CQI ESTIMATION IN A WIRELESS COMMUNICATION NETWORK
Techniques for estimating and reporting channel quality indicator (CQI) are disclosed. Neighboring base stations may cause strong interference to one another and may be allocated different resources, e.g., different subframes. A UE may observe different levels of interference on different resources. In an aspect, the UE may determine a CQI for resources allocated to a base station and having reduced or no interference from at least one interfering base station. In another aspect, the UE may determine multiple CQI for resources of different types and associated with different interference levels. For example, the UE may determine a first CQI based on at least one first subframe allocated to the base station and having reduced or no interference from the interfering base station(s). The UE may determine a second CQI based on at least one second subframe allocated to the interfering base station(s).
1 . A method for wireless communication, comprising:
determining at least one resource allocated to a base station and having reduced or no interference from at least one interfering base station; and
determining a channel quality indicator (CQI) based on the at least one resource.
2 . The method of claim 1 , wherein the determining at least one resource allocated to the base station comprises
receiving signaling conveying resources allocated to the base station, and
determining the at least one resource based on the received signaling.
3 . The method of claim 1 , further comprising:
sending the CQI to the base station; and
receiving a transmission of data sent by the base station based on the CQI.
4 . The method of claim 1 , wherein the CQI is determined by excluding resources allocated to the at least one interfering base station.
5 . The method of claim 1 , wherein the at least one resource corresponds to at least one subframe allocated to the base station.
6 . The method of claim 1 , wherein the at least one resource is semi-statically allocated to the base station via resource partitioning for the base station and the at least one interfering base station.
7 . An apparatus for wireless communication, comprising:
means for determining at least one resource allocated to a base station and having reduced or no interference from at least one interfering base station; and
means for determining a channel quality indicator (CQI) based on the at least one resource.
8 . The apparatus of claim 7 , wherein the means for determining at least one resource allocated to the base station comprises
means for receiving signaling conveying resources allocated to the base station, and
means for determining the at least one resource based on the received signaling.
9 . The apparatus of claim 7 , wherein the at least one resource is semi-statically allocated to the base station via resource partitioning for the base station and the at least one interfering base station.
10 . An apparatus for wireless communication, comprising:
at least one processor configured to determine at least one resource allocated to a base station and having reduced or no interference from at least one interfering base station, and to determine a channel quality indicator (CQI) based on the at least one resource.
11 . The apparatus of claim 10 , wherein the at least one processor is configured to receive signaling conveying resources allocated to the base station, and to determine the at least one resource based on the received signaling.
12 . The apparatus of claim 10 , wherein the at least one resource is semi-statically allocated to the base station via resource partitioning for the base station and the at least one interfering base station.
13 . A computer program product, comprising:
a computer-readable medium comprising:
code for causing at least one processor to determine at least one resource allocated to a base station and having reduced or no interference from at least one interfering base station, and
code for causing the at least one processor to determine a channel quality indicator (CQI) based on the at least one resource.
14 . A method for wireless communication, comprising:
receiving a channel quality indicator (CQI) determined by a user equipment (UE) based on at least one resource allocated to a base station and having reduced or no interference from at least one interfering base station; and
sending a transmission of data to the UE based on the CQI.
15 . The method of claim 14 , further comprising:
sending signaling conveying resources allocated to the base station.
16 . The method of claim 14 , wherein the at least one resource corresponds to at least one subframe.
17 . The method of claim 14 , wherein the at least one resource is semi-statically allocated to the base station via resource partitioning for the base station and the at least one interfering base station.
18 . An apparatus for wireless communication, comprising:
means for receiving a channel quality indicator (CQI) determined by a user equipment (UE) based on at least one resource allocated to a base station and having reduced or no interference from at least one interfering base station; and
means for sending a transmission of data to the UE based on the CQI.
19 . The apparatus of claim 18 , further comprising:
means for sending signaling conveying resources allocated to the base station.
20 . The apparatus of claim 18 , wherein the at least one resource is semi-statically allocated to the base station via resource partitioning for the base station and the at least one interfering base station.
21 . An apparatus for wireless communication, comprising:
at least one processor configured to receive a channel quality indicator (CQI) determined by a user equipment (UE) based on at least one resource allocated to a base station and having reduced or no interference from at least one interfering base station, and to send a transmission of data to the UE based on the CQI.
22 . The apparatus of claim 21 , wherein the at least one processor is configured to send signaling conveying resources allocated to the base station.
