TY - GEN
T1 - An adaptive limited feedback scheme for MIMO-OFDMA based on optimal stopping
AU - Chen, Jieying
AU - Berry, Randall A.
AU - Honig, Michael L.
PY - 2008
Y1 - 2008
N2 - We propose and analyze a limited feedback scheme for downlink MIMO-OFDMA. Our analysis explicitly accounts for the feedback overhead by assuming a time division duplex system in which all feedback and data transmission must occur with a coherence time. As the fraction of coherence time devoted to feedback increases, the base station can allocate resources more efficiently, but has less time available for data transmission. In the proposed scheme, the base-station sequentially receives feedback from the users and decides when to stop receiving additional feedback and begin data transmission. Each user feeds back their best codeword (beam) selected from a beam-forming codebook on each group of OFDM sub-channels, provided that the channel gain exceeds a given threshold. For a given feedback threshold, the optimal stopping rule used by the base station is derived. With this rule we show that the total throughput of this scheme scales linearly with the number of users, provided that the number of OFDM sub-channels also scales with fixed ratio. The effect of varying the coherence time and feedback rate is also characterized.
AB - We propose and analyze a limited feedback scheme for downlink MIMO-OFDMA. Our analysis explicitly accounts for the feedback overhead by assuming a time division duplex system in which all feedback and data transmission must occur with a coherence time. As the fraction of coherence time devoted to feedback increases, the base station can allocate resources more efficiently, but has less time available for data transmission. In the proposed scheme, the base-station sequentially receives feedback from the users and decides when to stop receiving additional feedback and begin data transmission. Each user feeds back their best codeword (beam) selected from a beam-forming codebook on each group of OFDM sub-channels, provided that the channel gain exceeds a given threshold. For a given feedback threshold, the optimal stopping rule used by the base station is derived. With this rule we show that the total throughput of this scheme scales linearly with the number of users, provided that the number of OFDM sub-channels also scales with fixed ratio. The effect of varying the coherence time and feedback rate is also characterized.
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U2 - 10.1109/ALLERTON.2008.4797547
DO - 10.1109/ALLERTON.2008.4797547
M3 - Conference contribution
AN - SCOPUS:64549130444
SN - 9781424429264
T3 - 46th Annual Allerton Conference on Communication, Control, and Computing
SP - 139
EP - 145
BT - 46th Annual Allerton Conference on Communication, Control, and Computing
T2 - 46th Annual Allerton Conference on Communication, Control, and Computing
Y2 - 24 September 2008 through 26 September 2008
ER -