Performing interference cancellation on received signals
A wireless device may receive configuration information associated with reduced transmission power time intervals of a first base station. Interference cancellation may be performed based on the configuration information and based on received signals to determine a signal corresponding to a second base station.
1. A method comprising:
receiving signals from a plurality of base stations;
generating, based on at least one of the received signals, an encoded first signal corresponding to a first base station;
generating a second signal corresponding to a second base station by at least performing, based on the encoded first signal, interference cancellation on the at least one of the received signals;
determining a control format indicator based on the second signal;
determining, based on the control format indicator, a quantity of orthogonal frequency division multiplexing (OFDM) symbols of a control region of the second base station; and
receiving, based on the quantity of OFDM symbols and from the second base station, a control signal in the control region.
2. The method of claim 1 , wherein the control format indicator comprises sixteen modulation symbols received starting from a first symbol in a subframe.
3. The method of claim 1 , wherein the performing the interference cancellation comprises:
subtracting the encoded first signal from the at least one of the received signals.
4. The method of claim 1 , wherein the encoded first signal corresponds to interference associated with the first base station.
5. The method of claim 1 , wherein the encoded first signal is associated with one or more of:
a physical downlink control channel; or
control information associated with the first base station.
6. The method of claim 1 , wherein the generating the encoded first signal comprises:
generating a first signal by at least decoding the at least one of the received signals; and
encoding the first signal to produce the encoded first signal.
7. The method of claim 1 , wherein the generating the encoded first signal comprises at least one of:
decoding the at least one of the received signals;
demodulating the at least one of the received signals; or
descrambling the at least one of the received signals.
8. The method of claim 1 , wherein the generating the encoded first signal comprises:
generating a first signal by at least decoding the at least one of the received signals;
at least one of: scrambling the first signal, modulating the first signal, or scaling the first signal; and
encoding the first signal to produce the encoded first signal.
9. The method of claim 1 , wherein the determining the control format indicator comprises at least one of: decoding the second signal, demodulating the second signal, or descrambling the second signal.
10. A method comprising:
receiving signals from a plurality of base stations;
generating, based on at least one of the received signals, an encoded first signal corresponding to a first base station;
generating a second signal corresponding to a second base station by at least performing, based on the encoded first signal, interference cancellation on the at least one of the received signals;
determining a physical broadcast message based on the second signal;
determining, based on the physical broadcast message, a plurality of system parameters of the second base station; and
receiving, based on at least one of the plurality of system parameters and from the second base station, a plurality of resource blocks.
11. The method of claim 10 , wherein the plurality of system parameters comprises:
system bandwidth information;
hybrid automatic repeat request (HARQ) indicator channel structure information; and
eight most significant bits of a system frame number.
12. The method of claim 10 , further comprising receiving the physical broadcast message via one or more antenna ports.
13. The method of claim 10 , wherein the encoded first signal corresponds to interference associated with the first base station.
14. The method of claim 10 , wherein the encoded first signal is associated with one or more of:
a physical downlink control channel; or
control information associated with the first base station.
15. The method of claim 10 , wherein the generating the encoded first signal comprises:
generating a first signal by at least decoding the at least one of the received signals; and
encoding the first signal to produce the encoded first signal.
16. The method of claim 10 , wherein the generating the encoded first signal comprises at least one of:
decoding the at least one of the received signals,
demodulating the at least one of the received signals; or
descrambling the at least one of the received signals.
17. The method of claim 10 , wherein the generating the encoded first signal comprises:
generating a first signal by at least decoding the at least one of the received signals;
at least one of: scrambling the first signal, modulating the first signal, or scaling the first signal; and
encoding the first signal to produce the encoded first signal.
18. The method of claim 10 , wherein the determining the physical broadcast message further comprises at least one of: decoding the second signal, demodulating the second signal, or descrambling the second signal.
19. A method comprising:
receiving, by a wireless device, signals from a plurality of base stations;
generating a first plurality of correlation values by correlating a first plurality of synchronization signals with at least one of the received signals;
determining, based on the first plurality of correlation values, a first synchronization signal transmitted by a first base station;
determining an updated received signal by at least performing, based on the first synchronization signal, interference cancellation on the at least one of the received signals;
determining, based on the updated received signal, a second synchronization signal transmitted by a second base station; and
receiving, based on the second synchronization signal, a message.
20. The method of claim 19 , wherein the first plurality of synchronization signals are identified by the wireless device before the first plurality of correlation values are generated.
21. The method of claim 19 , wherein the first synchronization signal has a greatest correlation value among the first plurality of correlation values.
22. The method of claim 19 , wherein the first synchronization signal is transmitted via seventy-two orthogonal frequency division multiplexing (OFDM) subcarriers substantially in a center of a carrier.
