Pulse or digital communications – Equalizers – Automatic
Patent
1997-11-12
2000-09-12
Chin, Stephen
Pulse or digital communications
Equalizers
Automatic
375343, H03H 730, H03H 740
Patent
active
061188166
ABSTRACT:
The invention relates to a digital transmission system comprising a receiver, in which system a trellis-based estimation method (3) with a number of states reduced as a result of feedback (5) of at least one feedback value (.xi.) forms estimates (a) for a received signal (r) by means of an estimated impulse response (h) of a transmission system (1), a feedback value (.xi.) being determined from at least one estimate (a). With reduced-state estimation methods for the digital transmission, the problem consists of the additional noise components caused by the feedback of preliminary false symbol decisions. To achieve optimum estimates (a) for the received signal (r) despite a reduced number of states due to feedback, the receiver forms the feedback value (.xi.) from at least one intermediate value (a.sub.SDF). In digital transmission systems, the transmit symbols (a) and the estimates (a) have the values -1 or 1 in the receiver. In the receiver according to the invention, intermediate values (a.sub.SDF) having a value in the range from -1 to 1 can be fed back, so that a better feedback value (.xi.) and thus better estimates (a) for the received signal (r) may be achieved.
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Gerstacker Wolfgang
Huber Johannes
Meyer Raimund
Muller Stefan
Chin Stephen
Halajian Dicran
McKiernan Thomas E
U.S. Philips Corporation
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