download pdf for engineering of digital electronics communication :-

#### Basic introduction of digital communication :-

1. The communication process : elements of a communication

2. sources of information

3. Baseband and Passband signals

4. Classification of communication

- Fourier series : definition and basic concept
- Exponential Fourier series (i.e complex exponential Fourier series)
- Fourier Transform : mathematical representation
- Inverse Fourier Transform : Mathematical Representation
- Properties of Fourier Transform
- Fourier transforms of Few standard signals

18. Power and energy theorems

19. spectral density functions

- Energy spectral density (ESD) : definition
- definition of ESD : definition
- Power spectral density (PSD) : definition

20. correlation of energy signals

- Auto correlation function for the energy signals
- cross correlation of energy signals
- auto correlation function of power signals
- cross correlation of power signals

### Probability theory and Random variables

7. Probability function or probability distribution of a Discrete Random variable

- properties of Cumulative distribution function (CDF)
- Cumulative distribution function for discrete Random variables

9. Probability Density function (PDF)

- Properties of probability density function (PDF)

10. Joint cumulative distribution function

- Properties of joint cumulative distribution function

11. The joint probability density function

- Properties of joint PDF
- The relationship between joint PDF and probability

12. Marginal Densities

13. Conditional probability density function

- properties of conditional PDF

14. Statistical Averages of Random Variables

- Mean or Average
- Mean value of discrete Random variable
- Mean Values of continuous Random Variables
- Moments and Variance ‘

15. Uniform Distribution

16. Gaussian or normal distribution

17. Rayleigh Distribution

18. Random process

- Ensemble and time averages
- Ensemble Averages
- time averages
- Stationary and non-stationary Random process
- Wide sense Stationary (i.e., Weakly stationary) process
- Ergodic process
- Gaussion process

19. Sum of Random processes

20. Correlation function

- Autocorrelation function
- properties of autocorrelation function of random process
- Cross correlation function

21. Spectral densities

- Power spectral density (PSD)
- energy spectral density (ESD)

22. Response of linear systems to Random Inputs

#### Sampling theory and pulse modulation

1. The sampling theorem

2. Proof of sampling theorem

- Important points about sampling theorem

3. Nyquist rate and Nyquist Interval

4. Reconstruction filter (low pass filter)

5. Signal reconstruction : the interpolation formula

6. Effect of under sampling : Aliasing

7. Sampling of Bandpass signal

8. sampling techniques

- Ideal sampling or instantaneous sampling or impulse sampling
- natural sampling
- Flat top sampling or rectangular pulse sampling

9. Aperture effect

10. Comparison of Various sampling techniques

11. Analog pulse modulation methods

12. Pulse amplitude modulation (PAM)

- Naturally sampled pulse amplitude modulated (PAM) signal
- Instantaneous or idealy sampled pulse amplitude modulated (PAM) signal
- Transmission Bandwidth in pulse Amplitude modulation (PAM)
- Demodulation of PAM signals
- Transmission of PAM signals
- Drawbacks of Pulse Amplitude modulated (PAM) signal

13. Pulse time modulation

- pulse width modulation (PWM)
- Frequency spectrum for PWM wave
- modulation of PWM signal or PWM generation
- Demodulation of PWM signal
- Advantages of PWM
- Disadvantages of PWM
- pulse position modulation
- Generation of PPM signal
- Advantages of PPM
- Disadvantages of PPM

14. comparison of Various pulse analog modulation methods

#### Waveform coding Techniques

1. Discretization in time and amplitude

2.concept of Quantization

3. Pulse code modulation (PCM)

4. A PCM generator or transmitter

5. PCM Transmission path

- Block diagram of a Repeater

6. PCM Receiver

7. Quantizer

- Classification of Quantization process
- A uniform Quantizer

8. working principle of quantizer

9. A uniform quantizer with incorrect

10. Transmission bandwidth in a PCM system

11. Quantization noise/error in PCM

12. Signal to quantization noise ratio for linear quantization

13. Influence of noise on the PCM system

14. various important aspects related to PCM

- Advantages of digital representation of a signal : salient Features
- Drawbacks
- difference between waveform coding and source coding
- encoding in PCM
- Multiplexing in PCM systems
- Synchronization in PCM

15. performance evaluation of PCM : probability of error for PCM

16. comparison of pcm and analog modulation

- benefits of pcm
- PCM is not used for radio Broadcasting

17. Robust quantization in a PCM system

18. Necessity of Nonuniform quantization for speech signal

19. Nonuniform quantization

20. Companding (i.e. companded PCM)

- Compressor characteristic
- Expander characteristics

21. compander characteristic

22. Different types of compressor characteristics

- μ law companding
- A – law companding

23. Applications of PCM

24. Advantages of PCM : salient features of PCM

25. Drawbacks of PCM

26. Delta modulation

- advantages of delta modulation : salient Features of delta modulation
- Drawbacks of delta modulation
- Bit rate (i.e. signaling rate) of delta modulation

