以超Nyquist码元速率传输时，会引起符号间干扰（ISI），传统理论认为这必然导致通信系统性能下降。1975年Mazo指出二进制码元极限传输速率只要不超过Nyquist速率的24.7%，尽管存在ISI，但信号最小欧氏距离没有变化，误码性能同样不受影响；2009年Rusek 等人将Mazo思想推广至多载波系统，研究证实：在误码性能不变情况下，系统频带利用率可比正交频分复用系统提高近一倍。尽管目前超Nyquist传输在信号设计及接收理论与方法等方面还不完善，但它的出现为高速通信及其传输理论提供了崭新的视角和方法，具有重要的理论及现实意义。. 本项目拟在超Nyquist码元传输速率下：1）研究最佳信号设计理论与方法；2）研究信号的最佳接收理论，并探索低复杂度接收机结构；3）推广到衰落信道，分析论证其可行性，以推进新型高效通信体制的探究。

Inter-symbol interference(ISI) will be caused when Faster-Than-Nyquist(FTN) signaling is applied, and it will degrade the system performance according to the traditional communication theory. In 1975, Mazo told us that system performance will not be degraded as long as the transmission rate is not beyond 24.7% faster than the Nyquist rate, because the minimum euclidean distance is not changed though ISI exists. In 2009, Rusek extended Mazo's idea of FTN to multicarrier system, and showed that the system spectral efficiency will be increased to two times of OFDM system while keep the same performance. Although FTN signaling and receive theroy are not thoroughly investigated, its concept provides a new viewpoint for high speed communication and transmission. So there will be significant practical and theoretical meaning. . The following contents about FTN transmission will be covered in this project. Firstly, we will investigate the optimal signal designing theory and method of FTN transmission system. Then the optimal receive theory and low complexity receiver framework will be investigated. Lastly, we will extend FTN technology to the fading channel and analyze the feasibility, to promote the reasearch of new style high spectral communication system.