1. Introduction
Objectives, Introduction, The Communication System, Classification of Communication, Line Communication, Wireless or Radio Communication, The Modulation-Demodulation, Types of Modulation, Need for Modulation, Analog and Digital Signals, Conversion of Analog Signals into Digital Signals, The Sampling Theorem, Analog and Digital Communication, Analog Communication, Digital Communication, Need of Digital Communication, Effect of Noise, Distance to be Covered, Service Provided, Comparison of Analog and Digital Communication System, Limitations of Communication System, Noise Limitation, Bandwidth Limitation, Equipment Limitation, Introduction to Signals, Continuous-Time and Discrete-Time Signals, Analog and Digital Signals, Periodic and Aperiodic Signals, Energy and Power Signals, Deterministic and Random Signals, Fourier Series, Exponential form of the Fourier Series, Normalized Power, Power Spectral Density, Effect of Transfer Function on Power Spectral Density, The Fourier Transform, Convolution, Autocorrelation, Probability, Mutually Exclusive Events, Joint Probability of Related and Independent Events, Random Variables, Cumulative Distribution Function, Probability Density Function, Relation between Probability and Probability Density, Average Value of a Random Variable, Variance of a Random Variable, The Gaussian Probability Density, The Error Function, Solved Problems, Summary, Review Questions, Multiple Choice Questions, Answer Key.
2. Amplitude Modulation
Objectives, Introduction, Frequency Translation, Frequency Multiplexing, Practicability of Antennas, Narrowbanding, Common Processing, A Method of Frequency Translation, Recovery of the Baseband Signal, Amplitude Modulation, Time Domain Representation, Spectrum of AM Signal, Single Tone Sinusoidal Modulation, Power Content in AM Wave, Transmission Efficiency of an AM Signal, Power of a Single tone AM Signal, Current Calculation for Single Tone AM, Multitone Sinusoidal Modulation, Power Content in Multitone Sinusoidal Modulation, Effective Modulation Index for Multitone Sinusoidal Modulation, Generation of Amplitude Modulated Wave, Square Law Modulator, Switching Modulator, Demodulation (Detection) of AM Wave, Square-Law Demodulation, Envelope Detector, Suppressed Carrier Modulation, Double-Sideband Suppressed Carrier (DSB-SC) Modulation, Generation of DSBSC Waves, Balanced Modulator, Ring Modulator, Demodulation of DSB-SC Signals, Synchronous Detector, Envelope Detector After Suitable Carrier Reinsertion, Hilbert Transform, Single-Sideband Suppressed Carrier (SSB-SC) Modulation, Frequency Domain Description, Time Domain Description, Generation of SSB-SC Signals, Frequency Discrimination Method, Phase-Shift Method, Demodulation of SSB-SC Signal, Synchronous or Coherent Detection, Carrier Pre-Insertion Technique, Vestigial Sideband Modulation, Frequency Domain Description, Time Domain Description, Generation of VSB Modulated Wave, Demodulation of VSB Modulated Wave, Multiplexing, Types of Multiplexing, AM Transmitter and Receivers, AM Transmitter, AM Receiver, Automatic Gain Control (AGC), Solved Problems, Summary, Short Questions, Review Questions, Unsolved Problems, Multiple Choice Questions, Answer Key.
3. Exponential Modulation Phase and Frequency Modulation
Objectives, Introduction, Concept of Instantaneous Frequency, Mathematical Representation of Frequency and Phase Modulation, Phase Modulation (PM), Frequency Modulation (FM), Relationship between Phase Modulation and Frequency Modulation, Types of Frequency Modulation, Narrow-Band Frequency Modulation (NBFM), Wide Band Frequency Modulation, Spectrum of FM, Effect of the Amplitude and Frequency of a Sinusoidal Modulating Signal on the Spectrum of the FM Signal, Transmission Bandwidth of FM Signals, Power Contents of Carrier and Sidebands in FM, FM Generation, Direct Method of Generation of FM, Indirect Method of Generation of FM (Armstrong’s Method), FM Demodulation, Basic Principle, Types of FM Demodulators, Simple Slope Detector, Balanced Slope Detector, Faster-seeley Discriminator or Centre Tuned Discriminator or Phase Difference Discriminator, Ratio Detector, FM Transmitters, Automatic Frequency Correction (AFC), Direct FM Transmitters, Indirect FM Transmitter-Armstrong Method, FM Receiver, Advantages of FM, Disadvantages of FM, Comparison of Angle Modulated Waves and Amplitude Modulated Wave, Comparison of FM and AM, Noise in FM Receivers, Pre-Emphasis and De-Emphasis in FM, PLL Demodulator, Solved Problems, Summary, Short Questions, Review Questions, Unsolved Problems, Multiple Choice Questions, Answer Key.
