| 摘要 |
First, a plurality of sinusoids is generated 502. Each sinusoid has one of a plurality of frequencies in a chosen test frequency range, and each sinusoid has the same number of cycles. A window function is then generated 503 and applied 504 to each sinusoid. The test signal (801,fig 8) is generated by sequencing the windowed sinusoids so that each two immediately consecutive sinusoids are not harmonically related and have no sideband frequency overlap. The test signal may then be used to determine the device under test's impulse response, total harmonic distortion, frequency response and phase response. The test signal is described as an audio test signal, but the same process may be applied to video broadcast systems, optics, telecommunications systems, electrical networks, and any other technologies in which frequency-dependent effects must be characterised. |
