Fundamentals of Spread Spectrum Modulation

Description

This lecture covers the fundamentals of spread spectrum modulation, which can be defined as any modulation technique that requires a transmission bandwidth much greater than the modulating signal bandwidth, independently of the bandwidth of the modulating signal. After reviewing basic digital modulation techniques, the principal forms of spread spectrum modulation are described. One of the most important components of a spread spectrum system is the spreading code, and several types and their characteristics are described. The most essential operation required at the receiver in a spread spectrum system is the code synchronization, which is usually broken down into the operations of acquisition and tracking. Means for performing these operations are discussed next. Finally, the performance of spread spectrum systems is of fundamental interest and the effect of jamming is considered, both without and with the use of forward error correction coding. The presentation ends with consideration of spread spectrum systems in the presence of other users. book.pdf......Page 0 INTRODUCTION......Page 7 REVIEW OF BASIC DIGITAL MODULATION TECHNIQUES......Page 9 TYPES OF SPREAD SPECTRUM MODULATION......Page 13 Frequency-Hop Spread Spectrum......Page 14 Summary......Page 16 Generation and Properties of m-Sequences......Page 17 Gold Codes Roger:1995, Sawate:1980, Gordon:2001......Page 23 Quaternary Sequences Kumar:1996, Hammons:1993......Page 25 Complementary Code Keying Geier:2001......Page 26 Walsh--Hadamard Sequences Sawate:1980, Gordon:2001......Page 28 CODE ACQUISITION AND TRACKING Roger:1995......Page 30 Serial Search Code Acquisition......Page 31 Matched Filter Code Acquisition Roger:1995, Andreas:1984......Page 47 Tracking in Spread Spectrum......Page 50 Summary......Page 55 PERFORMANCE OF SPREAD SPECTRUM SYSTEMS OPERATING IN JAMMING---NO CODING......Page 56 Barrage Noise Jamming......Page 57 Performance of FHSS in Partial Band Jamming......Page 60 Performance of DSSS with BPSK Data Modulation in Pulsed Jamming......Page 62 Performance of FHSS in Multiple Tone Jamming......Page 64 Conclusions......Page 67 PERFORMANCE OF SPREAD SPECTRUM SYSTEMS OPERATING IN JAMMING WITH FORWARD ERROR CORRECTION CODING......Page 68 Block Coding Concepts......Page 69 Convolutional Codes......Page 72 Example System Performances for Spread Spectrum Systems with Coding Operating in Jamming Environments......Page 74 PERFORMANCE IN MULTIPLE USER ENVIRONMENTS......Page 78 SUMMARY......Page 82