- frequency-direction spectrum
- 频率方向谱
Atmospheric Sciences (English-Chinese) dictionary. 2014.
frequency-direction spectrum
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Frequency-division multiplexing — (FDM) is a form of signal multiplexing where multiple baseband signals are modulated on different frequency carrier waves and added together to create a composite signal. Non telephoneFDM can also be used to combine multiple signals before final… … Wikipedia
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Single-frequency signaling — (SF) is line signaling (in telephony) in which dial pulses or supervisory signals are conveyed by a single voice frequency tone in each direction. SF and similar systems were used in 20th century carrier systems.An SF signaling unit converts DC… … Wikipedia
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