Implementation of the Alamouti OSTBC to a Distributed Set of Single-Antenna Wireless Nodes

The authors consider a system architecture whereby orthogonal space time block codes (OSTBCs) are applied to a distributed set of wireless nodes. The utility offered is that by employing diversity we are able to greatly reduce the necessary link margin usually required to combat fast fading. A distributed set of wireless nodes are particularly well suited for this task as they are typically separated with significant inter-node distance thus having highly uncorrelated channels to a collector. In a typical application, a wireless sensor network (WSN) will have nodes that may wish to transmit data to a possibly mobile standoff collection point. In this paper, the authors discuss many practical aspects necessary for a real-world implementation including time and frequency offset estimation as well as channel tracking. As the waveform has been targeted to field programmable gate array (FPGA) hardware, we look at the relative implementation complexity of each signal processing element.