Measured GPS performance under LTE-M in-device interference

ln this paper we present the measurement results for time-to-lix, position accuracy, and carrier-to-noise ratio of mass market Global Positioning System (CPS, receivers under the in device interference from an LTE-IVI transmitter. The laboratory measurement set-up is built using software-defined radio (SDR) platforms to conductively feed emulated (PS 1.1 signaLs and LTE-M interference signals to the antenna input of the CPS receivers. The ITE-M interference from second harmonics is accurately modelled taking into account the transmitter activity pallet-us in different coverage enhancement modes. According to measurements, there are large variations in interference tolerance between dilTerenI f;I'S receivers. HECIII was able to tolerate high level of interference during tracking and also in acquisition as long as the interference pulse duration is not too long (tens of milliseconds). Rh4112 performed clearly worse and tolerated only low levels of ITE-NI interference during both acquisition and (racking. The same measurement set-up can he used with any fa's receiver for designing proper isolation and filtering levels for co-existing I.TE-M Iransmitters.