Research On Spread-Spectrum In HF Communication

HF communication plays an important role in wireless communications, especially in the military communications because of its inherent characteristics. Spread-Spectrum Communication is widely applied into HF military communication. To compare with technology of equalization and anti-interference, Spread-Spectrum Communication is of strong ability of anti-interference, good privacy, apt to realize the advantages, and code division multiple access, etc. It is a new focus in the communication technology for wide development in civil communication in recent years.This dissertation at first, besides of introducing the character of the HF channel, has introduced correlated basic background knowledge and development on Spread-Spectrum Communications, including the principle of Spread-Spectrum Communications, some typical models. Then based on the theories of Spread Spectrum Sequence, the principles of pseudo random sequence (classify m-Sequence, Gold-Sequence and Orthogonal Spread Spectrum Sequence) are emphatically explained. Then a Rake receiver is used to realize the diversity reception to anti the multipath fading. Finally in MATLAB software, the simulation of PN Sequence, m Sequence, Gold Sequence and Orthogonal Spread Spectrum Sequence were given, and the influence for different Spread Spectrum Sequence in HF Communication system was analyzed.