Soft Network Coding in Wireless Two-Way Relay Channels

Application of network coding in wireless Two-Way Relay Channels (TWRC) has received much attention recently because of its ability to improve throughput significantly. In traditional designs, network coding operates at upper layers above (including) the link layer and it requires the input packets to be correctly decoded. However, this requirement may limit the performance and application of network coding due to the unavoidable fading and noise in wireless networks. In this paper, the authors propose a new wireless network coding scheme for TWRC, which is referred to as Soft Network Coding (SoftNC), where the relay nodes applies symbol-by-symbol soft decisions on the received signals from the two end nodes to come up with the network coded information to be forwarded.