| 释义 |
baseband, n. Telecommunications.|ˈbeɪsbænd|
[f. base n.1 + band n.2]
1. A frequency band with a lower frequency limit close to zero; spec. such a band containing a signal before it is modulated on to a carrier wave; the frequency band occupied by an unmodulated signal or a signal used for modulation. Also, a baseband system.
1960Times Rev. Industry Oct. 65/2 The overall channel characteristics [are]..fully up to agreed international standards even with basebands having as many as 2,700 channels. 1966M. Schwartz et al. Communication Syst. & Techniques iv. 173 The channel itself typically makes use of frequency ranges entirely different from those important in the baseband. 1972Sci. Amer. Sept. 138/3 Coaxial cables can carry the bit stream directly at ‘baseband’, that is, without modulation of a carrier signal. 1983E. Trundle Beginner's Guide Videocassette Recorders ix. 184 The provision of input sockets for audio and video signals at baseband. 1983Austral. Microcomputer Mag. Aug. 47/2 The alternatives provided between baseband and broadband provide a major division in local area network philosophies.
2. attrib., spec. designating: (a) a signal used to modulate a carrier or transmitted without a carrier; (b) a telecommunication system in which signals are transmitted in this way.
1961E. J. Baghdady Lect. Communication Syst. Theory xix. 445 There are situations in which each of several different baseband signals (or messages) is first made to modulate the frequency of a..sinusoidal carrier. 1975D. G. Fink Electronics Engineers' Handbk. xxii. 57 The baseband repeater..is the type usually employed for short-haul systems... The signal information is transferred within the repeater..at baseband frequencies and transmitted on a radio-frequency channel. 1982Giant Bk. Electronics Projects v. 201 The video and audio levels available from the baseband unit..are entirely compatible with such modulators. 1983Austral. Microcomputer Mag. Aug. 57/1 Time-division multiplexing permits baseband networks to carry multiple signals. 1987T. Housley Data Communications & Teleprocessing Syst. (ed. 2) vii. 103 Over short distances and/or at low transmission speeds, we can send..digital data signals straight down the line using a technique known as baseband signaling. |