Direct Sequence Spread Spectrum

In the field of communications, various techniques facilitate data transmission. One relatively straightforward approach is the Direct Sequence Spread Spectrum (DSSS) system. This system enhances data transmission reliability and security without significant complexity increases. In DSSS implementations, data is converted into sequences and mathematically combined (typically XOR operation) with a higher-rate pseudorandom noise (PN) sequence. This spreading process expands the data sequence into a longer chip sequence, improving resistance to interference through processing gain. From a coding perspective, key functions include: - PN sequence generation using linear feedback shift registers (LFSRs) - Spreading through bitwise multiplication of data and PN sequences - Correlation detection at the receiver for despreading The system can integrate encryption by using cryptographic PN sequences, making transmitted data more secure. Despite its simplicity, DSSS remains highly valuable and finds widespread application in wireless communications, GPS systems, and CDMA technologies due to its robustness against jamming and low probability of interception.