TRANSMIT POWER ALLOCATION FOR ADAPTIVE MULTI-CARRIER MULTIPLEXING MIMO SYSTEMS

• US 20120320869A1
• Filed: 08/31/2012
• Published: 12/20/2012
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Stadelmeier, Lothar, Schneider, Daniel
• Granted Patent: US 9,362,993 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/0426 Power distribution
• CPC Class Codes: H04B 7/043 using best eigenmode, e.g. beam forming or beam steering
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 76/00 Connection management
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The present invention relates to transmit power allocation in multi-carrier, multiplexing MIMO communication systems. The present invention especially relates to a MIMO communication device, a method of assigning transmit power to two or more communication channels and a software program product. A multiple-input-multiple-output, MIMO, communication device according to the present invention comprises a link controller adapted to assign transmit power to two or more transmission channels, each of said transmission channels having preassigned a portion of transmit power for each of a group of subcarriers, said link controller being further adapted to assign, for each subcarrier of said group of subcarriers, at least part of the preassigned transmit power portion of a transmission channel that is not used for transmitting information at the subcarrier, to one or more transmission channels that are used for transmitting information at the subcarrier.

Claims

1. A method of assigning transmit power in a MIMO two-stream transmission, comprising

receiving first and second symbol streams, the first symbol stream associated with a plurality of subcarriers in accordance with constellation information contained in a first tonemap and the second symbol stream associated with the plurality of subcarriers in accordance with constellation information in a second tone map,

if, according to the first tonemap, a subcarrier is not used for transmitting data for the first symbol stream and if, according to the second tonemap, that subcarrier is used for transmitting data for the second symbol stream, allocating, for that subcarrier, a preassigned transmit power portion for the first symbol stream to the second symbol stream;

and

if, according to the second tonemap, a subcarrier is not used for transmitting data for the second symbol stream and if, according to the first tonemap, that subcarrier is used for transmitting data for the first symbol stream, allocating, for that subcarrier, a preassigned transmit power portion for the second symbol stream to the first symbol stream.

2. The method according to claim 1, wherein

after allocating the transmit power portion to the first or second symbol stream, respectively, the transmit power portion for the first or second symbol stream is 3 dB more than the preassigned transmit power portion for the first or second symbol stream, respectively.

3. The method according to claim 1, wherein

for each of the plurality of subcarriers, if according to the first and second tonernaps one of the first and second symbol streams is not used for transmitting information at the subcarrier and the other one of the first and second symbol streams is used for transmitting information at the subcarrier, a preassigned transmit power portion for the one of the first and second symbol streams that is not used for transmitting information at the subcarrier is assigned to the other one of the first and second symbol streams which is used for transmitting information at the subcarrier.

4. The method according to claim 1, wherein

allocating a transmit power portion includes multiplying a symbol of the first or second symbol stream, respectively, with an amplification factor corresponding to the allocated transmit power portion.

5. The method according to claim 1, wherein

the MIMO two-stream transmission is a PLC MIMO two-stream transmission.

6. A MIMO communication device, comprising

a first symbol mapper adapted to receive a first data stream, performing a symbol mapping on the first data stream according to a first tone map for a plurality of subcarriers, and outputting a first symbol stream,

a second symbol mapper adapted to receive a second data stream, performing a symbol mapping on the second data stream according to a second tone map for the plurality of subcarriers and outputting a second symbol stream, and

a power allocation unit adapted to receive the first and second symbol streams and to assign, for a subcarrier, if according to the first and second tonemaps one of the first and second symbol streams is not used for transmitting information at the subcarrier and the other one of the first and second symbol streams is used for transmitting information at the subcarrier, a preassigned transmit power portion for the one of the first and second symbol streams that is not used for transmitting information at the subcarrier to the other one of the first and second symbol streams which is used for transmitting information at the subcarrier.

7. The MIMO communication device according to claim 6, wherein

by assigning the preassigned transmit power portion for the symbol stream that is not used for transmitting information at the subcarrier to the one of the first and second symbol streams which is used for transmitting information at the subcarrier, the preassigned transmit power portion of that symbol stream is increased by 3 dB.

8. The MIMO communication device according to claim 6,

wherein the power allocation unit is further adapted to assign, for each of the plurality of subcarriers, if according to the first and second tonemaps one of the first and second symbol streams is not used for transmitting information at the subcarrier and the other one of the first and second symbol streams is used for transmitting information at the subcarrier, a preassigned transmit power portion for the one of the first and second symbol streams that is not used for transmitting information at the subcarrier to the other one of the first and second symbol streams which is used for transmitting information at the subcarrier.

9. The MIMO communication device according to claim 6, wherein

the power allocation unit is further configured to multiply a symbol of the first or second symbol stream, respectively, with an amplification factor corresponding to the allocated transmit power portion.

10. The MIMO communication device according to claim 6, wherein

the MIMO communication device is a PLC MIMO communication device.