Locating method and system based on mixed TDOA and ToF

Abstract

The invention relates to a locating method based on mixed TDOA and ToF. The method is characterized by including the steps that firstly, a server selects a main base station and auxiliary base stations and time synchronization among the base stations is completed; secondly, a TDOA message is broadcast through a label and the distance differences between the label and the base stations are calculated through the differences of time when the message reaches the base stations; thirdly, a ToF message is sent to a specific base station through the label so that the distance between the label and the specific base station can be calculated; fourthly, through calculation results in the second step and the third step, the distances between the label and all the base stations are calculated; fifthly, the position of the label is calculated through the distances between the label and all the base stations. Through the improvement method, the same accuracy can be acquired inside and outside a triangle formed by the base stations.

Description

technical field [0001] The invention relates to the technical field of wireless real-time positioning, in particular to a technology for realizing two-dimensional or three-dimensional precise positioning by means of TDOA and TOF. Background technique [0002] The real-time positioning system is also RTLS (Real Time Location Systems). RTLS is a signal-based radio positioning method, which can be active or passive. RTLS enables real-time knowledge of the exact location of a located property, person, vehicle or other located object. [0003] TDOA-based RTLS: [0004] At present, there are two key technologies in the wireless TDOA method, one is time synchronization between base stations, and the other is tag sending messages. The base station calculates the time difference of arrival according to the time of receiving the message, and then adopts the hyperbolic algorithm. To achieve two-dimensional and three-dimensional positioning, the positioning accuracy is relatively high...

AI Technical Summary

Problems solved by technology

[0015] 1. The power consumption increases, the tag works for a long time, and the power consumption increases. In the simplest system, there are at least 3 base stations. Every time a base station is added, the tag needs to increase the ranging time, resulting in an increase in power consumption;

[0016] 2. The capacity of the system. According to the time of 1 second, if each tag and all the base stations measure the distance, the system capacity will be reduced. Time division or frequency division must be used to effectively increase the system capacity, but this will increase the system complexity

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