| Although widely used, satellite positioning technology has many disadvantages, such as cold start and large power consumption in terminals. Base station positioning technology can overcome the above disadvantages, but terminals should communicate with more than three base stations during the process of positioning. On the basis of base station positioning technology, positioning technology based on terminal cooperation can overcome the disadvantages and improve the positioning accuracy.This thesis starts research on overall implementation, algorithms,simulations, and evaluations. Specifically, this thesis proposes a project about the reference signal used by the direct communication between terminals. Besides, types of hyperbolic positioning equations and related solving algorithms in different scenarios are proposed by this thesis.What’s more, on the premise that the detection range and the number of direct communication links of terminals are limited, this thesis proposes a grouping method for terminals in the process of positioning based on terminal cooperation. Finally, two power allocation schemes are proposed to solve the problem of interference control between the downlink communication and the direct communication between terminals.The main research contents and innovative points of this thesis are as follows:Firstly, this thesis proposes a scheme of the reference signal for direct communication between terminals during the process of positioning based on terminal cooperation. Besides, the superposition ration of physical resource in this scheme is also ideal, which means less interference.Secondly, this thesis proposes hyperbolic positioning equations and related solving algorithms in different scenarios. Positioning method based on terminal cooperation can overcome the disadvantages of base station positioning method and achieve better positioning accuracy.Thirdly, in the scenario that the detection range and the number of direct communication links are limited, this thesis proposes a grouping method for terminals in the process of positioning based on terminal cooperation. The simulation result shows that the proposed grouping method can increase the number of direct communication links between terminals in one group and achieve better positioning accuracy.Fourthly, this thesis proposes two power allocation schemes in the scenario that the downlink communication from base stations to terminals and direct communication between terminals reuse the same frequency band. The related simulation result shows that positioning based on terminal cooperation can still improve the accuracy of positioning compared with base station positioning. To get better positioning accuracy, different power allocation schemes can be applied in different channels. |
