NB-IoT and link adaptation
In present paper was attempted a study in NB-IOT, which introduced by 3GPP in release 13 as a new radio access technology. NB-IOT systems requires at least 180 kHz bandwidth for both downlink and uplink transmission. Also, it can coexist with LTE technology by reusing the LTE design extensively, including numerologies, OFDMA in downlink, SC-FDMA in uplink, channel coding, rate matching and interleaving. NB-IOT focuses specifically in indoor coverage, low cost long battery life and high connection density. Furthermore, we got involved with link adaptation and especially uplink - link adaptation scheme for NB-IOT systems. Link adaptation has been studied in different types of wireless communication systems. We investigate the uplink adaptation scheme with the repetition number determination, which composed of the inner loop link adaptation to guarantee transmission reliability and improve throughput of NB-IOT systems. Finally, with simulation process in MATLAB we examine the following parameters in graphs: BLER to SNR with different modulation scheme coding, resource unites, number of repetition and transmit block size. Throughput to SNR with different modulation scheme coding, resource unites, number of repetition and transmit block size. Repetition to SNR with different modulation scheme coding and resource unites.