关键词: 环境信息感知, 激光雷达, Golumb序列, 距离速度测量, 非等间隔采样

Abstract: In view of the problems that upper limit of radiated peak power is low for continuous wave laser radar, which limits the maximum measurement range in the application of range and speed measurement, a waveform of modulating signal based on Golumb series was proposed, and the feasibility of simultaneously measuring target’s range and speed in road environments by the method was studied. Firstly, the problem of low transmitted peak power that exists in continuous wave modulated laser radar were analyzed by using a quasi-continuous, i.e., pseudo random noise (PN) code modulation as an example. Characteristics of Golumb series were discussed, and a modulation method based on the Golumb series was proposed for raising peak power of transmitting pulse. Then, method for analyzing spectrum of Doppler signal that is modulated by Golumb series was discussed, as well as the data accumulation method for locating signal delaying time, such that range and speed can be measured simultaneously. Finally, within the range of Dop-pler frequency that is generated by moving road targets in road environment, simulations were performed to verify the correctness of the proposed method. The results show that fast Fourier transform (FFT) can be used for obtaining frequency of Doppler signal even when sampling frequency provided by the pulse series is much lower than the Nyquist frequency, thus largely increase the peak power of single pulse under the condition that average transmission power keeps unchanged. Furthermore, data integration or cross correlation of Doppler signal can be used for locating laser pulse flight time by exploiting the non-uniform space properties of Golumb series, ensuring target range measurement from the same signal for speed measurement.

Key words: environment information sensing, laser radar, Golumb series, range and speed measurement, non-uniform sampling