Analog Communication

Unit - I (Chapter - 1) Introduction : Introduction to communication system, Need for modulation, Frequency division multiplexing, Amplitude modulation, Definition, Time domain and frequency domain description, Single tone modulation, Power relations in AM waves, Generation of AM waves, Square law modulator, Switching modulator, Detection of AM waves ; Square law detector, Envelope detector. Unit - II (Chapter - 2) DSB modulation : Double side band suppressed carrier modulators, Time domain and frequency domain description, Generation of DSBSC waves, Balanced modulators, Ring modulator, Coherent detection of DSB-SC modulated waves, COSTAS loop. Unit - III (Chapter - 3) SSB Modulation : Frequency domain description, Frequency discrimination method for generation fo AM SSB modulated wave, Time domain description, Phase discrimination method for generating AM SSB modulated waves. Demodulation of SSB waves, Vestigial side band modulation : Frequency description, Generation of VSB modulated waves. Time domain description, Envelope detection of a VSB wave pulse carrier, Comparison of AM techniques, Applications of different AM systems. Unit - IV (Chapter - 4) Angle modulation : Basic concepts, Frequency modulation : Single tone frequency modulation, Spectrum analysis of sinusoidal FM wave, Narrow band FM, Wide band FM, Constant average power, Transmission bandwidth of FM wave-Generation of FM Waves, Direct FM, Detection of FM waves : Balanced frequency discriminator, Zero crossing detector, Phase locked loop, Comparison of FM and AM. Unit - V (Chapter - 5) Noise : Noise in analog communication system, Noise in DSB and SSB systems, Noise in AM system, Noise in angle modulation system, Threshold effect in angle modulation system, Pre-emphasis and de-emphasis. Unit - VI (Chapter - 6) Transmitters : Radio transmitter - Classification of transmitter, AM transmitter, Effect of feedback on performance of AM transmitter, FM transmitter - Variable reactance type and phase modulated FM transmitter, Frequency stability in FM transmitter. Unit - VII (Chapter - 7) Receivers : Radio receiver - Receiver types - Tuned radio frequency receiver, Superheterodyne receiver, RF section and characteristics - Frequency changing and tracking, Intermediate frequency, AGC, FM receiver, Comparison with AM receiver, Amplitude limiting. Unit - VIII (Chapter - 8) Pulse Modulation : Time division multiplexing, Types of pulse modulation, PAM (Single polarity, Double polarity) PWM : Generation and demodulation of PWM, PPM, Generation and demodulation of PPM, TDM Vs FDM.