查询词典 baseband

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。

The receiver includes: an LNA and downconverter; complete synthe- sizers and VCOs; direct conversion from IF receiver with variable gain control; quadrature demodulator; I/Q base- band amplifiers; and, on-chip baseband filters.

该接收器包括：一LNA和下变频器；完成桑特- sizers和压控振荡器，从中频可变增益控制直接转换接收器；正交解调器，I / Q基带放大器，以及片上基带滤波器。

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)。

With the rapid expansion of GPS application areas, as well as the development of China's Beidou positioning system, it is necessary to have the knowledge of GPS and design with independent intellectual property rights of the GPS baseband chip.

随着GPS应用领域的迅速扩展以及我国北斗定位系统的发展，掌握GPS相关知识和设计具有自主知识产权的GPS基带芯片是必要的。

In the base of simply introduce the system design of GPS baseband chip, the thsis promote a verification strategy which is based on Synopsyss Designware VIP library and analysis of coverage.

在简单介绍GPS基带芯片系统设计的基础上，论文提出了基于Synopsys公司Designware VIP库和覆盖率分析的验证策略并详细叙述了整个系统级功能验证的验证方案以及验证平台的搭建。

A carrier gas such as nitrogen is directed through line 20 and valve 22 to connect with line 26 and mix with the gas sample.

如氮气之类的载体通过管线20和阀22引入，与管线26相通，与气体样品混合。

But for the most part, knaves and parasites had the command of his fortune

然而支配他的家产的大多是恶棍和寄生虫。