Modulation Techniques

Modulation Techniques

Ayush Gupta20CS3016

Modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a lower-frequency message signal. In mobile computing, modulation is crucial for transmitting information wirelessly.

Types of Shift Keying Modulation

Basic Types:

• Amplitude Shift Keying (ASK): Varies the amplitude of the carrier signal.

• Frequency Shift Keying (FSK): Varies the frequency of the carrier signal.

• Phase Shift Keying (PSK): Varies the phase of the carrier signal.

Amplitude Shift Keying (ASK)

• Definition: ASK is a modulation technique where the amplitude of the carrier signal is varied in proportion to the instantaneous amplitude of the message signal.

• Applications: Widely used in broadcasting (AM radio) due to its simplicity and ability to cover long distances.

• Advantages and Disadvantages:

Advantages: Simple implementation. Disadvantages: Susceptible to noise and interference.

Frequency Shift Keying (FSK)

• Definition: FSK is a modulation technique where the frequency of the carrier signal is varied in proportion to the instantaneous amplitude of the message signal.

• Applications: Commonly used in applications such as wireless data transfer and certain types of wireless keyboards.

• Advantages and Disadvantages:

Advantages: Better resistance to noise, simple demodulation. Disadvantages: Requires more bandwidth.

Phase Shift Keying (PSK)

• Definition: PSK is a modulation technique where the phase of the carrier signal is varied based on the instantaneous amplitude of the message signal.

• Applications: Used in applications like wireless LANs and digital communication systems.

• Advantages and Disadvantages:

Advantages: Less susceptible to noise. Disadvantages: More complex implementation.

Advanced Shift Keying Modulation Techniques

Quadrature Amplitude Modulation (QAM)

• Definition: QAM is a combination of amplitude and phase modulation, allowing for the transmission of multiple bits per symbol.
• Applications: Widely used in digital communication systems, including Wi-Fi and digital television.
• Advantages: Increased data transmission rates.

Orthogonal Frequency Division Multiplexing (OFDM)

• Definition: OFDM divides the signal into multiple narrowband channels to mitigate the effects of multipath interference.
• Applications: Commonly used in 4G LTE and Wi-Fi.
• Advantages: Improved spectral efficiency and resistance to interference.

Conclusion

• Summary: Shift keying modulation techniques are fundamental to the wireless physical layer of mobile computing, allowing for the efficient transmission of information.

• Importance: Emphasize the critical role of shift keying modulation in shaping the performance and capabilities of wireless communication systems.

Thanks!

Ayush Gupta20cs3016@rgipt.ac.in