第1讲 FTN传输基础理论  

Overview of Faster-Than-Nyquist Basic Theory

作　　者：童莹[1] 郭明喜[2] 沈越泓[2] 段昊[2] 聂晟昱 

机构地区：[1]解放军理工大学通信工程学院研究生5队,江苏南京210007 [2]解放军理工大学通信工程学院

出　　处：《军事通信技术》2014年第4期78-83,共6页Journal of Military Communications Technology

基　　金：国家自然科学基金资助项目(61301157)

摘　　要：传统理论认为,带限信道中传输码元的速率不能大于Nyquist速率,否则将会引起严重的码间串扰(ISI),降低通信系统的可靠性。然而在1975年Mazo提出,在加性白高斯噪声信道中,若码元速率超过Nyquist速率在25%以内,则仍可保证误码性能不下降。基于上述研究背景,文章结合基带传输系统无ISI传输的条件,给出了Nyquist速率的定义,介绍了利用部分响应系统实现Nyquist速率传输的思路和方法,并从进一步提高数据速率的角度,引出了FTN传输的概念,说明了部分响应与FTN的联系和区别,最后在介绍了信号空间、欧氏距离和均衡的基础上,结合波形阐述了FTN传输的基本思想和技术特点。Traditional opinion holds that Inter-Symbol Interference（ISI） occurs when Symbol rate is faster than Nyquist rate, and degrades the system reliability performance in the communication. However, in 1975 Mazo put forward a new theory which holds that BER performance could not degrade as long as the Symbol rate is within 25 % faster than Nyquist rate. Based on the above background. In this paper, a digital baseband system model was explained, non-inter-symbol-interference formula obtained, and then Nyquist transmission rate was introduced, including the basic principle of partial response, which can be used to realize Nyquist rate. From the point of further improving the data rate, the concept of Faster-Than-Nyquist（FTN） transmission was introduced, and the difference and relationship between partial response and FTN were also stated. In order to better understand FTN technique, the concepts of signal space and equalization were also introduced, and then the basic idea and main characteristics of FTN were intuitively stated with its waveform.

关 键 词：奈奎斯特速率 码间串扰 超奈奎斯特速率 

分 类 号：TN911[电子电信—通信与信息系统]