Ecole d'ingénieur et centre de recherche en télécommunications

Alamouti-based space-frequency coding for OFDM

Hutter, Andreas A;Mekrazi, Selim;Getu, Beza N;Platbrood, Fanny

Wireless personal communications, Volume 35 N°1-2, October 2005

We investigate space-frequency block coding for OFDM systems with multiple transmit antennas, where coding is applied in the frequency domain (OFDM carriers) rather than in the time domain (OFDM symbols). In particular we consider Alamouti's code, which was shown to be the optimum block code for two transmit antennas and time domain coding. We show that the standard decoding algorithm results in significant performance degradation depending on the frequency-selective nature of the transmission channels, such that a low coherence bandwidth results in a huge degradation. The optimum decoding algorithm that alleviates this problem is the maximum-likelihood decoder for joint symbol detection. We present a performance analysis for the investigated space-frequency decoders in terms of the achievable BER results. Furthermore we compare space-time and space-frequency coding and discuss the respective advantages and drawbacks of the different decoding algorithms in terms of their complexity. It should be noted that for the space-time approach we introduce the so-called matched-filter receiver, which shows significantly lower complexity compared to the maximum-likelihood decoder known from literature. The HIPERMAN system serves as an example OFDM system for quantitative comparisons.

Document Doi Bibtex

Mots Clés:Space-frequency coding;joint maximum-likelihood detection/decoding;transmit diversity;OFDM
Type:Journal
Langue:English
Date:
Département:Communications Mobiles
Eurecom ref:1879
Copyright: © Springer. Personal use of this material is permitted. The definitive version of this paper was published in Wireless personal communications, Volume 35 N°1-2, October 2005 and is available at : http://dx.doi.org/10.1007/s11277-005-8747-5
Bibtex: @article{EURECOM+1879, doi = {http://dx.doi.org/10.1007/s11277-005-8747-5}, year = {2005}, month = {10}, title = {{A}lamouti-based space-frequency coding for {OFDM}}, author = {{H}utter, {A}ndreas {A} and {M}ekrazi, {S}elim and {G}etu, {B}eza {N} and {P}latbrood, {F}anny}, journal = {{W}ireless personal communications, {V}olume 35 {N}°1-2, {O}ctober 2005}, url = {http://www.eurecom.fr/publication/1879} }