TOA Estimation with the IEEE 802.15.4a Standard

This paper discusses a ranging algorithm appropriate for impulse radio ultra-wideband signals compliant with the IEEE 802.15.4a standard. Three steps are indicated to locate the so-called ranging marker in the received signal. The first is to find the highest peaks in the channel responses to the transmitted pulses. The second consists in measuring the distance of each peak to the starting time of the response. The last one involves the identification of the first symbol of the physical-layer header. Algorithms to accomplish all these tasks are indicated. They are implemented in digital form and are in keeping with a non-coherent receiver structure. The achievable accuracy depends on the sampling rate. For example, at SNR = 20 dB and with a rate of 1 GHz the ranging errors are on the order of 20 cm.