J4 ›› 2010, Vol. 37 ›› Issue (5): 813-816+824.doi: 10.3969/j.issn.1001-2400.2010.05.007

• Original Articles • Previous Articles     Next Articles

Design and implementation of configurable  FFT/IFFT in the LTE system

LIU De-fu1;LEI Tian-min1;MA Zhuo2;LI Ying2;WANG Yang1   

  1. (1. School of Technical Physics, Xidian Univ., Xi'an  710071, China;
    2. State Key Lab. of Integrated Service Networks, Xidian Univ., Xi'an  710071, China)
  • Received:2009-08-14 Online:2010-10-20 Published:2010-10-11
  • Contact: LIU De-fu E-mail:defuruier@yahoo.cn

Abstract:

A design of the variable-point FFT/IFFT for non-2n is proposed in consideration of the characteristics of the variable-length and non-2n subcarriers in the 3GPP LTE system. A high speed and configurable FFT/IFFT is designed by using the mixed radix with radix-2, radix-3, and radix-4 based on the pipelined ping-pong architecture. It will save about  100kbits storage space since all the twiddle factors are stored in the same space and RAM is shared by I/O data after optimizing the address generation unit. Simulation results show that the design can satisfy the need of the FFT/IFFT for different bandwidths in a high-speed LTE system.

Key words: orthogonal frequency division multiplexing(OFDM), LTE, FFT/IFFT