Encoding device
AssigneeU.S. Philips Corporation
InventorsEduard F. Stikvoort, Arthur H. M. van Roermund, Peter J. A. Naus
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Abstract
A time-discrete amplitude-continuous or a time-discrete amplitude-discrete signal is converted in to a 1-bit encoded signal by means of a quantizer, the quantization-error signal being fed back via a loop filter. The transfer function of the loop filter is given by H(Z)=1-(Z-b).sup.n /(Z-a).sup.n, where n.gtoreq.3, b.perspectiveto.1 and 0<a<b. In order to preclude, the input signal of the loop filter is limited by a limiter.
Claims14
An encoding device comprising a quantizer for converting an input signal into an one-bit encoded signal, which quantizer comprises an input for receiving the input signal and an output for supplying the one-bit encoded signal, and further comprising error-feedback means for feeding back to the quantizer input a quantization-error signal caused by the quantizer, which error-feedback means comprise an at least third-order filter having an input and an output, wherein the transfer function of the filter is given by
- H.sub.n (Z)=1-(Z-b).sup.n /(Z-a).sup.n
- where:
- n.gtoreq.3 is the order of the filter
- b is a constant substantially equal to unity, and
- a is a constant for which 0<a<b,
- and in that the device comprises limiting means for limiting the quantization-error signal applied to the input of the filter.
Dependencies are inferred from the claim text.