MIMO COMMUNICATION SYSTEM HAVING DETERMINISTIC COMMUNICATION PATH AND ANTENNA ARRANGEMENT METHOD THERFOR

• US 20100135203A1
• Filed: 08/01/2008
• Published: 06/03/2010
• Est. Priority Date: 08/02/2007
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Maru, Tsuguo
• Granted Patent: US 8,571,125 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0242 using matrix methods
• CPC Class Codes: H04L 25/0248 Eigen-space methods

Abstract

A MIMO communication system having deterministic channels the orthogonality of which can be ensured even if a reflected wave other than the direct wave is present during line-of-sight communication is provided. The MIMO communication system is used in a line-of-sight environment and has deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged. The transmission side, the reception side, or both transmission and reception sides of the MIMO communication system have a channel matrix calculation processing means for calculating a channel matrix for establishing an orthogonal channel as a communication channel. The transmission and reception antennas forming the channel matrix are horizontally arranged with respect to the ground.

Claims

1. A MIMO communication system having deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged and used in a line-of-sight environment, the system comprising

channel matrix calculation processing means for calculating a channel matrix for constructing orthogonal channels as the channel on a transmission or reception side or both of the transmission and reception sides,

wherein the plurality of transmission antennas and plurality of reception antennas constituting the channel matrix are horizontally arranged with respect to the ground.

5. The MIMO communication system having deterministic channels according to claim 1, wherein

the channel matrix calculation processing means updates a channel matrix for constructing the orthogonal channels in accordance with a positional variation of a transmission antenna or reception antenna, positional variations of both of the transmission and reception antennas, or a variation of the channels.

9. The MIMO communication system having deterministic channels 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.

2. A MIMO communication system having deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged and used in a line-of-sight environment, the system comprising

channel matrix calculation processing means for calculating a channel matrix for constructing orthogonal channels as the channel on a transmission or reception side or both of the transmission and reception sides,

wherein the plurality of transmission antennas and plurality of reception antennas constituting the channel matrix are vertically arranged with respect to the ground, and antenna height from the ground is made an integral multiple of the antenna interval.

6. The MIMO communication system having deterministic channels according to claim 2, wherein

the channel matrix calculation processing means updates a channel matrix for constructing the orthogonal channels in accordance with a positional variation of a transmission antenna or reception antenna, positional variations of both of the transmission and reception antennas, or a variation of the channels.

10. The MIMO communication system having deterministic channels according to claim 2, 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.

3. A MIMO communication system having deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged, the system comprising

channel matrix calculation processing means for constructing orthogonal channels as the channels by setting geometric parameters of the channels concerning antenna distance so that the eigenvalue of the channel matrix becomes a multiplicity condition and performing, on the transmission or reception side, matrix calculation using a unitary matrix constituted based on singular vectors obtained from the eigenvalue or singular vectors obtained from the linear combination of eigenvectors,

wherein the plurality of transmission antennas and plurality of reception antennas constituting the channels are horizontally arranged with respect to the ground.

7. The MIMO communication system having deterministic channels according to claim 3, wherein

the channel matrix calculation processing means sets geometric parameters of the channels so that the eigenvalue of the channel matrix becomes a multiplicity condition and performs calculation of a unitary matrix constituted based on an eigenvector obtained from the eigenvalue or an eigenvector obtained from the linear combination of eigenvectors on one of the transmission and reception sides to thereby construct virtual orthogonal channels as the channels.

4. A MIMO communication system having deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged, the system comprising

channel matrix calculation processing means for constructing orthogonal channels as the channels by setting geometric parameters of the channels concerning antenna distance so that the eigenvalue of the channel matrix becomes a multiplicity condition and performing, on the transmission or reception side, matrix calculation using a unitary matrix constituted based on singular vectors obtained from the eigenvalue or singular vectors obtained from the linear combination of eigenvectors,

wherein the plurality of transmission antennas and plurality of reception antennas constituting the channels are vertically arranged with respect to the ground, and antenna height from the ground is made an integral multiple of the antenna interval.

8. The MIMO communication system having deterministic channels according to claim 4, wherein

the channel matrix calculation processing means sets geometric parameters of the channels so that the eigenvalue of the channel matrix becomes a multiplicity condition and performs calculation of a unitary matrix constituted based on an eigenvector obtained from the eigenvalue or an eigenvector obtained from the linear combination of eigenvectors on one of the transmission and reception sides to thereby construct virtual orthogonal channels as the channels.

11. An antenna arrangement method for a MIMO communication system having deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged and used in a line-of-sight environment, the method comprising

channel matrix calculation processing means for calculating a channel matrix for constructing orthogonal channels as the channel on a transmission or reception side or both of the transmission and reception sides,

wherein the plurality of transmission antennas and plurality of reception antennas constituting the channel matrix are horizontally arranged with respect to the ground.

12-14. -14. (canceled)

15. A transmitter of a MIMO communication system having deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged and used in a line-of-sight environment, the transmitter comprising

channel matrix calculation processing means for calculating a channel matrix for constructing orthogonal channels as the channel,

wherein the plurality of transmission antennas constituting the channel matrix are horizontally arranged with respect to the ground.

16-18. -18. (canceled)

19. A receiver of a MIMO communication system having deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged and used in a line-of-sight environment, the receiver comprising

channel matrix calculation processing means for calculating a channel matrix for constructing orthogonal channels as the channel,

wherein the plurality of reception antennas constituting the channel matrix are horizontally arranged with respect to the ground.

20-22. -22. (canceled)