Method for grouping transmission antennas in mobile communication system including multiple transmission/reception antennas

• US 20050128983A1
• Filed: 11/15/2004
• Published: 06/16/2005
• Est. Priority Date: 11/13/2003
• Status: Active Grant

• Current Assignee: Korea Advanced Institute of Science and Technology, Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Ho-Jin, Kim, Eung-Sun, Lee, Jong-Hyeuk, Chung, Jae-Hak, Chun, Joo-Hwan, Kim, Il-Han, Lee, Kyung-Chun
• Granted Patent: US 7,483,719 B2
• Time in Patent Office: Days
• US Class Current: 370/334
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04B 7/0874 using subgroups of receive antennas

Abstract

Disclosed is a method for configuring transmission antenna groups in a mobile communication system with multiple transmission antennas and multiple reception antennas. The method includes the steps of: receiving a first matrix having a size of ‘N_t×N_t’, which corresponds to N_t number of transmission antennas, fedback from the mobile terminal, generating combinations of sub-matrixes of the first matrix corresponding to N_r number of reception antennas, and calculating sums of maximum eigenvalues; determining combinations of the sub-matrixes having a maximum value from among the calculated sums of eigenvalues to be transmission antenna groups for the N_t number of transmission antennas; and transmitting different relevant symbols from each other through the transmission antenna groups.

Claims

1. A method for grouping N_t number of transmission antennas and transmitting a relevant symbol to N_r number of reception antennas by a base station in a mobile communication system which includes the base station having the N_t number of transmission antennas and a mobile terminal having the N_r number of reception antennas, the method comprising the steps of:

receiving a first matrix having a size of ‘

N_t×

N_t’

, which corresponds to the N_t number of transmission antennas, fedback from the mobile terminal, generating combinations of sub-matrixes of the first matrix corresponding to the N_r number of reception antennas, and calculating sums of maximum eigenvalues;

determining combinations of the sub-matrices having a maximum value from among the calculated sums of eigenvalues to be transmission antenna groups for the N_t number of transmission antennas; and

transmitting different relevant symbols from each other through the transmission antenna groups.

2. The method as claimed in claim 1, wherein the step of transmitting different relevant symbols further comprises transmitting an equal relevant symbol multiplied by different weight values through different transmission antennas in an equal transmission antenna group.

3. The method as claimed in claim 1, wherein the combinations of the sub-matrices of the first matrix for the transmission antennas are obtained by measuring eigenvalues by a number of times calculated by,

$\frac{N_r^{N_t}}{N_r!}-\frac{{\left(N_r-1\right)}^{N_t}}{\left(N_r-1\right)!}-\cdots$

- 1 N t 1 ! .

4. The method as claimed in claim 3, wherein the combinations of the sub-matrices of the first matrix for adjacent transmission antennas of the transmission antennas are obtained by measuring eigenvalues by the number of times calculated by,

$\left[\begin{array}{c}{N}_t-1\\ N_r-1\end{array}\right].$

5. The method as claimed in claim 1, wherein the step of generating combinations of the sub-matrixes of the first matrix and calculating the eigenvalue includes the steps of:

calculating a first maximum eigenvalue of a first sub-matrix of the first matrix;

calculating a second maximum eigenvalue of a second sub-matrix of the first matrix; and

adding the first maximum eigenvalue and the second maximum eigenvalue to represent the eigenvalue.

6. The method as claimed in claim 5, wherein combinations of sub-matrices having a maximum value from among the sums of the maximum eigenvalues of combinations of sub-matrices of the first matrix are determined to be transmission antenna groups for the N_t number of transmission antennas, according to,

$\underset{}{\arg }$

 

⁢

max n 1 , …

⁢

 

, n N r ⁢

∑

i = 1 N r ⁢

 

⁢

max ⁡

( eig ⁡

( R ii ) ) ⁢

 

⁢

such ⁢

 

⁢

that ⁢

 

⁢

∑

i = 1 N r ⁢

 

⁢

n i = N t ,

wherein R_ii represents the sub-matrices of the first matrix and is

$\underset{i=1}{\overset{N_r}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>n_i=N_t.$

7. The method as claimed in claim 1, wherein N_t=N_r.

8. The method as claimed in claim 1, wherein the mobile terminal detects a received symbol by a nulling and canceling scheme corresponding to the transmission antennas groups.

9. A method for increasing communication capacity in a mobile communication system having a base station, a plurality of transmission antennas and a mobile terminal having a plurality of reception antennas, the method comprising the steps of:

receiving a channel covariance matrix, which corresponds to the number of the transmission antennas,

generating combinations of transmission antennas corresponding to the reception antennas;

determining combinations of transmission antennas having a maximum signal-to-noise ratio from among the generated combinations of the transmission antennas to be the transmission antenna groups; and

classifying the transmission antennas into relevant groups corresponding to the transmission antenna groups and simultaneously transmitting a signal according to the transmission antenna groups.

10. The method as claimed in claim 9, wherein different signals are transmitted through different transmission antenna groups, and equal signals are multiplied by a specific weight value and simultaneously transmitted through an equal transmission antenna group.

11. A method for configuring antenna groups in a mobile communication system having N_t number of transmission antennas in a base station and N_r number of reception antennas in a mobile terminal, the method comprising the steps of:

generating a first matrix having a size of ‘

N_t×

N_t’

corresponding to the N_t number of transmission antennas,

generating a predetermined number of sub-matrices of the first matrix, each sub-matrix corresponding to a specific combination of the transmission antennas, the predetermined number being a function of the N_r number of reception antennas;

determining a corresponding eigenvalue for each of the specific combinations;

calculating maximum eigenvalue sums for each of the combination configurations;

determining the best transmission antenna group configuration corresponding to the combination configuration with the largest maximum eigenvalue; and

transmitting different relevant symbols from each of the transmission antenna groups.