Patent ID: 8442161

Claim:
A method for operating a receiver system, the method comprising: capturing, at an analog-to-digital converter (ADC) of the receiver system, samples {x(nT S ′)} of a received baseband signal, wherein n is a sample index, where T S ′ is a period of a sample clock of the ADC; computing, at a processor of the receiver system, a reference signal {r(n)} by operating on the baseband signal samples {x(nT S ′)} to perform carrier frequency offset (CFO) removal, carrier phase offset (CPO) removal and hard decision demodulation in order to obtain a bit stream and by remodulating the bit stream; computing, at the processor, an intermediate signal {Y(n)} by operating on the baseband signal samples {x(nT S ′)} to perform CFO removal and CPO removal using the reference signal {r(n)}; computing, at the processor, an error vector signal {e(n)} based on the intermediate signal {Y(n)} and the reference signal {r(n)}; computing, at the processor, an estimate Q for the absolute value |ε| of an offset parameter ε based on an average slope of an absolute value of the error vector signal {e(n)}, wherein the offset parameter ε represents a relative offset between the period T S ′ and an intended period T S of the sample clock of the ADC; fractionally resampling, at the processor, the baseband signal samples {x(nT S ′)} by a factor of (1+Q) to obtain a first set of adjusted samples {Z 1 (n)} corresponding to sample rate f 1 =(1+Q)/T S ′, and fractionally resampling, at the processor, the baseband signal samples {x(nT S ′)} by a factor of (1−Q) to obtain a second set of adjusted samples {Z 2 (n)} corresponding to sample rate f 2 =(1−Q)/T S ′; computing, at the processor, a first error vector signal {e 1 (n)} based on the first set of adjusted samples {Z 1 (n)} and the reference signal {r(n)}, and computing, at the processor, a second error vector signal {e 2 (n)} based on the second set of adjusted samples {Z 2 (n)} and the reference signal {r(n)}; and selecting, at the processor, either Q or −Q as an estimate for the offset parameter ε, wherein said selecting of either Q or −Q is based on whether or not a root mean square (RMS) value R 1 of the first error vector signal {e 1 (n)} is smaller than an RMS value R 2 of the second error vector signal {e 2 (n)} .