Software defined radio implementation of LTE R13 NB-IoT downlink vector signal generator

In this paper, we present a software defined radio (SDR) implementation for generating the downlink (DL) signal according to the LTE R13 narrowband internet-of-things (NB-IoT) spec. Given the NB-IoT DL parameters, all its six baseband physical (PHY) signals/channels are firstly generated in software. Then we turn the USRP SDR platform into a vector signal generator (VSG) to up convert the NB-IoT OFDMA I/Q waveform patterns to RF transmit signal. Finally, the DL signal is verified by using costly vector signal analyzer (VSA) with a preliminary NB-IoT option.