Apparatus and method for cooperative transmission in multi-antenna relay wireless communication system

• US 20080166975A1
• Filed: 01/09/2008
• Published: 07/10/2008
• Est. Priority Date: 01/09/2007
• Status: Active Grant

• Current Assignee: New Jersey Institute of Technology, Samsung Electronics Co. Ltd.
• Original Assignee: New Jersey Institute of Technology, Samsung Electronics Co. Ltd.
• Inventors: Kim, Yung-Soo, Kim, Dong-Ho, Simeone, Osvaldo, Bar-Ness, Yeheskel, Cho, Myeon-Kyun, Varanese, Nicola
• Granted Patent: US 8,195,089 B2
• Time in Patent Office: Days
• US Class Current: 455/68
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/46 in multi hop networks, e.g. wireless relay networks

Abstract

An apparatus and method for cooperative transmission in a multi-antenna relay wireless communication system are provided. A receiving end includes an estimator, a reader, a feedback unit and a detector. According to the present invention, the receiving end receives the signal from both the transmitting end and the relay station. Therefore, a reception gain is obtained and a high throughput can be ensured.

Claims

1. A receiving end apparatus in a multi-antenna relay wireless communication system using cooperative transmission, the apparatus comprising:

an estimator for estimating a channel between a transmitting end and a relay station;

a reader for reading channel gain information, which is feed-forwarded from the relay station, between the transmitting end and the relay station with respect to all antennas;

a feedback unit for determining a covariance matrix used to regulate power of a Transmit (Tx) signal with respect to all antennas of the transmitting end and a relay matrix used to process a signal from the relay station by using channel information received from the estimator and the reader, and for feeding back information on the determined matrices; and

a detector for detecting the Tx signal by combining a signal received from the transmitting end at a first Tx time, a signal received from the transmitting end at a second Tx time, and a signal received from the relay station at the second Tx time.

2. The apparatus of claim 1, further comprising a determining unit for determining whether the matrices are optimally configured.

3. The apparatus of claim 2, wherein, if the determining unit determines that the matrices are not optimally configured, the feedback information re-determines either the covariance matrix or the relay matrix, and feeds back information on the re-determined matrix.

4. The apparatus of claim 3, wherein the determining unit computes an improvement value of reception throughput as a result of the configuration of the matrices, and, if the improvement value of reception throughput is less than or equal to a threshold, determines that the matrices are optimally configured.

5. The apparatus of claim 4, wherein the determining unit measures the reception throughput by using one of a Signal to Interference and Noise Ratio (SINR), a Signal to Noise Ratio (SNR), and a Carrier to Interference and Noise Ratio (CINR).

6. The apparatus of claim 4, wherein, if the number of times of performing re-determination on either the covariance matrix or the relay matrix is equal to the threshold, the determining unit determines that the matrices are optimally configured.

7. The apparatus of claim 4, wherein, if the matrices are optimally configured, the feedback unit reports to the transmitting end and the relay station that the matrices are optimally configured.

8. A receiving end apparatus in a multi-antenna relay wireless communication system using cooperative transmission, the apparatus comprising:

an estimator for estimating a channel between a transmitting end and a relay station;

a reader for reading information on a Transmit (Tx) antenna of the transmitting end, wherein the information is feed-forwarded from the relay station and the Tx antenna has priority for the relay station;

a feedback unit for selecting the at least one of Tx antenna of the transmitting end by using channel information provided from the estimator and the reader, for feeding back antenna selection information to the transmitting end, and for feeding back channel information between the relay station and the receiving end to the relay station; and

a detector for detecting the Tx signal by combining a signal received from the transmitting end at a first Tx time, a signal received from the transmitting end at a second Tx time, and a signal received from the relay station at the second Tx time.

9. The apparatus of claim 8, wherein the feedback unit feeds back information on at least one of Tx antenna of the relay station to the relay station, wherein at least one of Tx antenna has priority for the receiving end.

