'Institute of Electrical and Electronics Engineers (IEEE)'
Doi
Abstract
A novel time division duplex massive MIMO technique is proposed based on performing a pilot-less channel estimation in the uplink (UL) utilizing reconstructed differentially encoded data. Spatial multiplexing and differentially encoded data is applied both in the UL and in the downlink (DL). In this system, a reference signal is the first one of the differentially encoded streams in the UL and DL, and the pilots for data estimation are avoided while maintaining spatial multiplexing capabilities. To improve the channel estimation we propose to use a linear Wiener filter and we also propose different symbols placing strategies in an OFDM grid. We also propose a detection improvement of the UL data utilizing the predicted channels. We perform an analysis of the MSE of the blind channel estimation using the differentially encoded data and analyze the symbol-error-rate for both the UL and the DL when channel aging is considered. The analysis is corroborated via numerical results and the proposed scheme is shown to outperform its pilot-based counterpart.This work was supported in part by the European Union Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie European Training Network (ETN) TeamUp5G under Grant 813391, and in part by the Spanish National Project IRENE-EARTH (MINECO/AEI/FEDER/UE) under Grant PID2020-115323RB-C33
