A ranging method for 60GHz OFDM system based on improved preamble sequence

This paper presents a ranging approach using an improved preamble sequence of orthogonal frequency-division multiplexing (OFDM) signal for 60 GHz system. The performance of range estimation with OFDM modulation under 60GHz channel is analyzed emphatically. In order to utilize the time-frequency characteristics of OFDM signal in the ranging system, the subcarriers phase difference algorithm with an improved training sequence is proposed. Under 60GHz channel, a real-valued pseudo-random noise (PN) sequence and Zadoff-Chu (ZC) sequence are introduced into the preamble sequence of OFDM signal to increase the accuracy of correlation detection in the time-domain at low Signal Noise Ratio (SNR). The orthogonality of OFDM signal in the frequency-domain is used to gain higher accuracy. The ranging method operates near Cramér-Rao lower bound (CRLB) in the additive white Gaussian noise (AWGN) channel. Simulation results with the proposed method are presented, which obtain high precision ranging results under the TSV channel model of 60GHz OFDM system.