Phase Noise in Communication Systems Modeling, Compensation, and Performance Analysis M. Reza Khanzadi Communication Systems Division Department of Signals and Systems Microwave Electronics Laboratory Department of Microtechnology and Nanoscience CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden THESIS FOR DEGREE OF DOCTOR OF PHILOSOPHY Phase Noise in Communication Systems Modeling, Compensation, and Performance Analysis M. Reza Khanzadi Communication Systems Division Department of Signals and Systems Microwave Electronics Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Göteborg, November 2015 Khanzadi, M. Reza Phase Noise in Communication Systems Modeling, Compensation, and Performance Analysis Doktorsavhandlingar vid Chalmers tekniska högskola ISBN 978-91-7597-277-0 Serial Number 3958 ISSN 0346-718X Communication Systems Division Department of Signals and Systems Chalmers University of Technology SE-412 96 Göteborg, Sweden Telephone: + 46 (0)31-772 1000 Microwave Electronics Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology SE-412 96 Göteborg, Sweden Telephone: + 46 (0)31-772 1000 Copyright ©2015 M. Reza Khanzadi except where otherwise stated. All rights reserved. Homepage: http://khanzadi.info This thesis has been prepared using LATEX. Front Cover: The figure on the front cover is the distorted received signal constellation of a 16-QAM communication system due to transmitter and receiver oscillator phase noise. Printed by Chalmers Reproservice, Göteborg, Sweden, October 2015. ToTo thosethose whowho havehave ddedicatededicated theirtheir liveslives toto makemake thethe worldworld a betterbetter place,place, toto mymy family,family, toto mymy belovedbeloved Fatemeh.Fatemeh. ABSTRACT The continuous increase in demand for higher data rates due to applications with massive number of users motivates the design of faster and more spectrum efficient communication systems. In theory, the current communication systems must be able to operate close to Shannon capacity bounds. However, real systems perform below capacity limits, mainly because of considering too idealistic or simplistic assumptions on the imperfections such as channel estimation errors or hardware impairments. Oscillator phase noise is one of the hardware impairments that is becoming a limiting factor in high data rate digital communication systems. Phase noise severely limits the performance of systems that employ dense constellations. Moreover, the level of phase noise (at a given off-set frequency) increases with carrier frequency, which means that the problem of phase noise may be worse in systems with high carrier frequencies. The focus of this thesis is on: i) finding accurate statistical models of phase noise, ii) designing efficient algorithms to mitigate the effect of this phenomenon, iii) analyzing the Shannon capacity of the single and multiple-antenna communication systems affected by phase noise. First, a new statistical model of phase noise valid for free-running and phase-locked- loop-stabilized oscillators is provided. The new model incorporates white and colored noise sources inside the oscillator circuitry. The new model is used in order to connect the performance of phase-noise affected communication systems, in terms of error-vector- magnitude, with oscillator phase-noise measurements. The results can be used by hard- ware and frequency generator designers to better understand the impairing effects of phase noise on the system performance and optimize their design criteria respectively. Second, the proposed phase-noise model is employed for estimation of phase noise generated from white and colored noise sources. A soft-input maximum a posteriori phase noise estimator and a modified soft-input extended Kalman smoother are proposed. The performance of the proposed algorithms is compared against that of those studied in the literature, in terms of mean square error of phase noise estimation, and symbol error rate of the considered communication system. The comparisons show that considerable performance gains can be achieved by designing estimators that employ correct knowledge of the phase-noise statistics. The performance improvement is more significant in low-SNR or low-pilot density scenarios. Finally, the capacity of single and multiple antenna communication systems affected by phase noise is investigated. For the SISO Wiener phase-noise channel, upper and lower i bounds on the capacity are obtained, which are tight for a wide range of SNR values. In addition, a family of input distributions, which result in a tight lower bound are introduced. The high-SNR capacity of single-input multiple-output (SIMO) and multiple- output single-input (MISO) phase-noise channels for two different oscillator