Patent ID: 7609795

Claim:
An interpolation module capable of recovering timing in a timing recovery apparatus comprising: a first symbol inverse unit for shifting phase of a digital input signal by 180 degrees to generate a first inverted signal that comprises a plurality of sampling values; an interpolator coupled to the first symbol inverse unit for interpolating the plurality of sampling values according to a fractional interval to generate an interpolated signal, which comprises a plurality of interpolants, wherein the fractional interval is output to the interpolator according to the digital input signal; and a second symbol inverse unit coupled to the interpolator for shifting phase of the interpolated signal by 180 degrees to output a second inverted signal; wherein the interpolator is a piecewise-parabolic interpolator outputting the plurality of interpolants, one interpolant is shown below: y[k]=x[m k +2](αμ k −αμ 2 k ) +x[m k +1](−(α+1)μ k +αμ 2 k ) +x[m k ](1+αμ k +αμ 2 k ) +x[m k −1](αμ k −αμ 2 k ) wherein k is a sample time, α is a predetermined positive fractional value, μ k is the fraction interval corresponding to the sample time k, and m k is another sample time corresponding to the sample time k, y is the interpolated signal, x is the digital input signal.