**ASK Generation & Detection:**

- Define ASK. Write the practical applications of ASK.
- Draw the waveforms of ASK scheme.
- Draw the Phasor diagrams of ASK.
- Write the equation of ASK wave.
- What are the applications of ASK?
- What are the advantages and disadvantages of ASK?
- Write the expression for Probability of error of ASK.
- What is the BW of ASK?
- Draw the signal constellation diagram of ASK.
- Draw the block diagram of ASK generator. Explain its working.
- Draw the block diagram of coherent ASK demodulator. Explain its working.
- Draw the block diagram of non-coherent ASK demodulator. Explain its working.
- How ASK is different from AM?
- If bit rate is 10µsec then calculate the band width of ASK.
- Which is the efficient modulation scheme among ASK and PSK give the reason.
- Write the relation between complementary error function and Q-Function.
- Write the P
_{e}of ASK in terms of Q function. - What is meant by Signal space diagram?
- A source generates three symbols with probability 0.25,0.25 and 0.5 at a rate of 3000 symbols/sec Assuming the symbols are generated independently from the source the most efficient source encoder would have
——————————.*average bit rate of*

**FSK Generation & Detection:**

- Define FSK. Write the practical applications of FSK.
- Draw the waveforms of FSK scheme.
- Draw the Phasor diagrams of FSK.
- Write the equation of FSK wave.
- What are the advantages and disadvantages of FSK?
- Write the expression for Probability of error of FSK.
- What is the BW of FSK?
- List some applications of FSK.
- Draw the block diagram of FSK generator and explain its working.
- Draw the block diagram of coherent FSK demodulator and explain its working.
- Draw the block diagram of non-coherent FSK demodulator and explain its working.
- Show that FSK is inferior to PSK by 3dB for a given probability of error.
- Define digital modulation schemes.
- Identify the differences between Pass band and Base band Communication.
- What is a matched filter?
- What are the properties of matched filter?
- What is MSK? What is the need for Minimum Shift Keying?
- For the given 8 bit data 10111010 draw the FSK output waveform.
- Draw the constellation diagram of FSK.
- What will happen if the same frequency is used for both the carriers?
- Draw FM signal and FSK signal differentiate those two signals.
- What are the applications of FM?
- How FSK is different from FM?
- Write the probability of error expression of FSK in-terms of Q function.
- Write the relation between complementary error function and Q-Function.
- Among FSK and PSK which is the most efficient scheme and why?

**PSK Generation & Detection:**

- Define PSK. Write the practical applications of PSK.
- Draw the waveforms of PSK scheme.
- Draw the signal space diagram of PSK.
- Write the equation of PSK wave.
- What are the applications of PSK?
- What are the advantages and disadvantages of PSK?
- Write the expression for Probability of error of PSK in terms of erfc()
- Write the expression for Probability of error of PSK in terms Q().
- Write the difference between erf(x) and erfc(x)..
- What is the BW of PSK?
- What are antipodal signals?
- Give the equation for average probability of symbol error for coherent binary PSK.
- Explain how QPSK differs from PSK in terms of transmission bandwidth and bit information it carries.
- What are the advantages of M-ary modulation scheme?
- Draw the constellation diagram for QPSK.
- Compare FSK and PSK.
- What do we infer from constellation diagrams of various modulation schemes?
- Draw the block diagram of PSK generator. Explain its working.
- Draw the block diagram of coherent PSK detector. Explain its working.
- How non coherent PSK is advantageous over coherent PSK?
- Other name of Non-coherent PSK is———–.
- Write the expression for a Gaussian function———————.

**DPSK Generation & Detection:**

- Define DPSK.
- Draw the waveforms of DPSK scheme.
- Write the equation of DPSK.
- What are the applications of DPSK?
- What are the advantages and disadvantages of DPSK?
- Write the expression for Probability of error of DPSK.
- What is the BW of DPSK?
- What are the applications of DPSK?
- Draw the DPSK system and explain its working.
- If the input sequence to a DPSK modulator is 10011100 write the following sequences, Deferentially encoded sequence if previous bit is 0 And the phase of the encoded sequence.
- The capacity of a band limited AWGN channel in terms of KBPS if the average received signal to noise power spectral density is 1000 and the BW is approximately infinite is…………..
- For error free channel conditional probability is ————-.
- The modulation technique that provides minimum probability of error is———-.

**QPSK Generation & Detection:**

- Define QPSK.
- Draw the waveforms of QPSK scheme.
- Draw the Phasor diagrams of QPSK.
- Write the equation of QPSK wave.
- What are the applications of QPSK?
- What are the advantages and disadvantages of QPSK?
- Write the expression for Probability of error of QPSK.
- Draw the block diagram of QPSK modulator. Explain its working.
- Draw the block diagram of coherent QPSK de modulator. Explain its working.
- Write the table for four di-bits with phases used in a QPSK modulation scheme.
- Write the equation of QPSK wave.
- What is the BW of QPSK?
- What are the applications of QPSK?
- Draw the constellation diagram for QPSK.
- In Minimum Shift Keying the relation between the signal frequencies and bit rate are————.
- A pulse for is passed through a matched filter then the impulse response of matched filter is—————————.
- A lossless channel means—————–.
- A distortion less channel means————————-.
- Write the channel matrix for a Binary symmetric channel——————–.

**Losses in fibre optics:**

- Define Transmission loss of Optical fibre?
- What are various losses in fibre optics?
- What are step index graded index optical fibers?

**Data Formats:**

- Compare NRZ-I and NRZ- L.
- What is the use of data formatting?
- Compare NRZ and biphase encoding.
- What is the relationship between quantization levels and number of bits in a code word?
- Give the advantages of Manchester encoding.
- Assume a data stream is made of ten 0s. Encode this stream using the following encoding schemes.
- How much change can you find for each scheme? a)NRZ b)RZ c)Bi phase

- List out the merits & demerits of each data formats.
- Represent the given data 11010100 in Manchester encoding and NRZ –M scheme.

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