a. Explain correlation type demodulator with a neat diagram. (5)

Determine the mean and variance of correlator output. (4) PART B

State and prove the Nyquist criteria for band-limited signals with no ISL (9)

a. Explain the mitigation of subcarrier fading using the coding with interleaving over
time (5) and frequency.

The binary sequence 1 1 1010010001 101 is the input to a precoder whose output is used (4) to
modulate a duobinary transmitting filter. Find the precoded sequence, the transmitted
amplitude levels, the received signal levels and the decoded sequence

Explain multicarrier modulation with overlapping subchannels. (9)

PART C

Draw the block diagrams for the Direct Sequence Spread Spectrum signal and briefly (12) explain
its operation.

Explain frequency- nonselective slowly fading channel. (12)
a. Explain about processing gain and jamming margin. (6) b. A DS binary PSK spread spectrum has

a processing gain of 500. What is the jamming (6) margin against a continuous — tone jammer

ifthe desired error probability is 10-