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2006
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Using Unclaimed Sub-Carriers in Opportunistic OFDMA Systems

8 years 11 months ago
Using Unclaimed Sub-Carriers in Opportunistic OFDMA Systems
Abstract— In this paper, we consider the unclaimed subcarriers that no user feeds back in an opportunistic OFDMA system with a per sub-carrier power constraint. Unclaimed subcarriers appear in OFDMA systems with reduced feedback, where the users concentrate the feedback on the sub-carriers with good channel quality. Here we propose and evaluate two ways to use these sub-carriers to improve the system performance. One approach is to transmit pilots symbols on the unclaimed subcarriers. A second approach is to schedule users based on their feedback about adjacent sub-carriers. Simulation results show that for low to moderate channel rms delay spread, it is more advantageous to transmit data on unclaimed sub-carriers, even at a low rate, than to use them for additional pilot symbols. For high delay spreads however, transmitting pilots on the unclaimed sub-carriers gives higher system throughput.
Patrick Svedman, Leonard J. Cimini Jr., Björn
Added 12 Jun 2010
Updated 12 Jun 2010
Type Conference
Year 2006
Where VTC
Authors Patrick Svedman, Leonard J. Cimini Jr., Björn E. Ottersten
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