Design and implementation of navigation synthetical baseband equipment

Chinese area positioning system (CAPS) is a new satellite navigation system with independent intellectual property rights in China. Based on the working mode of the satellite forwarding the navigation signal generated on the ground, the satellite navigation function is realized. Navigation integrated baseband is an important terminal equipment of the main control station of CAPS. The architecture of navigation integrated baseband is designed by software radio design. Standard PCI extensions for instrumentation (PXI) chassis structure and bus-based design with strong scalability is selected. The key technologies of baseband are described including frequency compensation technology of transmitting signals, high precision receiving technology, high stability delay keeping technology of equipment. The actual test results show the good performance of the integrated baseband equipment. The measurement accuracy of pseudorange is better than 0.20 ns. The stability of channel delay is better than 0.25 ns, and the accuracy of frequency compensation is better than 0.8 Hz, which can meet the needs of CAPS.