| 摘要 |
<p>A method and apparatus for a spread spectrum matched filter with Doppler correction suitable for using in a radio frequency receiver. A principal idea of the invention is to reduce a waveform representing Doppler correction values into a simple Boolean combination that can simply represent the waveform and be built into the processing in the matched filter. Advantages are (1) faster use of the matched filter, resulting in faster signal acquisition, and (2) lower power consumption because clocking to load signal and/or Doppler correction values is reduced. In particular, received samples can be Doppler corrected for the nominal or mean Doppler shift plus local oscillator error as they are stored. The remaining Doppler shift is relatively small and can be removed by building a relatively few Doppler offsets into the processing logic for each matched filter tap. This saves time because the Doppler shift can be changed almost instantly. It saves power because new signal or Doppler signals do not need to be shifted or scanned into the matched filter.</p> |
