Compressed Acquisition Method for Global Navigation Satellite System Signal

Compressed Acquisition Method for Global Navigation Satellite System Signal

In the acquisition of Global Navigation Satellite System (GNSS) receivers, the correlation process has computing-resource requirements. The paper introduces compressed sensing theory to GNSS signal acquisition and studies the methods of measuring the compressive correlation values and reconstructing acquisition information. First, the mathematical expressions of compressed parallelized correlation measurements are deduced. Second, the compressed parallelized correlation-measurement values are decomposed into the sensing matrix and the sparse signal containing the acquisition information. Finally, the sparse signal is reconstructed and detected to further estimate the acquisition information. The calculation cost and detection performance of the compressed acquisition processing method are analyzed. A real-time experiment shows that the method is feasible. Simulations show the probability of successful acquisition under different signal-to-noise ratios and dimension-reduction conditions, with a reduced calculation cost compared to the serial acquisition method. Though the detection performance is slightly degraded compared to the conventional acquisition method, low sampling rate and low digital computation cost will be achieved when realized with a correlation structure in the analog domain. The method has certain application value.