无线电指标

We had a very successful flyby today, today we still be waiting for the next day or so to get down imagery but our initial indications flying by the planet using just radio beacon information looks good.

我们今天的定点飞行非常成功，今天我们仍然要等待几天来记录数据，但是我们的初期数据表明仅用无线电指标信息定点飞行该行星似乎是成功的。

Today, we still be waiting for the next * day or so to solar get on imagery but our initial indications fly ing by the planet using just * radio beacon information now looks good.

今天，我们仍然需要等待几天以记录图像，但是我们初期表明仅用无线电指标信息定点飞行该行星似乎是成功的。

The DPSK signal's influences on the performance of airborne radio compass including bandwidth, direction finding and beacon recognition, were analyzed in detail.

分析了DPSK调制对现有机载无线电罗盘的工作带宽、定向及台识别等性能指标的影响。

Based on the requisition of wireless system debugging, this paper develops a novel radio-frequency beaconing. Design method and system constitution of a novel beaconing based on PLL IC PE3336 are given, and the accomplish method of the system's hardware and software arc expounded. The test results show that the beaconing adopted in this method has a reliable and stable frequency conversion features. The more applications in the wireless system find that the users can set necessary frequency conveniently. Especial1, the friendly man-machine interface makes the operation is more flexible. It is as excellent performance-price-ratio beaconing, and as a signal source, it can be used in the research and the debug procession of variable radio-frequency components.

根据无线电数据链系统及部件的调试需要，研制开发了一种新型的以锁相环为核心、由单片机控制的射频信标机；文中给出了基于锁相环芯片PE3336的新型信标机的设计方法与系统组成，阐述了系统硬件及软件的具体实现为法；测试结果表明，利用该方法设计的信标机具有稳定、可靠的变频特性，且各项指标均达到了要求；进一步在某无线电系统中的应用发现，用户可方便地设置所需频点；特别是友好的人机界面，使用户操作更为灵活方便，是一种性能价格比优良的信标机；并可作为信源用于不同的射频部件研制与调试过程中。

For a good performance, exact test data and supervisee of the EUT emission, this paper investigated and discussed the technique capability, field calibration...

为了使得电波暗室测试场地能够有效的发挥其测试能力，提供准确的测试数据，从而对无线电设备的电磁干扰提供有效的监管，本文深入研究和讨论了电波暗室测试场地的主要技术指标，场地校准测试方法，以及在电波暗室中进行的辐射骚扰测试和辐射抗扰度测试。

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。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。