1. A method of feedback for a 4-antenna downlink channel in a Multiple Input Multiple Output (MIMO) system, comprising:
detecting a downlink multiple-antenna channel;
determining a first codeword in a first level codebook corresponding to the rank of R according to a long-term broadband channel characteristic estimated from a result of the detection, wherein any codeword in the first level codebook is four diagonal matrices, two same 2\xd7C block matrices exist on a diagonal line, and C column vectors of the 2\xd7C block matrix are selected from Q1 discrete Fourier transform (DFT) beam vectors;
feeding back an index of the first codeword;
determining a second codeword in a second level codebook corresponding to the rank of R according to a short-term channel characteristic estimated from the result of the detection and the first codeword, wherein any codeword in the second level codebook is a 2C\xd7R matrix, and each column of the 2C\xd7R matrix is formed of one C\xd71 beam selection vector and one C\xd71 beam selection vector comprising phase offset information; and
feeding back an index of the second codeword.
2.-7. (canceled)
8. An apparatus of feedback for a 4-antenna downlink channel in a Multiple Input Multiple Output (MIMO) system, comprising:
a detection module, configured to detect a downlink multiple-antenna channel;
a first determination module, configured to determine a first codeword in a first level codebook corresponding to the rank of R according to a long-term broadband channel characteristic estimated from a result of the detection, wherein any codeword in the first level codebook is four diagonal matrices, two same 2\xd7C block matrices exist on a diagonal line, and C column vectors of the 2\xd7C block matrix are selected from Q1 discrete Fourier transform (DFT) beam vectors;
a feedback module, configured to feed back an index of the first codeword;
a second determination module, configured to determine a second codeword in a second level codebook corresponding to the rank of R according to a short-term channel characteristic estimated from the result of the detection and the first codeword, wherein any codeword in the second level codebook is a 2C\xd7R matrix, and each column of the 2C\xd7R matrix is formed of one C\xd71 beam selection vector and one C\xd71 beam selection vector comprising phase offset information; wherein
the feedback module is further configured to feed back an index of the second codeword.
9. The apparatus according to claim 8, wherein a column vector of a codeword in the first level codebook comprises DFT beam vectors with an equal stride and DFT beam vectors orthogonal to each other, or comprises DFT beam vectors with an equal stride but no DFT beam vectors orthogonal to each other.
10. The apparatus according to claim 8, wherein corresponding to the rank of 1, a column vector of any codeword in the second level codebook is configured as selecting a same or different DFT beam independently for each polarization, or configured as selecting a same DFT beam for each polarization.
11. The apparatus according to claim 8, wherein corresponding to the rank of 2, a column vector of any codeword in the second level codebook is configured as selecting a same or different DFT beam independently for each polarization and selecting a same DFT beam for each layer, or configured as selecting a same or different DFT beam for each layer independently and selecting a same DFT beam for each polarization, or configured as selecting a same or different DFT beam independently for each polarization and selecting a same or different DFT beam for each layer independently, or configured as selecting a same DFT beam for each polarization and selecting a same DFT beam for each layer.
12. The apparatus according to claim 8, wherein a first level codebook corresponding to the rank of 3 or 4 is a proper subset of a first level codebook corresponding to the rank of 1 or 2.
13. The apparatus according to claim 8, wherein corresponding to the rank of 3 or 4, a column vector of the 2\xd7C block matrix comprises DFT beam vectors orthogonal to each other, and a column vector of any codeword in the second level codebook is configured as selecting a same or different DFT beam independently for each polarization, or configured as selecting a same DFT beam for each polarization.
