Low complexity radix-4 butterfly design for the soft-decision Viterbi decoder

  • Authors:
  • Chau Yun Hsu;Tsung Sheng Kuo;Yuan Hung Hsu

  • Affiliations:
  • Institute of Communication Engineering, Tatung University 40, Chungshan N.Rd., 3rd Sec., Taipei, Taiwan;Institute of Communication Engineering, Tatung University 40, Chungshan N.Rd., 3rd Sec., Taipei, Taiwan;Institute of Communication Engineering, Tatung University 40, Chungshan N.Rd., 3rd Sec., Taipei, Taiwan

  • Venue:
  • Microprocessors & Microsystems
  • Year:
  • 2007

Quantified Score

Hi-index 0.00

Visualization

Abstract

This study presents a new radix-4 butterfly design for Viterbi decoders. The branch symmetry of the proposed radix-4 butterfly is exploited to design a low-complexity radix-4 butterfly module to simplify the implementation of the soft-decision Viterbi decoder. By exploiting the branch symmetry, only a half of branch metrics need to be computed, while other metrics can be derived from the computed branches. Therefore, the branch metric computation of the radix-4 butterfly can be reduced by a factor of 2. Considering the convolutional code in the DAB system as an example, experimental results indicate that the proposed radix-4 butterfly design can reduce the number of FPGA slices of the radix-4 butterfly module by 24% over the conventional design.