Pilot Decontamination based on Pilot Allocation for Large-Scale Distributed Antenna Systems

The performance of distributed antenna systems (DASs) will be severely impaired by pilot contamination unless a suitable pilot allocation scheme is utilized. In this paper, we propose an efficient algorithm based on the channel model considering both multipath arriving of angle (AoA) and distance information to mitigate pilot contamination. The normalized mean square error (NMSE) of the channel estimation and downlink ergodic rate are employed as metrics to measure the performance of the proposed scheme through simulation. Then, complexities of various algorithms are discussed as well. Under the comprehensive consideration of both simulation results and complexity analysis, the proposed strategy shows great performance with low complexity.