Wireless Digital Communication — Kamilo Feher Pdf
Dr. Kamilo Feher’s "Wireless Digital Communications: Modulation and Spread Spectrum Applications" (1995) is a foundational, design-oriented text bridging theoretical communication principles with practical cellular and personal communication system (PCS) implementation. The book emphasizes spectral efficiency, covering key modulation techniques like GMSK and QAM, spread spectrum technologies (DS-SS, FH-SS), and system-level designs to mitigate multipath fading. Legal access to the text is available through academic databases, libraries, and major publishers.
Summary
- Modulation Techniques: Such as QPSK, QAM, which are crucial for transmitting digital data over wireless channels.
- Error Correction Coding: Techniques like convolutional coding, turbo codes, and LDPC codes help in mitigating errors during transmission.
- Multiple Access Techniques: Including FDMA, TDMA, CDMA, and OFDM, which enable multiple users to share the same wireless channel.
- 5G NR: The constant struggle against PAPR (Peak to Average Power Ratio) in OFDM is a direct descendant of the problems Feher solved for QPSK in satellite links.
- LoRa (IoT): The chirp spread spectrum used in LoRa is a spiritual successor to the spread spectrum chapters in Feher’s book.
- Satcom: Modern Starlink terminals rely on highly efficient, non-linear amplifiers. Feher's work on predistortion and constant envelope modulation is embedded in their firmware.
System Performance: Detailed chapters are dedicated to error detection/correction (Hamming codes, Cyclic Redundancy Checks), adaptive equalization for fading channels, and synchronization for burst demodulators. About the Author: Kamilo Feher wireless digital communication kamilo feher pdf
1. The Non-Linear Amplifier Problem
Most modern textbooks assume linear amplification, which wastes power. Feher dedicates hundreds of pages to the reality of non-linear (Class C) amplifiers. He explains how to design modulation schemes that maintain constant envelope or quasi-constant envelope to avoid spectral regrowth. If you are designing a satellite link or a battery-powered IoT device, Feher’s chapters on amplifier back-off are worth their weight in gold. Modulation Techniques : Such as QPSK, QAM, which