Method of and system for delay estimation with minimized finger allocation
View Patent ↗A signal-path delay-estimation method includes correlating a computed coarse delay profile of at least one detected signal path cluster with a waveform to yield a strongest correlated peak for each of the at least one detected signal path cluster. The method also includes, for each of the at least one detected signal path cluster, using the strongest correlated peak to determine an adjusted delay-profile phase, re-sampling the computed coarse delay profile in accordance with the adjusted delay-profile phase, and detecting signal-path-cluster edges using the re-sampled computed coarse delay profile. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly acertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).
1. A signal-path delay-estimation method comprising:
correlating a computed coarse delay profile of at least one detected signal path cluster with a waveform to yield a strongest correlated peak for each of the at least one detected signal path cluster; and
for each of the at least one detected signal path cluster:
a) using the strongest correlated peak to determine an adjusted delay-profile phase;
b) re-sampling the computed coarse delay profile in accordance with the adjusted delay-profile phase; and
c) detecting signal-path-cluster edges using the re-sampled computed coarse delay profile.
2. The method of claim 1 , further comprising:
computing the coarse delay profile; and
detecting edges of the at least one signal path cluster of the computed coarse delay profile.
3. The method of claim 2 , wherein the step of detecting the edges of the at least one signal comprises a thresholding operation.
4. The method of claim 3 , wherein the thresholding operation comprises requiring that the at least one signal path cluster be greater than a pre-defined value times a delay-profile noise floor.
5. The method of claim 1 , further comprising, for each of the at least one detected signal path cluster, reporting the detected signal-path-cluster edges and delay-profile values of the re-sampled computed coarse delay profile.
6. The method of claim 1 , wherein at least two of the at least one detected signal path cluster have the same adjusted delay-profile phase.
7. The method of claim 1 , wherein:
the step of correlating is performed every N delay-estimation cycles; and
N is chosen so as to limit signal-path drift during N delay-estimation cycles to less than an input data sampling period T s .
8. The method of claim 2 , wherein, for each of the at least one detected signal path cluster, steps a), b), and c) are performed only if the strongest correlated peak is within a pre-defined time from a detected edge of the signal path cluster.
9. The method of claim 1 , wherein, for each of the at least one detected signal path cluster, steps a), b), and c) are performed only if the strongest correlated peak is the single defined peak within the signal path cluster.
10. The method of claim 9 , wherein the single defined peak is a peak that is a pre-defined amount greater than any other correlated peak.
11. The method of claim 1 , wherein the coarse delay profile is selected from the group consisting of a coarse complex delay profile and a coarse power delay profile.
12. The method of claim 1 , wherein a power-delay-profile correlation period is identical to a delay-estimation update period.
13. The method of claim 3 , wherein an identical threshold is used for each detected signal-path cluster.
14. The method of claim 1 , wherein the waveform is a single-path waveform.
15. The method of claim 1 , wherein the waveform is the inverse of a single-path pulse shape function.
16. The method of claim 1 , wherein the step of re-sampling the computed coarse delay profile is performed via interpolation.
17. An article of manufacture for signal-path delay estimation, the article of manufacture comprising:
at least one computer readable medium;
processor instructions contained on the at least one computer readable medium, the processor instructions configured to be readable from the at least one computer readable medium by at least one processor and thereby cause the at least one processor to operate as to:
correlate a computed coarse delay profile of at least one detected signal path cluster with a waveform to yield a strongest correlated peak for each of the at least one detected signal path cluster; and
for each of the at least one detected signal path cluster:
use the strongest correlated peak to determine an adjusted delay-profile phase;
re-sample the computed coarse delay profile in accordance with the adjusted delay-profile phase; and
detect signal-path-cluster edges using the re-sampled computed coarse delay profile.
18. The article of manufacture of claim 17 , wherein the computed coarse power delay profile is re-sampled via interpolation.
19. The article of manufacture of claim 17 , wherein the coarse delay profile is selected from the group consisting of a coarse complex delay profile and a coarse power delay profile.
20. A signal-path delay-estimation system comprising:
a delay estimator for:
correlating a computed delay profile of at least one detected signal path cluster with a waveform to yield a strongest correlated peak for each of the at least one detected signal path cluster; and
for each of the at least one detected signal path cluster:
a) using the strongest correlated peak to determine an adjusted delay-profile phase;
b) re-sampling the computed delay profile in accordance with the adjusted delay-profile phase; and
c) detecting signal-path-cluster edges using the re-sampled computed delay profile;
a channel estimator inter-operably connected to an output of the delay estimator; and
a despreader/combiner inter-operably connected to an output of the channel estimator and the output of the delay estimator.
21. The system of claim 20 , wherein the delay estimator is for:
computing the delay profile; and
detecting edges of the at least one signal path cluster of the computed delay profile.
22. The system of claim 21 , wherein the detection of the edges of the at least one signal comprises a thresholding operation.
23. The system of claim 22 , wherein the thresholding operation comprises requiring that the at least one signal path cluster be greater than a pre-defined value times a delay-profile noise floor.
24. The system of claim 20 , wherein the delay estimator is for, for each of the at least one detected signal path cluster, reporting the detected signal-path-cluster edges and delay-profile values of the re-sampled computed delay profile.
25. The system of claim 20 , wherein at least two of the at least one detected signal path cluster have the same adjusted delay-profile phase.
26. The system of claim 20 , wherein:
the correlation is performed every N delay-estimation cycles; and
N is chosen so as to limit signal-path drift during N delay-estimation cycles to less than an input data sampling period T s .
27. The system of claim 21 , wherein, for each of the at least one detected signal path cluster, the delay estimator performs a), b), and c) only if the strongest correlated peak is within a pre-defined time from a detected edge of the signal path cluster.
28. The system of claim 20 , wherein, for each of the at least one detected signal path cluster, the delay estimator performs a), b), and c) only if the strongest correlated peak is the single defined peak within the signal path cluster.
29. The system of claim 28 , wherein the single defined peak is a peak that is a pre-defined amount greater than any other correlated peak.
30. The system of claim 20 , wherein the delay profile is selected from the group consisting of a complex delay profile and a power delay profile.
31. The system of claim 20 , wherein a delay-profile correlation period is identical to a delay-estimation update period.
32. The system of claim 22 , wherein an identical threshold is used for each detected signal-path cluster.
33. The system of claim 20 , wherein the re-sampling of the computed delay profile is performed via interpolation.
34. The system of claim 20 , wherein the waveform is a single-path waveform.
35. The system of claim 20 , wherein the waveform is the inverse of a single-path pulse shape function.