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spread-spectrum technology
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Why do you use modulation in gsm?
in the case of communication through gsm technology we transmit our voice frequency to somewhere from the origin. normally human voice frequency lays between 300-3400khz. if all the people tends to transmit their voice, the signal wil be distroyed due to interference. also theoretically it need a very long antenna to transmit a low frequency. therefore it is necessary to modulate each and every signal to a high frequency carrier to transmit without any interference and make possible communication mohamed zawahir +94772260383
What is the use of connecting an integrator in delta modulation?
integrator converts the quantised signal to saw tooth signal which then compared with the present signal and error signal is generated,and error signal is quantised and the process continues
What is use of capacitor Ce across emitter resistance?
It can be used as a feedback and to ground unwanted signals and frequencies
What are the difference between carrier signal modulating signal modulated signal baseband and passband?
carrier signal- use for the purpose of conveying information. modulating signal- causes variations in some characteristics of carrier signal. modulated signal - carrier signal after altration in its characteristics is called modulated signal. example- if you want to see an object (suppose it is an modulating signal),you need light(light is carrier signal) and when light will reflect on object you will be able to see if (that is modulated signal)
Why we use 2 Tx and 2 Rx in transmission cables in telecom?
1 is for transmit and 1 is for redundancy
Why do you use modem?
modem means modulator demodulator. it converts digital signal to analog signal. it is use to transmit computer signal (digital signal) over the telephone line to communicate to other computers. modem converts the computer digital signal into frequency (analog signal) so that it can transmit over the telephone line and at the receiving end the modem converts the analog signal back to digital for the receiving computer to understand it.
In Army writing is the standard for correspondence is to use the passive voice?
transmit a clear message in multiple view
What modern fax machine use to transmit text?
To transmit text, a modern fax machine scans a page, turns that page into an auto signal, then transmits that signal to another fax machine over a phone line. That fax machine then decodes the signal and turns it back into an image, that is then printed out on a piece of paper.
Which modulation can reduce the noice of signal?
Signals of different frequencies cannot interfere with each other. For example can audio waves (speech) interfere with AM or FM signals?? So when we perform modulation we just transfer the message to another amplitude/frequency/phase. Hence they will never interfere with signals which are not in the same range as them. Regards Arvind
How radio repeaters work?
A radio repeater works by having the transmitter and receiver on separate frequencies. This allows the transmitter to re-transmit the received audio or data. To prevent the transmitter from opening due to noise on the receiver most systems will only re-transmit if they receive a keying tone at the start of the transmission, a sub audible tone which is transmitted with the normal modulation or a digital code. Some repeaters use a separate antenna for transmit and receive although most use a single antenna and a filtering arrangement to split the transmit and receive frequencies. This filter is called a duplexer as it permits duplex operation.
What characteristic of Digital Subscriber Line transmissions results in greater noise and signal loss than occurs in conventional transmissions?
They use higher frequencies
Which cable is use for similar device?
A crossover cable is necessary for two similar devices to talk to each other without the use of an intervening network connectivity device because the transmit and receive signals must be crossed between the two devices. This is what a hub or switch would normally do. If a normal, straight through cable were to be used it would connect the transmit signal to the transmit signal on the other device, which is equivalent to two people talking to each other at the same time with no way to listen to what they are saying. With a crossover cable the transmit signal on one end is connected to the receive signal on the other end so the two devices can talk and listen to each other.
Why do emergency services use radio waves in a wavelength range that no one else is allowed to use?
They unfortunately don't ... but they try to :to keep those frequencies clear for important messages (rather than chit-chat).Answer 2I don't know where you come from, but in most countries it is a criminal offence to transmit or listen into a frequency you are not allowed to use, including those of the emergency services.In order to use a frequency you need to get a licence for it from the government (with a few exceptions, for example the broadcast frequencies where you do not need a licence to listen, but do to transmit).
Can we transmit electricity at various frequency in the same wire simultaneously?
Internet broadband is probably the best useful example of this. We can also send radio signals between devices plugged into sockets on the same circuit in our houses, with the signal sent through the mains wiring. To transmit electricity for energy use at different frequencies is neither practical or efficient. To handle electricity on the scale of the super grid that serves us, frequencies and voltages need to be harmonized. An example of this is a wind turbine, which converts its varying a.c. supply to d.c. then back to a.c. at the correct frequency to be useful to the system it is connected to.
What method of signal transmission uses radio waves to carry signals?
The analog method of signal transmission uses radio waves to carry signals. Digital transmission involves the use of satellites to transmit signals.
To transmit and receive signals from multiple nodes in a three-story house what type of antenna should an access point use?
omnidirectional
What does AM mean on the radio?
Amplitude Modulation, the method of sending information through radio frequencies.
