Systems and methods of encoding using a reduced codebook with adaptive resetting
AssigneeApple Inc.
InventorsHosein Nikopourdeilami, Jun Yuan, Mo-Han Fong, Mohammadhadi Baligh
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Abstract
To feedback MIMO channel conditions, a codeword from a codebook is selected. To reduce signalling, the codewords are organized into codeword subsets. The receiver signals an index of a codeword into a current codeword subset previously made known to the transmitter. The current codeword subset is adaptively selected based on a threshold criterion. For example, if the best codeword from the current codeword subset is not sufficiently similar to the best codeword in the full codebook, a switch in the codeword subset is made.
Claims20
A method comprising:
- in respect of a plurality of codewords of a full codebook and a plurality of codeword subsets, each codeword subset containing a respective plurality of the codewords of the full codebook, repeatedly:
- determining a best codeword from the full codebook;
- adaptively selecting a codeword subset of the plurality of codeword subsets to be a current codeword subset by selecting, based on a threshold criterion, between a) the most recently selected current codeword subset and b) another codeword subset that contains the best codeword from the full codebook;
- if adaptively selecting results in a change in the current codeword subset, transmitting an indication of the current codeword subset;
- transmitting an index of a codeword within the current codeword subset of the plurality of codeword subsets.
An apparatus comprising:
- receive circuitry associated with a plurality of antennas;
- transmit circuitry associated with the plurality antennas;
- and
- a memory containing codeword subsets;
- a subset selector based on threshold criterion that causes the apparatus to perform a method comprising:
- in respect of a plurality of codewords of a full codebook and a plurality of codeword subsets, each codeword subset containing a respective plurality of the codewords of the full codebook, repeatedly:
- determining a best codeword from the full codebook;
- adaptively selecting a codeword subset of the plurality of codeword subsets to be a current codeword subset by selecting, based on a threshold criterion, between a) the most recently selected current codeword subset and b) another codeword subset that contains the best codeword from the full codebook;
- if adaptively selecting results in a change in the current codeword subset, transmitting an indication of the current codeword subset;
- transmitting an index of a codeword within the current codeword subset of the plurality of codeword subsets.
One or more non-transitory, computer readable storage media having instructions stored thereon that, when executed by a receiver, cause the receiver to implement:
- in respect of a plurality of codewords of a full codebook and a plurality of codeword subsets, each codeword subset containing a respective plurality of the codewords of the full codebook, repeatedly:
- determining a best codeword from the full codebook;
- adaptively selecting a codeword subset of the plurality of codeword subsets to be a current codeword subset by selecting, based on a threshold criterion, between a) the most recently selected current codeword subset and b) another codeword subset that contains the best codeword from the full codebook;
- if adaptively selecting results in a change in the current codeword subset, transmitting an indication of the current codeword subset;
- transmitting an index of a codeword within the current codeword subset of the plurality of codeword subsets.
Dependencies are inferred from the claim text.