多普勒频移

• The relative motion between the base station and the mobile results in random frequency modulation due to different doppler shifts on each of the multi - path components , also called time selective fading
  由于基站与移动台之间的相对运动，每条路径都会有一个明显的多普勒频移，导致信道的随机频率调制，也称时间选择性衰落。
• Multi - path fading and doppler shift of wireless mobile channels would generate interference to signals , as a result , waveform of the received signal would be distorted , and channels would be interrupted if the interference is severe
  无线移动信道的多径衰落和多普勒频移会对信号产生干扰,导致接收信号波形失真,严重者会造成通信的中断。
• In this paper , we analyze the reason that it is difficult to process the doppler frequency shift signal generated by low velocity moving target and discuss the kalmus filter performances for low velocity moving target detection
  本文分析了低速目标的多普勒频移信号难以处理的原因，并讨论了kalmus滤波器（零速率波器）对低速运动目标的检测性能。
• Finally , by system simulation and actual test with satellite , the system that we designed meets with the demand for satellite communication , which can receive the information from leo satellite and control doppler frequency offset
  最后，经过系统仿真和实际的卫星通信测试，达到了与卫星进行数据传输的要求，接收到卫星信息，并实现了对多普勒频移的控制。
• The results of simulation testify that wigner - ville distribution is able to show the frequency shift of lfm signals in the pulse compression , and a good qualitative visualization of the effect of the doppler shift is obtained too
  仿真结果表明wigner - ville分布能够清晰的描绘线性调频信号在脉冲压缩过程中的频率变化，能够定性的分析多普勒频移所带来的影响。
• A new dsp algorithm for doppler frequency measurement is constructed in the second method , where the circuit configuration is simplified , the balanced i / q channels can be available and the time for digital signal processing is reduced
  在第二种方案中，提出了一种测量多普勒频移的数字信号处理算法，简化了硬件，获得了平衡的i q信道输出，缩短了dsp处理时间。
• 2 . doppler frequency shifting and curve fitting differential methods for measuring velocity are analyzed and compared . the least - squares curve fitting methods based on power functions and orthogonal functions are analyzed and compared
  2 .对测量速度的两种方法,多普勒频移法和曲线拟合微分法作了分析和比较;对以幂函数族和以正交函数族为基底的最小二乘曲线拟合法作了对比分析。
• Numerical results show that the ber performances of ideal mrc are the lower bounds on the ber performances of non - ideal mrc and deteriorate as the maximum doppler frequency increases or the snr of channel estimate decreases
  数值分析结果表明，非理想信道估计下最大比合并的误码率性能是以理想信道估计的结果为下界，并随着最大多普勒频移的增加或信道估计信噪比的减小而逐渐劣化。
• A cornstarch - water slurry was driven by a pulsatile pump through tubing to simulate the blood flow within the heart , and the tubing was cyclically moved by a piston to simulate the heart motion
  结果在模拟心脏运动作用下，原来的模拟血流波形已不存在，代之以模拟心脏运动和模拟血流按速度矢量相加规律所组成的复合波，而模拟心脏运动所产生的多普勒频移信号的振幅和频率都未改变且与上述血流信号并存于频谱中。
• The computer simulations show the validity of the models . 3 . joint estimation of the time delay and doppler frequency based on short - time fourier transform ( stft ) and time - frequency analysis are studied to estimate the parameters of the underwater target echo
  针对主动回波信号参量的估计问题，重点研究了利用短时傅立叶变换、时频分析进行时延和多普勒频移联合估计，进而进行目标距离和速度参数的估计。