A broadband signal capture and tracking algorithm based on FPGA

Capture and tracking is key technology of spread spectrum communication baseband signal processing. For signal with high-speed spread spectrum pseudo code, the traditional capturing and tracking algorithm need to be improved. In order to be able to quickly capture the signal, and make stable tracking, use the NONCOHERENT parallel method, which speeds up the capture speed and efficiency, for tracking, using second-order FLL to aid third-order PLL. The algorithm is implemented in the FPGA with fixed point decimal method. For the pseudo code of 20Mbps rate, actual test results show that, the time for capturing is less than 2 seconds, and the receiver can stand the received signal frequency changes in more than 2 KHz/s at tracking state.