Distributed consensus estimator of hierarchical network transfer function in WPNC networks

Abstract

Wireless Physical Layer Network Coding (WPNC) network nodes determine their front-end, back-end, and node processing operation based on the knowledge of the global Hierarchical Network Transfer Function (H-NTF). The H-NTF can be derived from the network connectivity state and it is essential to set up properly WPNC processing at each node. The data payload in WPNC network uses a common signal space of mutually interacting signals superposing on the receive node antenna. There are no orthogonalized communication links that would allow traditional control-data signaling based approaches to determine the network state. The procedure where each node establishes a complete picture of the network state must be performed before the payload phase such that the superposing non-orthogonal pilot signals fully respect the WPNC paradigm. This paper proposes a distributed consensus-based estimator of the network state which operates on a common signal space shared by all nodes in the network. The algorithm allows each node to find the global network state based only on local neighbor superposed pilot observation.