A performance analysis of interference rejection technique in multi-subcarrier multiple access

The authors have been working on a multi-subcarrier multiple access method which enables unsynchronized stream data collection from battery-less and wireless sensor nodes leveraging the passive backscattering technology. The multi-subcarrier multiple access can be realized just by controlling an RF switch which is implemented in commercial RFID tags. As the compensation of low-cost and simply circuitry size to realize a multiple access, there are mutual interference among subcarriers. But the interference can be canceled by an interference rejection signal processing in the receiver. In this paper, the performance limitation of the interference rejection is evaluated experimentally in various signal to noise ratio with a prototype multi-subcarrier multiple access system. The result shows that the interference rejection method is effective up to the desired signal to interfering noise ratio is as worse as -16dB.