Providing CQI feedback to a transmitter station in a closed-loop MIMO system
First Claim
1. A method comprising:
- measuring, at a receiver station, channel qualities associated with receiving signals from a transmitter station for a first and a second spatial channel, the transmitter and receiver stations employing a closed-loop multiple-input multiple-output (MIMO) system;
selecting a first modulation coding scheme (MCS) entry among a plurality of ordered MCS entries, the first MCS entry identifying a first MCS for use by the transmitter station to transmit signals to the receiver station;
selecting, among the plurality of ordered MCS entries, a subset of lower ordered MCS entries relative to the first MCS entry;
selecting a second MCS entry from one of the selected subset of lower ordered MCS entries, the second MCS entry identifying a second MCS for use by the transmitter station to transmit signals to the receiver station;
determining a first channel Quality indicator (CQI) and a second CQI based at least in part on the measured channel qualities, wherein the first CQI directly indexes the first MCS entry in the ordered MCS entries, and the second CQI indirectly indexes the second MCS in the ordered MCS entries by indexing an MCS entry within the selected subset of lower ordered MCS entries relative to the indexed first MCS entry; and
transmitting from the receiver station to the transmitter station the first and the second CQI.
2 Assignments
0 Petitions
Accused Products
Abstract
Methods and apparatuses for reducing an amount of bandwidth required for feedback to a transmitter station in a closed-loop multiple-input multiple-output (MIMO) system are described herein. The methods may include initially measuring at a receiver station channel qualities associated with receiving signals from a transmitter station for a first and a second spatial channel, the transmitter and receiver stations employing a closed-loop MIMO system. The receiver station may then determine a first and a second channel quality indicator (CQI) based on the measured channel qualities and may then transmit to the transmitter station the first and the second CQI to directly and indirectly identify a first and a second modulation coding scheme (MCS) entry among a plurality of ordered MCS entries, respectively. The second MCS entry being one of a selected subset of lower ordered MCS entries relative to the first MCS entry. The transmitter station may selectively use the first and the second identified MCS to transmit signals to the receiver station over the first and the second spatial channel, respectively.
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Citations
18 Claims
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1. A method comprising:
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measuring, at a receiver station, channel qualities associated with receiving signals from a transmitter station for a first and a second spatial channel, the transmitter and receiver stations employing a closed-loop multiple-input multiple-output (MIMO) system; selecting a first modulation coding scheme (MCS) entry among a plurality of ordered MCS entries, the first MCS entry identifying a first MCS for use by the transmitter station to transmit signals to the receiver station; selecting, among the plurality of ordered MCS entries, a subset of lower ordered MCS entries relative to the first MCS entry; selecting a second MCS entry from one of the selected subset of lower ordered MCS entries, the second MCS entry identifying a second MCS for use by the transmitter station to transmit signals to the receiver station; determining a first channel Quality indicator (CQI) and a second CQI based at least in part on the measured channel qualities, wherein the first CQI directly indexes the first MCS entry in the ordered MCS entries, and the second CQI indirectly indexes the second MCS in the ordered MCS entries by indexing an MCS entry within the selected subset of lower ordered MCS entries relative to the indexed first MCS entry; and transmitting from the receiver station to the transmitter station the first and the second CQI. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 18)
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10. An apparatus comprising:
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one or more monitors to measure channel qualities associated with the apparatus receiving signals from a transmitter station for a first and a second spatial channel, the apparatus and the transmitter station employing a closed-loop multiple-input multiple-output (MIMO) system; a controller coupled to the one or more monitors, and configured to; select a first modulation coding scheme (MCS) entry among a plurality of ordered MCS entries, the first MCS entry identifying a first MCS for use by the transmitter station to transmit signals to the receiver station; select, among the plurality of ordered MCS entries, a subset of lower ordered MCS entries relative to the first MCS entry; select a second MCS entry from one of the selected subset of lower ordered MCS entries, the second MCS entry identifying a second MCS for use by the transmitter station to transmit signals to the receiver station; and determine a first and a second channel quality indicator (CQI) based at least in part on the measured channel qualities, wherein the first CQI directly indexes the first MCS entry in the ordered MCS entries, and the second CQI indirectly indexes the second MCS in the ordered MCS entries by indexing an MCS entry within the selected subset of lower ordered MCS entries relative to the indexed first MCS entry; and a transmitter configured to transmit to the transmitter station the first and the second CQI. - View Dependent Claims (11, 12, 13, 14)
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15. A system comprising:
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a plurality of omnidirectional antennas; a processor; and a communication chipset coupled to the antennas and the processor, and configured to; receive data signals from a transmitter station; measure channel qualities associated with the received data signals; select a first modulation coding scheme (MCS) entry among a plurality of ordered MCS entries, the first MCS entry correspondingly identifying a first MCS for use by the transmitter station to transmit signals to the receiver station; select, among the plurality of ordered MCS entries, a subset of lower ordered MCS entries relative to the first MCS entry; select a second MCS entry from one of the selected subset of lower ordered MCS entries, the second MCS entry correspondingly identifying a second MCS for use by the transmitter station to transmit signals to the receiver station; determine a first and a second channel quality indicator (CQI) based at least in part on the measured channel qualities, wherein the first CQI directly indexes the first MCS entry in the ordered MCS entries, and the second CQI indirectly indexes the second MCS in the ordered MCS entries by indexing an MCS entry within the selected subset of lower ordered MCS entries relative to the indexed first MCS entry; and transmit to the transmitter station the first and the second CQI. - View Dependent Claims (16, 17)
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Specification