A Time Division Multiple Access-Time Division Duplex combined with an Alternated Frequency Duplexer for Wireless Personal Communications

Katsuhiko KAWAZOE  Shuji KUBOTA  

Publication
IEICE TRANSACTIONS on Communications   Vol.E79-B   No.11   pp.1688-1695
Publication Date: 1996/11/25
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Mobile Communication
Keyword: 
TDMA,  TDD,  FDD,  fading,  diversity,  microcell,  

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Summary: 
An increase in the system capacity and maximum user bit rate is required for wireless multimedia communications that offer high speed signal transmission such as simultaneous voice and data transmission. This paper proposes a Time Division Multiple Access-Time Division Duplex method combined with an Alternated Frequency Duplexer (TDMA/TDD-AF) for TDMA based wireless personal communications. The newly proposed duplexing method uses the same frequency band and all time slots within a TDMA frame for both up-stream and down-stream transmission. This enables a two-fold increase in the number of time slots within a TDMA frame and the maximum user bit rate compared with the conventional TDMA/TDD method. Transmitter diversity is also applied to improve the transmission quality under multipath fading environments. The traffic performance of the proposed method is approximated theoretically compared with the conventional TDMA/TDD systems on the assumption that an infinite number of terminals are in a cell. The results indicate that the TDMA/TDD-AF method significantly improves the blocking probability when the system is asynchronized among adjacent cells and the number of usable carriers is high.