At function that the hardware realize and performance " s analysis we find out and spread spectrum modulator have good performance , can finish the request that put forward in the subject , and has possessed the characteristic of the software radio 从硬件实现的功能和性能分析可以看出该扩频调制器具有良好的性能，能完成课题中提出的要求，并且具备了软件无线电的特征。
The third part presents the design and implementation of the soc test model with large scale fpga device apex20k100e , and gives the whole soc simulation waves . the results show the design of the soc softcore is very effective and practicable 接着本文给出了扩频调制片上系统的测试设计方案，并且给出了仿真波形。根据片上系统的测试仿真结果表明，本文设计的片上系统设计方案是可行的。
In this kind spread spectrum modulator , we use direct digital frequencies synthesis ( dos ) and digital signal processors ( dsp ) chip as the key parts of spread spectrum modulator , by controlling the out of dos to achieve the goal of modulating with dsp 在这种扩频调制器中，使用数字信号处理器( dsp )和直接数字频率合成芯片( dds )作为调制器的核心部分，用dsp控制dds的输出来达到调制的目的。
It is from software programming realizations direct serial spread spectrum modulate ( ds - ss ) , frequency flip spread spectrum modulate ( fh - ss ) , spread spectrum and frequency flip mix spread spectrum modulate ( fh / ds ) and a lot of other spread spectrum modulate 通过软件编程实现了直接序列扩频( ds - ss )调制、频率跳变扩频( fh - ss )调制、跳频直扩混合扩频( fh ds )调制等多种扩频调制。
( 4 ) in the discrete wavelet transform domain , the watermark sequence is modulated with m - sequence at first , then the watermark information is embedded by quantifying the coefficient of the transform domain . the quantification procession is given ( 4 )在离散小波变换域，先对水印序列进行扩频调制，然后通过对变换域系数进行量化来嵌入水印信息，给出了量化方案；在水印的提取过程中不需要原始音频信号的参与。
We analyzed the anti - jam and band inside anti - interfere performance of the system , and the low probability intercept ( lpi ) of the traditional direct sequence spread spectrum ( dsss ) modulations in the uav platform ' s applications . so a new modulation technique using a multi - level pseudo noise ( pn ) code has been presented . the new multi - level pn code is built from a high speed pn code through a low passed filter ( lpf ) 分析了系统抗阻塞式干扰和抗带内频带干扰的性能，以及常规bpsk qpsk - dsss调制在无人机通信中存在的安全隐患，提出了一种用多电平pn码进行扩频调制的方法：采用高速pn码，经过低通滤波器，产生多电平pn码进行直序扩频调制，能在低信噪比情况下有效抵抗平方率检测器对系统载波的检测。
The design of cdma terminal chip is a very actual value and extensive application problem in the field of cdma technology application . with the development of micro - electronics technology , the design of integrated circuit has stepped into the age of soc ( system on chip ) , which provide a brand - new method for cdma communication system project . in this paper , a design of cdma2000 1x spread modulation soc has be researched with large scale field programmle gate array device , and make a certain results Cdma终端芯片设计是cdma技术应用领域中一个具有重要实际应用价值和广阔应用前景的研究课题。随着微电子技术的发展，集成电路设计进入了片上系统时代，这为cdma移动通信系统设计提供了一个全新的技术手段。本文将基于cdma技术，用大规模可编程逻辑器件对第三代移动通信cdma20001x的扩频调制片上系统设计做了进一步的探讨和研究，并取得了一定的成果。
The second part studies the characteristics of cdma2000 1x reverse link , and implements a softcore design of the cdma20001x rtl soc with hdl ( hardwire desciptionin language ) verilog in accordance with the is - 2000 specifications . the model include the softcore of a spread spectrum modulation and a simple 8 - bit processor . as the same time simulate all the parts of the soc softcore with software modesim ，本文的第二部分认真的研究了cdma20001x的反向链路的特点，设计反向链路的扩频调制片上系统方案。用硬件语言verilog设计cdma20001x的扩频调制片上系统的ip软核。其中包括扩频调制部分和一个8位的cpu设计。
Based on the communication engineering applications , this thesis study the intelligent transmission technology and the performance of the spread spectrum modulated sequence . in this thesis , some own conclusions have been concluded and testified using communication simulink under the possibility of the applied environment 本文在面向通信工程应用的基础上，对智能传输技术和扩频调制码的性能进行了一定的研究，提出了自己的结论并使用通信仿真技术对这些结论在可能的应用环境下进行了证明。
Finally the modulated signal is embedded in the coefficients with relatively large absolute value on middle frequency range detail signal adaptively . the original digital audio signal is necessary when detecting the watermark . equally , spreading spectrum technology can improve the performance of watermark technology greatly , but it will increase the capacity of channel and the calculation of the algorithm as cost 在应用扩频技术的算法中，首先将视觉上可辨的二值水印图像降维为一维序列，再将一维水印序列伪随机排序并与m序列作扩频调制，最后对数字音频信号进行分段离散小波变换，把经过调制的水印信息自适应地嵌入到原音频信号小波分解中等尺度绝对值较大的分量上。
