MIMO COMMUNICATION SYSTEM HAVING DETERMINISTIC CHANNELS AND METHOD

• US 20090296846A1
• Filed: 11/19/2007
• Published: 12/03/2009
• Est. Priority Date: 11/17/2006
• Status: Abandoned Application

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Maru, Tsuguo
• Application Number:
  US12/443,429
• Publication Number:
  US 20090296846A1
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 25/0244 with inversion
• CPC Class Codes: H04L 25/0248 Eigen-space methods

Abstract

A MIMO communication system having deterministic channels wherein MIMO is applied to line-of-sight channels having a fixed geometrical positional relationship so as to increase the channel capacity. A line-of-sight MIMO communication system having a plurality of channels includes a channel matrix calculation processing section on a transmission or reception side or both of the transmission and reception sides. The channel matrix calculation processing section updates an orthogonal channel formation matrix in accordance with a fluctuation of a transmission antenna position or reception antenna position or a fluctuation of the channels.

Claims

1. A line-of-sight MIMO (Multiple-Input Multiple-Output) communication system including a plurality of channels, comprising:

a channel matrix calculation processing section on a transmission or reception side or both of the transmission and reception sides, wherein

the channel matrix calculation processing section updates an orthogonal channel formation matrix in accordance with a fluctuation of a transmission antenna position or reception antenna position or a fluctuation of the channels.

2. The MIMO communication system according to claim 1, wherein,

for formation of virtual orthogonal channels, geometric parameters of the channels are set so that the eigenvalue of the channel matrix become multiplicity condition, and

calculation of a unitary matrix constituted based on an eigenvector obtained from the eigenvalue or an eigenvector obtained from the linear sum of eigenvector is performed on one of the transmission side or reception side.

3. The MIMO communication system according to claim 1, wherein

the MIMO communication system is a fixed point microwave communication system using a plurality of antennas and is constituted by using local oscillators provided independently for respective antennas on one or both of the transmission and reception sides.

4. The MIMO communication system according to claim 3, wherein

the matrix calculation processing for formation of the virtual orthogonal channels is performed only on the reception side.

5. The MIMO communication system according to claim 1, further comprising:

means for detecting a fluctuation of a transmission antenna position or reception antenna position or a fluctuation of the channels, wherein

based on a detection result from the means, a virtual orthogonal channel formation matrix is updated.

6. The MIMO communication system according to claim 5, further comprising:

means for transmitting pilot signals from the transmission side to reception side, wherein

a fluctuation of a transmission antenna position or reception antenna position or a fluctuation of the channels is detected by the pilot signals, and a virtual orthogonal channel formation matrix is updated based on a result of the detection.

7. The MIMO communication system according to claim 3, further comprising:

means for transmitting pilot signals of respective antennas from the transmission side to reception side, wherein

based on the pilot signals, matrix calculation processing for formation of the virtual orthogonal channels is performed only on the reception side.

8. The MIMO communication system according to claim 7, wherein

the pilot signals to be transmitted from the transmission side to reception side are generated before processing performed by the local oscillators.

9. The MIMO communication system according to claim 7, wherein

the detection of the pilot signals that have been transmitted from the transmission side to reception side is performed after processing performed by the local oscillators on the reception side.

10. The MIMO communication system according to claim 7, wherein

the pilot signals transmitted from the transmission side to reception side are orthogonal between transmission antennas.

11. The MIMO communication system according to claim 1, wherein

the plurality of channels are optical channels.

12. The MIMO communication system according to claim 1, wherein

the plurality of channels are line-of-sight radio channels.

13. The MIMO communication system according to claim 1, wherein

the plurality of channels are line-of-sight acoustic channels.

14. The MIMO communication system according to claim 2, wherein

one or both of the length between a plurality of transmission antennas or a plurality of reception antennas and direction of a plurality of transmission antennas or a plurality of reception antennas are made changeable.

15. A MIMO communication method for use in a line-of-sight communication system including a plurality of channels, comprising:

a step of performing channel matrix calculation processing on a transmission or reception side or both of the transmission and reception sides, wherein,

the step of performing updates an orthogonal channel formation matrix in accordance with a fluctuation of a transmission antenna position or reception antenna position or a fluctuation of the channels.

16. The MIMO communication method according to claim 15, wherein,

for formation of virtual orthogonal channels, geometric parameters of the channels are set so that the eigenvalue of the channel matrix become multiplicity condition, and calculation of a unitary matrix constituted based on an eigenvector obtained from the eigenvalue or an eigenvector obtained from the linear sum of eigenvector is performed on one of the transmission side or reception side.

17. The MIMO communication method according to claim 15, wherein

the communication system is a fixed point microwave communication system using a plurality of antennas and is constituted by using local oscillators provided independently for respective antennas on one or both of the transmission and reception sides.

18. The MIMO communication method according to claim 17, wherein

the matrix calculation processing for formation of the virtual orthogonal channels is performed only on the reception side.

19. The MIMO communication method according to claim 15, further comprising:

detecting a fluctuation of a transmission antenna position or reception antenna position or a fluctuation of the channels; and

updating, based on a result of the detection, a virtual orthogonal channel formation matrix.

20. The MIMO communication method according to claim 19, further comprising:

transmitting pilot signals from the transmission side to reception side;

detecting a fluctuation of a transmission antenna position or reception antenna position or a fluctuation of the channels by the pilot signals; and

updating a virtual orthogonal channel formation matrix based on a result of the detection.

21. The MIMO communication method according to claim 17, further comprising:

transmitting pilot signals of respective antennas from the transmission side to reception side; and

performing, based on the pilot signals, matrix calculation processing for formation of the virtual orthogonal channels only on the reception side.

22. The MIMO communication method according to claim 21, wherein

the pilot signals to be transmitted from the transmission side to reception side are generated before processing performed by the local oscillators.

23. The MIMO communication method according to claim 21, wherein

the detection of the pilot signals that have been transmitted from the transmission side to reception side is performed after processing performed by the local oscillators on the reception side.

24. The MIMO communication method according to claim 21, wherein

the pilot signals transmitted from the transmission side to reception side are orthogonal between transmission antennas.

25. The MIMO communication method according to claim 15, wherein

the plurality of channels are optical channels.

26. The MIMO communication method according to claim 15, wherein

the plurality of channels are line-of-sight radio channels.

27. The MIMO communication method according to claim 15, wherein

the plurality of channels are line-of-sight acoustic channels.

28. The MIMO communication method according to claim 16, wherein

one or both of the length between a plurality of transmission antennas or a plurality of reception antennas and direction of a plurality of transmission antennas or a plurality of reception antennas are made changeable.

29. A MIMO transmission apparatus of a line-of-sight MIMO communication system including a plurality of channels, comprising:

a channel matrix calculation processing section that updates an orthogonal channel formation matrix in accordance with a fluctuation of a transmission antenna position or a fluctuation of the channels.

30. A MIMO reception apparatus of a line-of-sight MIMO communication system including a plurality of channels, comprising:

a channel matrix calculation processing section that updates an orthogonal channel formation matrix in accordance with a fluctuation of a reception antenna or a fluctuation of the channels.

31. A control program for a MIMO transmission apparatus of a line-of-sight MIMO communication system including a plurality of channels, allowing the transmission apparatus to update an orthogonal channel formation matrix in accordance with a fluctuation of a transmission antenna position or a fluctuation of the channels.

32. A control program for a MIMO reception apparatus of a line-of-sight MIMO communication system including a plurality of channels, allowing the reception apparatus to update an orthogonal channel formation matrix in accordance with a fluctuation of a reception antenna or a fluctuation of the channels.