RF BiST för att detektera IQ-imbalanser avseende överhörningseffekter för avancerade antennsystem
(2018) EITM02 20181Department of Electrical and Information Technology
- Abstract (Swedish)
- Internet of Things (IoT) is a network constituted by uniquely identifiable commodity objects or devices equipped with some sensing system. To achieve high data rates required for IoT devices, a modern wireless communication system, known as Advanced Antenna Systems(AAS), leads to significant improvement, by increasing not only the data rate but also spectrum efficiency and the channel capacity. A certain type of analog signal distortions, i.e. the in-phase (I) and quadrature-phase (Q) imbalances can severely damage the performance of the RF transceivers. The IQ imbalances refer to gain mismatch, phase mismatch, DC offset in the I and Q branches. IQ Imbalances affect the efficiency and performance of the Radio Frequency (RF) Transceivers,... (More)
- Internet of Things (IoT) is a network constituted by uniquely identifiable commodity objects or devices equipped with some sensing system. To achieve high data rates required for IoT devices, a modern wireless communication system, known as Advanced Antenna Systems(AAS), leads to significant improvement, by increasing not only the data rate but also spectrum efficiency and the channel capacity. A certain type of analog signal distortions, i.e. the in-phase (I) and quadrature-phase (Q) imbalances can severely damage the performance of the RF transceivers. The IQ imbalances refer to gain mismatch, phase mismatch, DC offset in the I and Q branches. IQ Imbalances affect the efficiency and performance of the Radio Frequency (RF) Transceivers, present in the AAS. Hence a need for test architectures arises. In this thesis an existing BiST circuitry for one transmission chain is chosen, implemented and further extended to multiple transmission chains (up to 4). As the number of transmission chains increase, mutual coupling phenomenon leading to crosstalk effects are to be considered. Along with designed test signal, this BiST circuitry enables us to detect the transmitter impairment with low computational complexity.
In this thesis work 3 different cases have been implemented which are – one antenna setup, 2x1 antenna array setup and 4x1 antenna array setup. The first case has one transmission chain. We have utilized the Generalized Memory Polynomial (GMP) power amplifier model, and the BiST circuitry, called as Self-Mixing Envelope Detector method is implemented in Matlab. In the case of 2x1 Antenna array, implementation is partly carried out using the RF equipment for the signal generation stage, power amplifier stage, crosstalk effects (mutual coupling), and BiST circuitry stage, which was previously implemented in Matlab is utilized. The 4x1 antenna array setup, just like the one antenna setup, is entirely implemented in Matlab. Additionally, the coupling coefficients are extracted to model the mutual coupling phenomenon. In the one antenna setup & the 4x1 antenna array setup, the RMSE% of IQ imbalances are calculated. In the 2x1 antenna array setup, gain mismatch, phase mismatch, both the DC offsets are measured up to a certain accuracy.
The results obtained in all the three cases advocate that this method, successfully detect the IQ impairments present in the advanced antenna system, even when the crosstalk effects are considered. (Less) - Popular Abstract
- Internet of Things (IoT) is network constituted by day-to-day objects equipped
with some sensing system. These objects can also communicate with other objects for data exchange, wirelessly. This calls for a need of better wireless communication systems. New techniques using the 4G (Long-Term Evolution) have been developed to solve this problem, known as Advanced Antenna System (AAS). This new technique includes packing a large number of antennas in a small area, enabling the transmission of signals of the same frequency, at the same time. Closely packing the antennas, causes a phenomenon called as mutual coupling leading to crosstalk effects in the Radio Frequency(RF) system. Effect on an antenna due to the adjacent antenna is called... (More) - Internet of Things (IoT) is network constituted by day-to-day objects equipped
with some sensing system. These objects can also communicate with other objects for data exchange, wirelessly. This calls for a need of better wireless communication systems. New techniques using the 4G (Long-Term Evolution) have been developed to solve this problem, known as Advanced Antenna System (AAS). This new technique includes packing a large number of antennas in a small area, enabling the transmission of signals of the same frequency, at the same time. Closely packing the antennas, causes a phenomenon called as mutual coupling leading to crosstalk effects in the Radio Frequency(RF) system. Effect on an antenna due to the adjacent antenna is called mutual coupling and it leads to crosstalk effects. Due to the crosstalk effects the functioning of the antenna changes.
