Research On Synchronization Techniques In The Software Receiver

Relative to the digital receiver, the software receiver is implemented in softwareexcept for the data acquisition module, so it is low-cost and highly portable. Becausethe vector signal analysis (VSA) technology can provide the perfect signal measure-ment function, this thesis mainly focuses on the design of carrier synchronization andsymbol synchronization in the oscilloscope-based software receiver using the VSAtechnology.The usual analog/digital demodulation methods are introduced firstly, and a visualrepresentation of the effect of synchronization in the process of demodulation isobtained through simulation, then the synchronization algorithms used in the softwarereceiver are emphatically discussed. In terms of carrier synchronization, the structuresand principles of the Costas loop and the decision-directed phase-locked loop (PLL) areexplored based on the detailed analysis of the basic PLL parts, and a phasecompensation algorithm for the initial phase estimation is introduced, and then theperformance of the algorithms is validated by simulations. In terms of symbolsynchronization, the traditional early-late gate algorithm and Gardner algorithm areanalyzed, and the key research is focused on the maximum mean power timing estimatealgorithm, and the simulation results validate its practicality.Finally, the functions and development tools of the software receiver designed inthe research project are introduced and the main framework and functional modules areillustrated. The actual tests and applications indicate that the synchronization algorithmsused in the software receiver work well and the software receiver meets the designrequirements with good demodulation quality and perfect VSA functions.