Mitigating pilot contamination by pilot reuse and power control schemes for massive MIMO systems
2015 (English)In: IEEE Vehicular Technology Conference, IEEE , 2015Conference paper (Refereed)
The performance of massive multiple input multiple output systems may be limited by inter-cell pilot contamination (PC) unless appropriate PC mitigation or avoidance schemes are employed. In this paper we develop techniques based on existing long term evolution (LTE) measurements - open loop power control (OLPC) and pilot sequence reuse schemes, that avoid PC within a group of cells. We compare the performance of simple least-squares channel estimator with the higher-complexity minimum mean square error estimator, and evaluate the performance of the recently proposed coordinated pilot allocation (CPA) technique (which is appropriate in cooperative systems). The performance measures of interest include the normalized mean square error of channel estimation, the downlink signal-to-interference-plus-noise and spectral efficiency when employing maximum ratio transmission or zero forcing precoding at the base station. We find that for terminals moving at vehicular speeds, PC can be effectively mitigated in an operation and maintenance node using both the OLPC and the pilot reuse schemes. Additionally, greedy CPA provides performance gains only for a fraction of terminals, at the cost of degradation for the rest of the terminals and higher complexity. These results indicate that in practice, PC may be effectively mitigated without the need for second-order channel statistics or inter-cell cooperation.
Place, publisher, year, edition, pages
IEEE , 2015.
Channel estimation, Communication channels (information theory), Mean square error, MIMO systems, Mobile telecommunication systems, Power control, Signal to noise ratio, Telecommunication networks, Co-operative systems, Maximum ratio transmission, Minimum mean-square error estimators, Multiple input multiple output system, Normalized mean square error, Operation and maintenance, Power control schemes, Spectral efficiencies, Long Term Evolution (LTE)
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-175065DOI: 10.1109/VTCSpring.2015.7145932ISI: 000371404700346ScopusID: 2-s2.0-84940381086ISBN: 9781479980888OAI: oai:DiVA.org:kth-175065DiVA: diva2:881613
81st IEEE Vehicular Technology Conference, VTC Spring 2015, 11 May 2015 through 14 May 2015
QC 201512112015-12-112015-10-092016-04-11Bibliographically approved