Multi-Stage Doppler Search Correlator for Fast GNSS Acquisition

The patent divides the wide Doppler frequency search range into multiple sub-ranges and processes them in sequential stages. The first stage handles a coarse search over a wide range, then subsequent stages perform finer searches over narrower ranges. This segmentation reduces the number of bins that must be processed simultaneously, lowering operation complexity while maintaining complete coverage of the full search range.

The patent applies segmentation to the Doppler frequency search by dividing it into multiple stages. The first stage uses a coarser bin resolution to quickly eliminate unlikely frequencies, while subsequent stages use finer bin resolution only for the remaining candidate frequencies. This allows extended coherent integration times to be used effectively without proportionally increasing the total number of bins that must be searched across the entire frequency range.

The patent implements a dynamic, multi-stage search strategy where the bin width and search range are adjusted at different stages. Early stages use wider bins for rapid elimination of unlikely frequencies, while later stages narrow the bins for precise frequency measurement. This dynamic adjustment of parameters allows high measurement precision to be achieved without the operational complexity of using narrow bins throughout the entire search process.

The patent employs dynamic configuration of the correlator bank across multiple stages. The number of active correlators and their assigned frequency ranges are adjusted dynamically based on results from previous stages. This allows the system to concentrate computational resources on promising frequency regions while maintaining the ability to adapt to different search scenarios, thereby achieving both high productivity and good adaptability.