| 摘要 |
<p>A system and method for narrowing the range of frequency uncertainty of a Doppler shifted pilot signal in a satellite or other communications system (100) with relative signal source and receiver motion. The satellite communications system (100) includes a user terminal (124, 126) (for example, a mobile wireless telephone), a gateway (120, 122, 112) (terrestrial base station), and at least one satellite (116, 118) with unknown position and unknown relative velocity. The method includes the steps of shifting the pilot signal over a plurality of frequency hypotheses (309), coherently accumulating samples of the pilot signal over a plurality of chips (315), measuring the energy of the accumulated pilot signal samples (318), accumulating the energy measurements over a plurality of chips to produce an energy accumulation value (321), and determining which of the plurality of frequency hypotheses results in the highest energy accumulation value (324).</p> |
