Method and system for managing, controlling, and combining signals in a frequency selective multipath fading channel
Aspects of a method and system for managing, controlling and combining signals in a frequency selective multipath fading channel are presented. Aspects of the system may comprise a searcher that detects a maximum signal energy level among at least one of a plurality of individual distinct path signals in a signal cluster, and computes a first moment time associated with at least one of the plurality of individual distinct path signals. Aspects of the system may further comprise a rake receiver that receives at least a portion of the plurality of individual distinct path signals at a corresponding plurality of time instants based on the computed first moment time, wherein the received at least a portion of the plurality of individual distinct path signals is received within a duration comprising a delay spread.
1. A method for processing radio frequency (RF) signals, the method comprising:
performing by one or more processors and/or circuits:
detecting a maximum signal energy level among a plurality of individual distinct path signals in a signal cluster that is wirelessly received;
computing a first moment time associated with said plurality of individual distinct path signals in said wirelessly received signal cluster, wherein for said computed first moment time, an early aggregate power level associated with individual distinct path signals of said plurality of individual distinct path signals received at time instants preceding said computed first moment time is substantially equal to a late aggregate power level associated with individual distinct path signals of said plurality of individual distinct path signals received at time instants subsequent to said computed first moment time; and
receiving at least a portion of said plurality of individual distinct path signals at a corresponding plurality of time instants based on said computed first moment time wherein said received at least a portion of said plurality of individual distinct path signals is received within a duration comprising a delay spread of said signal cluster.
2. The method according to claim 1 , comprising computing at least one timing adjustment signal based on one or more of: said at least a portion of said plurality of individual distinct path signals, a generated code, and at least one computed aggregate power level.
3. The method according to claim 2 , comprising computing a timing reference signal based on said timing adjustment signal.
4. The method according to claim 1 , comprising generating a code based on one or more of: a start time associated with said wirelessly received signal cluster, a code identification, and a timing reference signal.
5. The method according to claim 4 , comprising computing a plurality of channel estimates based on one or more of: said received at least a portion of said plurality of individual distinct path signals, a timing reference signal, and at least one said generated code.
6. The method according to claim 5 , comprising computing a plurality of power levels corresponding to said computed plurality of channel estimates.
7. The method according to claim 6 , comprising computing said early aggregate power level based on a summation of at least a portion of said computed plurality of power levels corresponding to said received at least a portion of said plurality of individual distinct path signals received at time instants preceding said computed first moment time.
8. The method according to claim 6 , comprising computing said late aggregate power level based on a summation of at least a portion of said computed plurality of power levels corresponding to said received at least a portion of said plurality of individual distinct path signals received at time instants subsequent to said computed first moment time.
9. The method according to claim 6 , comprising computing a plurality of average power levels corresponding to said computed plurality of power levels.
10. The method according to claim 9 , comprising comparing said computed plurality of average power levels to at least one power threshold value.
11. The method according to claim 10 , comprising selecting at least a portion of said computed plurality of channel estimates based on said comparing.
12. The method according to claim 11 , comprising generating a plurality of indicators that indicate said selected at least a portion of said computed plurality of channel estimates.
13. The method according to claim 1 , comprising computing an initial value of said first moment time based on said detected maximum signal energy level.
14. The method according to claim 13 , comprising adjusting said computed initial value of said first moment time based on an error between said early aggregate power level and said late aggregate power level.
15. A system for processing radio frequency (RF) signals, the system comprising:
one or more circuits comprising a searcher, said one or more circuits are operable to detect a maximum signal energy level among a plurality of individual distinct path signals in a signal cluster that is wirelessly received;
said one or more circuits are operable to compute a first moment time associated with said plurality of individual distinct path signals in said wirelessly received signal cluster, wherein for said computed first moment time, an early aggregate power level associated with individual distinct path signals of said plurality of individual distinct path signals received at time instants preceding said computed first moment time is substantially equal to a late aggregate power level associated with individual distinct path signals of said plurality of individual distinct path signals received at time instants subsequent to said computed first moment time; and
said one or more circuits comprising a rake receiver, said one or more circuits are operable to receive at least a portion of said plurality of individual distinct path signals at a corresponding plurality of time instants based on said computed first moment time wherein said received at least a portion of said plurality of individual distinct path signals is received within a duration comprising a delay spread of said signal cluster.
16. The system according to claim 15 , wherein said one or more circuits comprising a cluster tracker are operable to compute at least one timing adjustment signal based on one or more of: said at least a portion of said plurality of individual distinct path signals, a generated code, and at least one computed aggregate power level.
17. The system according to claim 16 , wherein said one or more circuits comprising timing control circuitry are operable to compute a timing reference signal based on said timing adjustment signal.
18. The system according to claim 15 , wherein said one or more circuits comprising a code generator are operable to generate a code based on one or more of: a start time associated with said wirelessly received signal cluster, a code identification, and a timing reference signal.
19. The system according to claim 18 , wherein said one or more circuits comprising a channel estimator are operable to compute a plurality of channel estimates based on one or more of: said received at least a portion of said plurality of individual distinct path signals, a timing reference signal, and at least one said generated code.
20. The system according to claim 19 , wherein said one or more circuits comprising channel power circuitry are operable to compute a plurality of power levels corresponding to said computed plurality of channel estimates.
21. The system according to claim 20 , wherein said one or more circuits comprising a cluster moment generator are operable to compute said early aggregate power level based on a summation of at least a portion of said computed plurality of power levels corresponding to said received at least a portion of said plurality of individual distinct path signals received at time instants preceding said computed first moment time.
22. The system according to claim 20 , wherein said one or more circuits comprising a cluster moment generator are operable to compute said late aggregate power level based on a summation of at least a portion of said computed plurality of power levels corresponding to said received at least a portion of said plurality of individual distinct path signals received at time instants subsequent to said computed first moment time.
23. The system according to claim 20 , wherein said one or more circuits comprising a power filter are operable to compute a plurality of average power levels corresponding to said computed plurality of power levels.
24. The system according to claim 23 , wherein said one or more circuits comprising lock detect circuitry are operable to compare said computed plurality of average power levels to at least one power threshold value.
25. The system according to claim 24 , wherein said one or more circuits comprising a channel estimation gate are operable to select at least a portion of said computed plurality of channel estimates based on said comparing.
26. The system according to claim 25 , wherein said one or more circuits are operable to generate a plurality of indicators that indicate said selected at least a portion of said computed plurality of channel estimates.
27. The system according to claim 15 , wherein said one or more circuits are operable to compute an initial value of said first moment time based on said detected maximum signal energy level.
28. The system according to claim 27 , wherein said one or more circuits are operable to adjust said computed initial value of said first moment time based on an error between said early aggregate power level and said late aggregate power level.