What is modulation Why is it required to modulate a signal before transmission?

The signals within 20 Hz to 20 kHz frequency range can travel only a few distances. To send the message signal, the length of the antenna should be a quarter wavelength of the used frequency. Thus, modulation is required to increase the frequency of the message signal and to enhance its strength to reach the receiver.

Why do we need baseband modulation?

Modulation. A signal at baseband is often used to modulate a higher frequency carrier signal in order that it may be transmitted via radio. Modulation results in shifting the signal up to much higher frequencies (radio frequencies, or RF) than it originally spanned.

Why do we need to modulate digital signal?

Digital modulation is used to transfer a digital bit stream over an analog channel at a high frequency. This enables us to transmit signals generated in a digital circuit across a physical medium. This is because digital signals can be handled with higher security and digital systems are readily and widely available.

Why is it required to modulate the signal for distant wireless communication?

Need for Modulation The baseband signals are incompatible for direct transmission. For such a signal, to travel longer distances, its strength has to be increased by modulating with a high frequency carrier wave, which doesn’t affect the parameters of the modulating signal.

Why is demodulation necessary?

Need of demodulation The diaphragm of a telephone receiver or a loud speaker cannot vibrate with high frequency. Moreover, this frequency is beyond the audible range of human ear. So, it is necessary to separate the audio frequencies from radio- frequency carrier waves.

Why do we need a carrier signal?

It is used to carry signals from one location to another on the surface of earth. We need the carrier waves of high frequency for distant communication because high frequency carrier waves travel with the speed of light and do not require a material medium to propagate.

How is baseband signal modulated?

In baseband modulation the information is formated so that it is represented by digital symbols. Then pulse waveforms are assigned that represent these symbols. These waveform c:an then be transmitted over a c:able. Baseband signals are not appropriate for propagation through many transmission media.

What is the need of doing pre emphasis?

Pre-emphasis is done for boosting the relative amplitudes of the modulating voltages at higher audio frequencies. In this method, the artificial emphasis of high frequency components of message signal is done before modulation in the transmitter.

What is the function of a modulator?

A modulator is an electronic circuit that superimposes a low-frequency (information) signal onto a high-frequency (carrier) signal for the purpose of wireless transmission. The reason for this is that higher frequency signals can be received using shorter aerials, which are more practical than longer ones.

What is modulation and demodulation of signals?

Modulation and demodulation Modulation is the process of encoding information in a transmitted signal, while demodulation is the process of extracting information from the transmitted signal. Many factors influence how faithfully the extracted information replicates the original input information.

Why is modulation important in telecommunications?

Solution: When using modulation, the carrier wave (which has a much higher frequency) is used to carry the signal, meaning it can travel further and more quickly through space. Problem: Antenna length would be impractical for voice, video and bit streams without modulation.

What is modulation and why it is needed?

Modulation is simply a widely used process in communication systems in which a very high-frequency carrier wave is used to transmit the low-frequency message signal so that the transmitted signal continues to have all the information contained in the original message signal.