Spectrum detection method of cognitive radio system

Abstract

The invention discloses a spectrum detection method of cognitive radio system, comprising the following steps: calculating the signal energy of each cognitive node; performing spectrum detection judgment on each cognitive node; and carrying out united judging on the spectrum detection of a centre node. By the method disclosed by the invention, the frequency spectrum detection is performed on the centre node via performing the spectrum detection on each cognitive node and using the signal energy value of each cognitive node; when an authorized user signal is detected under quite low signal to noise ratio, simultaneously, whether an authorized user receiver normally receives and demodulates or not also can be detected. Therefore, during practical application, the cognitive radio system can improve the frequency spectrum utilization better under the condition of ensuring the detection performance and without interfering the normal receiving of the authorized user.

Description

technical field

[0001] The invention belongs to the technical field of communication, and in particular relates to a frequency spectrum detection method used in a cognitive radio system. Background technique

[0002] With the rapid development of wireless communication technology, multiple wireless communication access methods coexist, and the number of wireless users increases sharply, which leads to increasingly tight radio spectrum resources. As a precious non-renewable resource, the radio frequency spectrum is currently authorized by the government department. Generally, a specific licensed frequency band (LFB, Licensed Frequency Band) is allocated for different communication services, which can provide good protection for the corresponding communication services. . However, once a specific frequency band is authorized and assigned to a user (authorized user), other unlicensed users (secondary users) can no longer use the frequency band, even if the licensed frequency b...

Examples

Embodiment Construction

[0025] The present invention will be further described below in conjunction with specific examples.

[0026] In order to facilitate the understanding of the embodiments, the spectrum detection based on the absolute value method of the covariance matrix is ​​first explained: the received signal after the analog-to-digital conversion is a series of discrete data (digital signals), which are required by the signal detection algorithm The sample value of is represented by the symbol x(n), where n is a positive integer representing the nth data sample received. L consecutive data samples constitute the transpose of vector X(n), expressed as formula (1), where N s Represents the total number of data samples, and L is defined as a smoothing factor.

[0027] X(n)=[x(n) x(n-1)...x(n-L+1)] T , n=0,1,...N s -1 formula(1)

[0028] Use the obtained vector X(n) to construct the covariance matrix R x (N s ) is expressed as formula (2):

[0029] R x ...

technical field

[0001] The invention belongs to the technical field of communication, and in particular relates to a frequency spectrum detection method used in a cognitive radio system. Background technique

[0002] With the rapid development of wireless communication technology, multiple wireless communication access methods coexist, and the number of wireless users increases sharply, which leads to increasingly tight radio spectrum resources. As a precious non-renewable resource, the radio frequency spectrum is currently authorized by the government department. Generally, a specific licensed frequency band (LFB, Licensed Frequency Band) is allocated for different communication services, which can provide good protection for the corresponding communication services. . However, once a specific frequency band is authorized and assigned to a user (authorized user), other unlicensed users (secondary users) can no longer use the frequency band, even if the licensed frequency b...

Examples

Embodiment Construction

[0025] The present invention will be further described below in conjunction with specific examples.

[0026] In order to facilitate the understanding of the embodiments, the spectrum detection based on the absolute value method of the covariance matrix is ​​first explained: the received signal after the analog-to-digital conversion is a series of discrete data (digital signals), which are required by the signal detection algorithm The sample value of is represented by the symbol x(n), where n is a positive integer representing the nth data sample received. L consecutive data samples constitute the transpose of vector X(n), expressed as formula (1), where N s Represents the total number of data samples, and L is defined as a smoothing factor.

[0027] X(n)=[x(n) x(n-1)...x(n-L+1)] T , n=0,1,...N s -1 formula(1)

[0028] Use the obtained vector X(n) to construct the covariance matrix R x (N s ) is expressed as formula (2):

[0029] R x ...

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