Antenna and Multi-Carrier Combined Diversity System

Hideyuki TAKAHASHI  Masao NAKAGAWA  

Publication
IEICE TRANSACTIONS on Communications   Vol.E79-B   No.9   pp.1221-1226
Publication Date: 1996/09/25
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Personal Communications)
Category: Antenna and diversity techniques
Keyword: 
multi-carrier modulation,  TDD system,  pre-diversity,  

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Summary: 
An antenna and multi-carrier combined diversity system using Time Division Duplex (TDD) is proposed to combat with multi-path channel problem which produces frequency-selective fading and degrades the quality of signal transimission. So far multi-carrier modulation technique has been studied to solve this problem. On the other hand, TDD method has been studied to use a transmitter antenna diversity as pre-diversity against flat fading (non-selective fading). Our proposed system merges these two methods in a micro-cellular system as follows. On the reverse link, the base station can select the best combination between the carriers and antennas after receiving the multi-carrier signal from the mobile station. On the forward link, the same combination selected on the reverse link can be used to send the signal from the base station with multi-antenna to the mobile station with a single antenna and produces pre-diversity (transmitter diversity) effect which can reduce the complexity at the mobile station. The pre-diversity must be based on TDD function because the channel has to be observed before the signal transimission. By computer simulations we find that our proposed system can achieve far better performance than conventional systems.