Cooperative transmission in Poisson distributed wireless sensor networks: Protocol and outage probability

We study cooperative wireless communications in the physical layer of a Poisson distributed wireless sensor network, where the spatial diversity of multiple relay nodes I'S utilized to improve the link performance. The tradeoff among network power consumption, spectral efficiency, outage probability, and sensor node density is discussed under the proposed Cooperative Transmission Protocol for Sensor Networks (CTP-SN). CTP-SN is considered as a typical implementation of the two-phase cooperative transmission paradigm in wireless sensor networks. We derive an asymptotic upper bound for the capacity outage probability of CTP-SN. The bound is shown to be decreasing exponentially, when the sensor node density increases. Via the bound, we demonstrate that the cooperative protocol performs asymptotically much better than the non-cooperative direct transmission.