PhD Dissertation Defense for Sabah Razavi, ECE Department, WPI

Friday, January 11, 2019
2:00 pm
Floor/Room #: 
AK 218


The Problems of Channel Estimation Error, Oscillator Stability And Wireless Power Transfer in Wireless Communication With Distributed Reception Networks



In recent years the need for having advanced networks with distributed transmission or reception has increased rapidly. These types of networks have wide variety of applications especially in wireless networks and signal processing applications. This dissertation considers three major problems in distributed reception networks. In these types of networks, there is one or more transmitters and a cluster of receivers which are all connected using a wired or wireless local area network. The received signal at each receive node is exchanged with the other nodes over this local network. The first part of this dissertation investigates the effect of having channel estimation error on the system's performance in terms of SNR while hard decisions are being exchanged between the receivers in the cluster. These effects are obtained for two different modulation schemes, M-PSK and M2-QAM.


The other problem that has been investigated in this work, is the oscillator stability and phase noise modeling. In every distributed reception or cooperative networks with more than one transmitter or transmit antenna, it is necessary that all transmissions be synced with picosecond accuracy. Therefore, being able to accurately model the behavior of the oscillators and their phase noise responses in both transmitters and receivers is of a high importance. To answer this need, in this work a new method for modeling the oscillators have been proposed which uses a three-state model compared to the previous method which uses a two-state model for predicting phase noise behavior.

The last part of this work is dedicated to the problem of wireless power transfer in distributed reception networks. To be able to transmit maximum power to receive cluster, it is necessary for the transmitters to have optimum phases so the received signal at the receiver nodes are all in sync and the maximum power transfer is assured. For this purpose, first a convergence analysis of weighted received sum power at the receivers is done to obtain the equation for calculating optimum phase differences and ultimately the phases of transmitters. Then, three feedback decision rules which decide on the received one-bit feedback signals are proposed to do the transmitters’ phase update.


Research Advisor:

Prof. D. Richard Brown, III

ECE Department, WPI


Committee Members:

Prof. John McNeill

Dean of Engineering, WPI

Prof. Andrew Klein

Department of Engineering and Design, WWU