Cascade decode-and-forward: Spatial diversity reuse in sensor networks

In this paper, we consider a wireless sensor network that involves data transmitted through multiple relays to reach a destination. In particular we improve the decode-and-forward cooperative relaying scheme, by proposing the Cascade-Decode-and-Forward scheme, where the number of successful relays increases with each additional cooperation stage. The achieved effect is a cascade of relays that contribute towards achieving full spatial diversity at the destination.Arelationship between the achievable bit error rate and delay is derived for the proposed scheme. The results show that for a small delay constraint, the scheme can achieve full diversity. As the delay constraint increases, the protocol can achieve full diversity at signals levels 10-100 orders magnitude lower than the decode- And-forward protocol. The proposed protocol can dynamically trade-off transmission reliability with delay and a certain node connectivity density is required to achieve a cascading cooperation chain with an arbitrary low data extinction probability.