Techniques utilizing step size adaptation for differential beamforming in wireless networks
An embodiment of the present invention provides a method used in transmit beam forming, comprising, providing differential feedback by using variable differential codebooks across a plurality of feedbacks wherein the differential codebooks may have different shapes, and/or spans, and/or the numbers of codewords across feedbacks.
1. A method used in transmit beam forming, comprising:
providing differential feedback by using variable differential codebooks across a plurality of feedbacks, wherein said differential codebooks includes a variable polar cap with different polar cap sizes that can be rotated through different angles and said differential codebooks may have different shapes, and/or spans, and/or the numbers of codewords across feedbacks.
2. The method of claim 1 , wherein to use the same number of feedback bits across frames, said differential codebook for a first frame has a span greater than a differential codebook for latter frames.
3. The method of claim 1 , wherein said span is quantified by a polar cap size in angle for a given codebook.
4. The method of claim 3 , wherein said polar cap size is ring shaped and the greater the size of said ring, the greater the polar cap size.
5. The method of claim 4 , wherein said differential codebook may also have a shape other than a ring with a center or without a center and wherein said differential codebook may vary its shape, and/or span, and/or the number of codewords across feedbacks.
6. An apparatus, comprising:
a transceiver adapted for communication in a wireless network, said transceiver further adapted to use transmit beam forming; and
wherein said beam forming uses differential feedback by using variable differential codebooks across a plurality of feedbacks wherein said differential codebooks includes a variable polar cap with different polar cap sizes that can be rotated through different angles and said differential codebooks may have different shapes, and/or spans, and/or the numbers of codewords across feedbacks.
7. The apparatus of claim 6 , wherein to use the same number of feedback bits across frames, said differential codebook for a first frame has a span greater than a differential codebook for latter frames.
8. The apparatus of claim 7 , wherein said span is quantified by a polar cap size in angle for a given codebook.
9. The apparatus of claim 8 , wherein said polar cap size is ring shaped and the greater the size of said ring, the greater the polar cap size.
10. The apparatus of claim 9 , wherein said differential codebook may also have a shape other than a ring with a center or without a center and wherein said differential codebook may vary its shape, and/or span, and/or the number of codewords across feedbacks.
11. A non-transitory computer readable medium encoded with computer executable instructions, which when accessed, cause a machine to perform operations comprising:
providing differential feedback when using transmit beam forming by using variable differential codebooks across a plurality of feedbacks wherein said differential codebooks includes a variable polar cap with different polar cap sizes that can be rotated through different angles and said differential codebooks may have different shapes, and/or spans, and/or the numbers of codewords across feedbacks.
12. The non-transitory computer readable medium encoded with computer executable instructions of claim 11 , wherein to use the same number of feedback bits across frames, said differential codebook for a first frame has a span greater than a differential codebook for latter frames.
13. The non-transitory computer readable medium encoded with computer executable instructions of claim 12 , wherein said span is quantified by a polar cap size in angle for a given codebook.
14. The non-transitory computer readable medium encoded with computer executable instructions of claim 13 , wherein said polar cap size is ring shaped and the greater the size of said ring, the greater the polar cap size.
15. The non-transitory computer readable medium encoded with computer executable instructions of claim 14 , wherein said differential codebook may also have a shape other than a ring with a center and wherein said differential codebook may vary its shape, and/or span, and/or the number of codewords across feedbacks.