Carrier frequency offset estimation in a receiver
AssigneeQUALCOMM Incorporated
InventorsEunmo Kang, Koorosh Akhavan, Le Nguyen Luong
Life of this patent
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Abstract
Systems and methods are directed to low cost and low power carrier frequency offset (CFO) estimation in a receiver. In-phase (I) and quadrature (Q) samples of a wireless signal are received by the receiver and a first phase and a second phase are extracted from the outputs of a first autocorrelator with a first time-lag and a second autocorrelator with a second time-lag. The extracted first and second phases are combined to generate an estimated CFO of high accuracy and wide estimation range.
Claims24
A method for estimating carrier frequency offset (CFO) in a receiver, the method comprising:
- performing a first autocorrelation of received wireless signals in a first autocorrelator with a first time-lag to generate a first autocorrelation signal, wherein the received wireless signals comprise in-phase (I) and quadrature (Q) samples;
- extracting a first phase of the first autocorrelation signal in a first arctangent block;
- performing a second autocorrelation of the received wireless signals in a second autocorrelator with a second time-lag to generate a second autocorrelation signal;
- extracting a second phase of the second autocorrelation signal in a second arctangent block;
- and
- combining the first phase and the second phase to generate an estimated CFO.
An apparatus comprising:
- a receiver configured to receive a wireless signal comprising in-phase (I) and quadrature (Q) samples, the receiver further comprising:
- a first autocorrelator with a first time-lag, configured to perform a first autocorrelation of the received wireless signals to generate a first autocorrelation signal;
- a first arctangent block configured to extract a first phase of the first autocorrelation signal;
- a second autocorrelator with a second time-lag configured to perform a second autocorrelation of the received wireless signals to generate a second autocorrelation signal;
- a second arctangent block configured to extract a second phase of the second autocorrelation signal;
- and
- a combination block configured to combine the first phase and the second phase to generate an estimated CFO.
An apparatus comprising:
- means for performing a first autocorrelation of received wireless signals with a first time-lag, to generate a first autocorrelation signal, wherein the received wireless signals comprise in-phase (I) and quadrature (Q) samples;
- means for extracting a first phase of the first autocorrelation signal;
- means for performing a second autocorrelation of the received wireless signals with a second time-lag, to generate a second autocorrelation signal;
- means for extracting a second phase of the second autocorrelation signal;
- and
- means for combining the first phase and the second phase to generate an estimated CFO.
A non-transitory computer readable storage medium comprising code, which, when executed by a processor, causes the processor to perform operations for estimating carrier frequency offset (CFO) of received wireless signals, the non-transitory computer readable storage medium comprising:
- code for performing a first autocorrelation of the received wireless signals with a first time-lag, to generate a first autocorrelation signal, wherein the received wireless signals comprise in-phase (I) and quadrature (Q) samples;
- code for extracting a first phase of the first autocorrelation signal;
- code for performing a second autocorrelation of the received wireless signals with a second time-lag, to generate a second autocorrelation signal;
- code for extracting a second phase of the second autocorrelation signal;
- and
- code for combining the first phase and the second phase to generate an estimated CFO.
Dependencies are inferred from the claim text.