频移键控

• This paper puts forward the signals transmission method combining the msk technique with the radio technique of frequency modulated ultra - short waves
  文章提出了采用最小频移键控( msk )技术与调频超短波无线电技术相结合传输信号的方法。
• The central computer can communicate with any single chip computer to acquire temperature data . 3 . modem module the modem module enable the system communicating through long distance
  远程通信模块主要由单片的频移键控调制解调器构成，把数字信号调制成不同频率的模拟信号进行远距离传输。
• Abstract : the performances and characteristiss of the zero crossing digital demodulation is ana lysed through the comparison of various ways of fsk signal digital demodulation . and ideal conclusion is reached
  文摘:对各种频移键控信号的数字解调方法进行了研究和比较，并重点分析了零交点数字解调法的性能特征，最后得出了一个最佳结论
• In the future , we will increase the number of the frequency - hopped sub - bands . it will solve the inter - symbol interference ( isi ) perfectly . then the system will be used on the test out of labs
  后续的工作只要把十六进制改为八进制（此工作不难）的数字频移键控传输系统，借以提高跳频的子带数目，即增加跳频点，可期适于海上的应用。
• Fsk / psk radar signal is the signal with both fsk and psk modulation at one time . it is with large bandwidth time product ( bt ) , thumbtack - like ambiguity function and well ability of anti - emi . the fsk / psk signals of which the frequency - hopping and bi - phase sequences were randomly chosen often have high sidelobe level
  Fsk / psk信号是同时进行频移键控( fsk )和相移键控( psk )调制的信号,该信号具有大时带宽积( bt )和高分辨特性,并具有“图钉型”模糊图结构、低截获概率( lpi )特性和较好的抗干扰能力,受到了广泛的重视。
• So the acoustic wave is the only practical solution in this channel . an underwater acoustic channel is characterized as a multi - path channel due to signal reflections from the surface and the bottom of the sea . because of wave motion , the signal multi - path components undergo time - varying propagation delays that result in signal fading and inter - symbol interference ( isi )
  本文从分析浅海水声信道的传输特性入手，针对多途径效应引起的幅度衰落及码间干扰问题，提出一种适用于水声e - mail通信的十六进制(或八进制)数字频移键控( mfsk )传输系统。
• This thesis analyzed the error performance of mfsk and mpsk modulator in hf with optimal receiver , studied the shortcoming and strongpoint of several typical short - wave data transmission systems and their performance over fading and intersymbol interference channels . the theory and key technical of adaptive modem is discussed . in the last , an efficient modulation scheme - block coded modulation is introduced into hf radio systems to improve the efficiency of hf data transmission , this paper also proposes a hf data transmission system scheme composed of a block coded modulator and a decision feedback type adaptive equalizer
  本文在对短波数传两种常见调制方式fsk及psk最佳解调性能分析的基础上，讨论了几种采用典型调制技术的短波数传系统(如时频调制、多进制频移键控慢跳频、 chess系统)原理、优缺点以及抗衰落和抗符号间干扰的性能；分析了自适应串行数传系统抗短波信道衰落和多径干扰的原理、关键技术；在本文的最后引入一种有望解决短波数传系统低效率状况的调制方式bcm -分组编码调制，给出了一个采用bcm技术与自适应均衡技术相结合的短波数传系统方案，并通过计算机模拟进行了初部验证。
• This dissertation , basing on simulation , makes a deep research on simulating signal of gmsk ( gaussian filtered minimun frequency shift keying ) baseband modulation and demodulation in ais ( automatic identification system ) equipment . the technology related in the following makes the modulation and demodulation of baseband signal into realization by ti dsp , at the same time , provides a key technique to develop ais system inland
  本文着重对自动识别系统( ais - automaticidentificationsystem )设备的高斯滤波最小频移键控( gmsk - gaussianfilteredminimunfrequencyshiftkeying )基带调制解调信号进行了仿真研究,并在仿真的基础上,在ti的dsp上实现了基带信号的调制解调,为国内研制ais系统储备了关键技术。