Inventory time reduction in Gen2 with single-antenna separation of FM0 RFID signals

In this work single-antenna detection schemes for collided radio frequency identification (RFID) signals are proposed to achieve waveform separation and extract information when two RFID tags simultaneously transmit. Industry standard Generation 2 (Gen2) tags with FM0 (biphase-space) encoding are fully exploited, including FM0 inherent memory, in sharp contrast to tag separation prior art. It is shown that memory-assisted detection for two collided FM0 tags performs 3dB better in terms of bit-error-rate (BER), compared to memoryless detection. Information from waveform separation is used to significantly reduce the total inventory time for a given tag population in framed Aloha schemes, including the widely adopted Gen2. No modification of the existing readers´ RF front end is required, as the proposed techniques could operate with single-antenna readers. This might be important for portable UHF Gen2 RFID systems, where multiple-antennas are not always an option.