The Research Of Spread Spectrum Communication System Based On MATLAB

Spread spectrum communication means for transmitting the signalbandwidth of the channel is much larger than the signal bandwidth of acommunication mode, the anti-interference, multipath fading signal, codedivision multiple access, security and other aspects of having a traditionalwireless communication means there is nothing comparable to this advantage,in civil and military communication has been widely used in Matlab software;its strong scientific computing ability, precise circuit simulation capability andstrong simulation ability has become the most widely used system simulationsoftware, can finish spread spectrum communication system simulation.Spread spectrum communication system and other analog or digitalcommunication system, its concept is more abstract, more difficult technology,content is more complex, more difficult to learn and master. Based on this, thispaper elaborates on the spread spectrum communication development course,working principle and key technology on the basis, the Matlab simulationsoftware as a platform, through the integrity of the spread spectrumcommunication system simulation, the spread spectrum communicationsystem of the basic concepts and design ideas of organic and the image of thelink, thereby from the system level to spread spectrum communicationtechnology is a comprehensive and intuitive understanding of.The main work of this paper and research contents include the followingfour parts:First, it is platform with MATLAB, according to the Shannon formula,focused on the in channel capacity under the condition of same, through theaddition of signal transmission band width lower signal to noise ratio method.Through the simulation study found that, by increasing the signal transmissionbandwidth can be reduced on the signal to noise ratio requirements. Second, study the spread spectrum communication system two spreadway and receiving synchronous technology, channel coding technology andchannel interference technology. Gives a direct sequence spread spectrumcommunication system and frequency hopping communication systemsimulation model.In third, the spread spectrum communication direct sequence spreadspectrum communication system simulation and analysis are carried out, theresults show that direct spread system anti-interference ability is far greaterthan ordinary binary system, and with the spread spectrum gain increases, thesystem bit error rate is reduced, at the same time spread spectrum systemperformance depends largely on the characteristics of spread spectrum code.Fourth, to frequency hopping communication system is studied and thesimulation analysis, studies the frequency hopping sequence generatingmethod, and were given analog FM system and digital FM systemsynchronization method. The simulation results show that, the system has wellanti-jamming ability.