| 20100008288 | COMMUNICATION SYSTEM USING HIERARCHICAL MODULATION SCHEME OR NETWORK CODING SCHEME - A communication system using a hierarchical modulation scheme and/or a network coding scheme is provided. A relay node included in the communication system may generate a relay packet by applying a network coding scheme to a hierarchically modulated source packet and to a destination packet received from a destination node. The relay packet is transmitted to a source node and a destination node, and the source node and the destination node may extract a desired packet from a relay packet. The communication system also may adaptively determine an optimal communication mode. | 01-14-2010 |