What kind of modulation is used in satellite communication?

What kind of modulation is used in satellite communication?

The constant envelope modulation schemes such as FSK and PSK are the most suitable for satellite communications because they minimize the effect of nonlinear amplification in the high-power amplifier.

Why FM is used in satellite communication?

In the case of FM, Bandwith is large and noise immunity is high that’s why it is used in satellite communication.

Why is QPSK modulation used in satellite broadcasting?

In one such approach, quadrature phase-shift-keying (QPSK) modulation provides both spectral and power efficiency. In a QPSK modulator, two data streams simultaneously modulate a carrier signal. For optimum use of available satellite power, an unbalanced QPSK (UQPSK) modulator is often used.

What is a satellite modulator?

A satellite modem or satmodem is a modem used to establish data transfers using a communications satellite as a relay. A satellite modem’s main function is to transform an input bitstream to a radio signal and vice versa.

Is OFDM used in satellite communication?

As orthogonal frequency-division multiplexing (OFDM) has been adopted in the 3GPP standards, such as 4G LTE and the ongoing 5G new radio (NR), it will become an important feature of the satellite to achieve a high degree of commonality with the terrestrial cellular networks, i.e. LTE or 5G.

Why are VHF U HF and microwave signals used in satellite communication?

Why are VHF, UHF, and microwave signals used in satellite communication? Explanation: VHF, UHF, and microwave signals penetrate the ionosphere with little or no attenuation and are not refracted to earth. Lower frequencies undergo total internal refraction and get reflected back to earth.

What is modulation in communication?

Modulation is defined as the process of superimposing a low-frequency signal on a high-frequency carrier signal. Or. The process of varying the RF carrier wave in accordance with the information in a low-frequency signal.

How is OFDM different from FDM?

In FDM, Bandwidth (B) is committed to the different sources. Orthogonal Frequency Division Multiplexing (OFDM): It is also the multiplexing technique which is used in analog system. In OFDM, Guard band is not required and the spectral efficiency of OFDM is high which oppose to the FDM.

What is modulation with example?

For example, the modulation signal might be an audio signal representing sound from a microphone, a video signal representing moving images from a video camera, or a digital signal representing a sequence of binary digits, a bitstream from a computer. The carrier is higher in frequency than the modulation signal.

What frequency bands are used in satellite communication?

The major frequency bands used for satellite communication in India are S-band, C-band, Upper Extended C band, Ku band and Ka band. The INSAT/GSAT satellites carry transponders in these bands.

What is uplink and downlink in satellite communication?

In satellite telecommunication, a downlink is the link from a satellite down to one or more ground stations or receivers, and an uplink is the link from a ground station up to a satellite. Some companies sell uplink and downlink services to television stations, corporations, and to other telecommunication carriers.

What are the modulation techniques for satellite communications?

The modulation techniques for satellite communications require not only faster data rates but also minimizing the impacts of the channel impairments. This post discusses the modulation techniques for modern satellite communications.

What are the advantages of digital modulation over analogue modulation in satellite?

As the advance in technology and limitation of analogue modulation it is now most of the satellite using digital modulation techniques and providing some advantages over analogue modulation like better performance, error detection and correction efficiency, signal to noise ratio etc.

Which constant envelope modulation scheme is best for satellite communications?

The constant envelope modulation schemes such as FSK and PSK are the most suitable for satellite communications because they minimize the effect of nonlinear amplification in the high-power amplifier. Figure 2 illustrates the constellation diagrams of binary PSK (BPSK), quadrature PSK (QPSK), and 8PSK.

What is modulation in digital electronics?

In general view, modulation is the process where the characteristics (phase, frequency or amplitude) of high frequencies are varied along with baseband information. The baseband signal carries the basic information such as the output of video camera, voice coder or digital television.