Performance Improvement by Frequency-Domain Interleaving for OFDM/TDM Using MMSE-FDE in a Wireless Channel

Haris GACANIN  Fumiyuki ADACHI  

IEICE TRANSACTIONS on Communications   Vol.E92-B   No.5   pp.1813-1817
Publication Date: 2009/05/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E92.B.1813
Print ISSN: 0916-8516
Type of Manuscript: Special Section LETTER (Special Section on Radio Access Techniques for 3G Evolution)
OFDM/TDM,  MMSE-FDE,  frequency-domain interleaving,  channel frequency-selectivity,  

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The use of frequency-domain interleaving on a frame-by-frame basis for orthogonal frequency division multiplexing (OFDM) combined with time division multiplexing (OFDM/TDM) is presented. In conventional OFDM, FDE is not designed to exploit the channel frequency-selectivity and consequently, the frequency diversity gain cannot be obtained. To further improve the bit error rate (BER) performance of conventional OFDM an interleaving technique may be applied, but FDE cannot be fully exploited. In this letter, the OFDM/TDM signal (i.e., several concatenated OFDM signals) frequency components are interleaved at the transmitter and then, minimum mean square error frequency-domain equalization (MMSE-FDE) is applied at the receiver to obtain a larger frequency diversity gain. It is shown that frequency-domain interleaving on a frame-by-frame basis for OFDM/TDM using MMSE-FDE achieves improved BER performance in comparison with conventional OFDM due to enhanced frequency diversity gain.