Rate-Allocation Strategies for Closed-Loop MIMO-OFDM
نویسندگان
چکیده
A closed-loop MIMO-OFDM transmitter can exploit channel knowledge using eigenbeamforming to create MN parallel channels, where M is the number of antennas at both ends and N is the number of OFDM tones. We find that the penalty due to a flat-frequency constraint, which forces each tone to convey the same amount of information, becomes negligible as M grows. We propose low-complexity bit-allocation strategies by combining the flat-frequency constraint with previouslyreported spatial bit-allocation strategies [1]. A fixed (nonadaptive) allocation across space and frequency performs remarkably well with M as small as 4.
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