广义频分复用与正交频分复用的比较

The comparison of generalized frequency division multiplexing and orthogonal frequency division multiplexing

广义频分复用是德国5GNOW项目组提出的一种5G物理层解决方案,采用的是非矩形脉冲成型。首先对GFDM基本模型进行研究,指出其本质是DFT滤波器组,然后分别用DFT滤波器组实现OFDM和GFDM多载波调制系统,分析三者间的联系与区别,突出循环卷积降低GFDM计算复杂度的特点。从CP加入方式和原型滤波器两个方面对GFDM和OFDM进行比较,指出GFDM使用更少的CP,提高了频谱效率。最后通过实验仿真,对二者的原型滤波器频域响应性能和SER性能进行比较,强调非矩形滤波器有更好的频域响应性能,GFDM的SER性能较差是因为放弃了子载波的严格正交条件,导致子载波间干扰增大。

Generalized frequency division multiplexing is a kind of the physical layer solution scheme of the fifth generation mobile communication ,which was brought up by the group of 5GNOW in German. The paper first studied the basic model of GFDM, and pointed out that its essence is DFT filter bank. After that, GFDM and OFDM are both implemented by DFF filter bank, and then their features are compared, from two aspects of cyclic prefix and prototype filter, leading to a conclusion that GFDM uses less CP, improving the spectral efficiency. Lastly, the performance simulation results in MATLAB were presented, to compare the prototype filter frequency response and system SER performances, and the reasons of performance gap were given because the condition of subcarriers strictly orthogonal was given up, which increased the inter-subcarrier interference.