On the Impact of CW interference on 5G NR

Orthogonal frequency division multiplex (OFDM) is used in several modern wireless systems, for example in the fourth generation mobile system LTE (long term evolution), the wireless local area network (WLAN) standard IEEE 802.11, digital audio broadcasting (DAB) and digital video broadcasting (DVB). OFDM has also recently been included in the standard for the fifth generation mobile system, 5G. In this work, we analyze the vulnerability of 5G NR to different types of continuous wave (CW) interference, both a single CW signal or several synchronized CW signals. The analysed system includes OFDM and error correction by LDPC codes, with parameters chosen to resemble those of the 5G NR release 15 standard. An important conclusion of this work is that the 5G NR system is significantly more sensitive to CW interference than to white Gaussian noise. To improve the robustness against CW interference, different types of limiters on the received signal are also evaluated. Limiters in the frequency domain are shown to mitigate the impact from a single CW signal significantly. For an interfering signal consisting of several CW signals, a limiter in the time domain can reduce the impact of the interference signal so that its impact is below that of Gaussian noise with the same power.