Phase-shift keying (PSK) is a digital modulation scheme that conveys data by changing (modulating) the phase of a reference signal (the carrier wave). The modulation is impressed by varying the sine and cosine inputs at a precise time. It is widely used for wireless LANs, RFID and Bluetooth communication Frequency-shift keying (FSK) is a frequency modulation scheme in which digital information is transmitted through discrete frequency changes of a carrier signal.[1] The technology is used for communication systems such as amateur radio, caller ID and emergency broadcasts

1. GENERATION AND
DETECTION OF FSK AND
PSK
PRENSENTED BY
K.DEEPAK REDDY

2. OUTLINE
• Introduction
• • Coherent Digital modulation Techniques
• • PSK
• • FSK
• • Non-Coherent Digital modulation Techniques
• • FSK
• • Applications of ASK,FSK and PSK

3. INTRODUCTION
• •
In digital communication, the modulation process involves switching or keying the
amplitude, frequency or phase of the carrier in accordance with the input data.
• • There are three basic modulation techniques for the transmission of digital data. i.e.
• • Amplitude Shift Keying
• • Frequency Shift Keying
• • Phase Shift Keying

4. BINARY PHASE SHIFT KEYING(BPSK)
• The most basic (binary) form of PSK involves the process of switching the carrier
either in phase or out of phase, correspondence to a sequence of digital pulses
that constitute the information signal.
• • One binary digit is represented by the carrier wave and the other binary digit is
represented by the 1800 out of phase of the original carrier whereas the
Frequency remains fixed

5. BINARY PHASE SHIFT KEYING(BPSK)
Product
Modulator

6. DETECTION OF PSK SIGNAL

7. DISADVANTAGES OF PSK SIGNAL
• • To regenerate the carrier in the receiver we perform the squaring of the
received signal.
• • The recovered carrier is unchanged whether the input signal is (+ve) or (-
ve)(even if the input signal has changed its sign.)
• • It is not possible to find that whether the transmitted bit was +b(t) or –b(t)
hence Phase ambiguity is a problem in the demodulation of a BPSK signal.
• • This problem can be removed with the use differential phase shift keying.

8. BINARY FREQUENCY SHIFT KEYING(BFSK)
• The most basic (binary) form of FSK involves the process of varying the frequency
of a carrier wave by choosing one of the two frequencies (binary FSK) in
correspondence to a sequence of digital pulses that constitute the information
signal.
• • Two binary digits are represented by two frequencies around the carrier
frequency whereas the Amplitude remains fixed.

9. BINARY FREQUENCY SHIFT KEYING(BFSK)

10. DETECTION OF FSK SIGNAL

11. DISADVANTAGES OF BFSK SIGNALS
• The generation of BFSK is easier but it has many disadvantages compared to BPSK signal.
• • Bandwidth is greater in comparison to BPSK and is almost double the bandwidth of
BPSK.
• • The error rate of BFSK is higher

12. NON-COHERENT FSK DETECTION

13. APPLICATIONS OF FSK AND PSK
• FSK signal can be transmitted via telephone lines, fiber
• optics or wireless media. FSK is commonly used for
• caller ID and remote metering applications.
• • PSK is typically applied in wireless local area networks
• (WLAN), Bluetooth technology and radio frequency
• identification (RFID) standards used in biometric,
• passport and contactless payment systems.

14. REFERENCES
• • Lathi B.P. “Modern Digital and Analog Communication Systems” Oxford
Publications, Fourth Edition
• • J.S. Chitode “ Digital Communication ” Technical
• Publications, First Edition.
• • Taub H.,Schilling D.L.,Saha G. “Taub’s Principle of Communication Systems”,
McGraw-Hill, Third edition
• • Forouzan B. A, “Data Communications and Networking”, McGraw-Hill, 2nd Ed.,
2000
• • https://www.techopedia.com/definition/3004/frequency -shift-keying-fsk