DS-CDMA HARQ with overlap FDE

Kazuki Takeda, Hiromichi Tomeba, Kazuaki Takeda, Fumiyuki Adachi

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


Turbo coded hybrid ARQ (HARQ) is known as one of the promising error control techniques for high speed wireless packet access. However, in a severe frequency-selective fading channel, the HARQ throughput performance significantly degrades for direct sequence code division multiple access (DS-CDMA) system using rake combining. This problem can be overcome by replacing the rake combining by the frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion. In a system with the conventional FDE, the guard interval (GI) is inserted to avoid the inter-block interference (IBI). The insertion of GI reduces the throughput. Recently, overlap FDE that requires no GI insertion was proposed. In this paper, we apply overlap FDE to HARQ and derive the MMSE-FDE weight for packet combining. Then, we evaluate the throughput performance of DS-CDMA HARQ with overlap FDE. We show that overlap FDE provides better throughput performance than both the rake combining and conventional FDE regardless of the degree of the channel frequency-selectivity.

Original languageEnglish
Pages (from-to)3189-3196
Number of pages8
JournalIEICE Transactions on Communications
Issue number11
Publication statusPublished - 2007
Externally publishedYes


  • HARQ
  • Overlap FDE

ASJC Scopus subject areas

  • Software
  • Computer Networks and Communications
  • Electrical and Electronic Engineering


Dive into the research topics of 'DS-CDMA HARQ with overlap FDE'. Together they form a unique fingerprint.

Cite this