Digital signal processing method and implementation for pulse laser rangefinder

The laser echo pulses of a pulse laser rangefinder are narrow, weak and low SNR (signal-to-noise ratio) signals. Digital signal processing method was presented for such signals to improve SNR. A digital signal processing circuit of a pulse laser rangefinder was designed, based on DSP (digital signal processor) and CPLD chips. The algorithms of digital filtering, pulse accumulation, target detection and tracking are all implemented in the DSP chip. The CPLD chip was used to design the digital interface circuit. The experiments were completed and showed that compared with traditional pulse laser ranging method, digital signal processing method increased the SNR of echo pulse signal clearly, accordingly improved ranging ability of pulse laser rangefinder. At the same time, the high-speed DSP chip ensures real-time ranging.