基带

Baseband signal can control by serial each that one-chip computer produce phase place , DDS of generator control and bring in realizing, and the phase locking ring of the integration can produce the signal carrier within AD9856 chip, its frequency is set up through the interface of the outside one-chip computer.

基带信号可以由单片机产生的串行码元控制DDS发生器的相位控制端来实现，而AD9856芯片内部集成的锁相环可以产生载波，其频率也是通过外部单片机的接口来设置。

Baseband signal can control by serialeach that one-chip computer produce phase place , DDS of generatorcontrol and bring in realizing, and the phase locking ring of theintegration can produce the signal carrier within AD9856 chip, itsfrequency is set up through the interface of the outside one-chipcomputer.

基带信号可以由单片机产生的串行码元控制DDS发生器的相位控制端来实现，而AD9856芯片内部集成的锁相环可以产生载波，其频率也是通过外部单片机的接口来设置。

Subcarrier multiplexed addressing and wavel ength conversion based on cascaded semiconductor optical amplifier perform the f unctions of subcarrier signal with data multiplexing and transparent transmissio n of payload.

副载波复用和基于级联半导体光放大器的波长变换，实现了射频副载波路由信息与基带IP数据包的同步复用和IP数据包的透明传输。

The paper mainly researched the peak to average technology of the MC-CDMA system and realized the baseband design. It proposed the optimal condition of the spectrum code in the MC-CDMA system, and considered the peak value factor of spectrum code, the correlation characteristic, and the spectrum correlation characteristic.

论文主要研究MC-CDMA系统的峰平比技术及实现了基带信号处理，提出了在MC-CDMA系统中采用扩谱码的优选条件，即同时考虑扩谱码的峰值因子、相关特性、和谱相关特性。

The paper investigates both block-type pilot linear minimum mean square error algorithm and IEEE802.16 OFDM channel estimation analysis. Simulation results confirm the block-type pilot structure is more suitable for IEEE802.16 system. An optimal pilot setting algorithm, based on space frequency domain, is explored and the pilot chart is presented. The proposed algorithm finds its application in MIMO-OFDM. Simulation results show the algorithm presents a good approximation to the perfect channel state information curve, with about 2dB difference in SNR. The simulation results also demonstrate the algorithm achieves fairly high stability in the environment of fast fading, performance of the proposed algorithm is better that of pilot training channel estimation.3. Taking into account the characteristics of IEEE802.16 OFDM system, OFDM system simulation platform is constructed in Matlab, exploiting simulink as a tool. OFDM modulation and demodulation simulation system are configured on LabVIEW platform. All the system signal processing is simulated, including defining system parameters, designing modulation model, and verifying all the proposed algorithms under different environments, such as white Gaussian noise, multi-path fading, with or without guard interval etc. Bit error performance is evaluated. The research provides valid theoretical basis for practical OFDM system performance evaluation.4. Taking advantage of software radio, the paper designs a hardware platform with both 256-IFFT/FFT and 512-IFFT/FFT OFDM schemes co-existing in one platform. You can predetermine one from the two schemes to carry out almost the same model function with different system performance and parameter setting.5. Referring to IEEE802.16 standard, the paper proposes a design method for generating signals and frames suitable for laboratory investigations implemented in laboratory environment.6. Based on 6701evm digital evaluation card, combined with analogy front-end, the paper designs a DSP software model to deal with baseband signal processing. An overall OFDM scheme, with modulation and demodulation function, is accomplished.

