Channel estimation method and apparatus for use in wireless communication system

• US 10,270,624 B2
• Filed: 10/13/2016
• Issued: 04/23/2019
• Est. Priority Date: 10/13/2015
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Dongjae
• Primary Examiner(s): Tadese, Berhanu
• Application Number:
  US15/293,203
• Publication Number:
  US 20170104611A1
• Time in Patent Office: 922 Days
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/0256 Channel estimation using minimum mean square error criteria

Abstract

A channel estimation method includes receiving signals at Resource Elements (REs) designated for reference signals, converting the received signals to time-domain entries using a matched filter, organizing the entries output from the matched filter into groups by delay, determining whether an energy sum of the entries of each group is greater than a predetermined threshold, and selecting the entries belonging to the group of which the energy sum is greater than the threshold value into a candidate group for channel estimation.

Claims

1. A channel estimation method of a terminal, the method comprising:

receiving downlink signals at resource elements (REs) for reference signals from a base station;

converting the received downlink signals to time-domain entries using a matched filter;

organizing time-domain entries of output from the matched filter into groups based on delay;

determining whether an energy sum of time-domain entries of each group is greater than a first threshold;

selecting the time-domain entries belonging to a group of which the energy sum is greater than the first threshold into a candidate group for channel estimation;

performing zero forcing (ZF) on the time-domain entries belonging to the candidate group; and

removing ZF output from the received downlink signals.

2. The method of claim 1, wherein the reference signals are cell-specific reference signals (CRS).

3. The method of claim 1, wherein the received downlink signals are transmitted through at least two antenna ports, and the group is organized by selecting time-domain entries having the same delay among reference signal time-domain entries transmitted by respective transmit antennas.

4. The method of claim 1, further comprising performing a stage-wise orthogonal matching pursuit (StOMP) on the time-domain entries belonging to the candidate group.

5. The method of claim 1, further comprising repeating every step onto a residual vector obtained by removing the ZF output from the received downlink signals.

6. The method of claim 5, further comprising repeating every step for less than a predetermined number of times until a size of the residual vector becomes less than a second threshold.

7. A terminal comprising:

a transceiver configured to transmit and receive a signal; and

a controller configured to;

receive downlink signals at resource elements (REs) for reference signals from a base station,

convert the received downlink signals to time-domain entries using a matched filter,

organize time-domain entries of output from the matched filter into groups based on delay,

determine whether an energy sum of time-domain entries of each group is greater than a threshold,

select the time-domain entries belonging to the group of which the energy sum is greater than the threshold into a candidate group for channel estimation,

perform zero forcing (ZF) on the time-domain entries belonging to the candidate group, and

remove ZF output from the received downlink signals.

8. The terminal of claim 7, wherein the reference signals are cell-specific reference signals (CRS).

9. The terminal of claim 7, wherein the received downlink signals are transmitted through at least two antenna ports, and the group is organized by selecting the time-domain entries having the same delay among reference signal time-domain entries transmitted by respective transmit antennas.

10. The terminal of claim 7, wherein the controller is configured to perform a stage-wise orthogonal matching pursuit (StOMP) on the time-domain entries belonging to the candidate group.

11. The terminal of claim 7, wherein the controller is configured to repeat every step onto a residual vector obtained by removing the ZF output from the received downlink signals.

12. The terminal of claim 11, wherein the controller is configured to control repeating every step for less than a predetermined number of times until a size of the residual vector becomes less than a threshold.

13. A non-transitory computer readable medium comprising program code, that when executed by at least one processor, causes the at least one processor to:

receive downlink signals at resource elements (REs) for reference signals from a base station;

convert the received downlink signals to time-domain entries using a matched filter;

organize time-domain entries of output from the matched filter into groups based on delay;

determine whether an energy sum of time-domain entries of each group is greater than a first threshold;

select the time-domain entries belonging to a group of which the energy sum is greater than the first threshold into a candidate group for channel estimation

perform zero forcing (ZF) on the time-domain entries belonging to the candidate group; and

remove ZF output from the received downlink signals.

14. The non-transitory computer readable medium of claim 13, wherein the reference signals are cell-specific reference signals (CRS).

15. The non-transitory computer readable medium of claim 13, wherein the received downlink signals are transmitted through at least two antenna ports, and the group is organized by selecting time-domain entries having the same delay among reference signal entries transmitted by respective transmit antennas.

16. The non-transitory computer readable medium of claim 13, wherein the program code, when executed by at least one processor, further causes the at least one processor to perform a stage-wise orthogonal matching pursuit (StOMP) on the time-domain entries belonging to the candidate group.

17. The non-transitory computer readable medium of claim 13, wherein the program code, when executed by at least one processor, further causes the at least one processor to repeat every step onto a residual vector obtained by removing the ZF output from the received downlink signals.

18. The non-transitory computer readable medium of claim 17, wherein the program code, when executed by at least one processor, further causes the at least one processor to repeat every step for less than or a predetermined number of times until a size of a residual vector becomes less than a second threshold.