Pilot contamination is known to be one of the main impairments for massive MIMO multi-cell communications. Inspired by the concept of fractional frequency reuse and by recent contributions on pilot reutilization among non-adjacent cells, we propose a new pilot allocation scheme to mitigate this effect. The key idea is to allow users in neighboring cells that are closest to their base stations to reuse the same pilot sequences. Focusing on the uplink, we obtain expressions for the overall spectral efficiency per cell for different linear combining techniques at the base station and use them to obtain both the optimal pilot reuse parameters and the optimal number of scheduled users. Numerical results show a remarkable improvement in terms of spectral efficiency with respect to the existing techniques.
To the best of the knowledge of the authors, the concept of FPR was first introduced in REF .
Fractional Pilot Reuse in Massive MIMO Systems
2015 IEEE International Conference on Communication Workshop (ICCW)
2015 IEEE International Conference on Communication Workshop (ICCW)
Computer Science Mathematics