Reduced fading for RFID tags with multiple antennas

Using new, analytic expressions for the envelope probability density function (PDF) of the M times L times N dyadic backscatter channel, this paper demonstrates that modulating backscatter using multiple RF tag antennas can reduce small-scale fading. Several practical design guidelines are presented to exploit this property of the channel and to increase the RF tag range and reliability without a change in the signaling scheme.