We propose a novel pilot sequence design to mitigate pilot contamination inmulti-cell multiuser massive multiple-input multiple-output networks. Ourproposed design generates pilot sequences in the multi-cell network and devisespower allocation at base stations (BSs) for downlink transmission. The pilotsequences together with the power allocation ensure that the user capacity ofthe network is achieved and the pre-defined signal-to-interference-plus-noiseratio (SINR) requirements of all users are met. To realize our design, we firstderive new closed-form expressions for the user capacity and the user capacityregion. Built upon these expressions, we then develop a new algorithm to obtainthe required pilot sequences and power allocation. We further determine theminimum number of antennas required at BSs to achieve certain SINR requirementsof all users. Numerical results are presented to corroborate our analysis andto examine the impact of key parameters, such as the pilot sequence length andthe total number of users, on the network performance. A pivotal conclusion isreached that our design achieves a larger user capacity region than theexisting designs and needs less antennas at the BS to fulfill the pre-definedSINR requirements of all users in the network than the existing designs.
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