Special subframe configuration in wireless networks

1. A method comprising:

a) broadcasting, by a base station configured to communicate employing a plurality of carriers transmitting symbols in a sequential series of subframes, a first set of parameters identifying a first set of subframes on a first carrier in said plurality of carriers as special subframes; and

b) transmitting, by said base station, at least one unicast radio resource control message to a wireless device, said at least one unicast radio resource control message:

i) configured to cause configuration of:

(1) a second carrier; and

(2) cross carrier scheduling for said wireless device, said cross carrier scheduling configuration indicating that said first carrier carries scheduling information for packets transmitted to said wireless device on a data channel of said second carrier; and

ii) comprising:

(1) an index identifying a frequency of said second carrier;

(2) at least one physical layer parameter of said second carrier;

(3) at least one measurement parameter of said second carrier; and

(4) a second set of parameters identifying a second set of subframes on said second carrier as special subframes; and

wherein a majority of symbols of each special subframe have:

i) no signal being transmitted by said base station; or

ii) signals being transmitted at a special subframe power level that is substantially lower than a transmit power during a non-special subframe.

2. The method of claim 1 , further comprising configuring, by said base station, said second carrier to enter a special subframe for every subframe in which:

a) said first carrier enters a special subframe;

b) said cross carrier scheduling is configured; and

c) said second carrier is activated.

3. The method of claim 1 , wherein said at least one unicast radio resource control message is transmitted on said first carrier.

4. The method of claim 1 , wherein said at least one unicast radio resource control message configured to further cause configuration of measurement parameters of said second carrier for said wireless device, said measurement configuration comprising:

a) a first measurement subframe allocation bitmap configuring a first plurality of measurement subframes of said second carrier; and

b) a second measurement subframe allocation bitmap configuring a second plurality of measurement subframes of said second carrier, said second plurality of measurement subframes excluding subframes in said first plurality of measurement subframes.

5. The method of claim 4 , further comprising receiving, by said base station, first channel state information and second channel state information from said wireless device, said first channel state information measured on a first plurality of OFDM subcarriers of said second carrier on said first plurality of measurement subframes, said second channel state information being measured on a second plurality of OFDM subcarriers of said second carrier on said second plurality of measurement subframes.

6. The method of claim 5 , further comprising transmitting, by said base station, a plurality of data packets to said wireless device on said second carrier, said plurality of data packets encoded and modulated based, at least in part, on said first second channel state information and said second channel state information.

7. The method of claim 4 , wherein said measurement configuration further comprises:

a) one or more first parameters identifying a channel state information transmission resource;

b) one or more channel state information measurement resource parameters; and

c) one or more second parameters identifying a physical uplink control channel format.

8. The method of claim 7 , further comprising receiving, by said base station, channel state information on said channel state information transmission resource from said wireless device on said first carrier employing said physical uplink control channel format, said channel state information comprising:

a) first channel state information measured on a first plurality of OFDM subcarriers of said second carrier on one or more of said first plurality of measurement subframes, said first plurality of OFDM subcarriers determined, at least in part, by said one or more channel state information measurement resource parameters; and

b) second channel state information measured on a second plurality of OFDM subcarriers of said second carrier on one or more of said second plurality of measurement subframes, said second plurality of OFDM subcarriers determined, at least in part, by said one or more measurement resource parameters.

9. The method of claim 1 , further comprising, in said special subframe, transmitting a common reference signal only in a control region of said special subframe.

10. The method of claim 1 , wherein said at least one unicast radio resource control message configured to further cause configuration of measurement subframes of a plurality neighboring carriers in said wireless device.

11. A base station, configured to communicate employing a plurality of carriers transmitting symbols in a sequential series of subframes, comprising:

a) one or more communication interfaces;

b) one or more processors; and

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

i) broadcast a first set of parameters identifying a first set of subframes on a first carrier in said plurality of carriers as special subframes; and

ii) transmit at least one unicast radio resource control message to a wireless device, said at least one unicast radio resource control message is configured to cause configuration of cross carrier scheduling for a wireless device, said cross carrier scheduling configuration indicating that said first carrier carries scheduling information for packets transmitted to said wireless device on a data channel of a second carrier in said plurality of carriers, said at least one unicast radio resource control message comprising a second set of parameters identifying a second set of subframes on said second carrier as special subframes; and

wherein a majority of symbols of each special subframe have:

(1) no signal being transmitted by said base station; or

(2) signals being transmitted at a special subframe power level that is substantially lower than a transmit power during a non-special subframe.

12. The base station of claim 11 , wherein said instructions, when executed, further cause said base station to configure said second carrier to enter a special subframe for every subframe in which:

a) said first carrier enters a special subframe;

b) said cross carrier scheduling is configured; and

c) said second carrier is activated.

13. The base station of claim 11 , wherein said at least one unicast radio resource control message is transmitted on said first carrier.

14. The base station of claim 11 , wherein said at least one unicast radio resource control message configured to further cause configuration of measurement parameters of said second carrier for said wireless device, said measurement configuration comprising:

a) a first measurement subframe allocation bitmap configuring a first plurality of measurement subframes of said second carrier; and

b) a second measurement subframe allocation bitmap configuring a second plurality of measurement subframes of said second carrier, said second plurality of measurement subframes excluding subframes in said first plurality of measurement subframes.

15. The base station of claim 14 , further comprising receiving, by said base station, first channel state information and second channel state information from said wireless device, said first channel state information measured on a first plurality of OFDM subcarriers of said second carrier on said first plurality of measurement subframes, said second channel state information being measured on a second plurality of OFDM subcarriers of said second carrier on said second plurality of measurement subframes.

16. A method comprising:

a) broadcasting, by a base station configured to communicate employing a plurality of carriers transmitting symbols in a sequential series of subframes, a first set of parameters identifying a first set of subframes on a first carrier in said plurality of carriers as special subframes; and

b) transmitting, by said base station, at least one unicast radio resource control message to a wireless device, said at least one unicast radio resource control message is configured to cause configuration of cross carrier scheduling for a wireless device, said cross carrier scheduling configuration indicating that said first carrier carries scheduling information for packets transmitted to said wireless device on a data channel of a second carrier in said plurality of carriers, said at least one unicast radio resource control message comprising a second set of parameters identifying a second set of subframes on said second carrier as special subframes; and

wherein a majority of symbols of each special subframe have:

ii) no signal being transmitted by said base station; or

iii) signals being transmitted at a special subframe power level that is substantially lower than a transmit power during a non-special subframe.

17. The method of claim 16 , wherein said at least one unicast radio resource control message configured to further cause configuration of measurement parameters of said second carrier for said wireless device, said measurement configuration comprising:

a) a first measurement subframe allocation bitmap configuring a first plurality of measurement subframes of said second carrier; and

b) a second measurement subframe allocation bitmap configuring a second plurality of measurement subframes of said second carrier, said second plurality of measurement subframes excluding subframes in said first plurality of measurement subframes.

18. The method of claim 17 , further comprising receiving, by said base station, first channel state information and second channel state information from said wireless device, said first channel state information measured on a first plurality of OFDM subcarriers of said second carrier on said first plurality of measurement subframes, said second channel state information being measured on a second plurality of OFDM subcarriers of said second carrier on said second plurality of measurement subframes.

19. The method of claim 18 , further comprising transmitting, by said base station, a plurality of data packets to said wireless device on said second carrier, said plurality of data packets encoded and modulated based, at least in part, on said first channel state information and said second channel state information.

20. The method of claim 16 , wherein said at least one unicast radio resource control message further configures measurement subframes of a plurality neighboring carriers for said wireless device.