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This is also known as spread spectrum. It's a method of encoding a signal using a changing carrier frequency. FM radio is incoded using a single carrier frequency which is varied slightly to encode the information. Think of frequency hoping as FM, but with the carrier changing quickly. So instead of staying on 88.1, the signal starts on 88.1, then jumps to 95.2, then to 101.3, then to 81.5, etc. etc. Each transmitting and receiving device knows the pattern of carrier jumps, so it knows where to look for the information. This is how bluetooth works.
Wiki User
∙ 12y ago
Wiki User
∙ 9y agoFrequency-hopping spread spectrum is a way that radio signals are transmitted. This is done by rapidly switching the signal over a large number of frequencies.
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What is frequency response of a diode?
The frequency response is nothing but how fast the diode is responding for the given amount of voltage from source. The resulting waveform will be in the frequency domain representation system.
What is mobile allocation index offset?
For telecom engineers, it is very help full to know about MAIO. Basically there is a set of frequencies where the channels are hop to avoid interference that set of frequencies is called MA-LIST. suppose MALIST contained frequencies [A,B,C,D,E,F,G,H,I,J,K,L].Then MAIO corresponds the starting point of hopping sequence. suppose there are four TRx in one sector. then MAIO will be, for example, 0,2,4.for first TRx for traffic, the MAIO is 0. means that hopping sequence starts from first frequency in the MALIST, that is frequency A. and for MAIO 2 it starts from frequency C and for MAIO 4 it starts from frequency E.Also HSN (hopping sequence number), ranges from 0 to 63 . if we use HSN as, for example 4 it means that for MAIO 0, the sequence starts from frequency A and repeats frequencies in following manner.For MAIO 0 and HSN 4A,F,K,D,I,B,G,L,E,J,C,H,A,FFor MAIO 2 and HSN 4C,H,A,F,K,D,I,B,G,L,E,J,C,HFor MAIO 4 and HSN 4E,J,C,H,A,F,K,D,I,B,G,L,E,J
What causes sideband frequency?
If you subtract from the carrier frequency the frequency of the tone that modulates it, then filter out the carrier frequency, then you have a lower sideband frequency. If you add to the carrier frequency, filter out the carrier, then you have an upper sideband frequency.
What is frequency sensitivity?
the amount of frequency change in the carrier frequency per unit amplitude change in the message signal is the frequency sensitivity this term comes in the frequency moulation
What is frequency response?
Frequency response is the measure of the frequency of the output a device gives in response to a stimulus that it receives. The frequency response is a characteristic of the device.
Types of frequency hopping?
slow frequency hopping (SFH) technology. The difference between slow frequency hopping and fast frequency hopping is that the frequency of latter changes faster than frequency modulation
Why frequency hopping is used?
TSK
What is frequency hopping in gsm?
Multi wave propagation varies the signal strength which causes fading dips. This is known as Rayleigh fading which is frequency dependent. Frequency Hopping changes the frequency with time to eliminate frequency dependent Rayleigh fading. Frequency Hopping reduces the effects of interferences and gives a great support to cater the capacity upgrading as well.
Working of frequency hopping spread spectrum?
exlanation of fhss block diadram
What is the signaling method used by Bluetooth?
FHSS(Frequency Hopping Spread Spectrum)
What feature does the SINCGARS use to reduce the threat of jamming and minimize the use of direction-finding equipment to establish your location?
SINCGARS radio's frequency hopping covering the 30 to 87.975 MHz band in 2,320 channels. Older direction-finding equipment that use a conventional receiver channel will have trouble direction-finding a frequency hopping radio, but direction-finders sets that use what amounts to a spectrum analyzer can DF a frequency hopping radio, and probably can de-interleave a number of them, so the anti direction-finding part of the reason for frequency hopping is not too strong. Note that SINCGARS uses about 100 hops per second, which is considered a slow hop. It is not a direct sequence spread spectrum system like is used by GPS. Once a frequency hopping radio has been located by direction-finding equipment then it's possible to jam it. Not by knowing the hop sequence, but by listening for each new transmission (like using a very fast spectrum analyzer) and then jamming that transmission, then the next, and so on. So the advantage of Frequency Hopping against a sophisticated enemy has a short life.
What famous entertainer was presented an Electronic Frontier Foundation for invention of frequency hopping?
Hedy Lamarr
What do you mean by Antenna Hopping in GSM?
Antenna hopping is a feature in which the Tx/Rx is passed through all the available antenna paths in a sector. No frequency is changed during antenna hopping. This helps improve performance by providing spatial diversity.
Difference between Frequency hopping spread spectrum and direct sequence spread spectrum?
Spelling difference.... :)
Is the measure of how fast particles move crest or frequency?
frequency
What is the frequency blue tooth runs on?
Bluetooth technology operates in the unlicensed industrial, scientific and medical (ISM) band at 2.4 to 2.485 GHz, using a spread spectrum, frequency hopping.
Are gsm use sfh to improve signal?
Frequency Hopping is an old technique introduced firstly in military transmission system to ensure the secrecy of communications and combat jamming. Frequency Hopping is mechanism in which the system changes the frequency (uplink and downlink) during transmission at regular intervals. It allows the RF channel used for signaling channel (SDCCH) timeslot or traffic channel (TCH) timeslots, to change frequency every TDMA frame (4.615 ms). The frequency is changed on a per burst basis, which means that all the bits in a burst are transmitted in the same frequency.