23 . The apparatus of claim 21 , wherein the at least one resource is semi-statically allocated to the base station via resource partitioning for the base station and the at least one interfering base station.
24 . A computer program product, comprising:
a computer-readable medium comprising:
code for causing at least one processor to receive a channel quality indicator (CQI) determined by a user equipment (UE) based on at least one resource allocated to a base station and having reduced or no interference from at least one interfering base station, and
code for causing the at least one processor to send a transmission of data to the UE based on the CQI.
25 . A method for wireless communication, comprising:
determining a first channel quality indicator (CQI) based on at least one first subframe allocated to a base station and having reduced or no interference from at least one interfering base station; and
determining a second CQI based on at least one second subframe allocated to the at least one interfering base station.
26 . The method of claim 25 , further comprising:
sending the first CQI and the second CQI to the base station; and
receiving a transmission of data sent by the base station based on the first CQI, or the second CQI, or both.
27 . The method of claim 25 , further comprising:
receiving resource partitioning information from the base station; and
determining the at least one first subframe allocated to the base station and the at least one second subframe allocated to the at least one interfering base station based on the resource partitioning information.
28 . The method of claim 25 , wherein the determining the second CQI comprises determining the second CQI based on only the at least one second subframe allocated to the at least one interfering base station.
29 . The method of claim 25 , wherein the determining the second CQI comprises determining the second CQI by averaging over a set of subframes including the at least one second subframe.
30 . The method of claim 29 , wherein the set of subframes excludes subframes semi-statically allocated to the base station.
31 . The method of claim 29 , wherein the set of subframes excludes subframes semi-statically allocated to the base station and subframes semi-statically allocated to the at least one interfering base station.
32 . The method of claim 29 , wherein the number of subframes in the set of subframes is a fixed value, or is configured by the base station and signaled to the UE, or is determined based on resource partitioning for the base station and the at least one interfering base station.
33 . The method of claim 29 , further comprising:
receiving upper layer signaling conveying the set of subframes.
34 . The method of claim 25 , wherein the determining the second CQI comprises
estimating interference in the at least one first subframe allocated to the base station,
estimating interference in the at least one second subframe allocated to the at least one interfering base station,
estimating total interference based on the estimated interference in the at least one first subframe and the estimated interference in the at least one second subframe, and
determining the second CQI based on the estimated total interference.
35 . The method of claim 25 , further comprising:
determining the at least one second subframe based on an offset with respect to a subframe in which the second CQI is reported.
36 . The method of claim 35 , further comprising:
receiving signaling conveying the offset from the base station.
37 . The method of claim 35 , further comprising:
determining the offset by cycling through a set of offsets and selecting different subframes for determining the second CQI in different periods.
38 . The method of claim 37 , further comprising:
receiving signaling conveying the set of offsets, or the number of offsets, or both from the base station.
39 . The method of claim 25 , further comprising:
determining at least one additional CQI based on at least one additional subframe.
40 . The method of claim 25 , further comprising:
reporting the first CQI at a first periodicity; and
reporting the second CQI at a second periodicity different from the first periodicity.
41 . The method of claim 25 , further comprising:
reporting the first CQI based on a first CQI configuration; and
reporting the second CQI based on a second CQI configuration different from the first CQI configuration.
42 . An apparatus for wireless communication, comprising:
means for determining a first channel quality indicator (CQI) based on at least one first subframe allocated to a base station and having reduced or no interference from at least one interfering base station; and
means for determining a second CQI based on at least one second subframe allocated to the at least one interfering base station.
43 . The apparatus of claim 42 , further comprising:
means for receiving resource partitioning information from the base station; and
means for determining the at least one first subframe allocated to the base station and the at least one second subframe allocated to the at least one interfering base station based on the resource partitioning information.
44 . The apparatus of claim 42 , wherein the means for determining the second CQI comprises means for determining the second CQI by averaging over a set of subframes including the at least one second subframe.
45 . The apparatus of claim 42 , further comprising:
means for determining the at least one second subframe based on an offset with respect to a subframe in which the second CQI is reported.
46 . The apparatus of claim 42 , further comprising:
means for reporting the first CQI based on a first CQI configuration; and
means for reporting the second CQI based on a second CQI configuration different from the first CQI configuration.