AAS consists of multiple RF transmission chains, each transmission chain is made of an in-phase (I) and a quadrature-phase (Q) branch. In reality, there is always some imbalances present between I and Q branches of the RF transceivers.
The I & Q imbalances can severely damage the performance of RF transceivers.
These occur due to finite tolerances of the hardware components used in the RF
transceivers. These spurious effects are mainly due to amplitude & phase mismatches, and dc offsets between respective IQ branches and therefore known as IQ imbalances. These IQ imbalances are one of the most detrimental imperfections in the performance of an RF transceivers. Hence a need for a test architecture arises.
Testing a circuit requires the application of a test stimulus and the comparison of the actual circuit response with the correct response. If the system internally does this process and gives us a result which enables us to determine if the system is faulty or not, then it is referred to as a Built-In Self Test method of testing, commonly abbreviated as BiST. When this technique of testing is applied to an RF system, it is called RF BiST.
In this thesis, using an RF BiST method, we detect the IQ imbalances, considering crosstalk effects for Advanced Antenna System. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8963561
- author
- Khed, Kishore LU
- supervisor
-
- Erik Larsson LU
- organization
- alternative title
- RF BiST to detect IQ Imbalances considering Crosstalk Effects for Advanced Antenna System
- course
- EITM02 20181
- year
- 2018
- type
- H2 - Master's Degree (Two Years)
- subject
- report number
- LU/LTH-EIT 2018-675
- language
- English
- id
- 8963561
- date added to LUP
- 2018-11-29 08:12:53
- date last changed
- 2018-11-29 08:12:53
@misc{8963561,
abstract = {{Internet of Things (IoT) is a network constituted by uniquely identifiable commodity objects or devices equipped with some sensing system. To achieve high data rates required for IoT devices, a modern wireless communication system, known as Advanced Antenna Systems(AAS), leads to significant improvement, by increasing not only the data rate but also spectrum efficiency and the channel capacity. A certain type of analog signal distortions, i.e. the in-phase (I) and quadrature-phase (Q) imbalances can severely damage the performance of the RF transceivers. The IQ imbalances refer to gain mismatch, phase mismatch, DC offset in the I and Q branches. IQ Imbalances affect the efficiency and performance of the Radio Frequency (RF) Transceivers, present in the AAS. Hence a need for test architectures arises. In this thesis an existing BiST circuitry for one transmission chain is chosen, implemented and further extended to multiple transmission chains (up to 4). As the number of transmission chains increase, mutual coupling phenomenon leading to crosstalk effects are to be considered. Along with designed test signal, this BiST circuitry enables us to detect the transmitter impairment with low computational complexity.
In this thesis work 3 different cases have been implemented which are – one antenna setup, 2x1 antenna array setup and 4x1 antenna array setup. The first case has one transmission chain. We have utilized the Generalized Memory Polynomial (GMP) power amplifier model, and the BiST circuitry, called as Self-Mixing Envelope Detector method is implemented in Matlab. In the case of 2x1 Antenna array, implementation is partly carried out using the RF equipment for the signal generation stage, power amplifier stage, crosstalk effects (mutual coupling), and BiST circuitry stage, which was previously implemented in Matlab is utilized. The 4x1 antenna array setup, just like the one antenna setup, is entirely implemented in Matlab. Additionally, the coupling coefficients are extracted to model the mutual coupling phenomenon. In the one antenna setup & the 4x1 antenna array setup, the RMSE% of IQ imbalances are calculated. In the 2x1 antenna array setup, gain mismatch, phase mismatch, both the DC offsets are measured up to a certain accuracy.
The results obtained in all the three cases advocate that this method, successfully detect the IQ impairments present in the advanced antenna system, even when the crosstalk effects are considered.}},
author = {{Khed, Kishore}},
language = {{eng}},
note = {{Student Paper}},
title = {{RF BiST för att detektera IQ-imbalanser avseende överhörningseffekter för avancerade antennsystem}},
year = {{2018}},
}