Synthesizing optimal filters for crosstalk-cancellation for high-speed buses

We present practical algorithms for the synthesis of crosstalk canceling equalizing filters. We examine designs optimized for the traditional l₂ metric and introduce an approach based on the l_∞ metric. We compare the two approaches for realistic buses with tight wire spacings. We show bandwidth improvements of up to a factor of 2 using crosstalk cancellation when compared with no filtering or independent pre-emphasis for each wire. Using l_∞ optimization, we achieve roughly 50% better performance than the l₂ methods. We are aware of only one other published description of crosstalk cancellation for high-performance buses according to J. L. Zerbe et al. (2001). We believe that our work is the first to show the advantages of l_∞ optimization and to consider crosstalk cancellation for more than just nearest neighbors for high-speed buses.