| 摘要 |
<p>A method and apparatus for performing sampling, comprising: sampling an input signal (16) using a first sampling signal (22) to provide a first sampled signal (26); sampling the input signal (16) using a second sampling signal (24) to provide a second sampled signal (30); measuring a frequency of one of the first sampled signal (26) and second sampled signal (30); measuring a phase difference between the first and the second sampled signal (26, 30); and determining an input signal frequency using the frequency and the phase difference; wherein the second sampling signal (24) has substantially equal frequency to the first sampling signal (22); and a waveform of the second sampling signal (24) is shifted in time with respect to a waveform of the first sampling signal (22). Measuring a frequency of the first or second sampled signal may be performed within a Nyquist zone of an analogue-to-digital converter (12, 14).</p> |
