Fusion techniques for multi-hop relay wireless sensor networks

Wireless sensor networks have gained considerable interest in the research community during the last decade. In this paper, we target the lower layers in the protocol stack of wireless sensor networks, for the aim of providing a reliable backbone for multimedia applications where error propagation and relatively high error rates are a major concern. Decoding and fusion techniques are developed and evaluated for multi-hop relay wireless sensor networks incorporating the “Amplify and Forward” and “Decode and Forward” relaying protocols, based on turbo codes. Simulation results show a significant gain in bit error rate performance when the different streams are fused at the relays or clustering nodes, compared to the case where these streams are blended at the final fusion center. Results also show that in situations where transmission conditions do not allow for a good exploitation of multi-stream diversity at the fusion center, the “Amplify and Forward” protocol outperforms “Decode and Forward” in terms of improved BER performance and reduced relay complexity, at the expense of a linear increase in transmission rate.