Technical Publications, 2009 - 586 pages
Block Schematic of Communication System.Analog and Digital base band signals and their bandwidth requirements.Necessity of modulation and types of modulation-AM, FM and PM.Amplitude ModulationBlock schematic of DSBFC, DSBSC, SSB, VSB and ISB transmitters. Generation methods, Mathematical analysis, modulation index, frequency spectrum, power requirement.Block schematic of receivers for above transmission. Mixers, detectors, Tracking, AGC. Modulator and demodulator ICs.Performance parameters for receiver such as selectivity, sensitivity, fidelity, image frequency rejection.Double conversion technique in Communication receivers.Frequency ModulationBlock schematic of FM transmitters, Narrow band and wide band FM generation. Direct and Indirect methods of generation, Mathematical Analysis, modulation index, frequency spectrum and bandwidth requirement.Block schematic of FM receivers, FM discriminators, pre-emphasis and de-emphasis.Comparison of AM and FM, Noise triangle. FM modulator and demodulator ICs.Pulse ModulationNyquist Criteria, PAM, PWM, generation and detection.PCM & Multiplexing-Techniques.Radiation and PropagationConcept of radiation, basic antenna system - antenna gain, directivity and radiation pattern. Dipole antenna, Different R.F. bands used in communication, Mechanism of propagation. Groundwave, spacewave and skywave propagation, duct propagation, tropospheric scattering, fading, Diversity reception.Audio CommunicationMicrophones, Loudspeakers, loudspeaker enclosures, PA systems, Graphic equalizer, stereophony/Hi fi Systems, Recent trends in sound recording.TelephonyPrinciples of telephony, various tones, electronic telephone exchanges, DTMF pulsing techniques.NoiseSources of noise, Johnson noise, SNR, Noise figure, noise temperature.Internet Technology, basic architecture, Applications.