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Topic: Subcarrier


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In the News (Mon 17 Jun 19)

  
  Subcarrier - Wikipedia, the free encyclopedia
A subcarrier is separate analog or digital signal carried on a main radio transmission, which carries extra information such as voice or data.
Stereo is a subcarrier of an FM radio station, which takes the left channel and "subtracts" the right channel from it — essentially by hooking up the right-channel wires backward and then joining left and right.
Likewise, TV signals are transmitted with the fl and white luminance part as the main signal, and the color chrominance as the subcarriers.
en.wikipedia.org /wiki/Subcarrier   (645 words)

  
 NTSC - Wikipedia, the free encyclopedia
Due to certain technical considerations, the addition of the color subcarrier also required a slight reduction of the frame rate from 30 frames per second to 29.97 frames per second.
The phase relationship of the I and Q signals with the 3.579545 MHz subcarrier corresponds to the instantaneous color hue captured by a TV camera; its amplitude corresponds to the color saturation (purity) of the original signal.
A short sample of this reference signal is included in the NTSC signal as color burst, located on the back porch of each horizontal line, the time between the end of the horizontal synchronization pulse and of the blanking pulse on each line.
en.wikipedia.org /wiki/NTSC   (2558 words)

  
 [No title]   (Site not responding. Last check: 2007-11-07)
The subcarrier components of each of the electrical signals generated by the photodetectors are received and combined in a summing amplifier located at the second site and in the subcarrier channel of the communication network.
In addition, the subcarrier receiver can send the composite subcarrier modulation signal to a subcarrier modulation signal generator located in the subcarrier channel of the second site, where the composite subcarrier modulation signal can be applied to a transmitter site also located at the second site, to provide further network communication.
According to the present invention, a composite subcarrier modulation signal with an improved SNR is recovered in subcarrier channel 525 by summing amplifier 560.
www.wipo.int /cgi-pct/guest/getbykey5?KEY=99/17484.990408&ELEMENT_SET=DECL   (7107 words)

  
 [No title]
Subcarrier audio, like you are listening to now, is in a range of 5 to 8 Megahertz and rides along the top of the video.
The wide band subcarriers are around 100 KHz wide, and, actually closer to 200 I guess, around 180 or so, and the narrow band are somewhere between 60 and 70 KHz wide in FM deviation.
They have a subcarrier and I don't know what frequency, I would assume 19 KHz just like regular FM uses, and they did the left minus right thing on this subcarrier of a subcarrier.
www.nmia.com /~roberts/audio.fnl   (5132 words)

  
 Allowable Costs for Noncommercial Educational FM Licensees to Charge Radio Reading Services -- Audio Division (FCC) USA
If a station used its subcarrier for any noncommercial educational purpose, it was permitted to charge an amount which could not exceed the sum of the approximate cost of conducting the subcarrier operation (including purchase or lease of equipment, course material, personnel services, etc.), and the general overhead and operational costs attributable to such operations.
Technically, a subcarrier is an inherent part of the FM bandwidth used by the public radio station.
However, to the extent that the existence of the subcarrier decreases the quality of the station's signal or increases the possibility of interference to the transmision links, then any costs which the station incurs to correct those problems are properly chargeable to the radio reading service.
www.fcc.gov /mb/audio/decdoc/letter/1988--10--28--readsvc.html   (6293 words)

  
 [No title]   (Site not responding. Last check: 2007-11-07)
The radio frequency identification tag circuit is operable to extract the subcarrier from the emitted radio frequency carrier signal and the extracted subcarrier then functions as a clock, which operates to assist in the transfer of a modulated backscattered signal to the radio frequency identification reader circuit.
The subcarrier frequency modulation rate on the radio frequency carrier signal 60 should be equal to or less than the 1 KHz switching speed of the organic semiconductor material comprising the tag receiver circuit 80 used to extract the subcarrier modulation for the clock.
When coupling of the subcarrier modulated radio frequency carrier signal 60 is established, capacitor plates 81 and 82 on tag receiver circuit 80 are input to opposite ends of a diode bridge 83.
www.wipo.int /cgi-pct/guest/getbykey5?KEY=04/109932.041216&ELEMENT_SET=DECL   (2096 words)

