Uplink Performance Analysis and Pilot Scheduling for Dense Small-cell Networks
SUN Qiang①② XU Chen① WU Yongpeng③
①(School of Electronic and Information Engineering, Nantong University, Nantong 226019, China) ②(National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China) ③(Institute for Communications Engineering, Technical University of Munich, Munich D-80333, Germany)
Abstract：Considering Dense Small-Cell Networks (DSCNs) with limited pilot resource, estimating channel is carried out using pilot-reused Minimum Mean Square Error (MMSE) estimator, and then exact expressions of the uplink achievable rate are derived with maximal ratio combing receiver for arbitrary pilot reuse factors. Severer pilot contamination will result in degrading the uplink net achievable sum rate. To maximize uplink achievable sum rate, a greedy pilot scheduling algorithm is proposed using large-scale fading channel information to reduce pilot contamination. On this basis, a low-complexity semi-dynamic pilot scheduling algorithm is proposed to determine best pilot reuse factor. Simulation results are presented to verify the theoretical derivation, and the proposed semi-dynamic pilot scheduling algorithm can reduce pilot overhead, mitigate pilot contamination and boost uplink net achievable sum rate.
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