The design and realization of spread signal tracking loop based on FPGA

The technology of spectrum signal tracking and demodulation not only involves the designs of complex high-speed digital circuits, but also includes the designs of tracking algorithm. In the traditional design, the designers usually adopt the design methods based on FPGA&DSP to achieve all the above contents, which means that the carrier-DCO, code-DCO, the circuits of correlation and integral can be realized in the FPGA chip, while the tracking algorithms are realized in the DSP chip. Differing from the traditional design, this paper constructed one Nios II CPU core in the FPGA chip with the thought of SOPC technology, which made all the function modules could be realized in one FPGA chip.