  
 Subcarriers / SCA / Subsidiary Communications Authority       Audio Division (FCC) USA
These subcarrier channels are not receivable with a regular radio; special receivers are required.
Subcarrier use is secondary to the transmission of the main audio channel, and must not interfere with the main audio channel.
The arithmetic sum of all multiplex subcarriers may not exceed 20% modulation (15 kHz) (where 100% is 75 kHz deviation from the carrier).
www.fcc.gov /mb/audio/subcarriers   (1222 words)

  
 Encyclopedia: Subcarrier   (Site not responding. Last check: 2007-11-07)
Subsidiary Communications Authority (SCA), is the FCCs official designation for subcarrier channels transmitted by a broadcast FM radio station along with its main carrier.
The Canadian Radio-television and Telecommunications Commission (CRTC, in French Conseil de la radiodiffusion et des télécommunications canadiennes) was established in 1968 by the Canadian Parliament to replace the Board of Broadcast Governors.
Likewise, TV signals are transmitted with the fl and white luminance part as the main signal, and the color chrominance as the subcarriers.
www.nationmaster.com /encyclopedia/Subcarrier   (1916 words)

  
 Phase locked subcarrier regenerator - Patent 5021872
In this case, the additional subcarriers regenerated at the signal receiving side must be regenerated in a predetermined phase relationship with the additional subcarriers at the signal transmitting side.
The color subcarrier signal Fsc with its phase locked to the color burst is applied to the second input terminal of the AND gate 44.
An alternative method to generate the field alternate subcarrier signal Fc' is to store in memory the sampled data corresponding to the odd and even fields are and to apply the field discrimination signal as part of the read address signal, applied to the memory.
www.freepatentsonline.com /5021872.html   (2924 words)

  
 Digital modulation method for standard broadcast FM subcarrier - Patent 4660193
The amplitude modulated SCA subcarrier is combined with the stereo signal output of a stereo multiplexer to form the modulating signal for the station FM modulator.
The I and Q subcarriers are supplied respectively to I and Q AM modulators each of which also receives one bit of a modulating signal bit pair as a modulating signal.
The 61 kHz subcarrier is reinserted at SSB demodulator 106 which detects the audio and digital modulation on the 61 kHz subcarrier.
www.freepatentsonline.com /4660193.html   (3137 words)

  
 SECAM Subcarrier generator - Patent 4084177
These two subcarrier reference frequencies D.sub.R, D.sub.B are used to set the center frequency of the FM oscillator for alternate television lines during the horizontal blanking interval.
The most common prior art methods of generating the two subcarrier frequencies generally utilize a sharp, narrow pulse of approximately 0.1.mu.sec duration occurring at the horizontal line rate to drive a pulse transformer for generating a wide spectrum of harmonics of the horizontal line frequency.
The first and second subcarriers are now in the form of stable CW waveforms of negligible distortion locked in frequency and phase to each other with the undesired components at multiples of the line frequency more than 40db down.
www.freepatentsonline.com /4084177.html   (1281 words)

  
 Subcarrier Comunications v. Day
Subcarrier Communications, Inc. ("Subcarrier") searches for and leases sites on towers and buildings for communication companies to place their wireless communication devices.
Subcarrier sought and obtained a preliminary injunction enjoining its former employee and her new employer from benefitting from her misappropriation of a "Point of Contact" list that belonged to Subcarrier, despite the ex-employee's claims that she never used the information on the list and that this information was readily available in the public domain anyway.
The Court found Subcarrier's dual categorization "interesting" and "apparently novel" and held that any final determination by the Chancery Division must include a determination whether the lists compiled by Defendant were her property, Subcarrier's, or are shared property.
www.meislik.com /recentnj/blcases/blcase01.htm   (543 words)

  
 subcarrier - a Whatis.com definition   (Site not responding. Last check: 2007-11-07)
A subcarrier is one telecommunication signal carrier that is carried on top of another carrier so that effectively two signals are carried at the same time.
At the receiving end, the main carrier and subcarrier signals are demodulated separately.
A subcarrier can be used for some purpose entirely different from the purpose of the main carrier.
whatis.techtarget.com /gDefinition/0,294236,sid7_gci770512,00.html   (189 words)

