Method and apparatus for robust automatic frequency control in cdma systems with constant pilot signals
AssigneeThomson Licensing
InventorsWen Gao, Zoran Kostic, Alton Keel
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Abstract
There is provided a method for generating an error signal for an automatic frequency control (AFC) loop in a Code Division Multiple Access (CDMA) system. Sign information relating to phase differences in received pilot signals is accumulated. In one embodiment, the accumulated sign information is compared against predetermined threshold levels. The error signal is generated when at least one of the predetermined threshold levels is satisfied. In a second embodiment, the accumulated sign information is decimated. An output of the decimating step is utilized as the error signal for the AFC loop.
Claims58
A method for generating an error signal, comprising the steps of:
- accumulating sign information relating to phase differences in received signals;
- comparing the accumulated sign information against predetermined threshold levels;
- and
- generating the error signal when at least one of the predetermined threshold levels is satisfied.
A method for generating an error signal for an automatic frequency control (AFC) loop in a Code Division Multiple Access (CDMA) system, comprising the steps of:
- accumulating sign information relating to phase differences in received pilot signals;
- decimating the accumulated sign information;
- and
- utilizing an output of said decimating step as the error signal for the AFC loop.
An apparatus for generating an error signal, comprising:
- an accumulator for accumulating sign information relating to phase differences in received pilot signals;
- a comparator for thresholding the accumulated sign information against adaptable threshold levels;
- and
- an error signal generator for generating the error signal when at least one of the adaptable threshold levels is satisfied.
An apparatus for generating an error signal for an automatic frequency control (AFC) loop in a Code Division Multiple Access (CDMA) system, comprising:
- an accumulator for accumulating sign information relating to phase differences in received pilot signals;
- a decimator for decimating the accumulated sign information so as to output the error signal therefrom.
A method for generating a loop error signal for a delay-lock code tracking loop in a CDMA system, comprising the steps of:
- accumulating sign information relating to phase differences between samples of a received code sequence;
- comparing the accumulated sign information against adaptable threshold levels;
- and
- generating the loop error signal when at least one of the adaptable threshold levels is satisfied.
An apparatus for generating an error signal for a delay-lock code tracking loop in a CDMA system, comprising:
- an accumulator for accumulating sign information relating to phase differences between samples of a received code sequence;
- a comparator for comparing the accumulated sign information against adaptable threshold levels;
- and
- an error signal generator for generating the error signal when at least one of the adaptable threshold levels is satisfied.
A method for generating a loop error signal for a delay-lock code tracking loop in a CDMA system, comprising the steps of:
- accumulating sign information relating to phase differences between samples of a received code sequence;
- decimating the accumulated sign information;
- and
- utilizing an output of said decimating step as the loop error signal for the delay-lock code tracking loop.
An apparatus for generating a loop error signal for a delay-lock code tracking loop in a CDMA system, comprising:
- an accumulator for accumulating sign information relating to phase differences between samples of a received code sequence;
- and
- a decimator for receiving the accumulated sign information from said accumulator and for decimating the accumulated sign information,
- wherein an output of said decimator is utilized as the loop error signal for the delay-lock code tracking loop.
Dependencies are inferred from the claim text.