Practical null forming in millimeter-wave networks

Madani, Sohrab

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https://hdl.handle.net/2142/108711 Copy

Description

Title

Practical null forming in millimeter-wave networks

Author(s)

Madani, Sohrab

Issue Date

2020-07-17

Director of Research (if dissertation) or Advisor (if thesis)

Al-Hassanieh, Haitham

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

millimeter-wave, 5G, phased arrays, null forming

Abstract

We present Nulli-fi, the first practical nulling system for millimeter-wave wireless local area network (mmWave WLAN). Nulli-fi uses millimeter-wave phased arrays to create deep nulls in the antenna beam pattern that effectively reduce interference between links. This will in turn increase the overall signal to interference plus noise ratio, which allows multiple links to communicate at the same time without interfering, thereby improving the network data rate. A null is a direction in the radiation pattern where there is almost no transmitted or received power. In a phased array, nulls can be created by setting the complex weights behind each element. Nulli-fi can create nulls in practical systems with very limited control over these weights, such as phase-only setting with 2-bit resolution in phase (that is, only four values of phase per antenna element). We identify and address the challenges in creating nulls in such practical systems, and extensively test Nulli-fi's implementation using off-the-shelf 60 GHz 16-element phased arrays in different indoor locations and scenarios. These scenarios include different nulling directions, narrow and wide nulls, single and multiple nulls, and different levels of weight constraints.

Graduation Semester

2020-08

Type of Resource

Thesis

Permalink

http://hdl.handle.net/2142/108711

Copyright and License Information

© 2020 Sohrab Madani

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