幅度衰落 meaning in English
amplitude fading
Examples
- Lt is well anown that the multi ? ath effeet results in signal fading and intersymbol interference ( isd , wnich causes great difficulhes in pewces of transndssion in underwater acoushc cotnmnication . in this papef we used frequency diversity method to overcome the problem of signal fading , and used the frequency - hopping method to ebonate the isi caused by multi - path
水声信道多途特性引起的信号衰落和码间干扰是影响水下通信质量的主要因素，采用频率分集技术可以处理幅度衰落，而跳频技术则可以简单、有效地抗多途引起的码间干扰。 - 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。 - It has been proven that the spread spectrum technologies have good capabilities of overcoming isi in electromagnetic wireless channel . the feasibilities of their applications to underwater acoustic channel have been analyzed , the frequency hopping technology is chosen . instead of using time - frequency diversity , convolutional coding and viterbi decoding are employed to combat signal fading , consequently the bit - rate and bit - error - rate performance of the underwater acoustic voice communication system can be balanced and controlled
由于扩频技术在抗码间干扰方面具有优良的特性，因此在分析了各种扩频技术于本研究应用的可行性之后，确定了跳频技术作为具体实现方案；在克服幅度衰落方面，选用卷积编码和维特比译码方法来替代原有的分集技术以综合调节系统的通信速率与误码性能，达到差错可控的目的。 - With the characteristics of large ambient noise , very narrow bandwidth , low carrier frequency , great propagation latency and time - space - frequency variant multipath effect ( mpe ) , the stochastic ocean channel has demonstrated the greatest complexity and difficulty for underwater acoustic wireless communications . among them multipath effect ( mpe ) is the most difficult obstacle that results in signal fading and inter - symbol interference ( isi )
但是噪声高、带宽窄、载波频率低、传输时延大、多途径效应随时间?空间?频率变化等信道特性都会给有效、可靠的水声通信带来很大的麻烦，其中多途径效应是最主要的困扰因素，它会导致信号幅度衰落和码间干扰。