Closed-Form BER Analysis of Non-Coherent FSK in MISO Double Rayleigh Fading/RFID Channel

We provide a closed-form BER expression of non-coherent FSK for passive RFID channel with multiple tag antennas, where the channel can be modeled a summation of L double Rayleigh channels. We show a recursive relation of BER and report an asymptotic analysis. The results theoretically reveal that even without space-time coding, equipping multiple antennas at the tag side can significantly improve the BER performance. This property of double Rayleigh fading is essentially different from that of traditional Rayleigh fading channel.