Asymmetrical mimo wireless communications

• US 20050185575A1
• Filed: 11/01/2004
• Published: 08/25/2005
• Est. Priority Date: 02/19/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Shen, Ba-Zhong, Hansen, Christopher J., Tran, Hau Thien, Trachewsky, Jason A., Cameron, Kelly Brian, Seshadri, Nambirajan
• Granted Patent: US 7,746,886 B2
• Time in Patent Office: Days
• US Class Current: 370/208
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence

Abstract

A method for asymmetrical MIMO wireless communication begins by determining a number of transmission antennas for the asymmetrical MIMO wireless communication. The method continues by determining a number of reception antennas for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas exceeds the number of reception antennas, using spatial time block coding for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas does not exceed the number of reception antennas, using spatial multiplexing for the asymmetrical MIMO wireless communication.

Claims

1. A method for asymmetrical MIMO wireless communication, the method comprises:

determining a number of transmission antennas for the asymmetrical MIMO wireless communication;

determining whether the asymmetric MIMO wireless communication will use spatial multiplexing or space-time block coding based on the number of transmission antennas;

for spatial multiplexing, providing different constellation points for transmission on each of the number of transmission antennas; and

for space-time block coding;

during a first time interval;

providing, for transmission on a first one of the number of transmission antennas, a first constellation point; and

providing, for transmission on a second one of the number of transmission antennas, a second constellation point; and

during a second time interval;

providing, for transmission on the first one of the number of transmission antennas, an inverse complex conjugate of the second constellation point; and

providing, for transmission on the second one of the number of transmission antennas, a complex conjugate of the second constellation point.

2. The method of claim 1, wherein the determining whether the asymmetric MIMO wireless communication will use spatial multiplexing or space-time block coding further comprises:

determining a number of reception antennas; and

determining whether the asymmetric MIMO wireless communication will use spatial multiplexing or space-time block coding based on the number of reception antennas.

3. The method of claim 2, wherein the determining the number of reception antennas comprises:

receiving, from a receiving wireless communication device, the number of reception antennas.

4. The method of claim 2 further comprises:

using the spatial multiplexing when the number of reception antennas equals or exceeds the number of transmission antennas; and

using the spatial time block coding when the number of reception antennas is less than the number of transmission antennas.

5. The method of claim 2, wherein, when the number of transmission antennas exceeds the number of reception antennas by an odd number, the spatial time block coding comprises:

selecting one of the transmission antennas for transmitting non-spatial time block coding constellation points during the first and second time intervals; and

grouping remaining transmission antennas of the transmission antennas into at least one group of transmission antennas, wherein the at least one group of transmission antennas transmits spatial time block coding constellation points.

6. The method of claim 5, wherein the selecting one of the transmission antennas comprises:

from spatial-time coding interval to spatial-time coding interval, selecting another one of the transmission antennas for transmitting the non-spatial time block coding constellation points.

7. The method of claim 2, wherein, when the number of transmission antennas exceeds the number of reception antennas by an even number, the spatial time block coding comprises:

dividing the transmission antennas into at least two groups, where each of the at least two groups includes at least two of the transmission antennas; and

individually performing the spatial time block coding for the at least two groups.

8. The method of claim 7 further comprises:

from spatial-time coding interval to spatial-time coding interval, dividing the transmission antennas into at least two different groups.

9. A method for asymmetrical MIMO wireless communication, the method comprises:

determining a number of transmission antennas for the asymmetrical MIMO wireless communication;

determining a number of reception antennas for the asymmetrical MIMO wireless communication;

when the number of transmission antennas exceeds the number of reception antennas, using spatial time block coding for the asymmetrical MIMO wireless communication; and

when the number of transmission antennas does not exceed the number of reception antennas, using spatial multiplexing for the asymmetrical MIMO wireless communication.

10. The method of claim 9, wherein the determining the number of reception antennas comprises:

receiving, from a receiving wireless communication device, the number of reception antennas.

11. The method of claim 9, wherein, when the number of transmission antennas exceeds the number of reception antennas by an odd number, the spatial time block coding comprises:

selecting one of the transmission antennas for transmitting non-spatial time block coding constellation points during the first and second time intervals; and

grouping remaining transmission antennas of the transmission antennas into at least one group of transmission antennas, wherein the at least one group of transmission antennas transmits spatial time block coding constellation points.

12. The method of claim 11, wherein the selecting one of the transmission antennas comprises:

from spatial-time coding interval to spatial-time coding interval, selecting another one of the transmission antennas for transmitting the non-spatial time block coding constellation points.

13. The method of claim 9, wherein, when the number of transmission antennas exceeds the number of reception antennas by an even number, the spatial time block coding comprises:

dividing the transmission antennas into at least two groups, where each of the at least two groups includes at least two of the transmission antennas; and

individually performing the spatial time block coding for the at least two groups.

14. The method of claim 13 further comprises:

from spatial-time coding interval to spatial-time coding interval, dividing the transmission antennas into at least two different groups.

