Barrier Coverage Method Based On Bistatic Radar Sensor Model In WSN

Wireless sensor networks have always been a hot topic for researchers.In real life,sensor networks are widely used,such as border monitoring,medical care,military reconnaissance and target tracking.As one of the application modes of wireless sensor networks,barrier coverage has also attracted wide attention.It aims at real-time monitoring by deploying sensors to form continuous protection areas.Optimizing the appropriate sensor and its deployment location is an important issue in barrier coverage,which not only affects the detection performance of sensor barrier,but also affects the cost of barrier construction.Most of the existing studies focus on the barrier coverage of passive monitoring sensors such as 0/1 disc and probability sensing.Because bistatic radar sensor is an active monitoring radar sensor,the separation of transmitter and receiver has better monitoring ability and deployment flexibility.In recent years,the barrier coverage problem of bistatic radar has become a research hotspot of WSN coverage problem.This paper focuses on the enclosed perimeter barrier coverage of bistatic radar sensors and the barrier coverage of heterogeneous radar sensors.Aiming at the enclosed perimeter barrier coverage,this paper studies the optimal coverage method of circular barrier for bistatic radar,and proposes the construction method of circular barrier whose width is not less than a given threshold,which satisfies the monitoring performance of a given threshold.To solve this problem,we first study the blocking performance of different bistatic radar sensor deployment modes on the minimum circumferential circle in the region of interest,and prove the structural performance of the optimal placement sequence.Then we propose an algorithm to calculate the number of sub-rings and the number of receivers in the optimal deployment mode on each sub-ring to minimize the placement cost.Finally,we propose two minimum cost placement strategies:1)Circle-based equalization strategy,which enables bistatic radar sensors placed on sub-rings to form barriers of the same width.At the same time,these barriers will be combined to form a circular barrier that meets the width requirements.2)An adaptive radar sensor placement strategy.Such multiple sub-rings with the optimum width can form a circular barrier that meets the width requirements.The effectiveness of the algorithm is verified by detailed theoretical proof and experimental simulation.The existing research on barrier coverage of bistatic radar only considers homogeneous radar sensors,but in practical application,we still need to consider the application of heterogeneous sensors.In this paper,the optimal coverage problem based on heterogeneous bistatic radar sensor model is proposed for the first time,and the straight barrier deployment method with optimal monitoring performance is studied.Given the number of heterogeneous sensors and the length of straight barrier,how to deploy sensors is considered to maximize the overall received noise ratio of the constructed straight barrier.We propose a greedy algorithm to solve the barrier coverage problem.Firstly,the original problem is transformed into the problem of searching the signal-to-noise ratio threshold by dichotomy and constructing the coverage of the longest straight barrier under the determination of the signal-to-noise ratio threshold.Secondly,considering the difference of physical attributes between heterogeneous sensors,the maximum interval deployment scheme of sensors is given,and the construction method of the longest straight barrier under given transmitter placement order is analyzed.Then,considering the difference of barrier length caused by different placement order of transmitters,an optimal coverage scheme for heterogeneous barriers is proposed.We prove the effectiveness of the optimization algorithm through theoretical analysis and simulation experiments.