Transmitting and receiving apparatus and method in closed-loop MIMO antenna system using codebook

• US 20060279460A1
• Filed: 06/08/2006
• Published: 12/14/2006
• Est. Priority Date: 06/08/2005
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Dong-Seek, Hong, Sung-Kwon, Kim, Young-Kyun, Chae, Chan-Byoung, Yun, Sung-Ryul
• Application Number:
  US11/448,790
• Publication Number:
  US 20060279460A1
• Time in Patent Office: Days
• US Class Current: 342/377
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming

Abstract

A receiver and transmitter of a closed-loop MIMO antenna system using a codebook and a receiving and transmitting method thereof are provided. The receiver of the MIMO antenna system includes a window size decider and a beamforming weight selector. The window size decider stores a codebook with beamforming weights and selects the beamforming weights corresponding to a window size from the codebook, and the beamforming weight selector selects an optimal beamforming weight based on a current channel state among the beamforming weights outputted from the window size decider, and feeds back the selected optimal beamforming weight to a transmitter.

Claims

1. A receiver in a wireless communication system comprising:

a window size decider for storing a codebook comprising beamforming weights, and selecting, from the codebook, at least one of the beamforming weights corresponding to a window size; and

a beamforming weight selector for selecting an optimal beamforming weight based on a current channel state from among the at least one of the beamforming weights from the window size decider, and conveying the selected optimal beamforming weight to a transmitter.

2. The receiver of claim 1, wherein the beamforming weights of the codebook are aligned according to beam directions.

3. The receiver of claim 1, wherein the window size decider selects the at least one beamforming weights corresponding to a window size based on a previously selected beamforming vector.

4. The receiver of claim 1, wherein the window size is changed according to channel environment.

5. The receiver of claim 4, wherein an update period of the window size is changed according to the channel environment.

6. The receiver of claim 1, wherein the window size comprises a fixed value.

7. The receiver of claim 1, wherein the codebook comprises a design using Grassmannian Line Packing aligned according to beam directions.

8. The receiver of claim 1, wherein the beamforming weight selector conveys a codebook index of the selected beamforming weight to the transmitter.

9. The receiver of claim 1, further comprising a channel estimator for estimating a channel by using signals that are received through at least one RX antenna, and providing a channel coefficient matrix to the beamforming weight selector.

10. A transmitter in a wireless communication system comprising:

a beamforming weight decider for storing a codebook comprising beamforming weights aligned according to beam directions, and generating a beamforming weight according to a codebook index conveyed from a receiver; and

a beamformer for forming a beam by multiplying to-be-transmitted symbols by the beamforming weight from the beamforming weight decider.

11. The transmitter of claim 10, wherein the codebook comprises a design using Grassmannian Line Packing aligned according to beam directions.

12. A receiving method in a wireless communication system having a codebook with beamforming weights, the method comprising:

selecting at least one beamforming weight corresponding to a window size from a codebook; and

selecting an optimal beamforming weight based on a current channel state from among the at least one selected beamforming weight, and conveying the selected optimal beamforming weight to a transmitter.

13. The receiving method of claim 12, wherein the beamforming weights of the codebook are aligned according to beam directions.

14. The receiving method of claim 12, wherein the selecting of the at least one beamforming weight comprises:

checking a previously selected beamforming vector; and

selecting the at least one beamforming weight corresponding to the window size based on the previously selected beamforming vector.

15. The receiving method of claim 12, further comprising changing the window size according to a channel environment.

16. The receiving method of claim 12, further comprising changing a period of the window size according to a channel environment.

17. The receiving method of claim 12, wherein the window size comprises a fixed value.

18. The receiving method of claim 12, wherein the codebook comprises a design using Grassmannian Line Packing aligned according to beam directions.

19. The receiving method of claim 12, wherein the conveying of the optimal beamforming weight comprises:

selecting the optimal beamforming weight based on the current channel state from among the selected beamforming weights; and

conveying a codebook index of the selected beamforming weight to the transmitter.

20. The receiving method of claim 12, wherein the conveying of the optimal beamforming weight comprises:

generating a channel coefficient matrix by performing a channel estimation using at least one signal received through a plurality of RX antennas;

using the channel coefficient matrix to search for the optimal beamforming weight based on the current channel state from among the selected beamforming weights; and

conveying a codebook index of the searched optimal beamforming weight to the transmitter.

21. A receiving method of a MIMO antenna system having a codebook with beamforming weights, the method comprising:

aligning the codebook according to beam directions;

selecting beamforming weights corresponding to a window size from the aligned codebook; and

selecting an optimal beamforming weight based on a current channel state from among the selected beamforming weights and conveying the selected optimal beamforming weight to a transmitter.

22. The receiving method of claim 21, wherein the selecting of the beamforming weights comprises:

checking a previously selected beamforming vector; and

selecting the beamforming weights corresponding to the window size based on the previously selected beamforming vector.

23. The receiving method of claim 21, further comprising changing the window size according to channel environment.

24. The receiving method of claim 21, further comprising changing an update period of the window size according to channel environment.

25. The receiving method of claim 21, wherein the window size comprises a fixed value.

26. The receiving method of claim 21, wherein the conveying of the optimal beamforming weight comprises:

selecting the optimal beamforming weight based on the current channel state among the selected beamforming weights; and

conveying a codebook index of the selected beamforming weight to the transmitter.

27. A transmitting method in a wireless communication system comprising:

storing a codebook comprising beamforming weights aligned according to beam directions, and generating a beamforming weight according to a codebook index conveyed from a receiver; and

multiplying transmission symbols by the beamforming weight and transmitting the resulting signals through a plurality of TX antennas.

28. The transmitting method of claim 27, wherein the codebook comprises a design using Grassmannian Line Packing aligned according to beam directions.