February 06, 2017

Coordinated Hybrid Beamforming for Millimeter Wave Multi-User Massive MIMO Systems

  • Song N.
  • Sun H.
  • Yang T.

Massive Millimeter Wave (mmWave) Multiple Input Multiple Output (MIMO) systems utilize hybrid beamforming techniques to alleviate the implementation complexity of combining a large number of antennas. To solve the optimization problem in the hybrid design supporting multiple users and multiple data streams per user, we first propose a coordinated Radio Frequency (RF) beamforming technique based on the Generalized Low Rank Approximation of Matrices (GLRAM) approach and then develop an efficient Modified GLRAM (MGLRAM) algorithm. The proposed scheme only requires the information of the composite channel, instead of the complete physical channel matrix which is assumed to be known in the existing literature. It takes advantage of the coordination between the base station and users to achieve a maximal array gain and has no dimensionality constraint. The multiplexing gain is then exploited by applying the Block Diagonalization (BD) technique. It is shown that our proposed scheme is a practical and competing solution, which can be easily applied to both the Time Division Duplex (TDD) and Frequency Division Duplex (FDD) systems.

View Original Article

Recent Publications

August 09, 2017

A Cloud Native Approach to 5G Network Slicing

  • Francini A.
  • Miller R.
  • Sharma S.

5G networks will have to support a set of very diverse and often extreme requirements. Network slicing offers an effective way to unlock the full potential of 5G networks and meet those requirements on a shared network infrastructure. This paper presents a cloud native approach to network slicing. The cloud ...

August 01, 2017

Modeling and simulation of RSOA with a dual-electrode configuration

  • De Valicourt G.
  • Liu Z.
  • Violas M.
  • Wang H.
  • Wu Q.

Based on the physical model of a bulk reflective semiconductor optical amplifier (RSOA) used as a modulator in radio over fiber (RoF) links, the distributions of carrier density, signal photon density, and amplified spontaneous emission photon density are demonstrated. One of limits in the use of RSOA is the lower ...

July 12, 2017

PrivApprox: Privacy-Preserving Stream Analytics

  • Chen R.
  • Christof Fetzer
  • Le D.
  • Martin Beck
  • Pramod Bhatotia
  • Thorsten Strufe

How to preserve users' privacy while supporting high-utility analytics for low-latency stream processing? To answer this question: we describe the design, implementation and evaluation of PRIVAPPROX, a data analytics system for privacy-preserving stream processing. PRIVAPPROX provides three properties: (i) Privacy: zero-knowledge privacy (ezk) guarantees for users, a privacy bound tighter ...