23. The method of claim 19 , further comprising scaling the first synchronization signal by a scaling factor that is based on a characteristic of a wireless channel.
24. The method of claim 19 , further comprising:
determining, based on the second synchronization signal, timing information of the second base station.
25. The method of claim 19 , wherein the second synchronization signal is transmitted periodically with a fixed period.
26. The method of claim 19 , wherein the second synchronization signal comprises a Zadoff-Chu sequence.
27. The method of claim 19 , wherein the performing the interference cancellation comprises:
subtracting the first synchronization signal from the at least one of the received signals.
28. The method of claim 19 , wherein the first synchronization signal corresponds to interference associated with the first base station.
29. The method of claim 19 , wherein the receiving the message based on the second synchronization signal comprises receiving, based on a physical cell ID of the second base station, the message, wherein the physical cell ID is based on the second synchronization signal.
30. The method of claim 1 , wherein the encoded first signal comprises a second control format indicator associated with the first base station.
31. The method of claim 10 , wherein the encoded first signal comprises a second physical broadcast message associated with the first base station.
32. A wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the wireless device to:
receive signals from a plurality of base stations;
generate, based on at least one of the received signals, an encoded first signal corresponding to a first base station;
generate a second signal corresponding to a second base station by at least performing, based on the encoded first signal, interference cancellation on the at least one of the received signals;
determine a control format indicator based on the second signal;
determine, based on the control format indicator, a quantity of orthogonal frequency division multiplexing (OFDM) symbols of a control region of the second base station; and
receive, based on the quantity of OFDM symbols and from the second base station, a control signal in the control region.
33. The wireless device of claim 32 , wherein the control format indicator comprises sixteen modulation symbols received starting from a first symbol in a subframe.
34. The wireless device of claim 32 , wherein the instructions, when executed by the one or more processors, cause the wireless device to perform the interference cancellation by at least subtracting the encoded first signal from the at least one of the received signals.
35. The wireless device of claim 32 , wherein the encoded first signal corresponds to interference associated with the first base station.
36. The wireless device of claim 32 , wherein the instructions, when executed by the one or more processors, cause the wireless device to generate the encoded first signal by at least:
generating a first signal by at least decoding the at least one of the received signals;
at least one of: scrambling the first signal, modulating the first signal, or scaling the first signal; and
encoding the first signal to produce the encoded first signal.
37. The wireless device of claim 32 , wherein the encoded first signal comprises a second control format indicator associated with the first base station.
38. A wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the wireless device to:
receive signals from a plurality of base stations;
generate, based on at least one of the received signals, an encoded first signal corresponding to a first base station;
generate a second signal corresponding to a second base station by at least performing, based on the encoded first signal, interference cancellation on the at least one of the received signals;
determine a physical broadcast message based on the second signal;
determine, based on the physical broadcast message, a plurality of system parameters of the second base station; and
receive, based on at least one of the plurality of system parameters and from the second base station, a plurality of resource blocks.
39. The wireless device of claim 38 , wherein the plurality of system parameters comprises:
system bandwidth information;
hybrid automatic repeat request (HARQ) indicator channel structure information; and
eight most significant bits of a system frame number.
40. The wireless device of claim 38 , wherein the encoded first signal corresponds to interference associated with the first base station.
41. The wireless device of claim 38 , wherein the instructions, when executed by the one or more processors, cause the wireless device to generate the encoded first signal by at least:
generating a first signal by at least decoding the at least one of the received signals;
at least one of: scrambling the first signal, modulating the first signal, or scaling the first signal; and
encoding the first signal to produce the encoded first signal.
42. The wireless device of claim 38 , wherein the encoded first signal comprises a second physical broadcast message associated with the first base station.
43. A wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the wireless device to:
receive signals from a plurality of base stations;
generate a first plurality of correlation values by correlating a first plurality of synchronization signals with at least one of the received signals;
determine, based on the first plurality of correlation values, a first synchronization signal transmitted by a first base station;
determine an updated received signal by at least performing, based on the first synchronization signal, interference cancellation on the at least one of the received signals;
determine, based on the updated received signal, a second synchronization signal transmitted by a second base station; and
receive, based on the second synchronization signal, a message.
44. The wireless device of claim 43 , wherein the first synchronization signal has a greatest correlation value among the first plurality of correlation values.
45. The wireless device of claim 43 , wherein the instructions, when executed by the one or more processors, further cause the wireless device to determine, based on the second synchronization signal, timing information of the second base station.
46. The wireless device of claim 43 , wherein the second synchronization signal is transmitted periodically with a fixed period.
