Effect of Imperfect Artificial Noise on the Performance of Physical Layer Security for MU-Massive MIMO System

Physical Layer Security (PLS) in Multiple Input Multiple Output (MIMO) systems is crucial to achieving reliable communication. Artificial Noise (AN) is a commonly employed technique to provide PLS-based secure communication. This requires perfect knowledge of the channel between transmitter (Alice) and legitimate user (Bob). However, this channel information may be imperfect due to estimation errors. Thus, the claimed performance of AN-based PLS is questionable and requires thorough investigation. In this work, the effect of imperfect channel estimation on the performance of PLS for multiuser Massive (MU-Massive) MIMO system is investigated. The channel estimation error is modeled as a complex Gaussian variable. The performance measure in terms of Bit-error-rate (BER) is evaluated for different levels of channel estimation error. This investigation provides a good illustration of how the performance of AN-based PLS is affected by the channel estimation error in the MU-Massive MIMO system. This work shows the trend in BER increase with the increase in AN mismatch.