We explore twoor three-class association schemes. We study aspects of the structure of the relation graphs in association schemes which are not easily revealed by their parameters and spectra. The purpose is to develop some combinatorial methods to characterize the graphs and classify the association schemes, and also to delve deeply into several specific classification problems. We work with s...

In this paper, bandwidth ef£cient Type-I and Type-II hybridARQ (HARQ) schemes using turbo trellis coded modulation (TTCM) are proposed. These schemes combine the power ef£ciency of turbo codes with the bandwidth ef£ciency of trellis coded modulation (TCM) to create an effective hybrid FEC/ARQ system. Several packet combining schemes are presented for use in conjunction with iterative turbo deco...

In this paper, continuous research is undertaken to explore the underlying mechanism of numerical shock instabilities Godunov-type schemes for strong shocks. By conducting dissipation analysis and a sequence experiments, we are able clarify that instability may be attributed insufficient entropy production inside structure. As result, general entropy-control technique improving robustness vario...