27. Evaluation of maximum output signal to noise ratio

28. Delta sigma modulation

- Drawback of conventional delta modulation
- Advantages of use of Integrator
- Block diagram of delta sigma modulator
- Simplified sigma delta system in a simplified manner

29. Adaptive delta modulation

- Advantages of adaptive delta modulation : salient features

30. Differential pulse code modulation (DPCM)

31. Evaluation of output signal to noise ratio

- Importance of prediction gain
- types of predictors
- Advantage of DPCM : salient Features

32. comparison of digital pulse modulation methods

#### digital multiplexers

1. Multiplexing

- Frequency division multiplexing
- time division multiplexing (TDM)

2. A PAM/TDM system

- signaling rate and its determination in a PAM/TDM system
- Transmission Bandwidth of a PAM/TDM channel
- synchronization and its significant in PAM/TDM system
- concept of crosstalk in a PAM/TDM system
- concept of Guard time
- salient Features of TDM
- Drawbacks of TDM

3. Introduction to digital multiplexers

- principle of digital multiplexing

4. Classification of digital multiplexers

5. Multiplexing Hierarchy for digital communication

- calculation of Bit rate at Each level
- Bit rate and transmission channel Bandwidth
- Bandwidth Efficiency
- Advantages of digital Multiplexing : salient Features

6. North American Hierarchy

7. T lines

8. A PCM-TDM system : T1 Carrier system

9. E Lines

#### Digital Baseband Transmission

1. A Baseband digital communication system

2. Introduction to Discrete PAM signal (Digital data formats)

3. Line coding and its properties

4. Various PAM formats or line codes

5. Unipolar RZ and NRZ

6. Polar RZ and NRZ

7.Bipolar NRZ [Alternate mark inversion (AMI)]

8. Split phase Manchester format

9. polar quaternary NRZ format

10. High density Bipolar (HDB) signalling

11. B8ZS line code

12. Power spectra of Discrete PAM signals (Various line codes)

13. Power spectral density (PSD) of NRZ unipolar format

14. power spectral density (PSD) of NRZ polar format

15. Power spectral density (psd) of NRZ Bipolar format

16. Power spectral density (psd) of the Manchester format

- Salient Features of the psd of a Manchester format

17. Comparison of various Discrete PAM formats on the basis of power spectra

18. Difference between source coding and line coding

19. Introduction to matched filter and Intersymbol Interference (ISI)

20. Integrate and Dump filter (i.e. Receiver)

- Calculating of signal to noise Ratio for the integrate and Dump filter
- computation of Probability of error for Integrate and Dump filter receiver

21. The optimum filter (i.e. optimum receiver)

- Calculation of probability of error (Pc) for optimum filter
- Evaluation of transfer function for the optimum filter

22. Matched filter

- Calculation of Impulse response for the matched filter
- Calculation of probability of error (Pe) for the matched filter
- Few points about error probability of error , Pe of matched filter

23. The correlator : coherent Reception

24. Intersymbol interference (ISI)

25. Factors responsible for Intersymbol Interference (ISI)

26. Nyquist’s Criterion for distortionless basband Binary Transmission

27. Ideal solution

28. Raised cosine spectrum

29. concept of eye pattern

#### Introduction to signal space Analysis

1. concept of additive white gaussian noise (AWGN) channel

2. Concept of optimum receiver

3. Geometric Representation of signals

4. Schwarz Inequality

5. Gram schmidt orthogonalization procedure

#### digital modulation techniques

1. Digital modulation formats

2. types of digital modulation techniques

3. coherent binary modulation techniques

4. coherent binary amplitude shift keying or on off keying

- signal space diagram of ASK
- generation of ASK signal
- BASK reception : coherent detection or demodulation of binary ASK signal
- salient feature of BASK
- Drawback
- Bit error rate (BER) or probability of error

5. Binary phase shift keying (BPSK)

- generation of BPSK signal
- reception of BPSK signal : coherent detection
- the spectrum of BPSK signals
- A Geometrical representation for BPSK signals
- Bandwidth for BPSK signal
- Salient Features of BPSK
- Drawbacks of BPSK
- Bit error rate (BER) or probability of error

6. coherent Binary Frequency shift keying

- Generation of BFSK
- The spectrum of BFSK signal
- Bandwidth of BFSK signal
- BPSK receiver : coherent detection of BFSK
- Geometrical Representation of orthogonal BFSK
- comparison of three basic digital modulation techniques
- Geometrical representation of non orthogonal BFSK signals
- salient features of BFSK
- Drawback of BFSK

7. Non coherent binary modulation techniques

8. non coherent binary amplitude shift keying (ASK)

9. Non coherent detection of FSK

10. Differential phase shift keying (DPSK)

- Generation of DPSK
- detection of DPSK
- Evaluation of bandwidth of DPSK signal
- Advantages and disadvantages of DPSK
- performance comparison of BPSK and DPSK

