US 5,208,836 AGranted

Method for bit detection at the receiver end of differentially coded binary or quaternary PSK signals in differential-coherent demodulation

AssigneeDeutsche Forschungsanstalt fur Luft- und Raumfahrt e.V.

InventorFranz Edbauer

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Abstract

In a method for bit detection at the receiver end of differentially coded binary or quaternary PSK signals in differential-coherent demodulation, first received, processed signals (Y.sub.n) are supplied parallel to L symbol detectors (S1 to SL) of the order j (j=1,2,3, . . . , L; (L>1)). Then the conjugate complex signals (Y*.sub.n-1, Y*.sub.n-2, . . . Y*.sub.n-L), which are delayed by j symbol periods, and the unchanged, processed input signals (Y.sub.n) are multiplied in multiplication elements (M) to non-quantized output values z.sub.n.sup.(j) of the L symbol detectors and are subsequently complex conjugated. Thereafter, already detected, regenerated PSK symbols (a.sub.n-1, a.sub.n-2, . . . a.sub.n-L+1), delayed by time delay elements (T), are correspondingly fed back, and from this a symbol (a.sub.n) is determined, for which the sum of the squared distances .vertline.z.sub.n.sup.(j) -.epsilon.a.sub.n a.sub.n-1 a.sub.n-2. . . a.sub.n-j+1 .vertline..sup.2 with j=2,3, . . . L) of the L symbol detectors assumes a minimum.

Claims1

Dependent claims

A method for bit detection at the receiver end of differentially coded binary or quaternary phase shift keying signals in differential-coherent demodulation, wherein

a received, processed signal (y.sub.n) is supplied parallel to each of a number of L symbol detectors (S1 to SL) of the order j (j=1,2,3, . . . , L;
(L>1));
said each of said number of L symbol detectors delaying said received, processed signal (y.sub.n) by a respective j symbol period and outputting therein a conjugate complex signal (y.sub.n-1 *, y.sub.n-2 *, . . . y.sub.n-L *);
each said conjugate complex signal and a further said received processed signal (y.sub.n) inputted into a first multiplication element (M) of said each of said number of L symbol detectors and multiplied to a non-quantized output value z.sub.n.sup.(j) ;
said non-quantized output value being subsequently complex conjugated in said each of said number of L symbol detectors;
said complex conjugated non-quantized output value of said each of said number of L symbol detectors inputted into a bit detection unit;
said bit detection unit outputting detected phase shift keying symbols (a.sub.n-1, a.sub.n-2, . . . a.sub.n-L+1), which are subsequently delayed by time delay elements (T) and then fed back to said bit detection unit;
wherein a symbol (a.sub.n) is determined for which the sum of the squared distances of said number of L symbol detectors assumes a minimum.

5 more elements

Dependencies are inferred from the claim text.