To Communication System I is introduced in the Third Year – Second Part of BE Electronics and Communication course to make the student familiar with principles and building blocks of analog communication systems. It has 3 lecture, 0 tutorial and 3/2 practical. The following syllabus of Communication System I is as per the updated course of IOE. The marks distribution will be updated soon. Stay tuned.
- Introduction (4 hours)
- Analog and Digital communication sources, transmitters, transmission channels and receivers
- Noise, distortion and interference. Fundamental limitations due to noise, distortion and interference
- Types and reasons for modulation
- Representation of signals and systems in communication (4 hours)
- Review of signals (types, mathematical representation and applications)
- Linear/non‐linear, time variant/invariant systems. Impulse response and transfer function of a system. Properties of LTI systems
- Low pass and band pass signals and systems, bandwidth of the system, distortionless transmission, the Hilbert transform and its properties
- Complex envelops rectangular (in‐phase and quadrature components) and polar representation of band pass band limited signals.
- Spectral Analysis (4 hours)
- Review of Fourier series and transform, energy and power, Parseval’s theorem
- Energy Density Spectrum, periodogram, power spectral density function (psdf)
- Power spectral density functions of harmonic signal and white noise
- The autocorrelation (AC) function, relationship between psdf and AC function.
- Amplitude Modulation (12 hours)
- Time domain expressions, frequency domain representation, modulation index, signal bandwidth
- AM for a single tone message, carrier and side‐band components, powers in carrier and side‐band components, bandwidth and power efficiency
- Generation of DSB‐FC AM
- Double Side Band Suppressed Carrier AM (DSB‐AM), time and frequency domain expressions, powers in side‐bands, bandwidth and power efficiency
- Generation of DSB‐AM (balanced, ring modulators)
- Single Side Band Modulation, time and frequency domain expressions, powers
- Generation of SSB (SSB filters and indirect method)
- Vestigial Side Bands (VSB), Independent Side Bands (ISB) and Quadrature Amplitude Modulations (QAM)
- Demodulation of AM signals (6 hours)
- Demodulation of DSB‐FC, DSB‐SC and SSB using synchronous detection
- Square law and envelop detection of DSB‐FC
- Demodulation of SSB using carrier reinsertion, carrier recovery circuits
- Phase Locked Loop (PLL), basic concept, definitions, equations and applications, demodulation of AM using PLL
- Frequency Modulation (FM) and Phase Modulation (PM) (12 hours)
- Basic definitions, time domain expressions for FM and PM
- Time domain expression for single tone modulated FM signals, spectral representation, Bessel’s functions
- Bandwidth of FM , Carson’s rule, narrow and wideband FM
- Generation of FM (direct and Armstrong’s methods)
- Demodulation of FM and PM signals, synchronous (PLL) and nonsynchronous (limiter‐discriminator) demodulation
- Stereo FM, spectral details, encoder and decoder
- Pre‐emphasis and de‐emphasis networks
- The superheterodyne radio receivers for AM and FM
- Frequency Division Multiplexing (FDM) (3 hours)
- Principle of frequency division multiplexing, FDM in telephony, hierarchy
- Frequency Division Multiple Access (FDMA) systems‐ SCPC, DAMA, SPADE etc.
- Filter and oscillator requirements in FDM.
Experiments
- Demonstration of power spectrum of various signals using LF spectrum analyzer
- Generation of DSB‐SC, DSB‐FC and SSB signals
- Demodulation of AM signals (synchronous and non‐synchronous methods)
- Generation of FM signals
- Demodulation of FM signal (limiter‐discriminator)
- Operation of PLL, PLL as demodulator of AM and FM signals
References:
- S. Haykin, Analog and Digital communication systems, latest editions
- Leon Couch, Digital and analog communication systems, latest edition
- B.P.Lathi, Analog and Digital communication systems, latest edition
- J. Proakis, Analog and Digital communication systems, latest edition
- D. Sharma, Course manual “Communication Systems I”
Evaluation Scheme:
Marks distribution for all the chapters in the syllabus is shown in the table below.
Unit |
Hours |
Mark Distribution
(will be updated soon) |
1 |
4 |
|
2 |
4 |
|
3 |
4 |
|
4 |
12 |
|
5 |
16 |
|
6 |
12 |
|
7 |
3 |
|
Total |
55 |
|