Masters Theses


"The goal of this thesis it to develop a wireless networking framework for battery-free devices based on passive, backscatter communication. In contrast to traditional, active communication systems, where the radio signal has to be generated using large amount of energy from batteries, the passive systems reflect the RF signal. The information is encoded by modulating the reflected signal, which consumes significantly less energy than active transmission. The existing passive, backscatter systems have limited communication capabilities. For example, the Radio Frequency Identification (RFID) systems support short-distance, direct communication between active reader and passive tags. The communication range is limited due to power and sensitivity limitations of transmitters and receivers respectively. Moreover, in contrast to a multi-hop ad hoc and sensor networks, the traditional backscatter systems limit themselves to a single-hop topology due to limited capabilities of passive tags and different challenges in passive communication. Existing literature lacks of understanding how such multi-hop, passive, and asymmetric networks can be realized and what are their theoretical limits. This thesis aims at understanding the communication and coverage challenge in backscatter systems and addressing them through: (a) a distributed beamforming that increases the transmission range to a specific tag/location (PAPER I), and (b) a multi-hop framework for the backscatter communication that increases effective communication range (PAPER II). The proposed beamforming methodology employs spatially distributed, passive scattering devices located between transmitter and receiver to increase the RF signal strength. The theoretical limits of such scheme are analyzed mathematically and in simulations with two beamforming approaches being proposed. Furthermore, a novel architecture is proposed for multi-hop backscatter-based networking for a passive RF communication that is not currently present. The paper presents the generic analysis of the system capabilities and demonstrates the feasibility of such multi-hop network. Furthermore, the connectivity models are studied in terms of k-connectivity of such a network of tags"--Abstract, page iv.


Zawodniok, Maciej Jan, 1975-

Committee Member(s)

Sedigh, Sahra
Choi, Minsu


Electrical and Computer Engineering

Degree Name

M.S. in Computer Engineering


National Science Foundation (U.S.)


Missouri University of Science and Technology

Publication Date


Journal article titles appearing in thesis/dissertation

  • Distributed beamforming for RF propagation using a scattering network.
  • Multi-hop framework for battery-less devices using passive RF communication


xi, 59 pages

Note about bibliography

Includes bibliographical references.


© 2010 Vikram Reddy Surendra, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Wireless communication systems
Radio frequency identification systems

Thesis Number

T 10221

Print OCLC #


Electronic OCLC #