Equalization for Infrared Wireless Systems Using OOK-CDMA

Hiroe YAMAGUCHI  Ryoko MATSUO  Tomoaki OHTSUKI  Iwao SASASE  

Publication
IEICE TRANSACTIONS on Communications   Vol.E85-B   No.10   pp.2292-2299
Publication Date: 2002/10/01
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Optical Wireless Communications
Keyword: 
indoor infrared wireless system,  OOK-CDMA,  equalizer,  

Full Text: PDF>>
Buy this Article




Summary: 
In this paper, we propose an equalizer for indoor infrared wireless systems using on-off keying code-division multiple-access (OOK-CDMA). The proposed equalizer has a decision-feedforward filter to mitigate the effects of inter symbol interference (ISI) at the previous chip position of the sampling instant. We evaluate the performance of indoor infrared wireless systems using OOK-CDMA with three kinds of equalizers: the decision-feedback qualizer (DFE), the feedforward equalizer (FE), and the proposed equalizer. To estimate the impulse response, we use the training sequence that alternates '1' and '0' sequentially. Among three kinds of equalizers, we show that the system with the proposed equalizer can achieve the best bit error rate (BER) performance at high bit rate, while the system with the FE achieves the best BER performance when the bit rate is low.