47 . An apparatus for wireless communication, comprising:
at least one processor configured to determine a first channel quality indicator (CQI) based on at least one first subframe allocated to a base station and having reduced or no interference from at least one interfering base station, and to determine a second CQI based on at least one second subframe allocated to the at least one interfering base station.
48 . The apparatus of claim 47 , wherein the at least one processor is configured to receive resource partitioning information from the base station, and to determine the at least one first subframe allocated to the base station and the at least one second subframe allocated to the at least one interfering base station based on the resource partitioning information.
49 . The apparatus of claim 47 , wherein the at least one processor is configured to determine the second CQI by averaging over a set of subframes including the at least one second subframe.
50 . The apparatus of claim 47 , wherein the at least one processor is configured to determine the at least one second subframe based on an offset with respect to a subframe in which the second CQI is reported.
51 . The apparatus of claim 47 , wherein the at least one processor is configured to report the first CQI based on a first CQI configuration, and to report the second CQI based on a second CQI configuration different from the first CQI configuration.
52 . A computer program product, comprising:
a computer-readable medium comprising:
code for causing at least one processor to determine a first channel quality indicator (CQI) based on at least one first subframe allocated to a base station and having reduced or no interference from at least one interfering base station, and
code for causing the at least one processor to determine a second CQI based on at least one second subframe allocated to the at least one interfering base station.
53 . A method for wireless communication, comprising:
receiving a first channel quality indicator (CQI) and a second CQI from a user equipment (UE), the first CQI being determined based on at least one first subframe allocated to a base station and having reduced or no interference from at least one interfering base station, and the second CQI being determined based on at least one second subframe allocated to the at least one interfering base station; and
sending a transmission of data to the UE based on the first CQI, or the second CQI, or both.
54 . The method of claim 53 , further comprising:
sending resource partitioning information conveying subframes allocated to the base station and subframes allocated to the at least one interfering base station.
55 . The method of claim 53 , wherein the second CQI is determined by the UE based on only the at least one second subframe allocated to the at least one interfering base station.
56 . The method of claim 53 , wherein the second CQI is determined by the UE by averaging over a set of subframes including the at least one second subframe, the set of subframes excluding subframes semi-statically allocated to the base station, or subframes semi-statically allocated to the at least one interfering base station, or both.
57 . The method of claim 53 , wherein the second CQI is determined by the UE by estimating interference in the at least one first subframe allocated to the base station and estimating interference in the at least one second subframe allocated to the at least one interfering base station.
58 . The method of claim 53 , wherein the at least one second subframe is determined based on an offset with respect to a subframe in which the second CQI is reported.
59 . The method of claim 58 , further comprising:
sending signaling conveying the offset.
60 . An apparatus for wireless communication, comprising:
means for receiving a first channel quality indicator (CQI) and a second CQI from a user equipment (UE), the first CQI being determined based on at least one first subframe allocated to a base station and having reduced or no interference from at least one interfering base station, and the second CQI being determined based on at least one second subframe allocated to the at least one interfering base station; and
means for sending a transmission of data to the UE based on the first CQI, or the second CQI, or both.
61 . The apparatus of claim 60 , further comprising:
means for sending resource partitioning information conveying subframes allocated to the base station and subframes allocated to the at least one interfering base station.
62 . The apparatus of claim 60 , wherein the at least one second subframe is determined based on an offset with respect to a subframe in which the second CQI is reported.
63 . An apparatus for wireless communication, comprising:
at least one processor configured to receive a first channel quality indicator (CQI) and a second CQI from a user equipment (UE), the first CQI being determined based on at least one first subframe allocated to a base station and having reduced or no interference from at least one interfering base station, and the second CQI being determined based on at least one second subframe allocated to the at least one interfering base station, and to send a transmission of data to the UE based on the first CQI, or the second CQI, or both.
64 . The apparatus of claim 63 , wherein the at least one processor is configured to send resource partitioning information conveying subframes allocated to the base station and subframes allocated to the at least one interfering base station.
65 . The apparatus of claim 63 , wherein the at least one second subframe is determined based on an offset with respect to a subframe in which the second CQI is reported.
66 . A computer program product, comprising:
a computer-readable medium comprising:
code for causing at least one processor to receive a first channel quality indicator (CQI) and a second CQI from a user equipment (UE), the first CQI being determined based on at least one first subframe allocated to a base station and having reduced or no interference from at least one interfering base station, and the second CQI being determined based on at least one second subframe allocated to the at least one interfering base station, and
code for causing the at least one processor to send a transmission of data to the UE based on the first CQI, or the second CQI, or both.
