energy detection method only needs to know additionally the statistical values ​​of the sampled signal energy of the first few perception frames, the calculation complexity is low, but it only uses a threshold value in the second judgment. On the one hand, when the authorized user suddenly no longer When the licensed frequency band is occupied, the statistical value of the sampled signal energy of the perception frame of the cognitive user will decrease sharply, while the statistical value of the sampled signal energy of the previous few perception frames is relatively large, so the current perception frame is different from the previous few perception frames. The mean value of the energy statistics of the sampled signal may be higher than the threshold value and misjudgment occurs; The energy statistical value of the frame and the energy statistical value of the sampling signal of the previous perception frames are higher than the threshold value, and misjudgment occurs. Therefore, the improved energy detection method is likely to lead to a high false alarm probability, resulting in a decrease in spectrum sensing performance.

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