中文摘要：

超奈奎斯特（FTN,faster-than-Nyquist）传输技术作为一种能够有效提高系统频谱利用率的手段，受到了广泛的关注。针对该技术在信号检测中所具有的检测复杂度高的缺陷，提出一种基于多层叠加传输的FTN传输系统。通过理论推导给出了其每层最佳编码方案的选择依据，并通过仿真证明在每一层码率与功率同时变化的性能优于仅功率发生变化的情形，仿真结果同时表明在脉冲成形函数的滚降系数不为0的条件下，该系统的性能优于级联了更大星座的正交传输系统的性能。

英文摘要：

Faster-than-Nyquist(FTN)signaling technique has received much attention recently as an effective way of enhancing the spectral efficiency.In order to reduce the detection complexity for FTN signals,a multi-layer superposition transmission approach was present.In addition,how to calculate upper bounds on the highest information transmission rate was shown and how to choose suitable component codes was suggested.Numerical results show that the system with different code rates and power on each layer outperforms the system with only power variance on each layer,meanwhile results also imply that given the roll-off factor of the pulse shaping function is not zero,the proposed system is superior to the orthogonal system with a higher modulation format.