Patent ID: 8532234
Filing Date: 2013-09-10
Classification: H03J

Abstract:
1. An automatic frequency offset compensation method to compensate a frequency offset of a carrier frequency signal modulated by data between emitter and receiver of equipments, the method comprising carrying out a demodulation to obtain I (In Phase) and Q (Quadrature) parameters after signal digitalization and channel filtering, calculating the frequency offset from the I and Q parameters between received and local frequency of the equipment, and synthesizing corrected frequency based on the calculated offset, the method further comprising: initially performing the channel filtering with a wide bandwidth; performing a first frequency compensation based on a preamble of a frame by performing a coarse frequency offset evaluation by automatic frequency control, calculating a first frequency offset based on the coarse frequency offset evaluation, and programming a phase-locked loop/synthesizer based on the first frequency offset; performing a coarse detection of the preamble; performing a second frequency compensation based on the preamble by performing a fine frequency offset evaluation by automatic frequency control, calculating a second frequency offset based on the fine frequency offset evaluation, and programming the phase-locked loop/synthesizer based on the second frequency offset; deducing the corrected frequency based on the calculated offset; performing the channel filtering with a narrow bandwidth centered on the corrected frequency; and performing a fine detection of data of the frame.