Uplink pre-equalization using MMSE prediction for TDD/MC-CDMA systems

Yoshikazu Takei, Tomoaki Ohtsuki

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

4 Citations (Scopus)

Abstract

Recently, multi-carrier code-division multiple-access (MC-CDMA) has attracted much attention. To make smoothly connection with a base station (BS), time division duplex (TDD) systems using the reciprocity of uplink and downlink in the same frequency band is considered. If the coherence time is large compared with the duplexing time, TDD systems can provide the channel characteristics of uplink from that of downlink. Thus, the channel distortion can be compensated in advance as a pre-equalization at mobile terminals (MTs). The pre-equalization technique using zero-forcing equalization (ZFE) was proposed for the TDD/MC-CDMA system. The channel parameters obtained from the last pilot (LP) symbol in the downlink frame have the highest time correlations with the uplink channel parameters. Therefore, they can be used as the channel parameters of all the symbols in the following frame. However, when the coherence time is not so large compared with the duplexing time, it is expected that the system suffers from the channel mismatch by time-selective fading. In this paper, we propose a pre-equalization using MMSE channel prediction for TDD/MC-CDMA. As a derivation of the pre-equalization coefficients, we employ ZFE, Controlled Equalization (CE), and Minimum Mean Square Error Equalization (MMSEE). Simulation results show that the proposed channel prediction techniques are effective on time-selective fading channels.

Original languageEnglish
Title of host publication2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005
Pages291-295
Number of pages5
Publication statusPublished - 2005 Dec 1
Event2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005 - Berlin, Germany
Duration: 2005 Sep 112005 Sep 14

Publication series

NameIEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC
Volume1

Other

Other2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005
CountryGermany
CityBerlin
Period05/9/1105/9/14

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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    Takei, Y., & Ohtsuki, T. (2005). Uplink pre-equalization using MMSE prediction for TDD/MC-CDMA systems. In 2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005 (pp. 291-295). [1651445] (IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC; Vol. 1).