Abstract: In order to solve the problems of more communication conflicts and high label power consumption in the ranging process of UWB indoor positioning at present, an improved DS-TWR algorithm is proposed. This method calculates the time slots of the labels and base stations through a time slot allocation method based on Hash algorithm, so that each label and base station has a unique time slot, so as to reduce the label conflict phenomenon in the communication process. At the same time, different from the traditional TOA ranging process, this method sets up a master base station, the label only needs to communicate with the master base station, and the slave base station only needs to monitor. The DS-TWR algorithm is used to realize the ranging process between the label and the master-slave base station, and finally the indoor positioning is completed. The experimental results show that the improved scheme can effectively reduce the number of positioning communication. Assuming that there are N positioning base stations, the number of communication of the improved algorithm is about 4/3N of that of the traditional DS-TWR algorithm, and the more base stations, the more times to reduce, which has strong engineering application value. By reducing the number of communication, the label power consumption can be optimized and saved by 33.3%. Aiming at the problem of communication conflict in traditional ranging algorithm, after adding Hash algorithm, the communication conflict rate of base station label in the ranging process can be reduced by 13%, thus increasing the capacity of the system.

Key words: UWB, indoor positioning, TOA, DS-TWR, Hash algorithm