Successive Decoding with Hierarchical Interference Cancellation in Wireless (Physical Layer) Network Coding Systems

Abstract:
The intermediate network nodes (relays) in Wireless (Physical Layer) Network Coding (WNC) systems are allowed to process only some specific (“hierarchical") functions of user data (instead of separate decoding of individual user signals), which allows to overcome the rate limits induced by the conventional Multiple Access Channels capacity regions. Unfortunately, since the mapping between a specific decoded hierarchical function and the corresponding signal space representation is generally one-to-many, traditional successive decoding techniques with perfect interference cancellation (subtraction) of decoded signals cannot be directly employed in WNC systems. In this paper we show that even in this case the knowledge of hierarchical data can be efficiently exploited in the decoding process to significantly reduce the impact of interfering signal on the subsequent decoding operations in WNC systems.