Method and system for detecting enhanced relative grants in a wireless communications system
View Patent ↗Aspects of a method and system for detecting enhanced relative grants in a wireless communications system may include determining one or more signed signal power levels, wherein the one or more signed signal power levels may be positive E-RGCH signal levels or negative E-HICH signal levels. A probability density function may be estimated from the determined one or more signed signal power levels, and a decision threshold based on the estimated probability density function may be set. The probability density function may be estimated based on symmetry of the probability density function. The decision threshold may be set to achieve a desired probability of false positive detections. The decision threshold may be used to distinguish a received HOLD signal from a received DOWN signal for an E-RGCH channel, or to distinguish a received DTX signal from a received ACK signal for an E-HICH channel.
1. A method for processing communication signals comprising:
identifying a first power level for a first grant and a second power level for a second grant;
measuring a plurality of power levels of a signed signal on a communication channel;
calculating a first range of power levels based on the measured power levels,
wherein if the first power level is greater than the second power level, the calculation is based on measured power levels greater than the first power level, and
wherein if the first power level is less than the second power level, the calculation is based on measured power levels less than the first power level;
estimating a second range of power levels based on the first range; and
selecting a decision threshold based, at least in part, on the first range and the second range.
2. The method according to claim 1 , comprising selecting the decision threshold to achieve a desired probability of false positive detections.
3. The method according to claim 1 , comprising estimating the second range from an arbitrary estimation function based on the first range.
4. The method according to claim 1 , wherein the communication channel is a High Speed Uplink Packet Access channel.
5. The method according to claim 1 , wherein the first range is derived from a Hybrid ARO Indicator Channel (E-HICH) signal or an Enhanced Relative Grant Channel (E-RGCH) signal associated with an Enhanced Dedicated Channel (E-DCH), using the same Orthogonal Variable Spreading Factor code.
6. The method according to claim 1 , wherein the plurality of power levels are centered on zero.
7. The method according to claim 6 , wherein the zero level corresponds to a DTX level or a HOLD level.
8. A system for processing communication signals comprising:
a processor, circuit, or combination thereof configured to identify a first power level for a first grant and a second power level for a second grant;
a processor, circuit, or combination thereof configured to measure a plurality of power levels of a signed signal on a communication channel;
a processor, circuit, or combination thereof configured to calculate a first range of power levels based on the measured power levels,
wherein if the first power level is greater than the second power level, the calculation is based on measured power levels greater than the first power level, and
wherein if the first power level is less than the second power level, the calculation is based on measured power levels less than the first power level;
a processor, circuit, or combination thereof configured to estimate a second range of power levels based on the first range; and
a processor, circuit, or combination thereof configured to select a decision threshold based, at least in part, on the first range and the second range.
9. The system according to claim 8 , wherein a processor, circuit, or combination thereof is configured to set the decision threshold to achieve a desired probability of false positive detections.
10. The system according to claim 8 , wherein a processor, circuit, or combination thereof is configured to estimate the second range from an arbitrary estimation function based on the first range.
11. The system according to claim 8 , wherein the communication channel is a High Speed Uplink Packet Access channel.
12. The system according to claim 8 , wherein the first range is derived from a Hybrid ARO Indicator Channel (E-HICH) signal or an Enhanced Relative Grant Channel (E-RGCH) signal associated with an Enhanced Dedicated Channel (E-DCH), using the same Orthogonal Variable Spreading Factor code.
13. The system according to claim 8 , wherein the plurality of power levels are centered on zero.
14. The system according to claim 13 , wherein the zero level corresponds to a DTX level or a HOLD level.
15. The method of claim 1 , wherein the step of estimating the second range is based on a symmetry of the first range and the second range around the first power level.
16. The method of claim 1 , wherein the signed signal is an Enhanced Relative Grant Channel (E-RGCH), the first grant is a Hold grant, and the second grant is a Down grant.
17. The method of claim 1 , wherein the signed signal is a Hybrid ARQ Indicator Channel (E-HICH), the first grant is a DTX grant, and the second grant is an ACK grant.
18. The system of claim 8 , wherein the processor, circuit, or combination thereof is configured to estimate the second range based on a symmetry of the first range and the second range around the first power level.
19. The system of claim 8 , wherein the signed signal is an Enhanced Relative Grant Channel (E-RGCH), the first grant is a Hold grant, and the second grant is a Down grant.
20. The system of claim 8 , wherein the signed signal is a Hybrid ARQ Indicator Channel (E-HICH), the first grant is a DTX grant, and the second grant is an ACK grant.