Analog Communication and Signal ans System
Chapter 1: Introduction
Page 1
Overview of Communication Basics.
Focus on transmission and reception of information.
Page 2: Communication Basics
Communication: Principle of transferring information.
Involves three main aspects: transmission, reception, and processing.
Types:
Continuous signals (analog communication).
Discrete signals (digital communication).
Baseband transmission: Short distance transmission.
Page 3: Further on Communication Basics
For long distances:
Use of a high frequency component called a carrier.
Process of impressing information upon the carrier is called modulation.
Page 4: Need for Modulation
Purpose of modulation:
To translate low-pass signals to higher frequencies for effective transmission.
Required antenna dimensions relate to the signal wavelength:
Example: Low-frequency signal at 2 kHz results in impractical heights of antennas (75 km).
Page 5: Need for Modulation Continued
Simultaneous transmission from multiple sources:
Achieved through frequency division multiplexing.
Improves noise/interference immunity in communication channels.
Page 6: Frequency Translation
Modulation process shifts frequencies up to higher frequencies, creating upper and lower sidebands.
Frequency translation: Converting frequencies to different locations in the spectrum.
Page 7: Types of Modulation
Classification based on what is varied in the carrier:
Amplitude Modulation (AM)
Frequency Modulation (FM)
Phase Modulation (PM)
Pulse Modulation: Converts information into pulse form for long-distance transmission.
Page 8: Transmitter
Role of the transmitter:
Converts various signals (voice, music, etc.) into electrical signals for transmission.
Example components: carrier voltage, modulator, pre-amplifiers.
Page 9: Receiver
Function: Receives electromagnetic signals carrying information.
Tuned to specific frequencies to extract information.
Output typically processed by a transducer to become understandable signals.
Page 10: Multiplexing
Allows multiple signals to share a single communication channel:
Frequency Division Multiplexing (FDM): Different frequencies get allocated.
Time Division Multiplexing (TDM): Signals transmitted over time slots.
TDM involves sampling signals before transmission.
Chapter 2: Signals - An Introduction
Page 12: Signals
Definition: Functions carrying information, showing parameter variations over time or frequency.
Page 13: Classification of Signals
Types of signals:
Continuous vs. Discrete
Causal vs. Non-causal
Even and Odd
Deterministic vs. Random
Real and Complex
Energy and Power type
Page 14: Discrete and Continuous Signals
Example graphs representing discrete signals.
Continuous signal functions also presented in time vs. value graphs.
Page 15: Causal Signals
Definition and examples of causal signals.
Page 16: Even & Odd Signals
Function definitions based on time symmetry for even/odd classifications.
Page 17: Special Signals
Sinc function: Defined with respect to its mathematical definition.
Page 18: Signum Signals
Definition of Signum signals highlighting the signal behavior for positive/negative values.
Chapter 3: Amplitude Modulation
Page 29: Introduction to Amplitude Modulation
Explanation of AM: The amplitude of carrier signal varies based on the input message.
Carriers are required to be at higher frequencies than message signals.
Page 30: AM Waveform Characteristics
Graphical representation of AM signals with modulating signals illustrated.
Page 31: Frequency Spectrum of AM Waves
Spectrum layout showing the relationship between carrier and modulated signals.
Page 32: Power Spectrum of Amplitude Modulation
Key calculations involved in power distribution of AM signals, indicating compression and sidebands.
Page 33: Other AM Systems
Introduction to variants of AM systems:
Suppressed Carrier Systems
Double Side Band (DSB)
Single Side Band (SSB) Systems.
Page 34: AM Waveforms Comparison
Comparative analysis between AM, DSB, and SSB waveforms illustrated in graphical format.
Page 35: Advantages & Disadvantages of Single Sideband Modulation
Pros: Less power, bandwidth conservation, noise reduction.
Cons: Complexity at receiver and boost adjustments required for pilot carrier reception.
Page 36: AM Modulators
Categories of AM modulators based on functionality and level of modulation.
Page 37: Types of Modulators
Details on varied types of balanced modulators and their significance in SSB signal generation.
Page 38: Demodulation Techniques
Overview of AM Demodulators and potential distortions in signal reception.
Page 39: Low Level AM DSBFC Transmitter Design
An example of the AM transmitter roles and necessary components.
Page 40: High Level DSBFC Transmitter Overview
Explanation of high-level AM transmission structure and elements involved.
Page 41: SSB Transmitter Architecture
Features of SSB suppressed carrier Transmitter, emphasizing bandpass filter applications for signal conditioning.
Page 42: FM Overview
Insight into frequency modulation fundamentals and its distinctions from AM modulation.
Page 46: Chapter 4: Angle Modulation
Covers the relationship between FM and PM signal operations, focusing on their non-linear nature and practical implications.
Page 49: Phase Locked Loop (PLL)
Explains the functionality of PLLs as feedback systems in communication.
Page 75: Chapter 5: Pulse Modulation
Discusses the fundamentals of both analog and digital pulse modulation in communication technologies.