This paper has analyzed the performance of PPM and PAM under frequency dependence channel model, the results have shown that the PAM is better than the PPM in frequency dependence channel.

文章分析此类信道模型下脉冲位置调制和脉冲幅度调制的性能，结果表明，在频率依赖性信道中PAM调制优于PPM调制。

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According to the requirements of synchronous speed control of series conveying belt, several patterns which could realize the synchronous speed control under frequency conversion was analyzed.

针对多级胶带输送机同步运行要求，分析了胶带机变频拖动同步运行实现的几种模式。

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During the design of under frequency load shedding (UFLS) schemes, some simple models for frequency dynamics analysis are obviously inadequate since they do not take system voltage into account.

进行系统低频减载方案设计时，简单的频率响应模型由于未考虑系统电压对频率过程的影响而导致不少情况下无法适用。

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Digital television will eventually migrate to the 600MHz frequency under Ofcom's plans.

BBC: Data jam threat to UK mobile networks

The Acoustic Thermometry of Ocean Climate (ATOC) project is asking to extend its two-year permit to operate low-frequency sonar under the water off Kauai another five years.

CNN: waves

Bankrolled by its toy sales, it has moved into cordless telephones, and now has half the market in America for high-frequency models, under its own label and for Lucent and Sony.

ECONOMIST: Electronic toys