Multi-resolution precoding codebook
View Patent ↗Systems and methods are for generating a codebook by: generating a multi-resolution codebook by selecting a common precoder index from a low resolution codebook for a group of adjacent resource blocks (RB)s and for each RB within the group, selecting a high-resolution codebook to fine-tune each RB precoder; and generating feedback for the multi-resolution codebook by quantizing channel state variations.
1. A method implemented in a user equipment used in a wireless communications system for precoding data, comprising:
transmitting to a base station a low resolution precoder index that is common to a group of resource blocks (RBs); and
transmitting to the base station a high resolution precoder index for a resource block within the group of RBs,
wherein the base station determines a precoder using a multi-resolution codebook according to the low resolution precoder index and the high resolution precoder index.
2. The method of claim 1 , wherein a channel for the group of RBs is correlated in time or in frequency.
3. The method of claim 1 , wherein a channel for the group of RBs is correlated in frequency across different OFDM (orthogonal frequency-division multiplexing) tones.
4. The method of claim 1 , wherein the group of RBs are adjacent in time or in frequency.
5. The method of claim 4 , wherein the group of RBs are adjacent in frequency over OFDM (orthogonal frequency-division multiplexing) tones.
6. The method of claim 1 , wherein the multi-resolution codebook consists of two resolution levels of a first level and a second level.
7. A method implemented in a user equipment used in a wireless communications system for precoding data, comprising:
receiving data precoded with a precoder from a base station,
wherein the precoder is determined using a multi-resolution codebook according to a high resolution precoder index for a resource block within a group of resource blocks (RBs) and a low resolution precoder index that is common to the group of RBs.
8. The method of claim 7 , wherein a channel for the group of RBs is correlated in time or in frequency.
9. The method of claim 7 , wherein a channel for the group of RBs is correlated in frequency across different OFDM (orthogonal frequency-division multiplexing) tones.
10. The method of claim 7 , wherein the group of RBs are adjacent in time or in frequency.
11. The method of claim 10 , wherein the group of RBs are adjacent in frequency over OFDM (orthogonal frequency-division multiplexing) tones.
12. The method of claim 7 , wherein the multi-resolution codebook consists of two resolution levels of a first level and a second level.
13. A wireless communications system for precoding data, comprising:
a base station; and
a user equipment to transmit to the base station a high resolution precoder index for a resource block within a group of resource blocks (RBs) and a low resolution precoder index that is common to the group of RBs,
wherein the base station transmits data precoded with a precoder to the user equipment, and
wherein the precoder is determined using a multi-resolution codebook according to the low resolution precoder index and the high resolution precoder index.
14. The wireless communications system of claim 13 , wherein a channel for the group of RBs is correlated in time or in frequency.
15. The wireless communications system of claim 13 , wherein a channel for the group of RBs is correlated in frequency across different OFDM (orthogonal frequency-division multiplexing) tones.
16. The wireless communications system of claim 13 , wherein the group of RBs are adjacent in time or in frequency.
17. The wireless communications system of claim 16 , wherein the group of RBs are adjacent in frequency over OFDM (orthogonal frequency-division multiplexing) tones.
18. The wireless communications system of claim 13 , wherein the multi-resolution codebook consists of two resolution levels of a first level and a second level.