Abstract: For dealing with the problem that Doppler laser radar employing traditional wave methods cannot obtain high resolution for both parameters when it is used in range and speed measurement applications, a new measurement signal waveform modulated by both position and amplitude was proposed, which can solve the contradiction between measurement precision of range and speed, and make the two parameters independent in measurement process. In addition, the feasibility of applying the method for range and speed measurement in road environments for intelligent driving vehicles was analyzed. Firstly, the difficulties of classical modulation methods in range and speed measurement simultaneously were discussed, based on which a solution was designed for simultaneous modulation of the transmit signal waveform in position and amplitude, and the physical realizability of the proposed method was introduced by combing the amplifying properties of the in-line optical fiber amplifier. Then, the frequency calculation method for output heterodyne signal of laser radar employing position and amplitude modulation method and the data accumulation method for laser radar receiver output echo signal were discussed, so as to measure the range and speed independently. Finally, within the range of Doppler frequency that can be generated by moving targets in road environments, simulations were performed to verify the feasibility of the proposed method and the independence of the two measurement parameters, meanwhile, the measurement precision was analyzed. Simulation results show that the method of simultaneous position and amplitude modulation scheme can effectively measure the range and speed of targets even when the Signal-to-Noise Ratio (SNR) of laser radar receiver output signal is below 0 dB, and the measurement process of these two parameters to be measured are totally independent.

Key words: Doppler laser radar, position and amplitude modulation, pseudo-random code, non-uniform sampling, simultaneous measurement of range and speed

摘要： 针对传统波形方法在多普勒激光雷达测量目标距离和速度的应用中不能同时获得高测量精度的问题，提出一种使用位置和幅度同时调制的测量信号波形，以解决距离和速度测量精度之间的矛盾，同时使两个参数测量之间相互独立，并分析了该方法应用于智能驾驶道路环境中目标距离和速度测量的可行性。首先，讨论典型调制方法在同时测量目标距离和速度方面存在的困难，在此基础上，设计一种位置和幅度同时调制发射信号波形的解决方法，结合在线光纤放大器的放大特性给出该方法的物理可实现性；然后，讨论使用位置和幅度调制方法的激光雷达输出外差信号的频率计算方法以及激光雷达接收机输出回波信号的数据累加方法，从而分别测量出目标的速度和距离；最后，在道路移动目标可生成的多普勒频率范围内，通过仿真验证该方法的测量可行性以及两测量参数之间的独立性，并分析测量精度。仿真实验结果表明，位置和幅度同时调制的方法在激光雷达接收机输出信号的信噪比（SNR）低于0 dB时，可以有效测量目标的距离和速度，且这两个待测参数的测量过程完全独立。

关键词: 多普勒激光雷达, 位置幅度调制, 伪随机码, 非等间隔采样, 距离速度同时测量