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Ray-tracing based analysis of channel characteristics and capacity improvement capabilities of spatial multiplexing and beamforming at 15 and 28 GHz

Liao, Qingbi LU (2016) EITM02 20161
Department of Electrical and Information Technology
Abstract
In the previous decades, mm-Wave frequency bands have largely been ignored for cellular communication because of the high free space attenuation as well as the cost and complexity of mm-Wave RF circuits. However, with the improvement of RF and antenna technologies over the last decade, it has become feasible to con- sider mm-Wave bands for cellular communications. With the large bandwidths available in the mm-Wave range, this could enable much higher data rates, and could also alleviate the problem of limited frequency resources. Many bands in the frequency range above 6 GHz and into the mm-Wave range of 30-300 GHz are therefore interesting candidates for future 5G cellular systems. The utilisation of Multiple-input Multiple-output (MIMO)... (More)
In the previous decades, mm-Wave frequency bands have largely been ignored for cellular communication because of the high free space attenuation as well as the cost and complexity of mm-Wave RF circuits. However, with the improvement of RF and antenna technologies over the last decade, it has become feasible to con- sider mm-Wave bands for cellular communications. With the large bandwidths available in the mm-Wave range, this could enable much higher data rates, and could also alleviate the problem of limited frequency resources. Many bands in the frequency range above 6 GHz and into the mm-Wave range of 30-300 GHz are therefore interesting candidates for future 5G cellular systems. The utilisation of Multiple-input Multiple-output (MIMO) is almost a necessity at these frequencies. This makes it possible to implement different antenna processing techniques in order to improve coverage and system capacity. In the master thesis, the behaviour of 15 and 28 GHz channels in indoor and outdoor scenarios are simulated by us- ing a ray-tracing algorithm. By comparing indoor channel measurements with the ray-tracing results, it is possible to verify the performance and identify the limitations of the ray-tracing algorithm. In the outdoor scenario, channel characteristics such as received power and RMS delay spreads are analysed based on ray-tracing simulations. A metric called Channel Multiplexing Richness (CMR) is defined to indicate the scattering richness of a location. This thesis also investigates the capacity improving capabilities of beamforming (such as directional beamforming and dominant eigenmode transmission), spatial multiplexing and a hybrid technique which combines beamforming and spatial multiplexing. The link capacity for these different techniques is calculated based on ray tracing results for the single-user case, assuming full channel state information. The simulation results are also compared to different environment models, so that the influences of the material permittivity and the level of geometric details are investigated. (Less)
Popular Abstract
High speed and high-quality broadband communication services are required in modern society. The next generation of the wireless mobile communication system, also known as 5G, has focused on the new frequency bands above 6 GHz, especially the range of 30-300 GHz named as mm-Wave because the wavelength is in millimeter scale. In the past days, the mm-Wave frequency band has been ignored. The first reason is that, the higher frequency bands suffer from a much shorter coverage range. In order to improve this, special techniques have to be applied, where a large number of antenna elements are used to direct the transmitted energy in the desired direction. Second, the radio frequency (RF) circuit of mm- Wave is more complicated and cost more... (More)
High speed and high-quality broadband communication services are required in modern society. The next generation of the wireless mobile communication system, also known as 5G, has focused on the new frequency bands above 6 GHz, especially the range of 30-300 GHz named as mm-Wave because the wavelength is in millimeter scale. In the past days, the mm-Wave frequency band has been ignored. The first reason is that, the higher frequency bands suffer from a much shorter coverage range. In order to improve this, special techniques have to be applied, where a large number of antenna elements are used to direct the transmitted energy in the desired direction. Second, the radio frequency (RF) circuit of mm- Wave is more complicated and cost more money than the lower frequency circuit. Luckily, over the last decade, the development of antenna and RF technologies has made it possible to consider mm-Wave bands. Also, the sufficient frequency resources provided by mm-Wave band is an important reason why it is popular now. This project focuses on two frequency bands, 15 and 28 GHz. The multiple antenna system, which combines several antenna elements into an antenna array, is the key point of the 5G technology. The use of multiple antenna system is able to improve the communication performance. In this work, the communication performance is analysed based on the ray-tracing simulation, which is simpler way than the traditional measurement. The channel measurement usually takes a lot of time, and those measuring equipments are expensive. Some components, for example the antenna of 15 GHz, need to be manufactured specially. (Less)
Please use this url to cite or link to this publication:
author
Liao, Qingbi LU
supervisor
organization
course
EITM02 20161
year
type
H2 - Master's Degree (Two Years)
subject
keywords
5G, 15 GHz, 28 GHz, beamforming, capacity, channel multiplexing richness, hybrid beamforming, MIMO, mm-Wave, ray-tracing, spatial multiplexing
report number
LU/LHT-EIT 2016-547
language
English
id
8894344
date added to LUP
2016-11-01 10:51:09
date last changed
2016-11-08 08:26:28
@misc{8894344,
  abstract     = {In the previous decades, mm-Wave frequency bands have largely been ignored for cellular communication because of the high free space attenuation as well as the cost and complexity of mm-Wave RF circuits. However, with the improvement of RF and antenna technologies over the last decade, it has become feasible to con- sider mm-Wave bands for cellular communications. With the large bandwidths available in the mm-Wave range, this could enable much higher data rates, and could also alleviate the problem of limited frequency resources. Many bands in the frequency range above 6 GHz and into the mm-Wave range of 30-300 GHz are therefore interesting candidates for future 5G cellular systems. The utilisation of Multiple-input Multiple-output (MIMO) is almost a necessity at these frequencies. This makes it possible to implement different antenna processing techniques in order to improve coverage and system capacity. In the master thesis, the behaviour of 15 and 28 GHz channels in indoor and outdoor scenarios are simulated by us- ing a ray-tracing algorithm. By comparing indoor channel measurements with the ray-tracing results, it is possible to verify the performance and identify the limitations of the ray-tracing algorithm. In the outdoor scenario, channel characteristics such as received power and RMS delay spreads are analysed based on ray-tracing simulations. A metric called Channel Multiplexing Richness (CMR) is defined to indicate the scattering richness of a location. This thesis also investigates the capacity improving capabilities of beamforming (such as directional beamforming and dominant eigenmode transmission), spatial multiplexing and a hybrid technique which combines beamforming and spatial multiplexing. The link capacity for these different techniques is calculated based on ray tracing results for the single-user case, assuming full channel state information. The simulation results are also compared to different environment models, so that the influences of the material permittivity and the level of geometric details are investigated.},
  author       = {Liao, Qingbi},
  keyword      = {5G,15 GHz,28 GHz,beamforming,capacity,channel multiplexing richness,hybrid beamforming,MIMO,mm-Wave,ray-tracing,spatial multiplexing},
  language     = {eng},
  note         = {Student Paper},
  title        = {Ray-tracing based analysis of channel characteristics and capacity improvement capabilities of spatial multiplexing and beamforming at 15 and 28 GHz},
  year         = {2016},
}