Downlink transmission in a multiple-user multiple-input multiple-output (“MU-MIMO”) wireless communication system

1. A method for transmitting information in a multiple-input multiple-output (“MIMO”) wireless communication system, comprising:

updating channel quality information (“CQI”) values of a plurality of wireless devices, wherein updating said CQI values consider the effects of interference from transmissions to those wireless devices associated with a pre-assigned companion codeword set;

pairing said plurality of wireless devices using at least said CQI values, a precoding matrix index (“PMI”) value and said pre-assigned companion codeword set, wherein said pre-assigned companion codeword set, a pre-assigned companion codeword associated with said pre-assigned companion codeword set and said PMI value are updated for each of said plurality of wireless devices;

precoding the information for each of said plurality of wireless devices using said PMI value, said pre-assigned companion codeword or both; and

transmitting said precoded information to each of said plurality of wireless devices.

2. The method of claim 1 , wherein updating said channel quality information (“CQI”) values further comprise:

using single-user channel quality information (“SU-CQI) values, multiple-user channel quality information (“MU-CQI”) values or both to update said CQI values.

3. The method of claim 1 , wherein updating said channel quality information (“CQI”) values further comprise:

using single-user channel quality information (“SU-CQI”) values and CQI difference values to update said CQI values, wherein said CQI difference values represent the difference between said SU-CQI values and multiple-user channel quality information (“MU-CQI”) values.

4. The method of claim 1 , wherein said channel quality information (“CQI”) is calculated at said wireless devices and sent to a base station, estimated by said base station or both.

5. A base station in a multiple-input multiple-output (“MIMO”) wireless communication system, comprising:

a base station controller configured to receive feedback information including channel quality information (“CQI”) values from a plurality of wireless devices, wherein said CQI values include the effects of interference from transmissions to those wireless devices associated with a pre-assigned companion codeword set;

a MIMO pairing processor operative to pair said plurality of wireless devices using at least said CQI values and said pre-assigned companion codeword set, wherein pairing said plurality of wireless devices updates said pre-assigned companion codeword set and a precoding matrix index (“PMI”) value for each of said plurality of wireless devices;

a downlink (“DL”) transmit MIMO processor operative to precode the information for each of said plurality of wireless devices using said PMI value; and

a plurality of transmitters operative to use a plurality of antennas to transmit said precoded information to each of said plurality of wireless devices.

6. The base station of claim 5 , wherein said base station controller is further configured to use single-user channel quality information (“SU-CQI) values, multiple-user channel quality information (“MU-CQI”) values or both to update said channel quality information (“CQI”) values.

7. The base station of claim 6 , wherein the feedback of said single-user channel quality information (“SU-CQI”) values is compatible with long-term evolution (“LTE”) equipment.

8. The base station of claim 6 , wherein the feedback of said multiple-user channel quality information (“MU-CQI”) values is configured as additional said feedback information.

9. The base station of claim 5 , wherein said base station controller is further configured to use single-user channel quality information (“SU-CQI”) values and channel quality information (“CQI”) difference values to update said CQI values, wherein said CQI difference values represent the difference between said SU-CQI values and multiple-user channel quality indication (“MU-CQI”) values.

10. The base station of claim 5 , wherein said base station controller can change periodically, aperiodically or both said pre-assigned companion codeword set.

11. The base station of claim 5 , wherein said base station controller can change the type, rate, amount or any combination thereof of said feedback information, wherein said feedback information includes single-user channel quality information (“SU-CQI”) values, multiple-user channel quality information (“MU-CQI”) or both.

12. The base station of claim 5 , wherein said base station controller can change said pre-assigned companion codeword set to control the performance of the system.

13. The base station of claim 5 , wherein said base station controller can change said pre-assigned companion codeword set based on the number of said wireless devices associated with the base station.

14. The base station of claim 5 , wherein said base station controller can communicate said pre-assigned companion codeword set, a precoding matrix index (“PMI”) value or both to each of said plurality of wireless devices.

