Spread-spectrum techniques are methods by which energy generated in a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth. These techniques are used for a variety of reasons, including the establishment of secure communications, increasing resistance to natural interference and jamming, and to prevent detection
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
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 received GPS signal is a wide bandwidth, low-power signal (-160dBW) This property results from modulating the L-band signal with a PRN code in order to spread the signal energy over a bandwidth which is much greater than the signal information bandwidth This is done to provide the ability to receive all satellites unambiguously and to provide some resistance to noise and multipath
Radio frequency technology that requires no FCC site license The frequency is constantly changed following a known algorithm to relieve conflict from multiple users at one frequency
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
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
Radio frequency modulation that spreads the radio energy across a wide frequency spectrum, reducing the power at any one frequency This is used to reduce interference and make eavesdropping difficult Spread spectrum is a required modulation in the 2 4 GHz band, by FCC rules
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 (Back to top )
A communications technology where a signal is transmitted over a broad range of frequencies and then re-assembled when received
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 encryption and security in the process
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
[telecommunications] A wireless communication method that spreads transmissions across a spectrum instead of transmitting over a fixed radio frequency The Federal Communications Commission has authorized the three ISM bands for such transmissions The two types of SS transmission, direct sequencing (DSSS) and frequency hopping (FHSS), deter eavesdroppers because the signals are either encoded or are difficult to intercept See CDMA
Most wireless LAN systems use spread-spectrum technology, a wideband radio frequency technique developed by the military for use in reliable, secure, mission-critical communications systems Spread-spectrum is designed to trade off bandwidth efficiency for reliability, integrity, and security In other words, more bandwidth is consumed than in the case of narrowband transmission, but the tradeoff produces a signal that is, in effect, louder and thus easier to detect, provided that the receiver knows the parameters of the spread-spectrum signal being broadcast If a receiver is not tuned to the right frequency, a spread-spectrum signal looks like background noise There are two types of spread spectrum radio: frequency hopping and direct sequence
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
The term spread spectrum describes a modulation technique which makes the sacrifice of bandwidth in order to gain signal-to-noise performance Basically, the SS system is a system in which the transmitted signal is spread over a frequency much wider than the minimum bandwidth required to send the signal The fundamental premise is that, in channels with narrowband noise, increasing the transmitted signal bandwidth results in an increased probability that the received information will be correct If total signal power is interpreted as the area under the spectral density curve then signals with equivalent total power may have either a large signal power concentrated in a small bandwidth or a small signal power spread over a large bandwidth There are two basic types of spread spectrum modulation direct sequence (DS) and frequency hopped (FH) Some hybrid spread spectrum systems exist that combine both types
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
Also known as frequency hopping (FH), is a method by which information (voice or data) is put into packets which are spread out on different frequencies In the case of a phone call-the call is carried on several different frequencies, so that when one frequency is lost another picks up the call without the connection being broken
The received GPS signal is wide-bandwidth and low-power (-160 dBW) The L-band signal is modulated with a PRN 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
Type of radio transmission; reduces interference and jamming, and allows multiple user communications; originally developed by the military