Lecture 6 Frequency Shift Keying FSK Phase Shift

Lecture 6: Frequency Shift Keying (FSK) & Phase Shift Keying (PSK) 1 nd semester 1438 -1439 By: Adal ALashban 1

Outline - FSK (Frequency Shift Keying). - Digital Modulation (FSK). - PSK (Phase Shift Keying). - Digital Modulation Summary. 2

FSK (Frequency Shift Keying) - The frequency of the carrier signal is varied to represent binary 1 or 0. - Both peak amplitude and phase remain constant while the frequency changes. - The frequency of the signal during each bit duration is constant, and its value depends on the bit (0 or 1). 3

Digital Modulation (FSK) - Frequency Shift Keying (FSK): - 0 and 1 represented by different frequencies. - Switch between two oscillators accordingly. - Twice the bandwidth but more resilient to error. 4

PSK (Phase Shift Keying) - The phase of the carrier signal is varied to represent binary 1 or 0. - Both peak amplitude and frequency remain constant while the phase changes. - The phase of the signal during each bit duration is constant, and its value depends on the bit (0 or 1).

Digital Modulation Summary - Amplitude Shift Keying (ASK): 1 - Very simple. 2 - Low bandwidth requirements. 3 - Very susceptible to interference. - Frequency Shift Keying (FSK): 1 - Needs larger bandwidth. 2 - More error resilience than AM. - Phase Shift Keying (PSK): 1 - More complex. 2 - Robust against interference. - Other modulation schemes are mostly complex variants of ASK, FSK, or PSK…

Digital Modulation Summary

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