Introduction
In today’s world, digital modulation techniques play a significant role in the communication industry. Digital modulation techniques are methods used to encode digital information into analogue signals for transmission. The three most popular digital modulation techniques are ASK (Amplitude Shift Keying), PSK (Phase Shift Keying), and QAM (Quadrature Amplitude Modulation).
In this blog, we will discuss each of these digital modulation techniques and their applications in various communication systems.
Amplitude Shift Keying (ASK)
Amplitude Shift Keying (ASK) is a digital modulation technique where the amplitude of the carrier signal is varied according to the digital data being transmitted. The amplitude of the carrier signal is switched between two different amplitudes, one representing the binary 0 and the other representing binary 1.
For example, if we want to transmit the binary sequence 101011, we would switch the carrier signal’s amplitude to the high amplitude for binary 1 and the low amplitude for binary 0.
ASK is a simple and easy-to-implement modulation technique, but it has limited applications in modern communication systems due to its susceptibility to noise and interference.
Phase Shift Keying (PSK)
Phase Shift Keying (PSK) is a digital modulation technique where the phase of the carrier signal is varied according to the digital data being transmitted. The carrier signal’s phase is shifted by a fixed angle between 0 and 360 degrees, representing the binary 0 and binary 1.
For example, if we want to transmit the binary sequence 101011, we would shift the carrier signal’s phase by 180 degrees for binary 1 and leave it unchanged for binary 0.
PSK is widely used in modern communication systems due to its robustness against noise and interference. It is also less complex than other modulation techniques and provides high data rates.
Quadrature Amplitude Modulation (QAM)
Quadrature Amplitude Modulation (QAM) is a digital modulation technique that combines ASK and PSK to transmit data. QAM modulates two carriers that are 90 degrees out of phase with each other. The amplitude and phase of these carriers vary according to the transmitted digital data.
For example, if we want to transmit the binary sequence 101011 using 16-QAM, we would modulate two carriers that are 90 degrees out of phase with each other.
QAM is a widely used modulation technique in digital communication systems. It provides high data rates and is robust against noise and interference.
Conclusion
Digital modulation techniques play a significant role in the communication industry. The three most popular digital modulation techniques are ASK, PSK, and QAM. Each technique has advantages and disadvantages, and their selection depends on the communication system’s requirements. ASK is a simple and easy-to-implement modulation technique but has limited applications in modern communication systems.
PSK is widely used in modern communication systems due to its robustness against noise and interference. QAM is a widely used modulation technique in digital communication systems, providing high data rates and robustness against noise and interference.