Improving UHF RFID read rates by juggling selected bits

Increasing the robustness of EPCglobal Class 1 Generation 2 ultra-high frequency (UHF) Radio Frequency IDentification (RFID) communication is crucial for deployments in challenging scenarios, such as tags moving at high speeds or under harsh environmental conditions. It becomes even more important when sensor data has to be read at high data rates with low robustness modulation schemes. In this paper, our goal is to increase the RFID read rates for different modulation schemes at various Signal to Noise Ratios (SNRs). We propose and evaluate a selected subset of improvements, which can be implemented purely on the reader side and conform to the standard. First, we compare various combinations of clock recovery and bit decoding strategies. The results show, that the performance of individual combinations varies with the uplink encoding and SNR. The overall read rate can be improved if multiple combinations are used simultaneously. Second, we introduce and evaluate a basic soft-decision approach, which attempts to correct bit errors based on the calculated bit correlation scores. Overall, we can improve the read rates in our simulations by up to 31%.