4. Pulse Analog Modulation
Objectives, Introduction, Sampling Theorem, Proof of Sampling Theorem, Nyquist Rate and Nyquist Interval, Aliasing, Natural Sampling, Flat-Top Sampling, Pulse-Amplitude Modulation (PAM), Generation and Demodulation of PAM, Pulse-Width Modulation, Generation and Demodulation of PWM, Pulse Position Modulation, Generation and Demodulation of PPM, PAM-TDM, Solved Problems, Summary, Short Questions, Review Questions, Unsolved Problems, Multiple Choice Questions, Answer Key.
5. PCM and Delta Modulation Systems
Objectives, Introduction, Quantization, Uniform Quantizers, Non Uniform Quantizer, Quantization Error, Pulse Code Modulation, The PCM System, A PCM Generator (Transmitter), PCM Transmission Path, PCM Receiver, Transmission Bandwidth in a PCM System, Signal to Quantization Noise Ratio in PCM, Calculation of Quantization Noise, The Output Signal Power, The Effect of Thermal Noise, Output Signal to Noise Ratio in PCM, When Signal Power is Normalized, When the Input to the PCM System is a Sinusoidal Signal, Advantages and Limitations of PCM, Differential Pulse Code Modulation (DPCM), Delta Modulation, Slope Overload Distortion (Start-up Error), Granular Noise, Quantization Noise in Delta Modulation, The Output-Signal Power in Delta Modulation, Delta Modulation Output Signal to Quantization Noise Ratio, Adaptive Delta Modulation, Advantages of Adaptive Delta Modulation, A PCM-TDM System: T1 Carrier System, Some Important Terms, Optimum Filter, The Optimum Receiver, Maximization of Output Signal to Noise Ratio, Matched Filter, Physical Reliability of Matched Filter, Properties of Matched Filters, Approximations in Matched Filter, Probability of Error in PCM System, Comparison of Digital Pulse Modulation Methods, Solved Problems, Summary, Short Questions, Review Questions, Unsolved Problems, Multiple Choice Questions, Answer Key.
6. Base Band Transmission
Objectives, Introduction, A Digital Communication System, Various Line Codes or PAM Formats, Unipolar Return to Zero (RZ) and Non-Return to Zero (NRZ), Polar RZ and NRZ, Bipolar NRZ [Pseudo Ternary or Alternate Mark Inversion (AMI)], Polar Quaternary NRZ, Power Spectral Densities of Discrete PAM Signals (Various Line Codes), Power Spectral Density of Unipolar NRZ Format, Power Spectral Density (PSD) of Polar NRZ Format, Power Spectral Density (PSD) of Bipolar NRZ Format, Comparison of Various Line Codes, Intersymbol Interference, Effect of Intersymbol Interference, Remedy to Reduce ISI (Pulse Shaping), Nyquist’s Criterion for Distortionless Baseband Binary Transmission, Ideal Nyquist Channel, Raised Cosine Spectrum, Solved Problems, Summary, Short Questions, Review Questions, Unsolved Problems, Multiple Choice Questions, Answer Key.
7. Digital Modulation Techniques
Objectives, Introduction, Digital Modulation Formats, Basic Requirements for Passband Transmission Scheme, Passband Signal Detection Types, Geometric Interpretation of Signals, Orthogonalization, Completeness of an Orthogonal Set: The Fourier Series, The Gram-Schmidt Procedure, Binary Modulation Techniques, Binary Amplitude Shift Keying or On-Off Keying, Binary Phase Shift Keying (BPSK), Binary Frequency Shift Keying (BFSK), Quadrature Phase-Shift Keying (QPSK), Generation of QPSK Signal, Detection of QPSK Signal, Carrier Synchronization in QPSK, Power Spectral Density of QPSK Signal, Bandwidth of QPSK Signal, Advantages of QPSK, Minimum Shift Keying (MSK), Signal Space Diagram of MSK, Power Spectral Density of MSK, Bandwidth of MSK, Phase Continuity in MSK, Generation of MSK Signal, MSK Demodulator, Advantages of MSK as compared to QPSK, Drawbacks of MSK, Comparison of Digital Modulation Techniques, Calculation of Error Probabilities, Error Probability in the Coherent Detection of Binary ASK, Error Probability in the Coherent Detection of Binary Phase Shift Keying, Error Probability in Coherently Detected Binary Orthogonal FSK, Probability of Error for QPSK, Error Probability of MSK, Comparison of Noise Performances of Digital Systems, Solved Problems, Summary, Short Questionss, Review Questions, Unsolved Problems, Multiple Choice Questions, Answer Key.
8. Spread Spectrum Modulation
Objectives, Introduction, Basic Concept of Spread Spectrum System, Pseudo Noise Sequences (PN Sequences), Properties of PN Sequences, Generation of PN Sequences, Direct Sequence Spread Spectrum (DS-SS), Probability of Errors, DSSS Performance, Frequency Hopped Spread Spectrum (FH-SS), FHSS Performance, Applications of Spread Spectrum Technology, Definition of Spread Spectrum, Definition of CDMA, Basic Structure of CDMA System, Solved Problems, Summary, Short Questions, Review Questions, Unsolved Problems, Multiple Choice Questions, Ansker Key.
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