14. (canceled)
15. A user equipment, comprising the apparatus of claim 8.
16. A method for use in a base station having 4 transmit antennas in a Multiple Input Multiple Output (MIMO) system, comprising:
receiving a rank of downlink transmission, an index of a first codeword in a first level codebook, and an index of a second codeword in a second level codebook fed back by a user equipment, wherein any codeword in the first level codebook is four diagonal matrices, two same 2\xd7C block matrices exist on a diagonal line, C column vectors of the 2\xd7C block matrix are selected from Q1 discrete Fourier transform (DFT) beam vectors, any codeword in the second level codebook is a 2C\xd7R matrix, and each column of the 2C\xd7R matrix is formed of one C\xd71 beam selection vector and one C\xd71 beam selection vector comprising phase offset information; and
determining a downlink channel characteristic according to the rank, the index of the first codeword, and the index of the second codeword.
17.-21. (canceled)
22. An apparatus for use in a base station having 4 transmit antennas in a Multiple Input Multiple Output (MIMO) system, comprising:
a receiving module, configured to receive a rank of downlink transmission, an index of a first codeword in a first level codebook, and an index of a second codeword in a second level codebook fed back by a user equipment, wherein any codeword in the first level codebook is four diagonal matrices, two same 2\xd7C block matrices exist on a diagonal line, C column vectors of the 2\xd7C block matrix are selected from Q1 discrete Fourier transform (DFT) beam vectors, any codeword in the second level codebook is a 2C\xd7R matrix, and each column of the 2C\xd7R matrix is formed of one C\xd71 beam selection vector and one C\xd71 beam selection vector comprising phase offset information; and
a channel characteristic determination module, configured to determine a downlink channel characteristic according to the rank, the index of the first codeword, and the index of the second codeword.
23. The apparatus according to claim 22, wherein a column vector of a codeword in the first level codebook comprises DFT beam vectors with an equal stride and DFT beam vectors orthogonal to each other, or comprises DFT beam vectors with an equal stride but no DFT beam vectors orthogonal to each other.
24. The apparatus according to claim 22, wherein corresponding to the rank of 1, a column vector of any codeword in the second level codebook is configured as selecting a same or different DFT beam independently for each polarization, or configured as selecting a same DFT beam for each polarization.
25. The apparatus according to claim 22, wherein corresponding to the rank of 2, a column vector of any codeword in the second level codebook is configured as selecting a same or different DFT beam independently for each polarization and selecting a same DFT beam for each layer, or configured as selecting a same or different DFT beam for each layer independently and selecting a same DFT beam for each polarization, or configured as selecting a same or different DFT beam independently for each polarization and selecting a same or different DFT beam for each layer independently, or configured as selecting a same DFT beam for each polarization and selecting a same DFT beam for each layer.
26. The apparatus according to claim 22, wherein a first level codebook corresponding to the rank of 3 or 4 is a proper subset of a first level codebook corresponding to the rank of 1 or 2.
27. (canceled)
28. A base station equipment, comprising the apparatus of claim 22.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A light source assembly mechanism installed at one end of an LED lamp tube, comprising:
a base which includes a housing chamber communicating with two opposite sides thereof, and a first opening and a second opening at the two opposite sides thereof;
a lamp tube side cap which includes one side fastened to the one end of the LED lamp tube and another side covering the first opening and formed a fastening portion held in the housing chamber;
a turning module side cap which covers the second opening and includes a coupling portion extended into the housing chamber to fasten to the fastening portion; and
a turning rod running through the turning module side cap and fastened to lamp tube side cap,
wherein the housing chamber is formed in a cylindrical shape, and the turning module side cap includes a coupling ring extended axially into the second opening and coupled tightly in the housing chamber.
2. The light source assembly mechanism of claim 1, wherein the housing chamber includes a continuous undulant surface formed annularly in an inner side thereof, the coupling ring including a bump corresponding to the undulant surface.
3. The light source assembly mechanism of claim 1, wherein the base includes a holding plate with at least one fastening hole formed thereon.
4. The light source assembly mechanism of claim 3, wherein the base includes a latch bracket inserted by the holding plate.
5. The light source assembly mechanism of claim 1, wherein the base includes a magnet.
6. The light source assembly mechanism of claim 5, wherein the base includes a latch bracket inserted by the magnet.