15. The base station of claim 5 , wherein said base station controller can communicate periodically, aperiodically or both said pre-assigned companion codeword set, a precoding matrix index (“PMI”) value or both to each of said plurality of wireless devices.

16. The base station of claim 5 , wherein said base station controller can communicate said pre-assigned companion codeword set, a precoding matrix index (“PMI”) value or both to each of said plurality of wireless devices by using point-to-point communication, point-to-multipoint communication or both.

17. The base station of claim 5 , wherein said base station controller can communicate said pre-assigned companion codeword set to each of said plurality of wireless devices by sending a broadcast control channel message (“BCCH”).

18. The base station of claim 5 , wherein said base station controller can communicate said pre-assigned companion codeword set, a precoding matrix index (“PMI”) value or both to each of said plurality of wireless devices by sending a wireless device-specific control channel message (“PDCCH”).

19. The base station of claim 5 , wherein said base station controller can determine the number of transmission layers for each of said plurality of wireless devices.

20. A wireless device in a multiple-input multiple-output (“MIMO”) wireless communication system, comprising:

a downlink (“DL”) receive MIMO processor configured to determine channel quality information (“CQI”) values including for transmissions to those wireless devices associated with a pre-assigned companion codeword set; and

a wireless device controller configured to receive configuration information wherein said configuration information configures the MIMO feedback mode of a wireless device and includes said pre-assigned companion codeword set, and to feedback said CQI values to a base station consistent with the MIMO feedback mode of said wireless device.

21. The wireless device of claim 20 , wherein said downlink (“DL”) receive MIMO processor is further configured to calculate single-user channel quality information (“SU-CQI) values, multiple-user channel quality information (“MU-CQI”) values or both to determine said channel quality information (“CQI”) values.

22. The wireless device of claim 20 , wherein said downlink (“DL”) receive MIMO processor is further configured to determine said CQI values by calculating single-user channel quality information (“SU-CQI”) values and channel quality information (“CQI”) difference values, wherein said CQI difference values represent the difference between said SU-CQI values and multiple-user channel quality information (“MU-CQI”) values.

23. The wireless device of claim 20 , wherein said wireless device controller can feedback to said base station the wireless device's preferred combination of paired wireless devices based on said pre-assigned companion codeword set.

24. The wireless device of claim 20 , wherein said downlink (“DL”) receive MIMO processor performs interference rejection, cancellation or both using said pre-assigned companion codeword set.

25. A method for supporting information transmission in a multiple-input multiple-output (“MIMO”) wireless communication system, comprising:

receiving configuration information from a base station, wherein said configuration information configures the MIMO feedback mode of a wireless device and includes a pre-assigned companion codeword set;

determining channel quality information (“CQI”) values including the effects of interference from transmissions to those wireless devices associated with said pre-assigned companion codeword set; and

providing said CQI values to said base station consistent with the MIMO feedback mode of said wireless device.

26. The method of claim 25 , wherein determining said channel quality information (“CQI”) values further comprise:

calculating single-user channel quality information (“SU-CQI) values, multiple-user channel quality information (“MU-CQI”) values or both to determine said CQI values.

27. The method of claim 25 , wherein providing said channel quality information (“CQI”) values further comprise:

providing single-user channel quality information (“SU-CQI”) values and CQI difference values, wherein said CQI difference values represent the difference between said SU-CQI values and multiple-user channel quality information (“MU-CQI”) values.

28. The method of claim 25 , further comprising:

determining a precoding matrix index (“PMI”) value; and

providing said PMI value to said base station consistent with the MIMO feedback mode of said wireless device.

29. The method of claim 25 , further comprising:

determining a rank indicator (“RI”) value; and

providing said RI value to said base station consistent with the MIMO feedback mode of said wireless device.

30. The method of claim 25 , wherein said configuration information further includes a pre-coding matrix index (“PMI”) value, a rank indicator (“RI”) value or both.