The Application Of Pseudo-Random Code Broadband Spread Spectrum Technology In Ocean Exploration

This paper mainly studies broadband pseudo random code spread spectrum detection technology in the application of sea, according to the present commonly used at home and abroad typical underwater acoustic detection technology and equipment of some disadvantages, puts forward using broadband pseudo random code spread spectrum technology to improve the existing Marine detection system performance.At first, this paper made an in-depth discussion of spread spectrum technology theory,realized the spread spectrum technology to the improvement of the signal to noise ratio.Pseudo-random code sequence of pseudo random signal of spread spectrum system,and the design of the pseudo-random code has an important impact on system performance,in addition, when there are multiple system platform observation, pseudo random code can also be used as address code in code division multiple access technology.In this paper, the pseudo random code is given priority to with Gold sequence, and Gold sequence is based on m sequence optimization of produce, so this article discusses and explores the m sequence and Gold sequence generation condition, and carries on the comparison to its related properties, the final design for the balance of the spread spectrum system platform Gold sequence code set.Spread spectrum technology in the signal at the receiving end to achieve maximum signal-to-noise ratio, requires a kind of optimal linear filter and the matched filtering is needed for implementation, this paper also discusses the theory of matched filtering algorithm and the realization of time domain and frequency domain, and realized Gold sequence in the frequency domain matched filtering processing.The realization of the spread spectrum technology rely on digital signal processor(DSP)platform, thus this research by using digital signal processor, analog/digital to analog converter, memory and other hardware structures, a Marine exploration universal digital signal processor platform, and the signal generator and the matched filtering program written to the platform, become the core processors spread spectrum technology.For validation of pseudo random code spread spectrum technology to improve the performance of detection system of oceans and in the laboratory environment by emitting Gold sequence,the Chirp signal and the CW signal, and receives the signals at the receiving end,respectively using DSP in the matching algorithm for its matching the three kinds of signal processing, and matching evaluation of the three kinds of signal processing will affect the performance of the system.Results show that the Gold sequence has 6 order and Chirp signal relevant system processing gain, they gain is much taller than the CW signal, and Gold sequence has the best time to resolution.In addition, the digital signal processor ocean universal platform using the ocean acoustic tomography system, through the acoustic tomography system realize the spread spectrum technology in the practical application of ocean exploration.Plan layout in zhoushan peach blossom island waters tomographic base station, selection of target area of chromatography setting point, complete the chromatography of the base station design, and hydrological investigation of target area and the acoustics environment in the area were analyzed, and the system test for actual waters and after long-term observations provide acoustic tomography sonar system actual waters of acoustic environment data support.