Beamforming signaling in a wireless network

1. A wireless device comprising:

a) one or more communication interfaces;

b) one or more processors; and

c) memory storing instructions that, when executed, cause said wireless device to:

i) receive from a first base station a measurement information message;

ii) compute a precoding matrix indicator (PMI) employing, in part:

(1) at least one information element (IE) in said measurement information message;

(2) measurement of first signals received from one or more antenna ports of said first base station; and

(3) measurement of second signals received from one or more antenna ports of a second base station;

iii) transmit channel state information comprising said PMI to said first base station; and

iv) receive at least one data packet, transmission of said at least one data packet employing beamforming according to a precoding matrix identified by said PMI.

2. The wireless device of claim 1 , wherein measurement of said first signals comprises measurement of reference signals received from said one or more antenna ports of said first base station.

3. The wireless device of claim 1 , wherein measurement of said second signals comprises measurement of reference signals received from said one or more antenna ports of said second base station.

4. The wireless device of claim 1 , wherein said at least one IE is generated by said first base station based, at least in part, on one or more information elements received by said first base station from said second base station.

5. The wireless device of claim 1 , wherein said first base station communicates with said second base station information about said at least one IE.

6. The wireless device of claim 5 , wherein said information is related to at least one downlink resource block.

7. The wireless device of claim 5 , wherein said information is related to downlink signals transmitted by said first base station or said second base station.

8. The wireless device of claim 1 , wherein said channel state information further comprises a rank indicator and a channel quality indicator.

9. The wireless device of claim 1 , wherein said wireless device selects said PMI from a subset of a precoding codebook indicated by a codebook subset restriction bitmap parameter.

10. The wireless device of claim 1 , wherein said PMI is computed, in part, to reduce downlink inter-cell interference received from said second base station.

11. The wireless device of claim 1 , wherein said wireless device selects said PMI from a plurality of predetermined PMIs.

12. The wireless device of claim 1 , wherein said PMI is computed for a sub-band of a downlink carrier.

13. A first base station comprising:

a) one or more communication interfaces;

b) one or more processors; and

c) memory storing instructions that, when executed, cause said first base station to:

i) transmit to a wireless device a measurement information message;

ii) receive from said wireless device channel state information comprising a precoding matrix indicator (PMI) computed employing, in part:

(1) at least one information element (IE) in said measurement information message; and

(2) measurement of first signals received by said wireless device from one or more antenna ports of said first base station; and

(3) measurement of second signals received by said wireless device from one or more antenna ports of a second base station; and

iii) transmit signals to said wireless device, said transmission employing beamforming according to a precoding matrix identified by said PMI.

14. The first base station of claim 13 , wherein said PMI is selected from a plurality of predetermined PMIs employing, at least in part, said measurement of signals to reduce downlink inter-cell interference received from said second base station.

15. The first base station of claim 13 , wherein measurement of said second signals is related to computation of inter-cell interference from said second base station.

16. The first base station of claim 13 , wherein said wireless device selects said PMI from a subset of a precoding codebook indicated by a codebook subset restriction bitmap parameter.

17. The first base station of claim 13 , wherein said channel state information further comprises a rank indicator and a channel quality indicator.

18. A method for use in a wireless network, the method comprising:

a) receiving, by a wireless device from a first base station, a measurement information message;

b) computing, by said wireless device, a precoding matrix indicator (PMI) employing, in part:

i) at least one information element (IE) in said measurement information message;

ii) measurement of first signals received from one or more antenna ports of a first base station; and

iii) measurement of second signals received from one or more antenna ports of a second base station;

c) transmitting, by said wireless device to said first base station, channel state information comprising said PMI; and

d) receiving by said wireless device at least one data packet, transmission of said at least one data packet employing beamforming according to a precoding matrix identified by said PMI.

19. The method of claim 18 , further comprising said first base station communicating with said second base station information about said at least one IE.

20. The method of claim 18 , wherein said at least one IE is generated by said first base station based, at least in part, on one or more information elements received by said first base station from said second base station.