USRP-based indoor channel sounding for D2D and multi-hop communications

In wireless networks, mobile nodes with limited power budget must rely on multi-hop transmissions so as to achieve reliable communication with a distant peer device. Hence, it is of paramount importance to study the characteristics of wireless transmission over multihop links and its benefits over single-hop communication. In this work, a simulator is developed to assess the bit error rate (BER) performance of multi-hop, multi-carrier communication systems. The channel model used in the simulator is developed based on the channel statistics obtained through indoor channel measurements performed using the universal software radio peripherals (USRPs). As the bandwidth supported by a USRP device is much smaller than the channel bandwidth of interest, we use a frequency domain approach to measure the impulse response of wide band channel. By using the channel measurements, we show the impact of communication distance on the delay spread and coherence bandwidth of the channel. Our simulation results with orthogonal frequency division multiplexing (OFDM) systems show that the BER performance of multi-hop communication is better than the single-hop communication. The BER performance difference between the two cases becomes more significant for wider subcarrier frequency spacing.