| 摘要 |
Global Navigation Satellite System (GNSS) signals are first received and then down converted to an intermediate frequency (IF) and digitally sampled. The sampled signals are multiplied by a local replica of the incoming IF carrier (I ref generator and Q ref generator). The purpose is to remove the Doppler and move the results to baseband for later accumulation processing. Two parallel correlation kernel modules, one kernel assuming the navigation data D is 1 while the other assuming navigation data D = 0 or (-1), are provided. The correlation kernel takes the code numerically -controlled oscillator (nco) phase of the prompt signal as input, and generates four output signals that are multiplied by the Doppler-removed incoming sample signal. An implementation of the pulsed signals accommodates navigation data D = 1 and D = 0 or (-1). |
