Digital Communication and Telecommunications

4.

Digital Modulation and Demodulation

4.1.

Modulation Fundamentals

4.1.1.

Carrier Signal Properties

4.1.1.1.

Amplitude Parameters

4.1.1.2.

Frequency Characteristics

4.1.1.3.

Phase Relationships

4.1.2.

Modulation Necessity

4.1.2.1.

Frequency Allocation

4.1.2.2.

Signal Multiplexing

4.1.2.3.

Transmission Efficiency

4.1.2.4.

Antenna Size Considerations

4.1.3.

Modulation Classification

4.1.3.1.

Linear Modulation

4.1.3.2.

Nonlinear Modulation

4.1.3.3.

Coherent Detection

4.1.3.4.

Non-coherent Detection

4.2.

Amplitude Shift Keying

4.2.1.

ASK Modulation Process

4.2.1.1.

4.2.1.2.

4.2.1.3.

Signal Generation

4.2.2.

ASK Demodulation

4.2.2.1.

Envelope Detection

4.2.2.2.

Coherent Detection

4.2.2.3.

Performance Comparison

4.2.3.

ASK Applications and Limitations

4.2.3.1.

Optical Communication

4.2.3.2.

Power Line Communication

4.2.3.3.

Noise Sensitivity

4.3.

Frequency Shift Keying

4.3.1.

FSK Modulation Process

4.3.1.1.

4.3.1.2.

4.3.1.3.

Continuous Phase FSK

4.3.2.

FSK Demodulation

4.3.2.1.

Non-coherent Detection

4.3.2.2.

Coherent Detection

4.3.2.3.

Discriminator Detection

4.3.3.

4.3.3.1.

Minimum Shift Keying

4.3.3.2.

4.3.3.3.

Applications in Wireless Systems

4.4.

Phase Shift Keying

4.4.1.

PSK Modulation Principles

4.4.1.1.

4.4.1.2.

Signal Constellation

4.4.1.3.

Differential Encoding

4.4.2.

Binary Phase Shift Keying

4.4.2.1.

BPSK Signal Generation

4.4.2.2.

Constellation Diagram

4.4.2.3.

Bit Error Rate Performance

4.4.3.

Quadrature Phase Shift Keying

4.4.3.1.

QPSK Signal Structure

4.4.3.2.

I-Q Representation

4.4.3.3.

Bandwidth Efficiency

4.4.3.4.

4.4.4.

4.4.4.1.

4.4.4.2.

4.4.4.3.

Performance Trade-offs

4.5.

Quadrature Amplitude Modulation

4.5.1.

4.5.1.1.

Amplitude and Phase Modulation

4.5.1.2.

4.5.1.3.

Signal Space Representation

4.5.2.

QAM Constellation Diagrams

4.5.2.1.

4.5.2.2.

4.5.2.3.

4.5.2.4.

Higher Order QAM

4.5.3.

QAM Applications

4.5.3.1.

Cable Modem Systems

4.5.3.2.

Digital Television

4.5.3.3.

Wireless Broadband

4.5.4.

QAM Performance

4.5.4.1.

4.5.4.2.

Peak-to-Average Power Ratio

4.5.4.3.

Implementation Complexity

4.6.

Spread Spectrum Techniques

4.6.1.

Spread Spectrum Benefits

4.6.1.1.

Interference Resistance

4.6.1.2.

Security Enhancement

4.6.1.3.

Multiple Access Capability

4.6.1.4.

Low Probability of Intercept

4.6.2.

Direct-Sequence Spread Spectrum

4.6.2.1.

Spreading Code Generation

4.6.2.2.

Pseudonoise Sequences

4.6.2.3.

Processing Gain

4.6.2.4.

CDMA Applications

4.6.3.

Frequency-Hopping Spread Spectrum

4.6.3.1.

Hopping Pattern Generation

4.6.3.2.

4.6.3.3.

4.6.3.4.

Bluetooth Implementation

4.6.4.

Hybrid Spread Spectrum

4.6.4.1.

DS-FH Combination

4.6.4.2.

4.6.4.3.

Applications in UWB

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