Time and antenna diversity in wireless sensor and actuator networks

In this paper we focus on increasing error resilience in sensor networks by means of antenna diversity techniques. The potential of antenna diversity in wireless sensor networks is not fully exploited. Therefore in our study, we compare pure time diversity, time diversity with antenna switching and receiver selection diversity with CC2431 radio modules. We analyze our results for two types of data links i.e. with and without feedback channel and discuss options to increase bandwidth efficiency with current diversity techniques. The introduced schemes can be implemented with any commercially available IEEE 802.15.4 radios without any changes to the baseband processing. We present our experimental results for an indoor measurement setup and show that even when operating at a low signal to noise ratio, antenna diversity effect can significantly improve performance of the system.