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.