Multistatic Gen2 RFID over ethernet with commodity SDRs

Summarization: Industrial Gen2 RFID tags are limited by the tag's RF energy harvesting sensitivity, requiring relatively strong signals that impinge on the tag's antenna. Prior art has proposed dense reader antenna networks, that effectively bring the illuminating antenna closer to the tag, using either networks of RF cables, multiplexers and RF amplifiers or custom RF front-ends, wired to a baseband processor or even custom wireless RF front ends with proprietary protocols. This work distributes Gen2 operation and proposes multistatic networks of commodity, low-cost, software defined radios (SDR), connected over the (nowadays omnipresent) Ethernet. Thus, this work puts forth distributed reception of Gen2 RFID with potentially reduced (installation) cost. Bit error rate (BER)-optimal coherent and near-optimal noncoherent, linear complexity Miller sequence detection are tested, adhering to real time processing constraints. Experimental results demonstrate that under real time carrier frequency offset estimation with phased-lock loop (PLL), Gen2 RFID tags can be detected reliably, without rate-limiting preamble pilot bits, while more than one distributed SDR transmitters can boost area coverage. Multistatic setups allow for higher probability the tag antenna will be found closer to sufficiently strong illuminating field, overcoming the limitations of existing RF energy harvesting technology. Hopefully, this work will spark interest towards the convergence of Gen2 RFID with (current) Ethernet or (future) cellular telephony industry.Παρουσιάστηκε στο: 2019 IEEE International Conference on RFID Technology and Application