5EC4 ANALOG COMMUNICATION

UNIT 1

:

NOISE EFFECTS IN COMMUNICATION SYSTEMS:

Resistor noise, Networks with reactive

elements, Noise temperature, Noise bandwidth, effective input noise temperature, Noise figure. Noise

figure & equivalent noise temperature in cascaded circuits.

UNIT 2

:

AMPLITUDE MODULATION

: Frequency translation, Recovery of base band signal, Spectrum

& power relations in AM  systems. Methods of generation & demodulation of AM-DSB, AM-DSB/SC and

AM-SSB signals. Modulation & detector circuits for AM  systems. AM transmitters & receivers.

UNIT 3

:

FREQUENCY MODULATION

: Phase & freq. modulation & their relationship, Spectrum &

band width of a sinusoidally modulated FM signal, phasor diagram, Narrow band & wide band     FM.

Generation & demodulation of FM signals. FM transmitters & receivers.. Comparison of AM, FM & PM.

Pre emphasis & deemphasis. Threshold in FM, PLL demodulator.

UNIT 4: NOISE IN AM AND FM:

Calculation of signal-to-noise ratio in SSB-SC, DSB-SC, DSB with

carrier, Noise calculation of square law  demodulator & envelope detector. Calculation of S/N ratio in FM

demodulators, Super heterodyne receivers.

UNIT 5

:

PULSE ANALOG MODULATION :

Practical aspects of sampling: Natural and flat top sampling.

PAM, PWM, PPM modulation and demodulation methods, PAM-TDM.