Optical code division multiple access ( ocdma ) is a communication mode which introduces the code division multiple access ( cdma ) technology into optical fiber communication system . besides providing asynchronous communications access , ocdma system has many advantages , such as high capacity , security against interception , suppression of narrow band disturbances , capability in forming variable bit rate networks and multi - rate networks . it implies a great challenge for the development of future communication networks , especially all optical networks 光码分多址( ocdma )是将码分多址( cdma )技术与大容量的光纤通信技术相结合的一种通信方式，其主要优点表现在如下几个方面：允许多个用户随机地接入同一信道：可构成真正“透明”的全光通信网络；具有良好的安全性；允许可变速率或多速率传输，并可同时提供多种业务支持；具有优良好的抗干扰能力，并能够充分地利用石英光纤的可用带宽。
The use of multiple sampling rates offers many advantages , such as reducing computational complexity for a given task , speeding up transmission rate , and / or raising storage capacity . so the applications of multirate digital filter technology have been found in subband coding of images and speeches , communications , and in many other fields 由于多速率数字滤波技术可有效地降低信号的处理复杂度、加快数据的传输率和提高存储量等，所以它在图像编码、语音编码及通信等众多领域具有广泛的应用。
This paper discusses key technology in the digital intermediate frequency receiver with wide band based on software radio , including down - converter on condition of band - pass - sampling , digital down - converter , multi - rate digital signal processing , band - pass signal decimating , and achieves software system simulation based on under - sampling 摘要分析了基于软件无线电的宽带数字中频接收机中的关键技术带通采样下变频技术、数字下变频技术、多速率处理技术，并实现了欠采样技术条件的软件系统仿真。
Some robust stability conditions are derived . ( 4 ) a class of dual - rate input - output predictive model containing time delays is established . a new dual - rate predictive control algorithm for the time - delay system is presented , which makes up the shortcoming of multi - rate weighted minimum - variance control for time - delays system , and has solved the influence of time delays on the multi - rate system 针对输入更新速率比输出采样速率慢的双速率采样系统,建立了带有时滞的输入输出预测模型,给出了时滞双速率采样预测控制算法,弥补了已有文献中时滞多速率采样加权最小方差控制的不足,解决了时滞对多速率采样系统带来的影响
Based on much pre - work on modem technology , the author investigated the mmm technology for software receiver and build a sdr testbed . firstly , with a description of open and standardized hardware & software architecture and rf / adc / dsp devices , we discussed the bypass sampling theory and applied it in software radio receivers 本文基于作者在调制解调技术研究方面的积累，深入研究了多波段、多速率、多模式软件无线电接收技术，并结合软件无线电开放式、通用性软件、硬件系统结构的思想，提出和实现了一个多波段、多速率、多模式软件无线电的验证系统。
A simulation and modeling mechanism is studied and proposed for multirate transmission protocol . based on the wlan that adopts ofdm transmission technique , we first assumed that the small - scall fading and multipath in ofdm sub - channel is rayleigh , and large - scale path loss could be described by bi - linearity model , and then we analyzed the rationality 基于采用ofdm传输技术的wlan ，我们假设ofdm子信道的小尺度衰落服从rayleigh分布，路径损耗可以用双线性模型描述，并对假设的合理性进行了分析，将决定速率切换的误帧率等物理层性能参数和媒质控制协议有机地结合在一起，对多速率传输建模进行了有意的探索。
Software radio which promises well needs a kind of wideband high speed and resolution adc , but at present it is hard to realize . on the basis of the theory of multirate signal processing , the theory of filters , bandpass sampling theorem and adc principium , perfect reconstruction quadrature mirror filter ( prqmf ) banks adc system is proposed 基于此背景，本文在融合多速率数字信号处理理论、滤波器理论、带通采样定理以及adc原理的基础上，提出了prqmf滤波器组adc系统，并对该adc系统的原理、结构、特性进行了探讨和研究，其主要结论和创新之处如下： 1
Later on we discuss the basic theory of multi - rate signal processing , and the polyphase algorithm for interplation filter , then produce the efficient algorithms for interplation : half - band filter and cic filter . we analyze their computing quantity and performance , especially the mirror elimination feature and the at - tenuation in the passband 之后讨论了多速率信号处理的基本理论,比较了不同的内插算法,分析了半带滤波器和cic内插滤波器的计算代价、时频性能,以及各自的抑制镜像特性。
