A new error index for the determination of the number of averages in transfer-function estimation

✍ Scribed by Takahiko Ono; Kiminori Yamaguchi; Hideo Suzuki; Jun'ichi Kawaura; Masanao Ohashi

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 699 KB
• Volume: 28
• Category: Article
• ISSN: 0003-682X
• DOI: 10.1016/0003-682x(89)90028-5

✦ Synopsis

A BS TRA CT

A ratio of an input-output cross-power spectrum to an input auto-power spectrum is used as an estimation of a transfer, function of a linear transmission system. In this paper, an error index in determining an appropriate number of averages is proposed for a system with external noise at the output stage. The error index used here is calculated from the difference between two estimated transfer functions which are individually obtained by use of a sampling sequence of even and odd orders. The index is an indication of the effect of the external noise on the estimated transfer function. It decreases as the number of averages is increased if the input and the external noise are not correlated. The usefulness of the index is shown for various input signals and signal-to-noise ratios (SIN) by a computer simulation and by an experiment using an analog bandpass filter. The index is useful even for cases in which the SIN changes with time.