Method of improving receiver sensitivity of RFID Reader HW platforms with limited resources

We present a method and implementation to improve the receivers of radio-frequency identification (RFID) readers while focusing specifically on RFID measurement and test instruments targeting high sensitivity simultaneously reducing the required dynamic range of the real-time signal processing blocks. The article discusses the architecture of the software defined radio which allows tag answer analysis in real time by using a new approach. The main contributions are the implementation of the fast Fourier transform in fixed point arithmetic in an field programmable gate array to reduce hardware requirements and improvement of the dynamic range which allows use of commercially available IP cores. The proposed solution, its implementation on the universal software radio peripheral (USRP), and measurement in a real environment are also presented.