Broadband Wireless Data Link Information Transmission Technology Research And Implementation

With the development of space technology, the use of spread spectrum signal for measurement and data transmission gradually become the main means of aerospace measurement and control. This paper mainly makes a research on baseband signal processing of one wireless data link positioning system, it analyzes the system composition of the transmission and receiving channel, signal structure, and emphatically analyzes the capture, tracking algorithm of the broadband signal. Finally this paper discusses the implementation of the algorithm with high-speed FPGA and matters needing attention.This paper analyzes the common capture algorithm for spread spectrum signal, including sliding correlation capture algorithm and parallel capture algorithm based on FFT. Finally it analyzes the NONCOHERENT parallel capture method for broadband signals, and specific process of implementation in FPGA. For tracking, it discusses the structure of the carrier tracking loop with second-order FLL auxiliary third-order PLL in detail and the methods of realization. It analyzes the tracking strategy and the key parameters of the carrier loop, and the implementation in FPGA with fixed-point decimal.For the baseband signal processing algorithms of this wireless data link positioning system, the verification platform is one signal transceiver with a processing unit of Xilinx FPGA, The platform consists of signal transmission channel and receiving channel, which are used for the verification of data and image transmission. Test results show that the capturing and tracking algorithm for broadband receiver can achieve good effect, the performance meets system requirements. This paper has certain reference significance for broadband signal processing.