In chapter 5 the jamming such as phase modulation noise , binary pseudo random sequence and multiple pseudo targets are discussed 第五章对雷达干扰进行了阐述，主要的干扰信号有连续噪声调相干扰、伪随机码噪声干扰、多假目标干扰。
( 2 ) for the cepstrum - based pn period estimation under very low snr ( < ? 10db ) , a refined cepstrum algorithm is proposed which performs better 计算机仿真表明在低信噪比情况下( snr ? 10db ) ,可以对伪随机码周期有一个精确的估计。
As a result , pseudorandom code acquisition and tracking , carrier recovering , error correction and decoding functions are needed in the if digital receiver 因此，其中频数字接收机需要完成伪随机码捕获跟踪、载波恢复、纠错译码等功能。
This scheme can also adapt ds / dmpsk modulation and demodulation with different base data rate , different pseudo random codes and different intermediate frequency 该方案可以适应不同基带数据速率、不同伪随机码和不同中频的ds / dmpsk的调制和解调。
The project fulfills two of very important funcitons in a fh communication system - the generation of pn code and the synthesizing of hopping frequencies , and unites them together efficiently 该方案完成了跳频通信系统中极为重要的两个功能：伪随机码的产生和跳变频率的合成，并将它们有机地结合在一起。
Besides , the impacts of several different kinds of transmitted pulses on ber performance are investigated with numerical examples . further , we discuss the design of optimal pulse in the context of this thesis 此外,本文还比较了几种常见脉冲,常见伪随机码对系统误码率的影响,并对最优脉冲的设计进行了初步探讨。
Such conventional sequences get the merits of good auto - correlation and cross - correlation features . however the number - limited and short - period features of conventional sequence affect the performance of system greatly 传统码具有较好的自相关和互相关特性,大量的仿真试验已证实利用传统序列作为伪随机码的有效性。
And a few module of quasi random code modulation signal and a radar signal processing module which can extract the information of velocity and range are carried on . the result can be applied on radar systems 接下来实现了几种伪随机码调制信号的模块以及提取速度距离信息的雷达信号处理模块,成果可用于实际的雷达系统。
The computer simulation realized direct sequence spread spectrum system which used chaotic spreading sequences instead of pn codes and proved the applicability of using chaotic sequences as spreading codes 最后用计算机模拟实现了用混沌扩频序列取代伪随机码的直接序列扩频通信系统，说明了混沌扩频序列可作为扩频码使用。
Cyclic spectrum correlation technology is used to analyze the cyclostational signal , on the other hand , ds signal has cyclostation . so we can make use of cyclic spectrum correlation technology to detect ds signal and estimate the parameters of ds signal 循环谱相关技术的分析对象是具有循环平稳性的信号，而直扩信号是利用伪随机码调制的宽带信号，具有循环平稳性，所以可以利用循环谱相关技术来检测直扩信号。
