Multipath effects on time reversal OFDM communications between wireless sensors

Time reversal orthogonal frequency division multiplexing (TR-OFDM) has recently been received significant concerns in wireless sensor networks (WSNs) applications for its reliable, high-speed, and green communications in multipath environments. However, most publically reported studies were typically performed in strongly multipath channels. In more general non-rich multipath environments, the TR-OFDM performance has not been fully exploited. In this paper, we make a comparative analysis of TR-OFDM communications in different multipath environments. We find that TR-OFDM communications exhibit irremovable bit error floors (BEF) in their bit-error-rate (BER) curves if no channel equalization techniques are applied to the TR-OFDM systems. The underlying reason of the bit error floor is clearly revealed for the TR-OFDM wireless systems.