查询词典 frequency modulation

OFDM is actually one kind of multi-carrier modulation .and the main idea of OFDM is Channel will be divided into several subchannels orthogonal,and then turn High-speed data signals into parallel low-speed data-flow , modulation in each of the subchannels on transmission.

OFDM技术实际上是多载波调制的一种。其主要思想是：将信道分成若干正交子信道，将高速数据信号转换成并行的低速子数据流，调制到在每个子信道上进行传输。

The most popular solution to this question is using group adaptive modulation system, and usually group modulation type is decided by the subcarrier which has the worst channel information.

一个最常见的解决方法就是使用group adaptive系统，而通常决定group modulation type的方法都是使用最差的subcarrier的通道资讯。

The modulation port is implemented as a differential input, allowing the modulation control voltage and laser outputs to use different grounds.

调整港口实行差额作为投入，使电压调节和控制激光输出用不同的理由。

Finally both SNR and slope of modulation transfer spectra of I2 with different absorption length were compared experimentally while I2 cell temperature was held at -15 ℃. The results of comparison showed that modulation transfer spectra was optimal at three-pass (120 cm).

实验上比较了碘池温度为-15 ℃时一倍程(40 cm)，二倍程(80 cm)，三倍程(120 cm)和四倍程(160 cm)的光谱信号信噪比和谱线中心斜率，得到三倍程时信号信噪比和谱线中心斜率为最大，估算得到相应的激光稳频精度为9×10-14(1 s积分时间)。

This controller integrates pulse width modulation and pulse density modulation together,and can easily change between the two modulations.

该设计集成了脉冲宽度调制和脉冲密度调制两种调制方式，并可以在两者间切换。

Combined with the adaptive modulation and coding technology, this algorithm reallocates the residual power by effectively utilizing the discrete modulation orders according to the different prioriti es of sub-channels under the limitation of quality of service over the block fading channel.

在满足服务质量要求的前提下充分利用星座图尺寸的离散性，将残余功率按照各子信道的不同优先级进行二次分配，并结合自适应调制编码技术改善低信噪比时的系统吞吐量。

The transmitter has a physical layer transmitter for receiving data, formatting the received data into packets transmitting the packets and retransmitting packets in response to failure to receive a corresponding acknowledgment for a given packet; an acknowledgment receiver for receiving the corresponding acknowledgment; and an adaptive modulation and coding controller for collecting retransmission statistics and adjusting the particular data encoding/modulation using the collected statistics.

该发射器处的一物理层发射器是接收数据且将该接收到的数据格式化成具有一特殊编码/数据调制的数个分组。该物理层发射器包含n个信道，以发所述分组及相应未接收到相对应一给定分组的一相对应确认信息而再次发送分组。该发射器中的一适应性调制及编码控制器是收集再次发送的统计且使用该收集到的统计来调整该特殊编码/数据调制。该接收器具有一物理层n-信道接收器，以接收所述分组。

Residual amplitude modulation in electro-optical phase modulators results in unequal amplitude of modulation sidebands.

激光经电光相位调制后，由于剩余幅度调制的存在造成调制边带幅度不相等。

So the ultra-low frequency absolute vibration detection is a difficult problem in engineering measurement field. In this paper, the ""high-frequency-suppression and low-frequency-lifting"" compensation method was presented based on the analysis of the inertial sensor with "" mkc "" structure.

本文通过对mkc结构惯性式传感器机理的分析，提出了一种对传感器传递函数进行"抑高扬低"的补偿方法，并对此补偿网络和系统幅频特性进行了优化，较好地克服了惯性式传感器低频特性差的固有缺陷，实现了传感器的微型化。

It is found that traveling waves with either lower frequency or higher frequency can both eliminate the anti-spiral waves, while only the target waves with lower absolute value of frequency can eliminate the anti-spiral waves.

数值计算表明，对于行波，无论是低频行波还是高频行波，都可以成功地消除系统中的反螺旋波；而对于靶波，只有低频靶波才可以消除反螺旋波。

Go to your desktop and right click in a blank space.

请到您的桌面，然后右击一个空白。

Tara appears in Buddhism, Jainism, and particularly, Tibetan Lamaism, as a complex array of manifestations: goddess of ascetism and mysticism, mother creator, protectress of all humans as they cross the sea of life.

度母出现在佛教，耆那教里面，尤其是西藏的喇嘛教，作为一系列的陈列阵容；神秘的女神，创世之母，人类横过生命之海洋的女性保护者。