Cooperative frequency spectrum perception method based on difference between maximum and minimum feature values

Abstract

The invention relates to a cooperative frequency spectrum perception method based on a difference between maximum and minimum feature values. The method comprises the following steps: a cognition user receiving end randomly sampling received signals and calculating a receiving signal matrix; obtaining a sample covariance matrix through calculation of the receiving signal matrix, and performing feature value decomposition; selecting the difference between the maximum value and the smallest value as a detection statistical amount; calculating a threshold value in case that an authorized user exists; comparing the detection statistical amount with the threshold value, and determining whether primary users exist; and if the statistical amount is greater than or equal to the threshold value, indicating that the primary users exist, and otherwise, indicating that the primary users do not exist, such that secondary users can be conveniently accessed to a frequency range. According to the invention, the difference between the maximum and minimum feature values is taken as the detection statistical amount, the distribution function is a distribution rule based on the minimum feature value, and the obtained threshold value can be more accurate. Under the condition of cooperative perception of the multiple secondary users, quite high detection precision can be ensured, at the same time, a fewer number of sampling points are needed, and the system complexity is reduced.

Description

technical field [0001] The invention belongs to the field of cognitive radio technology, and in particular relates to a cooperative spectrum sensing method based on the difference between the maximum and minimum eigenvalues ​​for a cognitive radio system. Background technique [0002] With the rapid growth of wireless communication services, wireless spectrum resources are becoming increasingly scarce. Since the existing frequency spectrum adopts an exclusive allocation method, only the primary user can use the licensed spectrum, even if the primary user is idle, other users cannot use the frequency band. In order to improve this phenomenon, cognitive radio came into being. As an intelligent spectrum sharing technology, it can detect idle frequency bands that are not used by the primary user, and allow other users to access without affecting the primary user, thereby Improve spectrum utilization. [0003] Spectrum sensing technology is the key technology of cognitive radio...

AI Technical Summary

Problems solved by technology

These algorithms have effectively avoided the influence of noise uncertainty, but most of them use asymptotically approximate distribution laws, and the obtained threshold expression needs to be further improved.

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