Random User Selection Method for LPI in Multiuser MISO-OFDMA System

摘要

The problem of wireless security for the downlink of MISO-OFDMA systems operating over a frequency-selective channel is investigated.By exploiting the dimensions provided by multiuser MISO-OFDMA systems for random user selection and beamforming,a novel physical-layer security method is to achieve low probability of interception (LPI),which let the attacker's equivalent channel be a random one,is proposed in the paper.Meanwhile,hypothesis testing is used to determine which subcarriers belong to him by any intended user without user selection information.Numerical results have verified the effective-ness.