On pilot-based estimation of phase noise
Doctoral thesis, 2025
There is an ever-increasing demand for higher data rates in wireless communication systems for supporting, for example, the growing consumption of video streaming in today’s networks, and extremely data-intensive applications such as immersive communications in future networks. However, wireless communication equipment providing higher rates comes with more stringent hardware requirements. A large contributor to distortion is the phase noise related to up- and down-converting of signals to and from radio frequency. The main focus of this thesis is related to handling the carrier phase noise, balancing complexity and performance. For this, different alternatives for close-to-optimal low complexity pilot-based phase noise estimation methods are studied.
First, a seemingly simple approach is examined in Paper A, where a pilot tone in the form of a sinusoid is added to an unknown communication signal. The power of the transmitted signal is shared between the pilot tone and the communication signal. Several pilot-based phase noise estimation algorithms are studied, and an optimal signal-to-pilot power ratio is presented.
Second, pilot-based phase noise estimation of an OFDM signal affected by phase noise is studied in Paper B. The known pilots are allocated in the frequency domain and occupy a number of subcarriers within the OFDM symbols. A novel, low-complexity pilot-based phase estimator is proposed, which is close to optimal over a wide dynamic range of phase noise levels and signal-to-noise ratios.
Finally, Paper C examines the maximum rate of a line-of-sight MIMO system affected by phase noise, where known pilots are interleaved in the time domain together with the payload. To maximize the rate, a novel pilot-based estimator is proposed that jointly estimates both payload and phase noise.
First, a seemingly simple approach is examined in Paper A, where a pilot tone in the form of a sinusoid is added to an unknown communication signal. The power of the transmitted signal is shared between the pilot tone and the communication signal. Several pilot-based phase noise estimation algorithms are studied, and an optimal signal-to-pilot power ratio is presented.
Second, pilot-based phase noise estimation of an OFDM signal affected by phase noise is studied in Paper B. The known pilots are allocated in the frequency domain and occupy a number of subcarriers within the OFDM symbols. A novel, low-complexity pilot-based phase estimator is proposed, which is close to optimal over a wide dynamic range of phase noise levels and signal-to-noise ratios.
Finally, Paper C examines the maximum rate of a line-of-sight MIMO system affected by phase noise, where known pilots are interleaved in the time domain together with the payload. To maximize the rate, a novel pilot-based estimator is proposed that jointly estimates both payload and phase noise.
OFDM
MIMO systems
time domain pilots
carrier synchronization
phase noise
frequency domain pilots
Wireless communication
ED
Opponent: Prof. Alberto Tarable, Information Engineering and Telecommunication, Politecnico Di Torino, Italy
Author
Björn Gävert
Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks
Estimation of Phase Noise Based on In-Band and Out-of-Band Frequency Domain Pilots
IEEE Transactions on Communications,;Vol. 70(2022)p. 4780- 4792
Journal article
Phase noise estimation in OFDM systems
IEEE Transactions on Communications,;Vol. In Press(2024)
Journal article
Gavert, B., Coldrey, M., Eriksson, T. Analysis and Mitigation of Phase Noise in a Line-Of-Sight MIMO System
Wireless communication is an essential part of everyday life, even if many people do not realize it. It enables a wide range of services, from sending messages to streaming on-demand videos. The increasing consumption of video streaming significantly raises data rates. Additionally, the Internet of Things introduces more devices with machine-type wireless communication, though it is less visible to everyday users. Machine-type wireless communication covers everything from consumer devices to industrial machines, requiring efficient data transmission and reception. As both data rates and the number of connected devices grow, the demands on wireless mobile equipment become more stringent.
Digital wireless communication involves converting digital information into waveforms that are transmitted over the air. The receiver collects these noisy waveforms and attempts to reconstruct the original digital data by detecting the corresponding bits. This process relies on both digital and analog hardware. While digital processing is highly precise, analog components introduce noise and distortion, contributing to detection errors in the receiver. One major source of distortion is phase uncertainty, or phase noise, which occurs when translating signals to and from the radio carrier frequency. If not properly managed, phase noise can significantly impact transmission accuracy and lead to errors. This thesis explores pilot-based algorithms for mitigating phase distortion. Pilots are known waveforms that are periodically transmitted along with customer data to help measure and estimate phase noise. Various pilot transmission methods are analyzed, and corresponding near-optimal estimators are proposed.
Digital wireless communication involves converting digital information into waveforms that are transmitted over the air. The receiver collects these noisy waveforms and attempts to reconstruct the original digital data by detecting the corresponding bits. This process relies on both digital and analog hardware. While digital processing is highly precise, analog components introduce noise and distortion, contributing to detection errors in the receiver. One major source of distortion is phase uncertainty, or phase noise, which occurs when translating signals to and from the radio carrier frequency. If not properly managed, phase noise can significantly impact transmission accuracy and lead to errors. This thesis explores pilot-based algorithms for mitigating phase distortion. Pilots are known waveforms that are periodically transmitted along with customer data to help measure and estimate phase noise. Various pilot transmission methods are analyzed, and corresponding near-optimal estimators are proposed.
Areas of Advance
Information and Communication Technology
Subject Categories (SSIF 2025)
Communication Systems
Telecommunications
Signal Processing
ISBN
978-91-8103-189-8
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5647
Publisher
Chalmers
ED
Opponent: Prof. Alberto Tarable, Information Engineering and Telecommunication, Politecnico Di Torino, Italy