US 6,184,814 B2 · Method and arrangement for generation of a time mean-value free binary signal

Abstract

The present invention relates to the generation of a time mean value-free binary signal (O) from an input signal (IN). The device (10) comprises a feed-back loop adjusting the pulse ratio of the output signal by comparing its mean value to the mean value of a time mean value-free reference signal (J) and feeding-back the difference between said two mean values. The mean values are approximated by low pass filtering the binary signal (O) and the reference signal (J) with two filters (8, 7). If the filters (8, 7) are non-linear, the mean values of the filtered signals (S, FJ) can deviate from the mean values of the reference signal (O) and the reference signal (J). By constructing the filters (8, 7) as regards non-linearities, to be equal, the aforementioned discrepancy will be compensated, since the signals will deviate to the same degree from their theoretical values, when time mean value free.

Claims17

Dependent claims

A method for generating a time mean value-free binary signal (OUT) from an input signal (IN), comprising the steps of:

generating a first binary signal (O, O4) from an input signal and a control signal;
filtering the first binary signal (O, O4) through a first filter (8, 48) with substantially low pass characteristic, generating a first filtered signal (S, S4);
filtering a time mean value-free reference signal (J, J4) through a second filter (7, 47) with substantially low pass characteristic, generating a second filtered signal (FJ, FJ4);
and
generating the control signal (C, C4) based on a difference signal between the first filtered signal (S, S4) and the second filtered signal (FJ, FJ4), said control signal being substantially proportional to the sum of the difference signal multiplied by a first constant and a second constant multiplied by the integral of said difference signal;
wherein the first filter (8, 48) and said second filter (7, 47) are substantially equal, and said time mean value-free binary signal (OUT) is constituted of said first binary signal (O, O4).

3 more elements

Dependencies are inferred from the claim text.

Method and arrangement for generation of a time mean-value free binary signal

Life of this patent

Method and arrangement for generation of a time mean-value free binary signal

Life of this patent

Abstract

Claims17