A radio transmission technology that spreads the user information over a much wider bandwidth than otherwise required in order to gain benefits such as improved interference tolerance and unlicensed operation.
The ability to transmit data or information over a wide range of frequencies, and then reassemble the message when it is received.
Technique to reduce and avoid interference by taking advantage of statistical means to send a signal between two points. A figure of merit for spread spectrum systems is "spreading gain" measured in DB. The two types of commercial spread spectrum techniques are frequency hopping and direct sequence.
a signaling technique where the AC energy transmitted by a device is spread over a range of frequencies rather than remaining concentrated at one frequency (such as an AM radio station). CEBus uses spread spectrum techniques on the power line and radio frequency devices.
A method of transmitting a signal by "spreading" it over a broad range of frequencies (using a compatible receiver to reassemble the signal). This provides reduced interference (see "processing gain") and can increase the number of simultaneous users within a radio frequency band.
A form of wireless communication in which a signal's frequency is deliberately varied. This increases bandwidth and lessens the chances of interruption or interception of the transmitted signal.
A method of transmitting a signal by spreading it over a wide frequency band. Used initially by the military, it is becoming increasingly popular in commercial telecommunications as a way of helping to secure the signal, because spreading it over a wide spectrum makes it difficult to intercept and difficult to jam.
a type of high bandwidth, low power transmission system originally developed by the U.S. government that cannot be easily detected or intercepted. Current versions also use dynamic frequency hopping to change frequency if anything jams the signal. F.C.C. regulations do not require these radios to be licensed. Available commercially in 900Mhz, 2.4Ghz or 5.8Ghz versions.
A sequential signal structure that spreads the normally narrowband information signal over a relatively wide band of frequencies. Spread spectrum radios correlate the signals to retrieve the original signal. Spread spectrum radios are more immune to noise and interference.
This communications technique has been used in secure military systems for a number of years and is now becoming popular in commercial systems. This format involves transmitting information, which has been multiplied by a pseudo-random noise (PN) sequence which essentially "spreads" it over a relatively wide frequency bandwidth. The receiver detects and uses the same PN sequence to "despread" the frequency bandwidth and decode the transmitted information. This communications technique allows greater signal density within a given transmission bandwidth and provides a high degree of signal encrytion and security in the process.
A radio transmission technology that spreads the user information (intelligence) over a much wider bandwidth but at reduced power. The principal benefits are improved tolerance to interference and allowing unlicensed operation.
Spread spectrum radio is theoretically simple. Two radios communicate by hopping from frequency to frequency, transmitting and receiving packetized data. By spreading the radio signal over a bunch of different frequencies in sequence, it's almost impossible to intercept or jam.
Wideband radio frequency technique used for more reliable and secure data transmission.
A technique whereby radio communications energy is spread over a wide bandwidth, includes both direct sequence and frequency hopping equipment. FCC: 47 CFR 15.247.
The US military developed spread spectrum through-the-air radio transmission technology primarily to overcome the problem of intentional interference by hostile jamming and secondarily for security. A spread spectrum signal is created by modulating the original transmitted radio frequency (RF) signal with a spreading code that causes "hopping" of the frequency from one frequency to another. By contrast, conventional AM and FM radio uses only one frequency to transmit signal.
A wireless communications technology that scatters data transmissions across the available frequency band in a pseudorandom pattern. Spreading the data across the frequency spectrum greatly increases the bandwidth, it also makes the signal resistant to noise, interference, and snooping. Spread-spectrum modulation schemes are commonly used with personal communications devices such as digital cellular phones, as well as with WLANs and cable modems.
A technique used for wireless transmission of digital signals whereby the signal is distributed over a wide frequency range.
A wideband modulation which imparts noise-like characteristics to an RF signal. This communications technique spreads a signal over a wide range of frequencies for transmission and then de-spreads it to the original data bandwidth at the receiver.
Originally developed by the military, spread spectrum radio transmission essentially "spreads" a radio signal over a very wide frequency band to make it difficult to intercept and difficult to jam. Most spread-spectrum signals use a digital scheme called frequency hopping. The transmitter frequency changes abruptly, many times each second. Between "hops," the transmitter frequency is stable. The length of time that the transmitter remains on a given frequency between "hops" is known as the dwell time.
Is the term used to describe the modulation technique for 802.11 and Bluetooth. The spread spectrum technique is used to increase the robustness of the wireless network. Spread spectrum comes at a cost though, speed is traded for reliability.
A technique where a narrow-band signal is spread over a broader portion of the radio frequency band.
A technique in which an already modulated signal is modulated a second time in such a way as to produce a waveform which interferes in a barely noticeable way with any other signal operating in the same frequency band. With spread spectrum technique, signal is spread over wider bandwidth than is needed for transmission. This technique reduces the effect of interference. Also see DSSS and FHSS.
