Onboard Monitoring And Control The Spread Spectrum Receiver The Key Technologies

This dissertation regards the spectrum-spread digital receiver of measurement and control system on missile carrier as the main study object. Apply FPGA, software radio technology, principles of spectrum-spread communication and digital receiver, on the base of analyzing the system and spectrum-spread communication, adopt theoretical analysis, computer simulation and hardware debugging, give the realization of the key technology of the receiver, the main content includes four areas as follows:1. According to the norms of the project, give out the function and working way of the system, design the framework of the system including transmitter and receiver. Design the hardware of the digital part, on the base of the hardware, describe the process of signal disposing and the control of communication between the devices.2. Analyze the key technology of the spectrum-spread receiver under the condition of large dynamic range. Research the capture ways of pseudo-code synchronization; compare the serial-shift with the FFT-based through simulation, under the condition of large dynamic range the way of FFT-based could capture correctly. Give the simulation of pseudo-code tracing using the way DLL. Design the Costas to realize carrier synchronization and demodulate signal correctly. Research and simulate the bit synchronization way.3. Research the realization of the spectrum-spread receiver's main parts using FPGA, simulate and test. For data collecting, use FPGA to conform the sampling data according the timing of ADC. For pseudo-code synchronization, using FFT-based way to capture and based on it to realize pseudo-code tracing. For carrier and bit synchronization, realize those using relative ways.4. Based on the digital part of the system, test the spectrum-spread receiver at IF, under the condition of large dynamic range, verify the pseudo-code synchronization, carrier synchronization and bit synchronization.