Multiple antenna transmitter design under power constraints

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Abstract/Contents

Abstract
Multiple-antenna technique is one of the fundamental building blocks for modern wireless communication systems. The spatial degrees of freedom provided by multiple antennas when used with appropriate transmit coding and receive signal processing, offer several performance advantages including array gain, diversity gain and multiplexing gain. Most theoretical results in multiple-antenna theory assume a sum-power constraint for the transmit antennas. However, practical multiple-antenna transmitters are often subject to per-Power Amplifier (PA) constraint and sometimes also Effective Isotropic Radiated Power (EIRP) constraint. These constraints are motivated by bio-safety, interference reduction and lower cost. However, per-PA power constrained systems suffer from performance loss under imbalances in channel gains at the transmit antennas that often occur in the presence of fading. This thesis studies point-to-point and multi-point-to-point transmission under per-PA power and EIRP constraints, focusing on techniques to increase link performance and to reduce algorithmic complexity. The first part of this thesis studies the use of a Power Combining Network (PCN) to improve link performance under a per-PA power constraint. A PCN switches the outputs of PAs associated with antennas with poor channels to antennas with good channels. The PCN balances the higher coupling gain of the PA power with the loss of array gain or diversity gain. We also study PCN design when an additional EIRP constraint is imposed. We develop fast algorithms for determining the optimal PCN under both a per-PA power constraint alone or with an additional EIRP constraint. We demonstrate the effectiveness of PCN through performance analysis and numerical evaluation. The second part of this thesis is motivated by reducing computational complexity of transmit beamforming algorithms in multi-point-to-point, so called a Coordinated Multi-Point (CoMP), transmission. Algorithmic complexity is high in CoMP since calculating the joint optimal transmit beamformers typically involves an iterative computation of intermediate solutions across the multiple base stations. We present a low-complexity minimum-mean-squared-error beamforming algorithm for CoMP transmission under per-PA power constraint. We decompose the original beamforming problem at each base station into a series of simpler sub-problems. Solution of each sub-problem is derived in a closed-form, and convergence proof and complexity analysis are presented. We demonstrate significant saving in computational complexity without compromising performance which is confirmed by numerical evaluation.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2013
Issuance monographic
Language English

Creators/Contributors

Associated with Kim, Tae Min
Associated with Stanford University, Department of Electrical Engineering.
Primary advisor Katti, Sachin
Primary advisor Paulraj, Arogyaswami
Thesis advisor Katti, Sachin
Thesis advisor Paulraj, Arogyaswami
Thesis advisor Cioffi, John M
Advisor Cioffi, John M

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Tae Min Kim.
Note Submitted to the Department of Electrical Engineering.
Thesis Thesis (Ph.D.)--Stanford University, 2013.
Location electronic resource

Access conditions

Copyright
© 2013 by Tae Min Kim
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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