RFID reader with multi antenna physical layer collision recovery receivers

Radio Frequency Identification (RFID) is a wireless identification technology which often operates in environments with multiple RFID tags. Already introduced multiple antenna receivers can recover from a collision of up to M tags as long as M is less than the number of receive antennas and the channel is known at the receiver. This paper proposes a Zero-Forcing (ZF) and a Minimum Mean Square Error (MMSE) receiver which allows the separation of up to M=2N_R tags, where N_R is the number of receiving antennas on the reader. The proposed algorithms are verified through simulations.