67 . A method for wireless communication, comprising:
maintaining multiple setpoints for multiple subframe types associated with different levels of interference;
selecting a setpoint from among the multiple setpoints based on a subframe in which to transmit data to a user equipment (UE); and
transmitting data to the UE in the subframe based on the selected setpoint.
68 . The method of claim 67 , further comprising:
receiving a channel quality indicator (CQI) applicable for the subframe from the UE;
determining a transmit power level based on the selected setpoint and the CQI; and
transmitting data to the UE based on the determined transmit power level.
69 . The method of claim 67 , further comprising:
receiving a channel quality indicator (CQI) applicable for the subframe from the UE;
determining an amount of resources to use to transmit data to the UE based on the selected setpoint and the CQI; and
transmitting data to the UE based on the determined amount of resources.
70 . The method of claim 67 , wherein the maintaining multiple setpoints comprises determining a setpoint for each subframe type based on estimated interference for subframes of the subframe type, or a target level of performance, or both.
71 . The method of claim 70 , wherein the target level of performance is given by a particular target error rate, or a particular hybrid automatic retransmission (HARQ) target termination, or both.
72 . The method of claim 67 , wherein the maintaining multiple setpoints comprises maintaining the multiple setpoints for the multiple subframe types for the UE, and wherein a plurality of sets of setpoints are maintained for a plurality of UEs, one set of setpoints for each UE.
73 . The method of claim 67 , wherein the maintaining multiple setpoints comprises maintaining the multiple setpoints for the multiple subframe types for a particular physical channel, and wherein a plurality of sets of setpoints are maintained for a plurality of physical channels, one set of setpoints for each physical channel.
74 . The method of claim 67 , wherein the transmitting data to the UE comprises transmitting data on a physical downlink control channel (PDCCH), or a physical HARQ indicator channel (PHICH), or a physical downlink shared channel (PDSCH) to the UE.
75 . An apparatus for wireless communication, comprising:
means for maintaining multiple setpoints for multiple subframe types associated with different levels of interference;
means for selecting a setpoint from among the multiple setpoints based on a subframe in which to transmit data to a user equipment (UE); and
means for transmitting data to the UE in the subframe based on the selected setpoint.
76 . The apparatus of claim 75 , further comprising:
means for receiving a channel quality indicator (CQI) applicable for the subframe from the UE;
means for determining a transmit power level based on the selected setpoint and the CQI; and
means for transmitting data to the UE based on the determined transmit power level.
77 . The apparatus of claim 75 , wherein the means for maintaining multiple setpoints comprises means for determining a setpoint for each subframe type based on estimated interference for subframes of the subframe type, or a target level of performance, or both.
78 . The apparatus of claim 75 , wherein the means for maintaining multiple setpoints comprises means for maintaining the multiple setpoints for the multiple subframe types for the UE, and wherein a plurality of sets of setpoints are maintained for a plurality of UEs, one set of setpoints for each UE.
79 . An apparatus for wireless communication, comprising:
at least one processor configured to maintain multiple setpoints for multiple subframe types associated with different levels of interference, to select a setpoint from among the multiple setpoints based on a subframe in which to transmit data to a user equipment (UE), and to transmit data to the UE in the subframe based on the selected setpoint.
80 . The apparatus of claim 79 , wherein the at least one processor is configured to receive a channel quality indicator (CQI) applicable for the subframe from the UE, to determine a transmit power level based on the selected setpoint and the CQI; and to transmit data to the UE based on the determined transmit power level.
81 . The apparatus of claim 79 , wherein the at least one processor is configured to determine a setpoint for each subframe type based on estimated interference for subframes of the subframe type, or a target level of performance, or both.
82 . The apparatus of claim 79 , wherein the at least one processor is configured to maintain the multiple setpoints for the multiple subframe types for the UE, and to maintain a plurality of sets of setpoints for a plurality of UEs, one set of setpoints for each UE.
83 . A computer program product, comprising:
a computer-readable medium comprising:
code for causing at least one processor to maintain multiple setpoints for multiple subframe types associated with different levels of interference,
code for causing the at least one processor to select a setpoint from among the multiple setpoints based on a subframe in which to transmit data to a user equipment (UE), and
code for causing the at least one processor to transmit data to the UE in the subframe based on the selected setpoint.