February 20, 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.

Recent Publications

March 23, 2017

Performance Comparison of Capacity-Achieving Modulation Formats for Transoceanic Optical Systems

  • Fernandez De Jauregui Ruiz I.
  • Ghazisaeidi A.
  • Tran P.

We experimentally compare the performance of geometrically-shaped (64APSK) and probabilistically-shaped 64QAM (PS64QAM) formats considering linear and nonlinear penalties.

March 20, 2017

LWIP and Wi-Fi Boost Link Management

  • K S.
  • Kim B.
  • Ling J.
  • Lopez-Perez D.
  • Ming Ding
  • Vasudevan S.

3GPP LWIP Release 13 technology and its prestandard version Wi-Fi Boost have recently emerged as an efficient LTE and Wi-Fi integration at the IP layer, allowing uplink on LTE and downlink on Wi-Fi. This solves all the contention problems of Wi-Fi and allows an optimum usage of the unlicensed band ...

March 13, 2017

Advanced C+L-Band Transoceanic Transmission Systems Based on Probabilistically-Shaped PDM-64QAM

  • Brindel P.
  • Buchali F.
  • Carbo Meseguer A.
  • Charlet G.
  • Fernandez I.
  • Ghazisaeidi A.
  • Hu Q.
  • Renaudier J.
  • Rios-Muller R.
  • Schmalen L.
  • Tran P.

We review the most recent, advanced concepts and methods employed in the cutting-edge spectrally-efficient coherent fiber-optic transoceanic transmission systems, such as probabilistic shaping, adaptive digital nonlinear compensation, rate-adaptive spatially-coupled low density parity check codes, and dual-band C+L-band transmission. Building upon all these concepts and methods, we demonstrate transmission of 179 ...