Spread spectrum is a form of wireless communications in which the frequency of the transmitted signal is deliberately varied - this results in a much greater bandwidth than the signal would have if its frequency were not varied.
A system in which the transmitted signal is spread over a frequency band much wider than the minimum bandwidth needed to transmit the information being sent. This is done by modulating with a pseudo random code, for GPS.
The term used to describe a number of methods of spreading a radio signal over multiple frequencies, either simultaneously (direct sequence) or in series (frequency hopping.) Bluetooth uses spread spectrum for added security and to minimize radio frequency interference.
A system, in which the transmitted signal is spread over a frequency band much wider than the minimum bandwidth needed, to transmit the data being sent. This process is performed by modulating with a pseudo-random GPS code.
Means of transmission in which information is carried encoded into discrete packages of information, then spread over a wide bandwidth for transmission to specific receivers which filter out the coded material.
Jamming-resistant and initially devised for military use, this radio transmission technology "spreads" information over greater bandwidth than necessary for interference tolerance and is now a commercial technology.
A digital modulation scheme which increases the signal carrying capacity of a given bandwidth allowing multiple signals to occupy the same frequency and distinguishing each one by its unique “ address.” The modulation process causes each signal's bandwidth to increase.
The received GPS signal is wide bandwidth and low power. The L-band signal is modulated with a pseudo-random noise code to spread the signal energy over a much wider bandwidth than the signal information bandwidth. This provides the ability to receive all satellites unambiguously and to give some resistance to noise and multipath.
A communication technique in which the frequency of the transmitted signal is deliberately varied. This results in greater bandwidth and lessens the chances of interruption or interception of the transmitted signal. There are two types of spread spectrum radio: direct spread and frequency hopping. In direct sequence spread spectrum (DSSS), the stream of information to be transmitted is divided into small pieces, each of which is spread across the entire allocated spectrum. With frequency hopping spread spectrum (FHSS), a carrier spreads out information (voice or data packets) over different frequencies.
A radio technology that sends radio signals over multiple channels, changing the transmission and receipt frequency at programmed intervals. This type of spread spectrum is known as frequency-hopping spread spectrum and is the prevalent method used in cordless telephones.
A transmission technique developed by the U.S. military in World War II to provide secure voice communications, spread spectrum is the most commonly used WLAN technology today. It provides security by "spreading" the signal over a range of frequencies. The signal is manipulated in the transmitter so that the bandwidth becomes wider than the actual information bandwidth. De-spreading the signal is impossible for those not aware of the spreading parameters; to them, the signal sounds like background noise. Interference from narrowband signals is also minimized to background noise when it is de-spread by the receiver. Two types of spread spectrum exist: direct sequence and frequency hopping.
A method of transmitting a radio signal by spreading it over a wide range of frequencies. This reduces interference and can increase the number of users on one radio frequency band.
A method of transmitting a radio frequency (RF) signal by â€œspreadingâ€ it over a broad range of frequencies. This facilitates reduced interference and increased capacity within a particular radio frequency band. CDMA technology is based on spread spectrum. See Also: CDMA
The transmission of a signal using a much wider bandwidth and power than would normally be required. Spread spectrum also involves the use of narrower signals that are frequency hopped through various parts of the transponder. Both techniques produce low levels of interference Between the users. They also provide security in that the signals appear as though they were random noise to unauthorized earth stations. Both military and civil satellite applications have developed for spread spectrum transmissions.
A communications technology where a signal is transmitted over a broad range of frequencies and then re-assembled when received.
A method of transmitting a signal by â€œspreadingâ€ it over a broad range of frequencies. This technology allows for reduced interference and increased capacity within a particular radio frequency band.
A communication device that transmits over many frequencies at the same time. Known for reliability.
A radio data transmission modulation technique by which the transmitted signal is spread over a bandwidth wider than the information bandwidth.
Telecommunications techniques in which a signal is transmitted in a bandwidth considerably greater than the frequency content of the original information.
A communication technique that spreads a signal bandwidth over a wide range of frequencies for transmission and then de-spreads it to the original data bandwidth at the receiver.
(Wireless) A technique in which the transmitter sends (or spreads) a signal over a wide range of frequencies. The receiver then concentrates the frequencies in order to recover the information.
Initially devised for military use, this radio transmission technology "spreads" information over greater bandwidth than necessary to resist jamming and other interference.
Enables the successful transmission to hostile transmission environments.
Spread-spectrum techniques are methods by which energy generated at one or more discrete frequencies is deliberately spread or distributed in either the frequency or time domains. This is done for a variety of reasons, including the establishment of secure communications, increasing resistance to natural interference and jamming, and to prevent detection.