Modulated Laser Radar Decoding by Inter Symbol Interference

Pseudo Random Noise (PN) coded laser radar can improve the target detection ability without the demand on high power laser. However, the reflected echoes are generally so weak that they are buried in the thermal noise of the receiver, which raises the problem of choosing an optimal threshold for correctly decoding them since the power of echoes varies from time to time, and the voltage of light generated electrical signal by photo diode (PD) is always positive. In this work, we firstly show the problem we are going to discuss. Then, a novel method basing on Inter Symbol Interference (ISI) is proposed for solving the problem. Next, numerical simulations and experiments are performed to validate the method. Finally, we discuss the obtained results theoretically.