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

• 研究论文 • 上一篇    下一篇

LTE系统中可配置FFT/IFFT的设计与实现

刘德福1;雷天民1;马卓2;李颖2;王旸1   

  1. (1. 西安电子科技大学 技术物理学院,陕西 西安  710071;
    2. 西安电子科技大学 综合业务网理论及关键技术国家重点实验室,陕西 西安  710071)
  • 收稿日期:2009-08-14 出版日期:2010-10-20 发布日期:2010-10-11
  • 通讯作者: 刘德福
  • 作者简介:刘德福(1983-),男,西安电子科技大学硕士研究生,E-mail: defuruier@yahoo.cn.
  • 基金资助:

    国家863计划资助项目(2007AA01Z215)

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

摘要:

针对3GPP长期演进(LTE)系统中载波数目可变以及存在非2n点的特点,提出了一种点数可变、支持非2n点的快速傅里叶变换/逆变换(FFT/IFFT)设计方案.通过采用流水线乒乓结构,利用基2、基3、基4混合基结构实现了高速可配置的FFT/IFFT.将旋转因子统一存储,同时对地址生成单元进行优化,使输入、输出数据共用RAM,可以节约100kbit左右的存储空间.仿真和综合结果表明,该设计方案满足LTE高速系统中各种带宽下FFT/IFFT的要求.

关键词: 正交频分复用, 长期演进, 快速傅里叶变换/逆变换

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

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