The Third Generation Partnership Project (3GPP) published LTE release 13, which standardized a new radio access network (RAN) called Narrowband Internet of Things (NB-IoT). Such networks, particularly designed for massive machine-type communications (mMTC), inherit theIR functionalities from the existing LTE systems with slight differences and operate in a narrow frequency band of 180 kHz, consisting of one resource block (RB) of 12 LTE subcarriers. This thesis is mainly focused on single-tone in-band transmission with one 15 kHz subcarrier of the NB-IoT RB in the middle of the LTE RBs. The aim of this thesis is to examine the performance of both NB-IoT transmission and LTE transmission after certain enhancements of the NB-IoT transmitter. These additional approaches including time-domain windowing and filtering. Also a nonlinear power amplifier model for the NB-IoT transmitter is included in the study. It is worth to mention that NB-IoT and LTE signals are transmitted together through asynchronous channels to evaluate the effect of noise and Inter-Carrier Interference (ICI). In order to compare the effects of different modulation schemes, 4-QAM and 64-QAM are both considered for LTE transmission. Filters are designed to suppress the spectral sidelobes of transmitted signals to reduce the interferences due to asynchronous operation. What’s more, transmissions with one-subcarrier-wide guard band between the active NB-IoT and LTE subcarriers or without guard band are both examined from bit error-rate (BER) perspective.
展开▼
