New Architecture for a Wireless Smart Sensor Based on a Software-Defined Radio

Today, wireless sensor technology is based on monolithic transceivers that optimize cost but have a rigid hardware architecture. In this paper, a new architecture for wireless sensors is presented. It is based on a software-defined radio concept and shows impressive adaptability to external conditions. The proposed architecture, which is called the wireless ultrasmart sensor (WUSS), enables the use of a software programmable transceiver, which can simultaneously manage multiple radio communication channels or standards. In addition, the WUSS architecture can mix the flexible communication part of the smart device with the sensor conditioning part. This combination represents a new generation of general-purpose sensors for microwave measurements in the gigahertz range (e.g., displacement and position sensing) with enhanced versatility since the same radio-frequency front end is both used to communicate and make measurements. Experimental results demonstrate the feasibility of the proposed architecture. A prototype shows the following abilities: managing multiple protocols using a single antenna, interfacing standard sensors, making delay and phase measurements with a standard deviation of 3 ns, and assigning the time of arrival to incoming radio signals with an error on the order of 20 ns.