Patent ID: 7675998

Claim:
A method for determining a sampling instant of a clock signal for a circuit for determining symbols (Se) with discrete amplitudes from a digitized signal S of a modulation method, comprising: sampling the digitized and demodulated signal at a selectable sampling phase and providing a quadrature sampled signal; determining a first radius R for the quadrature sampled signal; determining a first quality value G for the quadrature sampled signal based on a desired radius and the first radius R for a first sampling phase φ i which is defined relative to a base clock instant; determining a second quality value G* based on the desired radius and a second radius R determined during a second sampling phase φ i2 that is varied relative to the first sampling phase φ i , the second sampling phase φ i2 defined as the first sampling phase φ i plus Δφ; and comparing the first quality values G and the second quality value G* to ascertain which of the first and second quality values is better, and adjusting the selectable sampling phase based upon which of the first and second quality values is determined to be better.