Study On Hybrid FH/DS Spread-spectrum Technology And Its Application In Underwater Acoustic Communication

With the increasingly development of exploiting and using ocean, it is imminently to research under water acoustic communication technology, and also, it is one of the most challenging tasks in acoustic field. The spread spectrum communication mode is used in anti-jamming communication and mobile communication abroad, because of its' many virtues, such as anti jamming, anti noise, anti-multipath, can be worked in the low power spectrum density, good security, multiplexing and precision ranging, etc. In this paper, a new-style of spread spectrum communication system mixed by direct sequence spread spectrum and frequency hopping spread spectrum, using the software of Systemview. This new system is used underwater acoustic communication, and based on the secrecy, anti jamming and the characteristics of the under water acoustic channel.The main work and originality in this paper can be summarized as below:1. The analysis and conclusion of Walsh function offers the theoretical foundation and reference for its' further appliance.2. Using Hardamard matrix created the Walsh function, and conformed frequency hopper, though the conventional way of conformation frequency hopper is through frequency synthesizer, this new technique reduced the system design cost.3. Designed, analyzed and resolved the problems about the system simulation delay, got the relationship between Signal-to-Noise and Bit Error Rate.4. Approved this new system possess biggish applied cost and long term potential in underwater acoustic communication, through the performance analysis and emulation of this new system.