讨论分析了MIMO-OFDM中一种基于空频域的最优导频设置算法，给出了导频图案，通过仿真实验表明，该算法与理想的信道状态信息曲线非常接近，信噪比差距约在2dB左右，并且在快衰落条件下具有较好的稳定性，其性能要优于基于前导训练的信道估计方法。3、根据IEEE802.16OFDM系统特点，论文分别在Matlab中应用Simulink工具构建OFDM系统仿真平台、在LabVIEW平台上实现了OFDM调制解调仿真系统，模拟了整个系统的信号流程，进行了OFDM仿真系统参数的选择和调制模块的仿真设计、论证各算法性能，并根据各种不同的条件：例如高斯噪声、多径衰落、有无保护间隔等，对系统的误码特性进行了评估，为正确评价实际OFDM系统的性能提供了有效的理论依据。4、论文以软件无线电思想作为指导，提出了以256点IFFT／FFT为核心和以512点IFFT／FFT为核心的两种OFDM算法模式并存于同一个硬件平台、且可预选的方案，它们在参数选取和性能指标上有所差异，均实现了相似的模块和功能。5、论文参考IEEE 802.16无线网络标准的参数设置，针对本设计系统的应用环境和系统硬件的性能速率，提出了一种应用于实验室环境的信号结构、帧格式等参数设计。6、论文基于TI公司的6701evm数字评估板卡，结合模拟前端搭建数字中频平台，设计了基带处理的DSP软件模块并进行系统调试，基本实现了一套完整的OFDM调制解调方案。

The digital users signals comprising in-phase component and quadrature component are converted to analog baseband signals by digital-to-analog converters 104 and 114, which are followed by lowpass filters 106 and 116 for removing harmonics at unwanted frequencies.

包括同相分量和正交分量的数字用户信号通过数模转换器104和114转换成模拟基带信号，在数模转换器104和114的后面具有低通滤波器106和116，低通滤波器106和116用于去除在不期望频率处的谐波。

The method for determining a phase-noise spectrum comprises generating real complex samples, by digitally sampling a phase component and phase quadrature component of the input signal in baseband, determining ideal complex samples from generated real samples, establishing complex quotients from the real and ideal complex samples, generating modified complex quotients by assigning the value 1 to the complex quotients, and subjecting the modified complex quotients to a Fourier transform.

所述方法包括以下步骤：通过对基带中的所述输入信号的相位分量和相位正交分量进行数字采样，产生实际复数采样Areal(n(S100)；根据产生的实际采样Areal(n确定理想复数采样Aideal(n(S101)；根据实际复数采样Areal(n和理想复数采样Aideal(n形成复数商ΔA1(n＝Areal/Aideal；通过对所述复数商指定值1，产生经修正复数商B(n(S106)；以及对经修正复数商B(n进行傅立叶变换(S107)。

Secondly this paper analyzes the research present conditions and development trend of transmitter and miniature wireless in missile at home and abroad thoroughly ,then designs the PCM-CDMA-QPSK system of integrated miniature wireless beacon which based on the technology of CDMA and DUC.

其次，在深入分析和比较国内外弹载发射设备和无线信标技术研究现状的基础上，针对多目标测量的需求，基于码分多址和直接上变频技术原理，设计了PCM-CDMA-QPSK体制的微小型无线信标系统总体，完成了无线信标系统中基带扩频电路的调试，结果表明，基于码分多址的多信标测量方法是可行性，所设计的系统可靠有效。

Under certain ratio of signal-to-noise and through the computer simulations and calculations, the performances in Mbius digital base band communication system of five often used modem function set, those are the even and odd symmetrical triangle wave, even and odd symmetrical square wave and saw-tooth wave and their inverse transforms, are simulated 10000 times, and the fluctuation ranges of the error rate P(subscript b are observed.

在一定信噪比的前提下，通过计算机仿真和编程计算，对Mbius数字基带通信系统中偶对称三角波、奇对称三角波、偶对称方波、奇对称方波和锯齿波这5种常用的调制解调函数族及其逆变换进行仿真1万次，观察错误概率P

Bius digital base band communication system of five often used modem function set, those are the even and odd symmetrical triangle wave, even and odd symmetrical square wave and saw-tooth wave and their inverse transforms, are simulated 10000 times, and the fluctuation ranges of the error rate P(subscript b are observed.

bius数字基带通信系统中偶对称三角波、奇对称三角波、偶对称方波、奇对称方波和锯齿波这5种常用的调制解调函数族及其逆变换进行仿真1万次，观察错误概率P

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。