About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
ISIT 1997
Conference paper
Trellis precoding for channels with spectral nulls
Abstract
Trellis-enhanced precoding for trellis-coded transmission over ISI channels allows coding and shaping gains to be achieved with minimal transmit power penalty for arbitrary signal constellations, provided the ISI channels are linearly invertible. If the channel exhibits spectral nulls, infinite error propagation can occur within the inverse precoder. We assume ISI channels with spectral nulls and possibly a rational transfer function. First, we investigate methods to stop error propagation in the inverse precoder. This is accomplished by exploiting knowledge about the signal region to which the transmit signal, which needs to be recovered in the inverse precoder, must be confined. Then, we consider combining the concept of feedback trellis encoding with Tomlinson-Harashima (1971, 1972) precoding, whereby error propagation is completely prevented, but only certain signal constellations are allowed. We demonstrate the effectiveness of the proposed methods for dual-duplex baseband data transmission at 100 Mbit/s over unshielded telephone-grade twisted-pair cables in office building environments. © 1997 IEEE.