configurations is investigated. The provided analysis shows that driving antennas at the base station by separate (independent) local oscillators is beneficial for the SIMO channel compared to driving all the antennas with a common oscillator. In contrast, larger gains are achieved for the MISO channel when a common oscillator is employed. Keywords: Oscillator phase noise, free-running oscillator, phase-locked loop, colored phase noise, phase noise model, Bayesian Cramér-Rao bound, maximum a posteriori estimator, extended Kalman filter/smoother, mean square error, channel capacity, Wiener process, capacity achieving distribution, multiple antennas, distributed oscillators. LIST OF PUBLICATIONS Appended Publications Paper A M. Reza Khanzadi, Dan Kuylenstierna, Ashkan Panahi, Thomas Eriksson, and Her- bert Zirath, "Calculation of the Performance of Communication Systems from Measured Oscillator Phase Noise," IEEE Transactions on Circuits and Systems I, May. 2014. Paper B M. Reza Khanzadi, Rajet Krishnan, and Thomas Eriksson, "Estimation of Phase Noise in Oscillators with Colored Noise Sources," IEEE Communications Letters, Nov. 2013. Paper C M. Reza Khanzadi, Rajet Krishnan, Johan Söder, and Thomas Eriksson, "On the Capacity of the Wiener Phase-Noise Channel: Bounds and Capacity Achieving Distribu- tions," IEEE Transactions on Communications, Jul. 2015. Paper D M. Reza Khanzadi, Giuseppe Durisi, and Thomas Eriksson, "Capacity of SIMO and MISO Phase-Noise Channels with Common/Separate Oscillators," IEEE Transactions on Communications, Sep. 2015. iii Other Publications Below are other contributions by the author which are not included in this thesis, either due to contents overlapping with that of the appended publications, or due to contents not related to this thesis. Patents [P1] M. Reza Khanzadi, Mats Rydström, "Phase Noise Suppression For Large An- tenna Array Communication Systems," Patent Application, Jul. 2015. Journal Papers [J1] Rajet Krishnan, M. Reza Khanzadi, Narayanan Krishnan, Yongpeng Wu, Alexan- dre Graell i Amat, Thomas Eriksson, and Robert Schober, "Linear Massive MIMO Pre- coders in the Presence of Phase Noise: A Large-Scale Analysis," IEEE Transactions on Vehicular Communications, Jan. 2015. [J2] Rajet Krishnan, M. Reza Khanzadi, Thomas Eriksson, and Tommy Svensson, "Soft metrics and their Performance Analysis for Optimal Data Detection in the Presence of Strong Oscillator Phase Noise," IEEE Transactions on Communications, Jun. 2013. [J3] Cristian B. Czegledi, M. Reza Khanzadi, and Erik Agrell, "Bandlimited Power- efficient Signaling and Pulse Design for Intensity Modulation," IEEE Transactions on Communications, Aug. 2014. [J4] Rajet Krishnan, M. Reza Khanzadi, Narayanan Krishnan, Alexandre Graell i Amat, Thomas Eriksson, Nicolò Mazzali, and Giulio Colavolpe, "On the impact of oscilla- tor phase noise on the uplink performance in a massive MIMO-OFDM system," Submitted to IEEE Signal Processing Letters, 2015. [J5] Hani Mehrpouyan, M. Reza Khanzadi, Michail Matthaiou, Robert Schober, and Yingbo Hua, "Improving Bandwidth Efficiency in E-band Communication Systems," IEEE Communications Magazine, Sep. 2012. Conference Papers [C1] M. Reza Khanzadi, Rajet Krishnan, and Thomas Eriksson, "Receiver Algorithm based on Differential Signaling for SIMO Phase Noise Channels with Common and Sep- arate Oscillator Configurations," IEEE Global Communications Conference (GLOBE- COM), Dec. 2015. [C2] M. Reza Khanzadi, Giuseppe Durisi, and Thomas Eriksson, "High-SNR Capac- ity of Multiple-Antenna Phase-Noise Channels with Common/Separate RF Oscillators," IEEE International Conference on Communications (ICC), Jun. 2015. [C3] Rajet Krishnan, M. Reza Khanzadi, Narayanan Krishnan, Yongpeng Wu, Alexan- dre Graell i Amat, Thomas Eriksson, and Robert Schober, "Large Scale Analysis of Linear Massive MIMO Precoders in the Presence of Phase Noise," IEEE International Confer- ence on Communications (ICC), Jun. 2015. [C4] M. Reza Khanzadi, Rajet Krishnan, Dan Kuylenstierna, and Thomas Eriksson, "Oscillator Phase Noise and Small-Scale Channel Fading in Higher Frequency Bands," IEEE Global Communications Conference (GLOBECOM), Dec. 2014. [C5] Cristian B. Czegledi, M. Reza Khanzadi, and Erik Agrell, "Bandlimited Power- Efficient Signaling for Intensity Modulation," IEEE European Conference on Optical Com- munications (ECOC), Sep. 2014. [C6] M. Reza Khanzadi, Rajet Krishnan, and Thomas Eriksson, "Effect of Synchroniz- ing Coordinated Base Stations on Phase Noise Estimation," IEEE Conference on Acoustic, Speech, and Signal Processing (ICASSP), May. 2013. [C7] M. Reza Khanzadi, Ashkan Panahi, Dan Kuylenstierna, and Thomas Eriksson, "A model-based analysis of phase jitter in RF oscillators," IEEE International Frequency