查询词典 Base Band

Program is divided into three parts: phase.m symbol of the baseband shaping pulse sequences, optional rectangular pulse, the square root raised cosine pulse and raised cosine pulse model.m-based procedures, completed a variety of base-band signal constellation mapping , pulse shaping and modulation command.m given spectrum shows a simple test.

程序分成三个部分：phase.m对基带码元序列进行脉冲成型，可选矩形脉冲，升余弦脉冲和平方根升余弦脉冲； model.m 为主程序，完成各种信号的基带星座图映射、脉冲成型和调制； command.m给出一个简单的频谱显示测试。

This pulse also helps "train" the base-band coupling capacitor in the ASH radio for best data slicer noise rejection.

这也有助于脉搏"一条龙"在灰无线电基带耦合电容器最佳的数据限幅器的噪声抑制。

That is to say, by using the special digital converter or running relevant arithmetic, it converts the radio signal to intermediate frequency signal and completes the base-band signal process that isn"t the veriest SR and is named "software defined radio. This paper introduces the rapid system prototype into the design of software radio system, which has great advantage because rapid system prototype technology can be used to describe the future application.

由于受到硬件性能如A／D、D／A及DSP芯片处理速度的限制，目前的软件无线电系统多采用折中的实现方案，增加专用的数字变频器或者运行数字变频算法，将射频信号变频到中频，然后再进行基带信号处理，这样的软件无线电系统又被称之为"软件定义无线电"，它并不是真正意义上的软件无线电。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

Base Band Interpolator Pulse Shaping filter is a key component of all digital modulator.

基带内插脉冲成形滤波器是全数字调制器的核心模块之一。

A second set of decimation filters (226, 228) decimates and filters the output of the summers (222, 224) applying a filter function that is matched to a pulse shape of a base band signal present in the IF signal.

利用与IF信号内存在的基带信号的脉冲波形匹配的滤波器函数，第二组抽取滤波器(226，228)抽取并滤波加法器(222，224)的输出。

Some research was dealed with in multirate signal process and digitizes the channel from IF, 455 KHz, to base band in HF system.

本文对多采样率信号处理理论作了一定的研究，并在455KHz中频到基带的信道上实现了数字化。

Some research was dealed with in multirate signal process and digitizes the channel from IF, 455 KHz, to base band in HF system.

本文以HSP50415和AD6620为核心，以TI公司的TMS320VC5509和TMS320VC33作为控制单元，设计了一种通用中频数字化处理平台并完成了调试，在该平台上实现了单音信号(如1.2KHz)到455KHz的中频，再由455KHz中频到基带的过程。

Then, a design of an ARM-based multimedia system is proposed and the communication interfaces between base band and the ARM processor W99702 are d...

同时，提出了系统的软件设计方法，分层次地介绍了如何通过软件实现各部分的功能，最终完成样机的开发，并通过了测试。

Through analyzing the features and performances of CIC filters,HB filters and multiphase-filter,we combine them with decimators and decimate the A/D data,thus reducing the digital signal rate and the load of DSP when processing the base band signal.

通过分析CIC滤波器、HB滤波器和多相滤波器的特点和性能，将它们与抽取器相结合，对A/D转换后的数据进行抽取，降低了信号采样率，减轻了后续DSP处理基带信号的压力。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。