Almost blank subframe indication in wireless networks
A base station transmits a first unicast control message configuring transmission parameters of a first carrier for a wireless device. The base station transmits at least one second unicast message configuring measurement parameters of a second carrier. The measurement configuration comprises a first and a second measurement subframe allocation bitmap for the second carrier. The base station receives first and second channel state information from the wireless device. The base station transmits data packets to the wireless device. The data packets are encoded and modulated based on the first and second channel state information.
1. A base station 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 first parameters identifying a first set of subframes on a primary carrier as almost blank subframes;
ii) transmit to a wireless device at least one unicast control message comprising:
(1) second parameters identifying a second set of subframes on a secondary carrier as almost blank subframes;
(2) a first measurement subframe allocation bitmap identifying a first plurality of measurement subframes of said secondary carrier; and
(3) a second measurement subframe allocation bitmap identifying a second plurality of measurement subframes of said secondary carrier; and
iii) receive first channel state information (CSI) and second CSI from said wireless device, said first CSI being measured on a first plurality of OFDM subcarriers of said secondary carrier on said first plurality of measurement subframes, said second CSI being measured on a second plurality of OFDM subcarriers of said secondary carrier on said second plurality of measurement subframes.
2. The base station of claim 1 , wherein said second plurality of measurement subframes exclude subframes in said first plurality of measurement subframes.
3. The base station of claim 1 , wherein in said almost blank subframes:
a) no signal is transmitted by said base station; or
b) signals are transmitted at an almost blank subframe power level that is substantially lower than a transmit power during a non-almost blank subframe.
4. The base station of claim 1 , wherein said at least one unicast control message comprises at least one cross carrier scheduling parameter indicating that said primary carrier carries scheduling information for packets transmitted to said wireless device on a data channel of said secondary carrier.
5. The base station of claim 4 , wherein, during the time said cross carrier scheduling is configured and said secondary carrier is activated, when said primary carrier enters an almost blank subframe, said secondary carrier also enters an almost blank subframe.
6. The base station of claim 1 , wherein during the time said second carrier is configured and activated, when said primary carrier enters an almost blank subframe, said secondary carrier also enters an almost blank subframe.
7. The base station of claim 1 , further comprising, in said almost blank subframe, transmitting a common reference signal only in a control region of said almost blank subframe.
8. The base station of claim 1 , wherein said at least one unicast control message further comprises at least one measurement subframe parameter of a plurality neighboring carriers.
9. The base station of claim 1 , wherein said at least one unicast control message further comprises:
a) one or more third parameters identifying a CSI transmission resource;
b) one or more CSI measurement resource parameters; and
c) one or more fourth parameters identifying a physical uplink control channel format.
10. The base station of claim 9 , wherein said instructions, when executed, further cause said base station to transmit a plurality of data packets to said wireless device on said secondary carrier, said plurality of data packets encoded and modulated based, at least in part, on one of said first and second CSI.
11. 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 base station a broadcast message comprising first parameters identifying a first set of subframes on a primary carrier as almost blank subframes;
ii) receive from said base station at least one unicast control message comprising:
(1) second parameters identifying a second set of subframes on a secondary carrier as almost blank subframes;
(2) a first measurement subframe allocation bitmap identifying a first plurality of measurement subframes of said secondary carrier; and
(3) a second measurement subframe allocation bitmap identifying a second plurality of measurement subframes of said secondary carrier; and
iii) transmit first channel state information (CSI) and second CSI, said first CSI being measured on a first plurality of OFDM subcarriers of said secondary carrier on said first plurality of measurement subframes, said second CSI being measured on a second plurality of OFDM subcarriers of said secondary carrier on said second plurality of measurement subframes.
12. The wireless device of claim 11 , wherein said second plurality of measurement subframes exclude subframes in said first plurality of measurement subframes.
13. The wireless device of claim 11 , wherein in said almost blank subframes:
a) no signal is transmitted by said base station; or
b) signals are transmitted by said base station at an almost blank subframe power level that is substantially lower than a transmit power during a non-almost blank subframe.
14. The wireless device of claim 11 , wherein said at least one unicast control message comprises at least one cross carrier scheduling parameter indicating that said primary carrier carries scheduling information for packets transmitted to said wireless device on a data channel of said secondary carrier.
15. The wireless device of claim 14 , wherein, during the time said cross carrier scheduling is configured and said secondary carrier is activated, when said primary carrier enters an almost blank subframe, said secondary carrier also enters an almost blank subframe.
16. The wireless device of claim 11 , wherein during the time said second carrier is configured and activated, when said primary carrier enters an almost blank subframe, said secondary carrier also enters an almost blank subframe.
17. The wireless device of claim 11 , further comprising, in said almost blank subframe, transmitting a common reference signal only in a control region of said almost blank subframe.
18. The wireless device of claim 11 , wherein said at least one unicast control message further comprises at least one measurement subframe parameter of a plurality neighboring carriers.
19. The wireless device of claim 11 , wherein said at least one unicast control message further comprises:
a) one or more third parameters identifying a CSI transmission resource;
b) one or more CSI measurement resource parameters; and
c) one or more fourth parameters identifying a physical uplink control channel format.
20. The wireless device of claim 19 , wherein said instructions, when executed, further cause said wireless device to receive a plurality of data packets from said base station on said secondary carrier, said plurality of data packets encoded and modulated based, at least in part, on one of said first and second CSI.