为了解决脉冲压缩技术运用于超宽带(ultra-wideband,UWB)雷达系统中在增加其最远探测距离的同时也增加了探测盲区这一问题,提出一种利用长短脉冲相组合的伪随机(pseudo random noise,PRN)码调制的二相编码UWB信号作为雷达信号发射源,在满足短脉冲的最大探测距离大于长脉冲的最小探测盲区的条件下,解决UWB脉冲压缩雷达系统探测盲区的问题。Matlab仿真结果表明了理论分析的正确性及所提出的方法可以很大程度减小雷达探测盲区,说明所提出方法的可行性与优越性。
We propose a scheme for spread-spectrum communications using true random sequences generated by chaotic semiconductor lasers as spreading codes.These sequences can eliminate the inherent periodicity of pseudorandom sequences,enlarge the capacity of spread-spectrum codes,improve communication security,and increase the number of users of the system.When a true random sequence with an appropriate length is used as the spread-spectrum code and the information speed is maintained constant,the system acquires a greater spreadspectrum gain and a lower bit-error ratio(BER) than the traditional spread-spectrum system.The communication security is also enhanced.The BER smoothly increases with the number of users,which indicates the good multipleaccess capability of the system.
