Research Article
Closed-Loop Extended Orthogonal Space Frequency Block Coding Techniques for OFDM Based Broadband Wireless Access Systems
@INPROCEEDINGS{10.1109/BROADNETS.2008.4769120, author={NASRELDIN Eltayeb and Shakiru Kassim and Jonathon Chambers}, title={Closed-Loop Extended Orthogonal Space Frequency Block Coding Techniques for OFDM Based Broadband Wireless Access Systems}, proceedings={5th International ICST Conference on Broadband Communications, Networks, and Systems}, publisher={IEEE}, proceedings_a={BROADNETS}, year={2010}, month={5}, keywords={Closed-loop (EO-SFBCs) Phase rotation array gain diversity gain coding gain.}, doi={10.1109/BROADNETS.2008.4769120} }- NASRELDIN Eltayeb
Shakiru Kassim
Jonathon Chambers
Year: 2010
Closed-Loop Extended Orthogonal Space Frequency Block Coding Techniques for OFDM Based Broadband Wireless Access Systems
BROADNETS
IEEE
DOI: 10.1109/BROADNETS.2008.4769120
Abstract
A simple extended orthogonal space-frequency coded multiple input single output (MISO) orthogonal frequency division multiplexing (OFDM) transmitter diversity technique for wireless communications over frequency selective fading channels is presented. The proposed technique utilizes OFDM to transform frequency selective fading channels into multiple flat fading sub-channels on which space-frequency coding is applied. A four-branch transmitter diversity system is implemented without bandwidth expansion and with only one receive antenna. The associated simulations verify that the four-branch transmitter diversity scheme achieves a significant improvement in average biterror rate (BER) performance. The proposed scheme also outperforms the previously reported scheme due to Yu, Keroueden, and Yuan with only single phase feedback, and that improvement is retained with quantized feedback. Since the angle feedback is on a per tone basis, the feedback information would be too large for any practical OFDM system. However, we adopt a method which exploits the correlation among the feedback terms for the subcarriers, i.e. a group based quantization technique to reduce the feedback overhead significantly, rendering this scheme attractive to broadband wireless access systems. The performance improvement of convolutionally concatenated space-frequency block coding (CCSBC) schemes is also investigated.