10. An operation method of a receiving end in a multi-antenna relay wireless communication system using cooperative transmission, the method comprising:

estimating a channel between a transmitting end and a relay station;

reading channel gain information, which is feed-forwarded from the relay station, between the transmitting end and the relay station with respect to all antennas;

determining a covariance matrix used to regulate power of a Transmit (Tx) signal with respect to all antennas of the transmitting end and a relay matrix used to process a signal from the relay station by using channel information;

feeding back information on the determined matrices; and

detecting the Tx signal by combining a signal received from the transmitting end at a first Tx time, a signal received from the transmitting end at a second Tx time, and a signal received from the relay station at the second Tx time.

11. The method of claim 10, further comprising:

determining whether the matrices are optimally configured; and

if the determination result shows that the matrices are not optimally configured, re-determining either the covariance matrix or the relay matrix, and feeding back information on the re-determined matrix.

12. The method of claim 11, wherein the determining whether the matrices are optimally configured comprises:

computing an improvement value of reception throughput as a result of the configuration of the matrices; and

if the improvement value of reception throughput is less than or equal to a threshold, determining that the matrices are optimally configured.

13. The method of claim 12, wherein the reception throughput is measured by using one of a Signal to Interference and Noise Ratio (SINR), a Signal to Noise Ratio (SNR), and a Carrier to Interference and Noise Ratio (CINR).

14. The method of claim 11, wherein the determining whether the matrices are optimally configured comprises, if the number of times of performing re-determination on either the covariance matrix or the relay matrix is equal to the threshold, determining that the matrices are optimally configured.

15. The method of claim 11, further comprising, if the matrices are optimally configured, reporting to the transmitting end and the relay station that the matrices are optimally configured.

16. An operation method of a receiving end in a multi-antenna relay wireless communication system using cooperative transmission, the method comprising:

estimating a channel between a transmitting end and a relay station;

reading information on a Transmit (Tx) antenna of the transmitting end, wherein the information is feed-forwarded from the relay station and the Tx antenna has priority for the relay station;

selecting at least one of Tx antenna of the transmitting end by using channel information provided as a result of estimating and reading;

feeding back antenna selection information to the transmitting end, and feeding back channel information between the relay station and the receiving end to the relay station; and

detecting the Tx signal by combining a signal received from the transmitting end at a first Tx time, a signal received from the transmitting end at a second Tx time, and a signal received from the relay station at the second Tx time.

17. The method of claim 16, wherein channel information that is fed back to the relay station is information on at least one of Tx antenna of the relay station, wherein at least one of Tx antenna has priority for the receiving end.

18. A multi-antenna relay wireless communication system using cooperative transmission, the system comprising:

a receiving end for determining a covariance matrix used to regulate power of a Transmit (Tx) signal with respect to all antennas of the transmitting end and a relay matrix used to process a signal from a relay station by using channel information between a transmitting end and the relay station, between the transmitting end and the receiving end, and the relay station and the receiving end, and for feeding back information on the determined matrices;

the transmitting end for transmitting signals at a first Tx time and a second Tx time by regulating Tx power for each antenna according to the covariance matrix; and

the relay station for receiving a signal from the transmitting end at the first Tx time and for transmitting the received signal at the second Tx time.

19. The system of claim 18, wherein the receiving end detects the Tx signal by combining the signal received from the transmitting end at a first Tx time, the signal received from the transmitting end at a second Tx time, and the signal received from the relay station at the second Tx time.

20. The system of claim 18, wherein the receiving end determines whether the matrices are optimally configured, and, if the determination result shows that the matrices are not optimally configured, re-determines either the covariance matrix or the relay matrix, and feeds back information on the re-determined matrix.

21. The system of claim 20, wherein the receiving end computes an improvement value of reception throughput as a result of the configuration of the matrices, and, if the improvement value of reception throughput is less than or equal to a threshold, determines that the matrices are optimally configured.

22. The system of claim 21, wherein the receiving end measures the reception throughput by using one of a Signal to Interference and Noise Ratio (SINR), a Signal to Noise Ratio (SNR), and a Carrier to Interference and Noise Ratio (CINR).

23. The system of claim 20, wherein, if the number of times of performing re-determination on either the covariance matrix or the relay matrix is equal to the threshold, the receiving end determines that the matrices are optimally configured.

24. The system of claim 20, wherein, if the matrices are optimally configured, the receiving end reports to the transmitting end and the relay station that the matrices are optimally configured.