Design Of Digital Integration Baseband Equipment Of Test System Of Spread-Spectrum Responder

The spread spectrum responder is main component of the satellite measure and control equipment. It works with earth station to complete the task of control and measure. The test equipment of spread spectrum responder is used to test responder's performance and function.Digital integration baseband equipment is core of the test equipment of spread spectrum responder, with responsibility for generating the test signal and receiving the feedback signal from ronsponder. In order to simulate the dynamic feature of the signal at the responder,we use two stage phase accumulator in the baseband equipment to get the sending signal. The receive function of digital integration baseband equipment is acquisition ,tracking,demuldulation ,despread and forwarding data.This paper mainly describes the design of DSP controlling module of the baseband equipment. Firstly, assigns the software/hardware resource of system and design the macro-flow of DSP controlling module. Then, describes the significant modules respectively. Some key technologies, which are applied in the baseband equipment, are researched, including Direct Digital Synthesization ,simulation of dynamic feature of signal and PLL .At the end of the paper , verifies the equipment by using general test equipment. The test result indicate that on the transmit side, a customed spread-spectrum signal is generated correctly, on the receive side, acquisition and tracking, demodulation and despread spectrum, bit/frame synchronization and communication with PC are well done.