US 5,353,310 A · Data transmission system with reduced error propagation

Abstract

For avoiding error propagation as a result of decision feedback equalization, the data to be transmitted are coded with a coder 2 which has a transfer function substantially inverse to the transfer function of the channel 4. Consequently, instantaneous decisions about the received symbol may be made at the receiver 6 without intersymbol interference causing a disturbance. If the channel transfer function differs from the transfer function of the precoder 2, intersymbol interference will again occur, so that the symbol error rate will increase. In order to restrict this increase of the symbol error rate as much as possible, the receiver comprises a cascaded circuit of an adaptive filter 18 which has an inverse transfer function to that of the channel and a decoder 21 which has an inverse transfer function to that of the precoder 2.

Claims7

Dependent claims

Transmission system for transmitting signals from a source to a destination, comprising

a) a channel, for providing a channel output signal;
b) a transmitter coupled to the channel, which transmitter includes coding means for converting input symbols into channel symbols;
c) a receiver coupled to an output of the channel, which receiver includes
i) subtracter means for determining a difference signal between the channel output signal and a feedback signal,
ii) quantizing means for obtaining a quantized difference signal from said difference signal,
iii) filter means for deriving the feedback signal and a feed-forward signal from the quantized difference signal, which filter means includes
A) a first filter for deriving the feedback signal, which first filter is channel-adaptive, and
B) a second filter, differing from the first filter, for deriving the feed-forward signal, and
iv) decoding means for detecting output symbols in the difference signal and the feed-forward signal.

6 more elements

Dependencies are inferred from the claim text.

Data transmission system with reduced error propagation

Life of this patent

Data transmission system with reduced error propagation

Life of this patent

Abstract

Claims7