Method and device for controlling the timing of a digital receiver
OwnerHeinrich Schenkinventor
Life of this patent
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Abstract
For controlling the sampling timing of a digital data receiver (2) with the aid of a timing control loop (3-6), it is proposed that the timing control criterion (Trk) for the timing control loop is obtained by combining a first portion (Trk1) with a second portion (Trk2). The first portion (Trk1) of the timing control criterion is obtained by evaluating the input and output signals of the decision element (8) of the digital receiver (2), while the second portion (Trk) is obtained by evaluating at least one coefficient (C−1) of the adaptive equaliser (7) of the digital receiver (2). In this way, favourable jitter characteristics and also a stable control response are achieved.
Claims23
A method for controlling the sampling timing of a digital receiver, whereby the digital receiver (2) comprises an adaptive equaliser (7) for equalizing an input signal and a decision element (8) for determining symbol values of the input signal, and whereby a timing control criterion (Trk) is obtained from the input signal and in dependence on the timing control criterion sampling timing of the digital receiver (2) is controlled, characterised in that a first timing control criterion portion (Trk1) is obtained by evaluating the input signal and the output signal of the decision element (8), wherein a second timing control criterion portion (Trk2) is obtained by evaluating at least one coefficient of the adaptive equaliser (7) and wherein the timing control criterion (Trk) is obtained by combining the first timing control criterion portion (Trk1) and the second timing control criterion portion (Trk2).
A method according to one of the above claims, characterised in that the individual values of the first timing control criterion portion are determined by the equation
- Trk1(k)=Δy(k)×a(k−1)−Δy(k−1)×a(k)orTrk1(k)=sgn (Δy(k))×sgn (a(k−1))−sgn (Δy(k−1))×sgn (a(k))where Δy(k)=y(k)−a(k)
- whereby k designates the time point, Trk1(k) the values of the first timing control criterion portion, y(k) the input values of the decision element (8) and a(k) the output values of the decision element (8).
A method according to any one of the above claims, characterised in that the second timing control criterion portion (Trk2) is obtained by evaluating maximum two coefficients of the adaptive equaliser (7).
A device for controlling the sampling timing of a digital receiver, whereby the digital receiver (2) comprises an adaptive equaliser (7) for equalizing an input signal and a decision element (8) for determining symbol values of the input signal with a device (3) for obtaining a timing control criterion (Trk) from the input signal, and with a timing control loop (3-6) for producing timing of the digital receiver (2) controlled in dependence on the timing control criterion (Tkr), characterised in that the device (3) for obtaining the timing control criterion (Trk) comprises first means (10) for obtaining a first timing control criterion portion (Trk1) by evaluating the input signal and the first output signal of the decision element (8), wherein the device (3) for obtaining the timing control criterion (Trk) comprises second means (9) for obtaining a second timing control criterion portion (Trk2) by evaluating at least one coefficient of the adaptive equaliser (7), and wherein combination means (11) for obtaining the timing control criterion (Trk) by combining the first timing control criterion portion (Trk1) with the second timing control criterion portion (Trk2) are provided.
Dependencies are inferred from the claim text.