HARQ throughput performance of multicode DS-CDMA with MMSE turbo equalization

Kazuaki Takeda, Fumiyuki Adachi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

8 Citations (Scopus)

Abstract

Hybrid automatic repeat request (HARQ) is an indispensable technique for packet access. This is employed in high speed downlink packet access (HSDPA) using the orthogonal multicode direct sequence code division multiple access (DS-CDMA). As the data rate increases, the frequencyselectivity of the channel becomes severer and some equalization technique other than rake combining is necessary. The use of MMSE frequency-domain equalization (MMSE-FDE) can significantly improve the throughput performance. However, the residual inter-cbip-inference (ICI) after MMSE-FDE produces the orthogonality distortion among the spreading codes and the throughput performance is far from the theoretical lower bound. In this paper, we study an MMSE turbo equalization for HARQ using multicode DS-CDMA It is shown by computer simulation that MMSE turbo equalization can significantly improve the throughput performance. An E s /N 0 reduction of as much as 2.5∼3 dB from the no turbo equalization case is obtained for a throughput range of 2∼2.5 bit/s/Hz.

Original languageEnglish
Title of host publication2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring
Pages1603-1607
Number of pages5
DOIs
Publication statusPublished - 2007 Aug 2
Event2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring - Dublin, Ireland
Duration: 2007 Apr 222007 Apr 25

Publication series

NameIEEE Vehicular Technology Conference
ISSN (Print)1550-2252

Conference

Conference2007 IEEE 65th Vehicular Technology Conference - VTC2007-Spring
Country/TerritoryIreland
CityDublin
Period07/4/2207/4/25

Keywords

  • Component
  • DS-CDMA
  • Frequency-domain equalization
  • MMSE turbo equalization

ASJC Scopus subject areas

  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics

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