| 摘要 |
<p>A control system comprises an electrical circuit (108) that produces distortion where the electrical circuit has a frequency band of operation. A pilot modulated carrier signal (produced by 182, 184) is frequency hopped about the frequency band of operation. The hopping pilot modulated carrier signal does not interfere with any signal applied to or generated by the electrical circuit as it is not at any time located within the frequency band of operation. Information obtained from the hopping pilot modulated carrier is provided to the control system which uses such information to cancel the distortion produced by the electrical circuit. <IMAGE></p> |
