Blind Compensation of Impairments in Wireless Transceivers

Aziz, Mohsin

Blind Compensation of Impairments in Wireless Transceivers

dc.contributor.advisor	Ghannouchi, Fadhel M.
dc.contributor.author	Aziz, Mohsin
dc.contributor.committeemember	Helaoui, Mohamed
dc.contributor.committeemember	Fapojuwo, Abraham Olatunji
dc.contributor.committeemember	Potter, Michael E.
dc.contributor.committeemember	Sawan, Mohamad
dc.date	2018-11
dc.date.accessioned	2018-07-25T13:48:18Z
dc.date.available	2018-07-25T13:48:18Z
dc.date.issued	2018-07-24
dc.description.abstract	Modern wireless communication systems suffer from hardware imperfections that degrade the quality of transmission signals and make the detection of signal quite difficult at the receiver. This thesis focuses on the gain and phase imbalances caused by the modulators and demodulators and nonlinearity stemming from the transmitter power amplifier. Broadly, the contribution of this thesis is two folds: Blind solutions to mitigate the above mentioned hardware impairments of the wireless link through the proposal of a methodology based on the derivation of closed form expressions for the probability density functions (PDFs) of the signals in the presence of these impairments. In this regards, firstly, a PDF in the presence of modulator’s and demodulator’s in-phase and quadrature phase imbalances has been derived and validated. A maximum likelihood estimation of the imbalance parameters has been proposed to mitigate these imperfections. The proposed methodology has been evaluated using extensive simulations and measurements. To evaluate the static performance of the proposed methodology, 10 KHz modulated signal has been used. Measurement results show that an image rejection of greater than 30 dB can be achieved. For a larger bandwidth signal of 1 MHz, around 19 dB improvement in NMSE can be achieved using the proposed methodology, as compared to the uncompensated case. Secondly, a closed form PDF in the presence of gain and phase imbalances and the transmitter’s power amplifier nonlinearity has been derived and validated. A cumulative distribution function-based methodology has been adopted to mitigate the effects of power amplifier’s amplitude distortions. For the modulator’s impairments, a maximum likelihood estimation of the imbalance parameters has been used to estimate and compensate for the modulator’s imperfections. Using measurements, for a 3 MHz LTE signal, a normalized mean squared error and an error vector magnitude of -35 dB and 1.5% can be achieved, respectively.	en_US
dc.identifier.citation	Aziz, M. (2018). Blind Compensation of Impairments in Wireless Transceivers (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/32684	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/32684
dc.identifier.uri	http://hdl.handle.net/1880/107503
dc.language.iso	eng
dc.publisher.faculty	Graduate Studies
dc.publisher.faculty	Schulich School of Engineering
dc.publisher.institution	University of Calgary	en
dc.publisher.place	Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject.classification	Engineering	en_US
dc.subject.classification	Engineering--Electronics and Electrical	en_US
dc.title	Blind Compensation of Impairments in Wireless Transceivers
dc.type	doctoral thesis
thesis.degree.discipline	Electrical and Computer Engineering
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.item.requestcopy	true