查询词典 signal noise ratio

Firstly, the Signal Noise Ratio characteristic of matched filter despread symbol and the distribution of coherent phase estimation error are derived. Secondly, the exact integration formula of BER for fading channel is presented, moreover, by using the Maclaurin series expansion of MPSK conditional Symbol Error Rate, the simplified BER approximations for BPSK and QPSK are derived over AWGN, Nakagami-m fading and Rayleigh fading channel.

首先推导了匹配滤波解扩符号的信噪比特性和相干相位估计误差的分布；然后给出了衰落信道中误比特率的精确积分式，并利用MPSK条件误符号率的麦克劳林级数形式，推导了AWGN，Nakagami-m衰落和瑞利衰落信道中BPSK，QPSK误比特率的简化逼近式。

The maximum likelihood estimator approach is an important one in frequency estimation domain. This approach has the merit such as exhibiting best performance and requiring minimum threshold of signal noise ratio in calculation.

最大似然频率估计法是该领域中的一种重要的研究方法；该方法具有估计结果准确，计算所要求的信噪比门限值低等特点。

This paper is based on the algorithm of wave field reconstruction from the rate of the displacement spectrum of horizontal radial component of P wave to its vertical component.The observed data are selected from 4 teleseismic records of different depth at the Yichang Station with a good signal-noise ratio.

在远场正演计算的基础上，运用30°～90°的四个不同深源远震记录波形，通过试错法选取台站下方的结构，借助波场反向重建算法，反演确定宜昌台站下方的速度结构。

Using CHAMP observational data samples, the profiles of atmospheric bending, refractivity, pressure, and temperature were retrieved in turn by the series of signal noise ratio.

利用CHAMP卫星的GPS掩星观测资料，通过观测信噪比序列进行了大气弯曲角、大气折射率、大气压、温度剖面的反演计算；并与相位反演结果进行了比较和讨论。

When compared with conventional mathematical morphology Top-hat algorithm, several groups of experimental results demonstrate that the presented algorithm can suppress background effectively and the signal-noise ratio and contrast of image is improved efficiently.

与数学形态学Top-hat算法比较，实验结果表明本文所提算法能有效地抑制图像背景，从而较好地提高图像的信噪比和对比度。

Laser Doppler Velocimeter is adapted to measure the velocity distribution of the flow field. A new forward-scattering setup is adapted to improve the signal noise ratio which is reduced by the flame. Distribution of the velocity was measured.

介绍了激光多普勒测速方法及其在火焰测量中的特殊应用技术，针对燃烧中多普勒信号信噪比低的特点，建立了新的前向散射系统，取得了良好的效果。

In seismic data processing, people generally deem that signal/noise ratio im-provement and resolution improvement are very contradictious each other.

引言在地球物理数据处理中，提高地震记录的信噪比及分辨率是两大主要手段。

The Pick-pick Signal Noise Ratio PSNR or Mean Square Error MSE does not conform to subjective psychological sensation, while subjective assessment is usually inexactly and has subjectivity.

通常使用的峰—峰信噪比或均方误差与主观感觉并不相符，而主观评价又存在主观性和不确定性，其结果往往因人而异。

In consideration of the in-pulse phase modulation and Doppler frequency rate-of-change's subtleness, a fast and accurate algorithm is proposed. The influence to parameter estimation with phase modulation is dismissed by time domain correlation between neighboring pulses. Signal noise ratio is increased by frequency domain accumulation.

该文针对信号脉内相位调制和多普勒频率变化率信息非常微弱的特点，提出了一种快速高精度估计算法，通过相邻脉冲间的时域相关消除了相位调制对参数估计的影响，频域积累增强了信噪比，利用脉冲间的相参特性进行频谱相关消除了相位模糊，并放大了多普勒频率变化率信息。

How to improve the signal-noise-ratio of the received thermo-acoustic signals in terms that the irradiating microwave power should be decrease possibly is the keystone of a successful system.

如何在减小激励微波功率的前提下，尽量提高热致超声波的信噪比是这一系统的成败关键。

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％。