Pilot Reuse Among D2D Users in D2D Underlaid Massive MIMO Systems.

In a device-to-device (D2D) underlaid massive multiple-input multiple-output system, D2D transmitters reuse the uplink spectrum of cellular users (CUs), leading to cochannel interference. To decrease pilot overhead, we assume pilot reuse (PR) among D2D pairs. We first derive the minimum-mean-square-error estimation of all channels and give a lower bound on the ergodic achievable rate of both cellu...