A Robust Real-Time Demodulation Scheme for Backscatter Transponder Based Wireless Positioning Systems

In this paper, we present a robust algorithm for demodulation and evaluation of backscatter transponder induced beat signals in wireless positioning systems. In particular, an analysis filter bank based on Goertzel filter is used for signal detection. A particle swarm optimizer controls the configuration of the filter bank and is used to measure the range of the transponder based on spectral evaluation of the beat signal with very high resolution. A Kalman-Filter is applied for optimum estimation of the range with noise suppression. An implementation and system demonstrator based on an heterogeneous FPGA and software implementation with an FMCW radar is presented to evince the proposed demodulation scheme. It allows gapless processing in chirp sequence radar systems and high output rates with high resolution and low noise.