47. The wireless device of claim 43 , wherein the instructions, when executed by the one or more processors, cause the wireless device to perform the interference cancellation by at least subtracting the first synchronization signal from the at least one of the received signals.
48. The wireless device of claim 43 , wherein the instructions, when executed by the one or more processors, cause the wireless device to receive, based on a physical cell ID of the second base station, the message, wherein the physical cell ID is based on the second synchronization signal.
49. A non-transitory computer-readable medium storing instructions that, when executed, configure a wireless device to:
receive signals from a plurality of base stations;
generate, based on at least one of the received signals, an encoded first signal corresponding to a first base station;
generate a second signal corresponding to a second base station by at least performing, based on the encoded first signal, interference cancellation on the at least one of the received signals;
determine a control format indicator based on the second signal;
determine, based on the control format indicator, a quantity of orthogonal frequency division multiplexing (OFDM) symbols of a control region of the second base station; and
receive, based on the quantity of OFDM symbols and from the second base station, a control signal in the control region.
50. The non-transitory computer-readable medium of claim 49 , wherein the control format indicator comprises sixteen modulation symbols received starting from a first symbol in a subframe.
51. The non-transitory computer-readable medium of claim 49 , wherein the instructions, when executed, configure the wireless device to perform the interference cancellation by at least subtracting the encoded first signal from the at least one of the received signals.
52. The non-transitory computer-readable medium of claim 49 , wherein the encoded first signal corresponds to interference associated with the first base station.
53. The non-transitory computer-readable medium of claim 49 , wherein the instructions, when executed, configure the wireless device to generate the encoded first signal by at least:
generating a first signal by at least decoding the at least one of the received signals;
at least one of: scrambling the first signal, modulating the first signal, or scaling the first signal; and
encoding the first signal to produce the encoded first signal.
54. The non-transitory computer-readable medium of claim 49 , wherein the encoded first signal comprises a second control format indicator associated with the first base station.
55. A non-transitory computer-readable medium storing instructions that, when executed, configure a wireless device to:
receive signals from a plurality of base stations;
generate, based on at least one of the received signals, an encoded first signal corresponding to a first base station;
generate a second signal corresponding to a second base station by at least performing, based on the encoded first signal, interference cancellation on the at least one of the received signals;
determine a physical broadcast message based on the second signal;
determine, based on the physical broadcast message, a plurality of system parameters of the second base station; and
receive, based on at least one of the plurality of system parameters and from the second base station, a plurality of resource blocks.
56. The non-transitory computer-readable medium of claim 55 , wherein the plurality of system parameters comprises:
system bandwidth information;
hybrid automatic repeat request (HARQ) indicator channel structure information; and
eight most significant bits of a system frame number.
57. The non-transitory computer-readable medium of claim 55 , wherein the encoded first signal corresponds to interference associated with the first base station.
58. The non-transitory computer-readable medium of claim 55 , wherein the instructions, when executed, configure the wireless device to generate the encoded first signal by at least:
generating a first signal by at least decoding the at least one of the received signals;
at least one of: scrambling the first signal, modulating the first signal, or scaling the first signal; and
encoding the first signal to produce the encoded first signal.
59. The non-transitory computer-readable medium of claim 55 , wherein the encoded first signal comprises a second physical broadcast message associated with the first base station.
60. A non-transitory computer-readable medium storing instructions that, when executed, configure a wireless device to:
receive signals from a plurality of base stations;
generate a first plurality of correlation values by correlating a first plurality of synchronization signals with at least one of the received signals;
determine, based on the first plurality of correlation values, a first synchronization signal transmitted by a first base station;
determine an updated received signal by at least performing, based on the first synchronization signal, interference cancellation on the at least one of the received signals;
determine, based on the updated received signal, a second synchronization signal transmitted by a second base station; and
receive, based on the second synchronization signal, a message.
61. The non-transitory computer-readable medium of claim 60 , wherein the first synchronization signal has a greatest correlation value among the first plurality of correlation values.
62. The non-transitory computer-readable medium of claim 60 , wherein the instructions, when executed, further configure the wireless device to determine, based on the second synchronization signal, timing information of the second base station.
63. The non-transitory computer-readable medium of claim 60 , wherein the second synchronization signal is transmitted periodically with a fixed period.
64. The non-transitory computer-readable medium of claim 60 , wherein the instructions, when executed, configure the wireless device to perform the interference cancellation by at least subtracting the first synchronization signal from the at least one of the received signals.
65. The non-transitory computer-readable medium of claim 60 , wherein the instructions, when executed, configure the wireless device to receive, based on a physical cell ID of the second base station, the message, wherein the physical cell ID is based on the second synchronization signal.