  
 SCPC and Subcarrier Satellite Transmission Comparisons   (Site not responding. Last check: 2007-11-07)
In a Subcarrier system, a bunch of individual audio signals are converted to different low frequency FM signals, called subcarriers.
Since all audio subcarriers must be added together and sent to the satellite from a common dish, all the originators of the audio signals must budget their signals transported to the common uplink site.
Second, the baseband signal is routed to subcarrier demodulators which tune and demodulate the individual audio signals.
www.big-z.com /700comp.htm   (503 words)

  
 Subcarrier Communications   (Site not responding. Last check: 2007-11-07)
Subcarrier brings together a team of professionals and managers comprised of some of the most talented, experienced people in the industry, to offer comprehensive site acquisition, development, and long-term management services.
At Subcarrier we integrate both the science and art and utilize both disciplines to bring creative and practical solutions to meet our client's objectives.
Subcarrier Communications, Inc. is strongly committed to protecting the privacy of consumers of its interactive products and services.
www.subcarrier.com /about.html   (631 words)

  
 News - FM Subcarrier ITS Issues Move to CEMA's Arena   (Site not responding. Last check: 2007-11-07)
At issue is standardizing the means of sending traveler-related information to a wide audience using FM subcarrier wavelengths that are simulcast along with the more familiar FM broadcasts.
It is not the first time proponents of the different technical approaches to subcarrier delivery have squared off.
Adding more complexity to the issue is the possibility that delays in creating a standard for using the FM subcarrier channel would allow single-point wireless interests, such as cellular phone companies, to seize the market for wireless delivery of traveler-related information.
www.itsa.org /ITSNEWS.NSF/4e0650bef6193b3e852562350056a3a7/480e2bf83fac88a68525666e006243af?OpenDocument   (527 words)

  
 IRIG 106-99 Chapter 3   (Site not responding. Last check: 2007-11-07)
The data bandwidth of one format type is proportional to the subcarrier center frequency, while the data bandwidth of the other type is constant, regardless of subcarrier frequency.
In these systems, one or more subcarrier signals, each at a different frequency, are employed to frequency modulate (FM) or phase modulate (PM) a transmitter in accordance with the RF conditions specified in chapter 2.
The letters A, B, C, D, E, F, G, and H identify the channels for use with maximum subcarrier deviations of ±2, ±4, ±8, ±16, ±32, ±64, ±128, and ±256 kHz, along with maximum frequency responses of 2, 4, 8, 16, 32, 64, 128, and 256 kHz.
www.spiraltechinc.com /otis/IRIG_Files/IRIG_Chapter3.htm   (635 words)

  
 Subcarrier B/S/QPSK Modulator - PSK006 - GDP Space Systems - Telemetry Systems, Synchronizers, BERTS, Demodulaters, ...
The PSK006 module is a B/S/QPSK subcarrier modulator, a programmable psuedo-random number (PRN) data generator and an IRIG-106 code converter with convolutional encoding and V.35 and V.35M data randomizing.
The selected data source is used to BPSK, QPSK or SQPSK (Staggered QPSK) modulate a subcarrier, which is tunable to 10 MHz.
The PRN generator bit rate is tunable to 10 Mbps and may be programmed to output a pseudo-random pattern up to 223-1 bits in length or one of several preset recirculating word patterns.
www.gdpspace.com /flash/psk006.htm   (199 words)

  
 LAB1401 - SCH Phase Adjustment
The CH 2 input was the CW subcarrier signal.
Adjusting the CW subcarrier phase moved the subcarrier zero crossing with respect to the 50% horizontal sync transition.
Subcarrier phase was adjusted for the two points to be coincident (See Figure 5).
www.lecroy.com /tm/Library/labs/LAB1401?menuid=2   (753 words)

  
 Orban
The heart of the Amigo SCA is its digitally-synthesized subcarrier generator.
The subcarrier frequency and deviation level of the unit are easily changed in the field.
The subcarrier injection level is adjusted via a front panel mounted control.
www.orban.com /orban/products/crlsystems/amigo_sca.html   (367 words)

  
 SCA Technology   (Site not responding. Last check: 2007-11-07)
At the receiver, the subcarriers are converted back down to their original frequencies.
At 57 kHz is the RDS subcarrier used for data to carry such information as the station's callsign, and the name of the selection currently playing.
The technical nomenclature for SCA transmissions is: FM subcarrier on FM carrier, frequency division multiplexing.
www.compolinc.com /sca_technology.htm   (379 words)

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