1) quaternary phase shift
四相相移
2) four-step phase-shifting
四步相移
1.
The four-step phase-shifting algorithm for quantitative analysis of the Ronchigram is derived from the wave theory of Ronchi test.
通过传统的朗契检测法的物理光学原理和条纹分析中的相移技术相结合，推导出了定量分析朗契图的四步相移算法，从而为朗契检测法定量进行像质评价提供了一种简单而有效的方法
3) quarternary phase shift
四相移
1.
Studied are the structure and operation principle,spectrum property,correlation property of OCDMA encoder/decoder based on quarternary phase shifted superstructure fiber Bragg grating(SSFBG) by using transmission matrix method.
利用传输矩阵法研究了四相移超结构光纤布拉格光栅(SSFBG)光码分多址(OCDMA)编/解码器的结构和工作原理、频谱特性、相关特性。
4) QDPSK
四相相对移相
1.
Based on analyzing the modulation and demodulation principle for QDPSK signal, an improved modulation solution for QDPSK signal based on FPGA is proposed.
在分析四相相对移相QDPSK信号调制解调原理的基础上,设计一种由FPGA实现的改进的数字化QDPSK信号调制系统,在信号的调制过程中将码元的调制波形分为稳定区和过渡区,并通过调用不同包络衰减函数的正弦函数样值序列来产生调制波形,该系统调制信号高频分量少,解码误码率较低。
5) QPSK
四相相移键控
1.
A new OCDM technology of QPSK coherent phase encoding in time domain for Tbit/s ultra-fast optic fiber transmission system is proposed according to family a of 4-phase sequences, which can improve the transmission rate and spectral efficiency greatly.
介绍了光码分复用(OCDM)的原理,分析比较了常用OCDM技术的优缺点,根据四相位序列中的A序列提出了用四相相移键控(QPSK)实现时域相干相位编码的OCDM新技术,并通过数值模拟计算选出了相关特性好的4个码组,用于实现Tbit/s超高速光纤传输实验系统,可大大提高传输速率及频带利用率。
2.
The technology of complete digital QPSK(Quaternary Phase Shift Keying) modulation and demodulation is suitable for the digital communication in the future for its flexibility and versatility.
数字信号的四相相移键控调制与解调技术以其灵活性和通用性而得到广泛的应用,符合未来数字通信技术发展的方向。
6) QPSK
四相移相键控
1.
In order to study the ambiguity function character of the QPSK radar signal to help the choice and design of the radar signals,the paper has built models by Simulink to simulate two different modulation ways that produce the QPSK signals,and then leads the signals\' data to the Matlab\'s workspace and plots the ambiguity diagram respectively.
为便于雷达信号的选择与设计,从研究四相移相键控(QPSK)雷达信号的模糊函数特性入手,通过Simulink建模和仿真2种不同的产生QPSK信号的调制方法,并将信号数据导入到Matlab的工作空间中,由Matlab分别画出其模糊函数图;指出并论证了与2路码长互素码速率相同的BPSK正交构成QPSK的调制方法相比,直接QPSK调制方法的优越性。
补充资料：四不相
1.即四不像。因形状奇特，在某些神话小说中被描写成有仙术的怪兽。
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条