Receiver and method for calibrating frequency offset

1. A receiver, comprising:

an I/Q demodulator configured to generate an angular signal by demodulating an in-phase branch and a quadrature branch of a received signal;

a filter communicatively coupled to the I/Q demodulator and configured to generate a filtered angular signal by filtering out a noise signal having a frequency higher than a predetermined frequency value from the angular signal;

an angle subtractor communicatively coupled to the filter and configured to generate a phase signal based on the filtered angular signal;

a phase calibrator communicatively coupled to the angle subtractor and configured to generate a calibrated phase signal based on at least one received preamble signal corresponding to the phase signal and a known value of the at least one received preamble signal corresponding to the phase signal; and

a symbol decider communicatively coupled to the phase calibrator and configured to generate an output symbol based on the calibrated phase signal;

wherein the received signal includes a payload symbol corresponding to the at least one received preamble, wherein the at least one received preamble signal comprises a plurality of received preamble signals, and wherein the phase calibrator further comprises a phase compensator communicatively coupled to a phase estimator and configured to generate the calibrated phase signal by calibrating the payload symbol based on an average difference between the plurality of received preamble signals and known values of the plurality of received preamble signals.

2. The receiver of claim 1 , wherein the phase estimator is communicatively coupled to the angle subtractor and configured to estimate the average difference between the plurality of received preamble signals and the known values of the plurality of received preamble signals.

3. The receiver of claim 1 , wherein the I/Q demodulator further comprises a COordinate Rotation DIgital Computer (CORDIC) configured to generate the angular signal by obtaining an arctangent value of the ratio between the in-phase branch and the quadrature branch of the received signal.

4. The receiver of claim 1 , wherein the received signal comprises a Differential Phase Shift Keying (DPSK) signal.

5. The receiver of claim 1 , wherein the received signal comprises a Quadrature Phase Shift Keying (QPSK) signal.

6. The receiver of claim 1 , further comprising a mixer communicatively coupled to the I/Q demodulator, wherein the mixer is configured to generate the in-phase branch and the quadrature branch of the received signal by mixing an input signal with an intermediate frequency local oscillation signal.

7. A method of calibrating frequency offset by a receiver, comprising:

generating, by an I/Q demodulator, an angular signal by demodulating an in-phase branch and a quadrature branch of a received signal;

generating, by a filter communicatively coupled to the I/Q demodulator, a filtered angular signal by filtering out noise signal having a frequency higher than a predetermined frequency value from the angular signal;

generating, by an angle subtractor communicatively coupled to the filter, a phase signal based on the filtered angular signal;

generating, by a phase calibrator communicatively coupled to the angle subtractor, a calibrated phase signal based on at least one received preamble signal corresponding to the phase signal and a known value of the at least one received preamble signal corresponding to the phase signal; and

generating, by a symbol decider communicatively coupled to the phase calibrator, an output symbol based on the calibrated phase signal;

wherein the at least one received preamble signal comprises a plurality of received preamble signals, and wherein generating, by the phase calibrator communicatively coupled to the angle subtractor, the calibrated phase signal comprises generating, by a phase compensator communicatively coupled to a phase estimator, the calibrated phase signal based on an average difference between the plurality of received preamble signals and known values of the plurality of received preamble signals.

8. The method of claim 7 , wherein generating, by the phase calibrator communicatively coupled to the angle subtractor, the calibrated phase signal further comprises estimating, by the phase estimator communicatively coupled to the angle subtractor, the average difference between the plurality of received preamble signals and known values of the plurality of received preamble signals.

9. The method of claim 7 , wherein generating, by the I/Q demodulator, the angular signal further comprises generating, by a COordinate Rotation DIgital Computer (CORDIC), the angular signal by obtaining an arctangent value of the ratio between the in-phase branch and the quadrature branch of the received signal.

10. The method of claim 7 , wherein the received signal comprises a Differential Phase Shift Keying (DPSK) signal.

11. The method of claim 7 , wherein the received signal comprises a Quadrature Phase Shift Keying (QPSK) signal.

12. The method of claim 7 , further comprising generating, by a mixer communicatively coupled to the I/Q demodulator, the in-phase branch and the quadrature branch of the received signal by mixing an input signal with an intermediate frequency local oscillation signal.