11. Quadrature phase shift keying (QPSK)

12. Generation of QPSK

- Reception of QPSK (i.e. detection of QPSK)
- concept of carrier synchronization in QPSK
- signal space representation in QPSK signals
- spectrum of QPSK signal
- Bandwidth of QPSK signal
- Advantages of QPSK

13. Minimum shift keying (MSK)

- signal space representation of MSK and distance between the signal points (i.e. geometrical representation of MSK)
- power spectral density (PSD) and bandwidth of MSK
- Generation of MSK
- reception of MSK (i.e. detection of MSK)
- Advantages and Drawbacks of MSK as compared to QPSK

14. Gaussian minimum shift keying (i.e. GMSK)

15. GMSK for wireless data transmission

16. GMSK from MSK

17. Detection of Binary modulation techniques in presence of noise

- Probability of error for PCM system

18. Calculation of error probability in ASK

19. error probability in BPSK

20. Error probability in BPSK

21. comparison of digital modulation schemes using a single carrier

- probability of error

#### Information theory

1. what is information ?

2. information sources

3. Information content of a discrete memoryless source (DMS)

4. Information content of a symbol (i.e. Logarithmic measure of information)

5. Entropy (i.e. Average information)

6. Information rate

7. The discrete memoryless channels (DMC)

- Channel representation
- The channel matrix

8.Types of chennals

- lossless channel
- Deterministic channel
- noiseless channel
- Binary symmetric channel (BSC)

9. The conditional and Joint Entropies

10. The mutual information

11. The channel capacity

- channel capacity per symbol (Cs)
- channel capacity per second (C)
- capacities of special channel

12. Entropy relations for a continuous channel

13. Capacity of an additive white gaussian noise (AWGN) channel : shannon Hartley law

14. channel capacity : a detailed study

15. Transmission of continuous signals

16. Uncertainty in the transmission process

17. Exchange of Bandwidth for signal to noise Ratio

18. The source coding

- Few terms related to source coding process
- the source coding theorem
- classification of codes
- the kraft Inequality

19. Entropy coding

- Shannon Fano coding
- The Huffman coding

#### Error control coding

1. Introduction of error control coding

- Detection and correction of errors
- classification of codes
- classification of errors
- error detection techniques
- error correction techniques

2. generation and detection of coded signals

- Drawbacks of coding technique
- classification of error correcting codes

3. Overview of error control coding techniques

- types of error control
- Forward error correction (FEC) technique for error control

4. ARQ system (Automatic repeat request)

- basic ARQ system

5. classification of codes

- Block codes
- Convolutional codes

6. Transmission errors : Random and Burst errors

- Interleaving : definition
- concatenated codes

7. power and bandlimited channels

- classical error control system
- types of channels
- Bandlimited channels
- power limited channels

8. discrete memoryless channel (DMC)

9. Error detection methods

- parity checking
- checksum error detection
- error detection using VRC and LRC

10. Important definitions related to codes

11. Linear block codes

12. Hamming codes

- error detection and correction capabilities of hamming code
- encoder of (7,4) hamming code

13. syndrome decoding for block codes

- error correction using syndrome vector
- syndrome decoder for (n,k) block codes
- decoding of a linear block code

14. cyclic codes

- code word polynomial
- generator polynomial for the cyclic code
- Generation of Non systematic code words
- Generation of systematic code words
- Generator and Parity check matrices of the cyclic codes
- systematic form of generator matrix
- Encoder for cyclic codes
- Difference between source coding , line coding and error detection codes
- syndrome decoding for the cyclic codes
- syndrome calculator for the systematic cyclic codes
- decoder for cyclic codes
- cyclic redundancy check (CRC)

15. other codes

- Golay codes
- Bose chaudhuri Hocquenqthem (BCH) codes
- how to use table
- Reed solomon codes (R-S codes)

16. convolutional codes

- Encoder for convolutional coding
- Practical convolutional encoder
- Few definitions Related to convolutional codes
- Time domain approach
- Transform domain approach
- Graphical representation for convolutional encoding
- The code tree
- Code Trellis
- state diagram

17. Decoding methods of convolutional codes

- Viterbi Algorithm
- Metric Diversion effect
- Free distance and coding gain
- Transfer function of the convolutional codes

18. Sequential decoding

- stop and wait ARQ system
- Go back N ARQ
- selective repeat ARQ system

#### Spread spectrum modulation techniques

1. pseudo noise (PN) sequences

- properties of maximal length sequences
- choosing a maximal length sequence

2. A Basic Idea of spread spectrum

3. Direct sequence spread spectrum (DS – SS) with BPSK

4. Frequency Hopped spread spectrum (FH – SS)

5. Performance of direct sequence spread spectrum system

6. Performance of frequency hopping spread spectrum

7. Modulation performance in Fading and multipath channel

8. Performance of digital modulation in slow flat fading channels

9. Digital modulation in Frequency selective mobile channels