In both analog and digital communications, there are 2 types of communication in the literature: Baseband Communication and Carrier Communication. You can find the brief introduction to each of the communication techniques:

1. Analog Baseband Communication - In this technique, the original signal is transmitted without modulation. It is typically used in low-bandwidth applications such as voice communication.

An Example of Analog Baseband Communication

• In active sonar applications, the signal that is transmitted and received is an analog acoustic wave.
• The communication in sonar refers to the exchange of information between the sonar system and the environment, such as the reflection of the acoustic wave by objects in the environment.
• The communication technique used in sonar applications is an analog baseband communication, as the signal being transmitted and received is an analog acoustic wave.
• Signal processing techniques such as pulse compression, matched filtering, and beamforming are typically used to enhance the detection and extraction of information from the received acoustic wave and improve the signal-to-noise ratio (SNR) of the received signal.

1. Amplitude Modulation (AM) - In AM, the amplitude of the carrier signal is varied in proportion to the modulating signal. This technique is commonly used in broadcasting radio signals.
2. Double Sideband Amplitude Modulation (DSB-AM) - In DSB-AM, the carrier signal is modulated with the information signal, resulting in two sidebands (upper and lower) containing the same information.
3. Single Sideband Amplitude Modulation (SSB-AM) - In SSB-AM, only one sideband of the modulated signal is transmitted, which allows for more efficient use of bandwidth in long-distance communication.
4. Vestigial Sideband Modulation (VSB) - In VSB, a small part of one sideband is transmitted, which results in better frequency utilization while maintaining the same bandwidth as SSB-AM.
5. Frequency Modulation (FM) - In FM, the frequency of the carrier signal is varied in proportion to the modulating signal. This technique is commonly used in broadcasting high-fidelity audio signals.

1. Digital Baseband Communication - In this technique, digital signals are transmitted without modulation. It is commonly used in computer networking and other digital communication systems.

1. Phase Modulation (PM) - In PM, the phase of the carrier signal is varied in proportion to the modulating signal. This technique is commonly used in digital communication systems such as Wi-Fi and Bluetooth.
2. Quadrature Amplitude Modulation (QAM) - In QAM, both the amplitude and phase of the carrier signal are varied to represent digital data. It is commonly used in digital communication systems such as cable modems and DSL.
3. Phase Shift Keying (PSK) - In PSK, the phase of the carrier signal is varied to represent the digital data being transmitted. It is commonly used in digital communication systems such as Wi-Fi, Bluetooth, and satellite communication.
4. Frequency Shift Keying (FSK) - In FSK, the frequency of the carrier signal is varied to represent the digital data being transmitted. It is commonly used in applications such as remote controls and wireless sensors.

1. Analog Baseband Communication - In this technique, the original signal is transmitted without modulation. It is typically used in low-bandwidth applications such as voice communication.
2. Digital Baseband Communication - In this technique, digital signals are transmitted without modulation. It is commonly used in computer networking and other digital communication systems.

1. Amplitude Modulation (AM) - In AM, the amplitude of the carrier signal is varied in proportion to the modulating signal. This technique is commonly used in broadcasting radio signals.
2. Double Sideband Amplitude Modulation (DSB-AM) - In DSB-AM, the carrier signal is modulated with the information signal, resulting in two sidebands (upper and lower) containing the same information.
3. Single Sideband Amplitude Modulation (SSB-AM) - In SSB-AM, only one sideband of the modulated signal is transmitted, which allows for more efficient use of bandwidth in long-distance communication.
4. Vestigial Sideband Modulation (VSB) - In VSB, a small part of one sideband is transmitted, which results in better frequency utilization while maintaining the same bandwidth as SSB-AM.
5. Frequency Modulation (FM) - In FM, the frequency of the carrier signal is varied in proportion to the modulating signal. This technique is commonly used in broadcasting high-fidelity audio signals.
6. Phase Modulation (PM) - In PM, the phase of the carrier signal is varied in proportion to the modulating signal. This technique is commonly used in digital communication systems such as Wi-Fi and Bluetooth.
7. Quadrature Amplitude Modulation (QAM) - In QAM, both the amplitude and phase of the carrier signal are varied to represent digital data. It is commonly used in digital communication systems such as cable modems and DSL.
8. Phase Shift Keying (PSK) - In PSK, the phase of the carrier signal is varied to represent the digital data being transmitted. It is commonly used in digital communication systems such as Wi-Fi, Bluetooth, and satellite communication.
9. Frequency Shift Keying (FSK) - In FSK, the frequency of the carrier signal is varied to represent the digital data being transmitted. It is commonly used in applications such as remote controls and wireless sensors.
10. Amplitude Shift Keying (ASK) - In ASK, the amplitude of the carrier signal is varied to represent digital data. It is commonly used in applications such as RFID and remote controls.
11. On-Off Keying (OOK) - In OOK, the presence or absence of the carrier signal is varied to represent digital data. It is commonly used in optical communication systems.
12. Pulse Amplitude Modulation (PAM) - In PAM, the amplitude of a series of pulses is varied to represent digital data. It is commonly used in digital communication systems such as Ethernet and fiber-optic communication.