This paper presents a downlink performance analysis of a Layered Random Beamforming (LRB) - MIMO-OFDMA Physical Layer (PHY) with feedback reduction as applicable to future generation wireless communication systems. OFDMA is a popular multiple access candidate for future generation cellular communication systems which facilitates multi-user diversity by enabling multiple access in the frequency domain. LRB enables the exploitation of spatial multi-user diversity gain, spatial multiplexing capacity gain and layer spatial multi-user diversity gain, which is achieved by enabling the multiplex of data transmitted simultaneously to different destinations. Unlike a conventional beamforming system, an LRB system only requires effective signal to interference and noise ratios (ESINR) as feedback from every spatial layer of the MIMO channels and thus has potentially lower feedback requirements than a system which requires feedback of more detailed channel information. By combining the LRB technique with OFDMA, LRB-OFDMA can achieve an additional spectral multi-user diversity gain compared to the single carrier LRB system. However, in this case ESINR feedback on a per-sub-carrier basis is required in principle and the feedback requirements may thus increase substantially. This feedback requirement can be reduced by generating the feedback information on a cluster (group of sub-carriers) basis rather than on an individual sub-carrier basis. In this way, the system can exploit any correlation in the frequency response of the channel. The design of an LRB-OFDMA system is presented in this paper and the performance of the system is evaluated for different degrees of feedback reduction using various statistical channel models.
|Translated title of the contribution||Performance analysis of layered random beamforming OFMDA with feedback reduction|
|Title of host publication||IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC 2007), Athens|
|Publisher||Institute of Electrical and Electronics Engineers (IEEE)|
|Pages||1 - 5|
|Number of pages||5|
|Publication status||Published - 3 Sep 2007|
|Event||18th International Symposium on Personal, Indoor and Mobile Radio Communications (2007) - Athens, Greece|
Duration: 1 Sep 2007 → …
|Conference||18th International Symposium on Personal, Indoor and Mobile Radio Communications (2007)|
|Period||1/09/07 → …|
Bibliographical noteRose publication type: Conference contribution
Additional information: With accompanying conference poster
Sponsorship: The authors wish to acknowledge the financial support of Dorothy Hodgkin Postgraduate Awards (DHPA) and Toshiba
Research Europe Limited (TREL) and to thank Dr. Magnus Sandell of TREL for his technical input.
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- random beamforming