| 摘要 |
A GPS receiver that acquires and tracks a split-C/A code separately aligns with the received signal the phases of a locally-generated 10.23 MHz square wave, which can be thought of as a 20.46 MHz square-wave code, and a locally-generated 1.023 MHz C/A code. The receiver first aligns the phase of the locally-generated square-wave code with the received signal, and tracks one of the multiple peaks of the split-C/A code autocorrelation function. It then shifts the phase of the locally-generated C/A code with respect to the phase of the locally-generated square-wave code, to align the local and the received C/A codes and position the correlators on the center peak of the split-C/A. The receiver then tracks the center peak directly, using a locally-generated split-C/A code.
|
