Apparatus and method for interference cancellation and synchronization maintenance over interference channel estimation in communication system based on full-duplex relay

• US 20090180404A1
• Filed: 01/14/2009
• Published: 07/16/2009
• Est. Priority Date: 01/14/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, John-Ho, Yun, Sang-Boh, Jung, Sung-Yoon, Lee, Joo-Hyun
• Granted Patent: US 8,155,046 B2
• Time in Patent Office: Days
• US Class Current: 370/279
• CPC Class Codes: H04B 7/15585 by interference cancellation
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/0244 with inversion
• CPC Class Codes: H04L 25/025 using least-mean-square [LMS] method
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/143 for modulated signals H04L5/1469 takes precedence
• CPC Class Codes: H04L 5/1461 Suppression of signals in the return path, i.e. bidirectional control circuits

Abstract

An apparatus and method for interference cancellation and synchronization maintenance over interference channel estimation in a communication system are provided. An interference channel estimator fixes synchronization and estimates an interference signal. An interference signal controller eliminates the estimated interference signal from a received RF signal. A synchronization unit unfixes fixed synchronization and tracks synchronization when the interference signal cancellation is stable. A data buffer stores data from which the interference signal is canceled.

Claims

1. An apparatus for interference cancellation and synchronization maintenance over interference channel estimation in a communication system based on full-duplex relay, the apparatus comprising:

an interference channel estimator for fixing synchronization and estimating an interference channel from a transmit modem to a receiver modem, upon receipt of a radio frequency (RF) signal;

an interference signal controller for canceling an estimated interference signal from the received RF signal using the interference channel;

a synchronization unit for unfixing fixed synchronization and tracking synchronization, when the interference signal cancellation is stable; and

a data buffer for storing data from which the interference signal is canceled.

2. The apparatus of claim 1, wherein the transmit modem transmits the data stored in the data buffer.

3. The apparatus of claim 1, wherein, before receiving the RF signal, the receive modem performs initial synchronization.

4. The apparatus of claim 1, wherein, if there is synchronization loss,-the transmit modem stops data transmission and performs initial synchronization.

5. The apparatus of claim 1, wherein, when the interference signal cancellation is not stable, the interference signal controller stops synchronization tracking, fixes synchronization, and repeatedly eliminates the estimated interference signal.

6. The apparatus of claim 1, further comprising a channel estimator for performing channel estimation for the received signal from which the interference signal is canceled.

7. The apparatus of claim 1, wherein the interference channel estimator estimates the interference channel in a moving average and direct inversion method of accumulating a received signal for a predetermined symbol.

8. The apparatus of claim 1, wherein the interference channel estimator recursively estimates the interference channel on the basis of weighted averaging.

9. A method for interference cancellation and synchronization maintenance over interference channel estimation in a communication system based on full-duplex relay, the method comprising:

fixing synchronization and estimating an interference channel from a transmit modem to a receiver modem, upon receipt of a radio frequency (RF) signal;

cancelling a estimated interference signal from the received RF signal using the interference channel;

.

unfixing fixed synchronization and tracking synchronization, when the interference signal cancellation is stable; and

storing data from which the interference signal is canceled.

10. The method of claim 9, further comprising transmitting the stored data.

11. The method of claim 9, wherein, before receiving the RF signal, initial synchronization is performed.

12. The method of claim 9, further comprising, if there is synchronization loss, stopping data transmission and performing initial synchronization.

13. The method of claim 9, wherein, when the interference signal cancellation is not stable, synchronization tracking is stopped, synchronization is fixed, and the estimated interference signal is repeatedly eliminated.

14. The method of claim 9, further comprising performing channel estimation for the received signal from which the interference signal is canceled.

15. The method of claim 9, wherein the interference channel estimation estimates the interference channel in a moving average and direct inversion method of accumulating a received signal for a predetermined symbol.

16. The method of claim 9, wherein the interference channel estimation recursively estimates the interference channel on the basis of weighted averaging.