基于Intel AVX2的LTE DFT和IDFT快速算法

The fast algorithm of LTE IDFT based on GPP platform

通用处理器(GPP,General Purpose Processor)技术的快速发展,为LTE基带信号实时处理提供了一条新的途径。在LTE系统中,DFT和IDFT分别是手机上行发送和基站上行接收中的重要模块。根据3GPP协议,LTE DFT和IDFT处理点数是复合数,文章通过混合基算法以取代直接计算算法,并充分利用GPP平台大存储量的优势及Intel AVX2指令进行并行计算能力,最终使得该算法实现平均每处理1点仅耗时2个cycles,接近FPGA硬件处理性能,满足了LTE系统的实时性要求。经验证,基于GPP平台的DFT和IDFT模块运行结果正确,并且耗时极短。

The rapid development of technology of general-purpose processor GPP provides a new way for us to process LTE baseband signal in real time. In LTE system, transform DFT and IDFT directly has much time complexity. While considering the number of DFT and IDFT points is composite number in LTE system, so mixed radix IDFT is introduced to reduce computing efforts. And the algorithm is further improved according to the characteristics of GPP platform. The implementation of this al- gorithm adequately takes advantage of the GPP platform＇s large storage capacity, Intel AVX2 （Advanced Vector Extensions 2） parallel processing technology, which satisfies the real-time requirements of the LTE system. Experiment shows that the algor- ithm on the GPP platform result is correct, and uses a very short running time.