| 摘要 |
PURPOSE:To measure a phase and a frequency simultaneously even by a low- speed arithmetic means by measuring the phase difference between a carrier signal received from an artificial satellite and a reference signal simultaneously with the frequency difference without expanding the band of a low-pass filter. CONSTITUTION:A signal mixer 4 performs operation corresponding to a phase comparator. An accumulator 1 integrates frequency control data DELTAthetam outputted by a loop arithmetic means 7 at the rate of a clock DELTAT to generate and store an instantaneous phase phiv(nDELTAT) in the accumulator 1. This integration is repeated (p) times to advance the phase by pDELTAthetam, which means that the frequency offset of a frequency difference component fv. Namely, the DELTAthetam and fv are proportional to each other, so when one is known, the other is also known. Then the instantaneous phase phiv is converted 2 into orthogonal trigonometric function signals, which are mixed by an orthogonal signal mixer 3 to generate IL(nDELTAT), QL(nDELTAT), etc., as variable reference signals. Those variable reference signals are mixed 4 with a received signal s(t) and then a phase-locked loop is completed.
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