The maximum Doppler shift in some typical non-GEO satellite channels are figured out.
计算出了几种典型非静止轨道卫星信道的最大多普勒频移。
Time-selective Rayleigh fading of channels is caused by Doppler shift and carrier frequency offset.
接收端的高速运动或者载频的偏移,会引起信道的时间选择性衰落。
Using this method, the synchronized PN code phase and approximation value of Doppler shift are got.
该捕获方法在捕获到同步长周期伪码的同时,也得到了多普勒频偏值的近似值。
Thus, the Doppler shift compensation is implemented only or mainly in good enough channel conditions.
因此,可以只在或主要在信道状况足够好的情况下才进行多普勒频移补偿。
Experimental results show that this method has advantages in achieving the Doppler shift of the satellite tracking.
实验表明,此方法在实现对卫星多普勒频偏跟踪中具有更大的优越性。
The formulas of Doppler shift due to the reflected signal and that travelling through the ionosphere are thus derived.
在此基础上得到电离层反射信号的多普勒频移公式以及穿过电离层的信号的多普勒频移公式。
DTMF has perfect anti-interference and some anti-Doppler shift ability and is widely used for low rate communication in audio channel.
DT MF信号具有优良的抗干扰性能和一定的抗多普勒频移的能力,广泛应用于语音信道的低速数据通信。
But both of them are sensitive to carrier frequency shift, further, they have comparative BER under AWGN and Doppler shift environment.
但两者都对载波频率偏移敏感,且在AWGN和多普勒频移环境下表现相当。
Doppler shift is unavoidable in underwater acoustic communications because of relative moving between the transmitter and the receiver.
在水声通信中,由于发射和接收平台之间的相对运动,多普勒频移是无法避免的。
A general formula of relativistic Doppler shift is obtained from Lorentz transformation, and the supersonic motion is discussed as well.
利用洛伦兹变换导出了相对论性的多普勒颇移的普遍公式,并且讨论了波源的超音速运动情况。
There is provided a Doppler type ultrasonic flowmeter (1) for measuring a flow rate of a fluid (10) by using an ultrasonic Doppler shift.
提供了一种通过利用超声波多普勒频移来测量流体(10)的流速的多普勒型超声波流量计(1)。
In this paper, with Rayleigh fading the random characteristics of multipath time delay and Doppler shift in HF ionospheric channels is discussed.
本文在瑞利衰落模型下,研究了高频电离层信道中多径时延与多普勒频移的随机特性。
High dynamic environment may cause a large Doppler shift, thus the general GPS receiver is difficult to work reliably without outside assistance.
高动态环境会造成较大的多普勒频移,这使得一般的GPS接收机在没有外界辅助的情况下难以可靠工作。
In the satellite navigation and positioning system, Doppler shift is one of the key problems that may degrade the performance of the satellite receiver.
在卫星导航定位系统中,多普勒频率偏移是影响接收机性能的关键因素之一。
A biological recognition method by feature detection of human body on the move was presented, and the mathematical model of Doppler shift was established.
根据生物的生命体行为特征,提出一种新的生物识别方法,并建立了多普勒频移数学模型。
We report the Doppler shift of Na spectroscopy changing with the slow wave factor in a slow wave microwave field the reason of the phenomenon is discussed.
报道了在慢波场中原子波谱多普勒频移随微波慢波系数的变化,并讨论产生这种现象的原因。
Compared with normal mobile communications environment, the most prominent problem of high mobility environment is the impact of Doppler shift on communication.
与普通的移动通信环境相比,高速移动环境最突出的问题是多普勒频移对通信产生的影响。
This paper has discussed the way of probing Doppler shift signal based on crossed phase detecting method in detail and introduced each function circuits briefly.
本文详细的论述了依据正交相位检测法提取多普勒频移信号的方法,并对各部分实现电路作一简要的介绍。
By calculating the Doppler shift and its uncertainty in the signal covering area, the relation between Doppler shift and the position of the receiver is obtained.
通过对地面卫星信号覆盖区内的多普勒频率偏移及不确定性范围的计算,给出了卫星导航系统信号的多普勒频率偏移与接收机位置之间的关系。
The channel of LEO satellite is different from wireless channels on the ground. Low SNR and large Doppler shift are the two characteristic of LEO satellite channel.
低轨卫星的信道与地面无线信道具有不同的特点,低信噪比与大多普勒频移是低轨卫星信道的两个显著特征。
The acquisition performance of the system had been analyzed in detail with phase error of PN sequences, Doppler shift and background noise taken into consideration.
在综合考虑伪码相位误差,多普勒频移和噪声干扰的基础上,详细分析了系统的捕获性能。
This paper researches several comb waveforms on their transmitting efficiencies, resolutions in range and reverberation suppression properties based on Doppler shift.
研究了若干种主动声纳梳状谱信号的发射效率、测量精度以及基于多普勒的抗混响性能。
Then a new method of computing Doppler shift is presented, in which the variation of link length is regarded as the relative velocity between satellite and earth station.
随后给出了一种以链路距离变化率作为相对速度来计算多普勒频移的新方法。
When there is faint Doppler echo in noise, the system output is intermittent chaotic, and the Doppler shift can be obtained accurately by calculating the interval of chaotic state.
当噪声中含有微弱的多普勒回波时,通过理论分析可知系统输出为阵发混沌状态,且可根据混沌状态的间隔周期较准确地求出回波信号的多普勒频移。
Their main function is to simulate the satellite signal from the really satellite on the satellite orbit through changing code phase, Doppler shift, carrier and signal-to-noise ratio.
其主要功能就是通过改变码相位、多普勒频移、载波和信噪比来模拟卫星轨道上真实卫星发射的信号。
As Doppler shift signal can significantly reflect the speed of flow, the abstracting of Doppler shift signal is the key of blood flow speed testing in a ultrasonic blood flow detector.
超声血流仪实现其测量血流速度的关键是多普勒频移信号的提取,多普勒频移信号是血流速度的真实反映。
The measurements of HF Doppler shift in the ionosphere have long been a powerful tool in monitoring the ionospheric disturbances due to its features of continuity in time and simplicity.
由于地面电离层多普勒频率偏移测量具有时间连续、设备相对简便等固有特征,它特别适合于扰动监测。
Using two-dimensional signal vectors, the process of Doppler shift modulation and demodulation is analyzed, and a signal processing method for extracting flow speed information is derived.
如何测量回波的多普勒频移,实现测流速的目的。 文中从二维信号矢量的角度分析了多普勒频移调制和解调的过程,推导出提取速度信息的信号处理方法。
The frequency of the self-mixing interference signal is acquired by time-frequency analysis, and this frequency is equal to the Doppler shift, so the velocity of external object is gained easily.
该方法通过时频分析获得自混合信号频率随时间的变化,利用激光与外部物体相互作用后的多普勒频移与信号频率相等的关系,非常方便的获得了外部运动物体的速度历史信息。
The frequency of the self-mixing interference signal is acquired by time-frequency analysis, and this frequency is equal to the Doppler shift, so the velocity of external object is gained easily.
该方法通过时频分析获得自混合信号频率随时间的变化,利用激光与外部物体相互作用后的多普勒频移与信号频率相等的关系,非常方便的获得了外部运动物体的速度历史信息。
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