Cooperative spectrum sensing method in cognitive vehicular ad-hoc network

Abstract

The invention discloses a cooperative spectrum sensing method in a cognitive vehicular ad-hoc network. The main process is that each cognitive vehicle receives authorized user signals in a band of interest and the following operation is carried out: (1) a cyclic ambiguity function method is adopted to carry out Doppler frequency shift estimation on the received authorized user signals; (2) a double-threshold cyclic spectrum energy detection method is adopted for spectrum sensing, and when the cyclic spectrum energy value is larger than a large threshold value or smaller than a small threshold value, the local judgment result acquired by the cognitive vehicle and the position information are transmitted to a road side unit on a public control channel; and finally, the road side unit fuses information of cognitive vehicles participating in cooperation through a position relative decision method to judge whether the authorized user band is free. The method considers influences on detection by the Doppler frequency shift, the spectrum information at all cyclic frequencies is used, a cooperative weighting factor is changed dynamically according to the real-time change of the relative position between the cognitive vehicles, and the detection performance is improved.

Description

technical field [0001] The present invention relates to the field of cognitive radio technology and vehicular wireless ad hoc network technology, in particular to a cooperative spectrum sensing method in cognitive vehicular ad hoc network. Background technique [0002] In the context of the steady development of urbanization and the continuous expansion of cities, more and more vehicles are driving on urban roads. Road safety and vehicle entertainment have attracted widespread attention. In order to meet this demand, a large number of Suitable for new applications and services in the in-vehicle environment, such as safety and traffic monitoring, navigation, multimedia streaming, etc. To support these new vehicular applications, Vehicular Ad-hoc Network (VANET, Vehicular Ad-hoc Network) technology emerges as the times require. The vehicle ad hoc network is established on the basis of point-to-point communication between vehicles equipped with wireless interfaces, that is, mo...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the existing vehicular frequency bands cannot meet the needs of vehicular communication, and to provide a cognitive vehicular ad hoc network cooperative spectrum sensing method, which is a vehicular communication method with cognitive functions and can make adaptive judgments Whether to enable cognitive functions and perform accurate detection of licensed frequency bands of interest

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