对要发送的序列进行上变频，上变频到21MHz后进行发送。-change the frequence uop to the one that suit for transmission,which here is 21MHz.

设计一个半带滤波器，将信号进行2倍内插后进行滤波。-design a half band filter. twice frequence and then filter.

关于分数频率复用(FFR)系统的C++程序仿真。分数频率复用技术是LTE系统中十分重要的分支。-This is code is the basic introduction of Fractional Frequence Reuse technique,which is a quite important branch of LTE communication system.