A trust-based dual-threshold cooperative spectrum sensing method

Abstract

The invention discloses a double-threshold frequency spectrum perception method based on a trust degree. The method has both of cognitive-radio-system reliability and low load. The method includes: a system uses preferentially cognitive nodes which meet a double-threshold demand to participate in collaborative perception; when the number of cognitive nodes which meet the double-threshold demand is not sufficient, cognitive nodes which meet trust degree parameter demands are added to participate in the collaborative perception; and a fusion center stores a detection record of the cognitive nodes and uses the detection record as a local detection result to set a fusion weight. In the method, perception parameters which need to be transmitted are reduced and an occupied channel bandwidth is reduced. At the same time, because of the reduction of unreliable cognitive nodes, detection performance of the method is improved further. Moreover, compared with most methods which only improve disadvantages of a specific performance index of the system, the system is capable of adapting to different types of wireless services through adjustment of the value of a parameter n<t> and has a specific flexibility.

Description

technical field [0001] The invention relates to the technical field of computer wireless communication, in particular to a trust-based double-threshold cooperative spectrum sensing method. Background technique [0002] Computer wireless communication and personal communication have developed rapidly in the past few decades, and various system structures, protocol standards and network architectures have emerged in an endless stream. With the rapid growth of wireless communication services, the contradiction between the increasing spectrum demand and limited spectrum resources has become one of the main bottlenecks restricting the development of wireless communication. In addition to the allocation of very few ISM open frequency bands, most of the current frequency use policies in the world adopt a license system, that is, authorized users use the specified frequency bands, and non-authorized users are not allowed to use them. And studies have shown that the actual utilizati...

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Problems solved by technology

[0004] The existing cooperative spectrum sensing methods generally focus on a certain performance index of the system, and cannot take into account various performance requirements.

For example, although a system that requires all cognitive nodes to participate in cooperation can improve the perceived reliability of the system, the load of the system often causes channel congestion, and the perceived delay is often large, which cannot be performed well in limited channel bandwidth and real-time communication. get applied

Another example is that although a system that requires some cognitive nodes to participate in cooperation can reduce the perception overhead, the detection performance is often not ideal. Many existing methods select some cognitive nodes that participate in cooperation based on double thresholds. If the double threshold is not set properly, it will Too many or too few cognitive nodes participating in collaboration

When there are too many cognitive nodes, the load of the system will not be greatly improved; when there are too few cognitive nodes, the system performance will be poor or even cause perception failure

If the weighted fusion method is used to further improve the perceptual reliability, the transmission fusion weight parameters will further affect the channel congestion and perceptual delay

Although some methods do not use double thresholds to select cognitive nodes (such as using trust parameters), verifying whether each cognitive node is reliable through trust parameters and then deciding whether to participate in cooperation will increase the complexity of the system and lead to perception time. increase in delay

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