15. A radio frequency (RF) transmitter comprises:

a baseband processing module operably coupled to convert outbound data into an outbound symbol stream; and

a transmitter section operably coupled to convert the outbound symbol stream into outbound RF signals, wherein the transmitter section includes transmission antennas, and wherein the baseband processing module is further operably coupled to;

determine a number of the transmission antennas for the asymmetrical MIMO wireless communication;

determine whether the asymmetric MIMO wireless communication will use spatial multiplexing or space-time block coding based on the number of the transmission antennas;

for spatial multiplexing, provide different constellation points for transmission on each of the transmission antennas; and

for space-time block coding;

during a first time interval;

provide, for transmission on a first one of the transmission antennas, a first constellation point; and

provide, for transmission on a second one of the transmission antennas, a second constellation point; and

during a second time interval;

provide, for transmission on the first one of the transmission antennas, an inverse complex conjugate of the second constellation point; and

provide, for transmission on the second one of the transmission antennas, a complex conjugate of the second constellation point.

16. The RF transmitter of claim 15, wherein the baseband processing module is further operably coupled to determine whether the asymmetric MIMO wireless communication will use spatial multiplexing or space-time block coding by:

determining a number of reception antennas; and

determining whether the asymmetric MIMO wireless communication will use spatial multiplexing or space-time block coding based on the number of reception antennas.

17. The RF transmitter of claim 16, wherein the baseband processing module is further operably coupled to determine the number of reception antennas by:

receiving, from a receiving wireless communication device, the number of reception antennas.

18. The RF transmitter of claim 16, wherein the baseband processing module is further operably coupled to:

use the spatial multiplexing when the number of reception antennas equals or exceeds the number of transmission antennas; and

use the spatial time block coding when the number of reception antennas is less than the number of transmission antennas.

19. The RF transmitter of claim 16, wherein the baseband processing module is further operably coupled to, when the number of transmission antennas exceeds the number of reception antennas by an odd number, perform the spatial time block coding by:

selecting one of the transmission antennas for transmitting non-spatial time block coding constellation points during the first and second time intervals; and

grouping remaining transmission antennas of the transmission antennas into at least one group of transmission antennas, wherein the at least one group of transmission antennas transmits spatial time block coding constellation points.

20. The RF transmitter of claim 19, wherein the baseband processing module is further operably coupled to select one of the transmission antennas by:

from spatial-time coding interval to spatial-time coding interval, selecting another one of the transmission antennas for transmitting the non-spatial time block coding constellation points.

21. The RF transmitter of claim 16, wherein the baseband processing module is further operably coupled to, when the number of transmission antennas exceeds the number of reception antennas by an even number, perform the spatial time block coding by:

dividing the transmission antennas into at least two groups, where each of the at least two groups includes at least two of the transmission antennas; and

individually performing the spatial time block coding for the at least two groups.

22. The RF transmitter of claim 21, wherein the baseband processing module is further operably coupled to:

from spatial-time coding interval to spatial-time coding interval, divide the transmission antennas into at least two different groups.

23. A radio frequency (RF) transmitter comprises:

a baseband processing module operably coupled to convert outbound data into an outbound symbol stream; and

a transmitter section operably coupled to convert the outbound symbol stream into outbound RF signals, wherein the transmitter section includes transmission antennas, and wherein the baseband processing module is further operably coupled to;

determine a number of transmission antennas for the asymmetrical MIMO wireless communication;

determine a number of reception antennas for the asymmetrical MIMO wireless communication;

when the number of transmission antennas exceeds the number of reception antennas, use spatial time block coding for the asymmetrical MIMO wireless communication; and

when the number of transmission antennas does not exceed the number of reception antennas, use spatial multiplexing for the asymmetrical MIMO wireless communication.

24. The RF transmitter of claim 23, wherein the baseband processing module is further operably coupled to determine the number of reception antennas by:

receiving, from a receiving wireless communication device, the number of reception antennas.

25. The RF transmitter of claim 23, wherein the baseband processing module is further operably coupled to, when the number of transmission antennas exceeds the number of reception antennas by an odd number, perform the spatial time block coding by:

selecting one of the transmission antennas for transmitting non-spatial time block coding constellation points during the first and second time intervals; and

grouping remaining transmission antennas of the transmission antennas into at least one group of transmission antennas, wherein the at least one group of transmission antennas transmits spatial time block coding constellation points.

26. The RF transmitter of claim 25, wherein the baseband processing module is further operably coupled to select one of the transmission antennas by:

from spatial-time coding interval to spatial-time coding interval, selecting another one of the transmission antennas for transmitting the non-spatial time block coding constellation points.

27. The RF transmitter of claim 23, wherein the baseband processing module is further operably coupled to, when the number of transmission antennas exceeds the number of reception antennas by an even number, perform the spatial time block coding by:

dividing the transmission antennas into at least two groups, where each of the at least two groups includes at least two of the transmission antennas; and

individually performing the spatial time block coding for the at least two groups.

28. The RF transmitter of claim 23, wherein the baseband processing module is further operably coupled to:

from spatial-time coding interval to spatial-time coding interval, divide the transmission antennas into at least two different groups.