An approach for implementation of ranging and positioning methods on a software defined radio

In this paper an approach for implementation of a time of flight ranging methods on a software defined radio (SDR) platform is presented. The proposed approach is intended to be implemented in software running on a host computer without changing the existing hardware of the SDR platform. This approach can be easily extended for use in positioning methods. Using this approach a two way ranging (TWR) method is implemented on a SDR platform. All of the necessary processing is performed using software written in C/C++. This implementation was tested in the 2.4/5 GHz ISM band, with a channel bandwidth of 25 MHz. With this approach a nanosecond precision time of arrival estimation is achieved. This precision is needed in time of flight based ranging and positioning applications. A ranging accuracy better than 1 meter was obtained and demonstrated using the proposed approach. The developed TWR system performs 100 distance estimations per second. Nevertheless, with the processing power of the currently available general purpose processors a distance estimation rate of over 500 estimations per second can be achieved. The proposed approach can be also used in positioning scenarios, by performing TWR with multiple anchor nodes.