Patent ID: 7299023

Claim:
A method for automatically correcting a frequency error of a local oscillator in a receiver, the method comprising: receiving a carrier signal, the carrier signal including a code sequence known to the receiver; down-converting the carrier signal to a baseband signal; sampling the baseband signal to generate samples; performing a correlation of the samples and the code sequence with a plurality of block correlators to generate a plurality of correlation values, each of the block correlators performing a correlation of a portion of the samples and a corresponding portion of the code sequence; generating a conjugate product and sum of the plurality of correlation values by multiplying correlation values generated by consecutive block correlators in a conjugate sense to generate a plurality of conjugate products and summing the conjugate products; computing an angle value of the conjugate product and sum; computing a frequency error estimate by multiplying a constant to the angle value; generating a correction signal based on the frequency error estimate; and feeding the correction signal to the local oscillator to correct the frequency error.