A mixed-radix design of DFT/IDFT in the uplink LTE system

摘要

In this paper, a mixed-radix Discrete Fourier Transformation (DFT) is proposed to compute 34 kinds of DFT / IDFT points in the uplink long term evolution (LTE) system. Large points DFT are decomposed into prime factors and computed through the small points DFT instead. By making use of the common factor of different points, twiddle factors can be shared to reduce the storage space obviously. In addition, the relatively high precision and low complexity are ensured through the block floating point algorithm. Compared with the traditional radix-2 FFT, the proposed algorithm has the advantages of low complexity, small storage space, and the short running time. At last, our design has been tested through matlab and the results are consistent with the theoretical value. Thus, it can be used as a solution in the follow-up implementations of hardware.