Interference Analysis in the LTE and NB-IoT Uplink Multiple Access with RF impairments

G. GONZÁLEZ; F. GREGORIO; J. E. COUSSEAU

Shanghai

Conferencia; 23rd International Conference on Digital Signal Processing (DSP 2018); 2018

IEEE Circuits and Systems Society

Narrowband internet of things (NB-IoT) considersthe connection of thousands of devices to a single LTE base station(BS). To make possible the coexistence with classic LTE userequipements (UE)s, the BS allocates several IoT UEs into specialphysical resource blocks (PRB)s. These special PRBs reduce theIoT transmitter complexity but make the LTE signal interferewith the IoT PRBs. IoT nodes are in general low-cost and thereforeprone to suffer from RF impairments. The LTE interferenceand the RF impairments compromise the performance of IoTnodes. In this paper, we analyze the coexistence of LTE and IoTin the multiple access uplink, considering RF impairments. Weanalyze the use of guard bands to reduce the interference fromLTE in IoT. Also, we evaluate the allowable carrier frequencyoffset (CFO) and I/Q imbalance levels that ensures a reasonablesystem performance.