March 01, 2017

Group-Blind Detection for Uplink of Massive MIMO Systems

  • Ferrante G.
  • Geraci G.
  • Quek T.
  • Win M.

When paired with traditional channel estimation and detection, massive MIMO is severely affected by pilot contamination. While sticking to the traditional structure of the training phase, where orthogonal pilot sequences are reused in different cells, we propose a new group-blind detector that takes into account the presence of pilot contamination. Our detector uses the excess antennas to partially remove interference during the data transmission phase, thus outperforming conventional non-group-blind schemes. We derive asymptotic expressions for the SINR gain, and find that it depends on the number of cells and channel gains only. Implementing the group-blind detector requires an estimate of the aggregate out-of-cell channel covariance. We propose a simple scheme, referred to as method of silences, to obtain such estimate. Numerical results confirm our analysis in scenarios of practical interest, and show cases where a scheme as simple as the method of silences achieves a large fraction of the promised SINR gain over conventional detectors.

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Recent Publications

June 19, 2017

COMBINING BELIEF PROPAGATION AND SUCCESSIVE CANCELLATION LIST DECODING OF POLAR CODES ON A GPU PLATFORM

  • Cammerer S.
  • Hoydis J.
  • Leible B.
  • Stahl M.
  • Ten Brink S.

The decoding performance of polar codes strongly depends on the decoding algorithm used, while also the decoder throughput and its latency mainly depend on the decoding algorithm. In this work, we implement the powerful successive cancellation list (SCL) decoder on a GPU and identify the bottlenecks of this algorithm with ...

June 04, 2017

A New PRACH Transmission Scheme in Unlicensed Spectrum

  • Luo Z.
  • Meng Y.
  • Tao T.

For the unlicensed spectrum, the occupied bandwidth requirement is demanded by some regulations. The legacy scheme of Physical Random Access Channel (PRACH) for Long Term Evolution (LTE) cannot satisfy it. In this paper, we propose a novel PRACH transmission scheme to satisfy the requirement of unlicensed spectrum based on preamble ...

June 01, 2017

Mutual service processes in Euclidean spaces: existence and ergodicity

  • Baccelli F.
  • Mathieu F.
  • Norros I.

Consider a set of objects, abstracted to points of a spatially stationary point process in R-d, that deliver to each other a service at a rate depending on their distance. Assume that the points arrive as a Poisson process and leave when their service requirements have been fulfilled. We show ...