Scaling Analysis of Hardware-Impaired Two-Way Full-Duplex Massive MIMO Relay

We consider a multipair two-way full-duplex massive multiple-input multiple-output (mMIMO) hardwareimpaired relay, and derive a novel closed-form spectral efficiency (SE) expression for the zero-forcing (ZF) relay processing. We scale the hardware impairments for an N-antenna relay as N
^Z
with z ≥ 0, and analyze the asymptotic SE limits for three relay power scaling schemes. This current letter provides valuable insights in deciding favorable z values for the ZF relay processing, using which the hardware impairments can be scaled for the three relay power scaling schemes considered herein while maintaining a high SE.