Research On D2D Cooperative Positioning Technology Based On Bluetooth And 5G Signal

In recent years,with the development of science and technology,Location-Based Services(LB S)have played an increasingly important role in people's lives,and have attracted extensive attention at home and abroad due to their broad application prospects.Although the global positioning system has become the best solution for outdoor positioning in recent years,in the indoor environment,due to the dynamic and complex positioning environment,accurate and reliable indoor positioning is still a great challenge.As a key candidate for 5G,Device to Device(D2D)can increase the probability of the Line of Sight(LOS)signal received by the target for indoor positioning.It has been widely used for solving non-line-of-sight(NLOS)problems and improving positioning accuracy.In order to improve the indoor positioning accuracy in the NLOS and LOS mixed environment,a Probabilistic Position Selection Algorithm(PPSA)based on the ranging signal and Pedestrian Dead Reckoning(PDR)is proposed.For the complex indoor environment which the mobile terminal can't receive enough signals for positioning,using the D2D technology in 5G mobile communication system,the cooperative positioning technology under multi-terminal and node selection algorithm are studied,and an area optimization and node selection based sum-product algorithm over a wireless network(AN-SPAWN)are proposed at the same time.The work is as follows:Firstly,to overcome the shortage of existing indoor positioning scheme in complex indoor environment,this paper proposes a probability location selection algorithm based on ranging signal and PDR.In order to solve the NLOS errors existing in the positioning process,a low-complexity NLOS recognition scheme is proposed to analyze the channel transmission state of the signal.The experimental results show that the proposed algorithm has better localization accuracy and better resistance to NLOS errors than the traditional positioning algorithm in the NLOS and LOS mixed environment.In the experimental environment built in the article,compared with Trilateration + PDR and MLE + PDR,the mean positioning accuracy is improved by 49.62%and 60.54%,respectively.Next,in the positioning nodes sparse scenario where the mobile terminal can't receive enough positioning signals,based on the probabilistic location selection algorithm proposed above and Sum-product algorithm over a wireless network(SPAWN),an improved cooperative positioning algorithm based on Bluetooth and 5G signals is proposed in this paper.In order to reduce the complexity of the cooperative positioning algorithm,filter out the cooperative nodes that have little contribution to the positioning and build an optimal cooperative cluster,a cooperative node selection scheme based on Cramer-Rao bound and NLOS recognition is proposed.The experiment and simulation show that the proposed cooperative localization algorithm has better localization accuracy and better resistance to NLOS errors than the traditional cooperative positioning algorithm.In the cooperative simulation environment built in this article,compared with H-SPAWN and SPAWN,the mean cooperative positioning accuracy is increased by 36.87%and 46.73%,respectively.