  In the framework of 5G-and-beyond Industry 4.0, jamming attacks for denial of
service are a rising threat which can severely compromise the system
performance. Therefore, in this paper we deal with the problem of jamming
detection and mitigation in indoor factory deployments. We design two jamming
detectors based on pseudo-random blanking of subcarriers with orthogonal
frequency division multiplexing and consider jamming mitigation with frequency
hopping and random scheduling of the user equipments. We then evaluate the
performance of the system in terms of achievable BLER with ultra-reliable
low-latency communications traffic and jamming missed detection probability.
Simulations are performed considering a 3rd Generation Partnership Project
spatial channel model for the factory floor with a jammer stationed outside the
plant trying to disrupt the communication inside the factory. Numerical results
show that jamming resiliency increases when using a distributed access point
deployment and exploiting channel correlation among antennas for jamming
detection, while frequency hopping is helpful in jamming mitigation only for
strict BLER requirements.
