Periodic Reporting for period 1 - TALENT (Lower THz rAdio propagation channeL sounding, parameter Estimation and modeliNg Towards 6G and beyond)
Période du rapport: 2022-07-01 au 2024-06-30
Research on the sixth generation (6G) wireless systems towards 2030 is now the center of attention as 5G is becoming a commercial reality. To realize a high-fidelity holographic society, connectivity for all things and time-sensitive applications, even larger system bandwidths are required in 6G along with new physical layer techniques and higher layer capabilities. New frequency band from 100 GHz to 1 THz is thus considered as a candidate for 6G. Especially, the D-band (110-170 GHz) is very attractive for its low atmospheric absorption loss and wide spectrum, which is promising for advanced applications such as wireless backhaul, WiFi access, velocity sensors, passive cameras, radar, navigation, on-body communication, etc. As the first step to design any new generation system, it is essential to investigate the radio propagation channels because they are distinct at different frequency bands and fundamentally constrain the system design. The propagation research aims to measure radio channels (channel sounding), extract channel parameters e.g. delays, angles-of-arrival/departure, polarization matrix and Doppler shifts of path components from recorded data (parameter estimation) and build mathematical representations of radio channels (channel modeling). Since the early developments of wireless communications in the 1950s and 1960s, extensive channel sounding efforts have been made to investigate the radio channels. However, only a handful of recent works have been performed to investigate the lower THz propagation channels, and little is known about their characteristics. The main challenges include difficulties in developing double-directional channel sounders for dynamic channel characterization, extracting channel parameters from the measurement data efficiently and accurately, and establishing comprehensive and realistic 6G-compatible channel models.
Therefore, the main research goal of this project is to explore the new lower THz frequency band by creating novel and basic theory, technology and knowledge in channel sounding, parameter estimation and modeling for lower THz channels, hence gain the very first understanding and provide guidelines for developing wireless systems operating at the lower THz band. The project will achieve its ambition by the following three specific objectives:
1) developing a novel real-time lower THz channel sounder that can capture dynamic channels. Meanwhile, other parameter domains including delay, double directions and dual polarizations are also well considered (WP1)
2) developing a novel, generic and low-complexity high-resolution-parameter-estimation (HRPE) algorithm that is applicable for the lower THz channels (WP2)
3) establishing comprehensive and realistic lower THz channel models compatible for 6G-oriented applications, i.e. not only for communications but also for positioning and sensing purposes (WP3).
The proposed ideas have become realistically achievable, valuable and a must due to the advancements and demands in developing a new generation wireless system. The successful project is vital for realistic system design and performance analysis of communication, positioning and sensing at the lower THz band and will open up for many interesting future projects in those areas. The project output and results also contribute to Europe’s Digital Decade, i.e. Europe’s digital transformation by 2030, by facilitating an efficient, low-cost, credible, better, and timely development of 6G and beyond wireless systems.
Therefore, the main research goal of this project is to explore the new lower THz frequency band by creating novel and basic theory, technology and knowledge in channel sounding, parameter estimation and modeling for lower THz channels, hence gain the very first understanding and provide guidelines for developing wireless systems operating at the lower THz band. The project will achieve its ambition by the following three specific objectives:
1) developing a novel real-time lower THz channel sounder that can capture dynamic channels. Meanwhile, other parameter domains including delay, double directions and dual polarizations are also well considered (WP1)
2) developing a novel, generic and low-complexity high-resolution-parameter-estimation (HRPE) algorithm that is applicable for the lower THz channels (WP2)
3) establishing comprehensive and realistic lower THz channel models compatible for 6G-oriented applications, i.e. not only for communications but also for positioning and sensing purposes (WP3).
The proposed ideas have become realistically achievable, valuable and a must due to the advancements and demands in developing a new generation wireless system. The successful project is vital for realistic system design and performance analysis of communication, positioning and sensing at the lower THz band and will open up for many interesting future projects in those areas. The project output and results also contribute to Europe’s Digital Decade, i.e. Europe’s digital transformation by 2030, by facilitating an efficient, low-cost, credible, better, and timely development of 6G and beyond wireless systems.
In this project, a switched array-based millimeter wave channel sounder has been developed. It can measure 128*256 dual-polarized massive MIMO channels in several hundred milliseconds at 28 GHz. This is a world class channel sounder with such advanced capabilities. Based on the hardware and software setup, we have successfully developed and verified the mirror-based channel-sounding technique for the THz band. The conference paper about the mirror setup has been awarded the Best Student Paper in VTC-Fall 2024. Moreover, high-resolution parameter estimation algorithms have been developed or are under development to process the measurement data measured using the developed sounders. Papers regarding channel modeling and radio-based localization have been published. In total, more than 20 journal and conference papers regarding channel sounding, parameter estimation, modeling, and radio-based localization were published. The project results were mainly at mm-wave bands. However, this does not mean the project was not implemented well. It is quite the opposite; we have produced significant results for the mm-wave channels that lay the foundation for the THz investigation. Several different projects from the Swedish Research Council, the Crafoord Foundation and ELLIIT have been secured by the fellow, and an application to the ERC Starting Grant submitted by the fellow, to continue the work defined in this project, with substantial leaps to understand the THz channels.
Besides other achievements, the key results that are beyond the state-of-the-art can be summarized as follows:
1. A switched array-based millimeter wave channel sounder has been developed. It can measure 128*256 dual-polarized massive MIMO channels in several hundred milliseconds at 28 GHz. This is a world-class channel sounder with such advanced capabilities. The link to the publication is https://scholar.google.com/citations?view_op=view_citation&hl=zh-CN&user=YHMetUUAAAAJ&sortby=pubdate&citation_for_view=YHMetUUAAAAJ:iH-uZ7U-co4C(s’ouvre dans une nouvelle fenêtre)
2. We have successfully developed and verified the mirror-based channel-sounding technique for the THz band. The conference paper about the mirror setup has been awarded the Best Student Paper in VTC-Fall 2024. This concept will change of the way of high-frequency channel sounding within the propagation research community. The link to the publication is https://scholar.google.com/citations?view_op=view_citation&hl=zh-CN&user=YHMetUUAAAAJ&sortby=pubdate&citation_for_view=YHMetUUAAAAJ:g5m5HwL7SMYC(s’ouvre dans une nouvelle fenêtre)
3. We have investigated the propagation mechanisms of the propagation channels within buildings. Physical interacting points were identified and investigated. This is good work for channel modeling with explainable physics. The link to the publication is https://scholar.google.com/citations?view_op=view_citation&hl=zh-CN&user=YHMetUUAAAAJ&sortby=pubdate&citation_for_view=YHMetUUAAAAJ:J_g5lzvAfSwC(s’ouvre dans une nouvelle fenêtre)
4. Furthermore, based on the deep understanding of the propagation channels, we proposed a new simultaneous localization and mapping algorithm, by exploiting different map features within the environments. In this case, we can localize the device and distinguish between point scatterers and virtual anchors of the environment map. The link to the publication is https://scholar.google.com/citations?view_op=view_citation&hl=zh-CN&user=YHMetUUAAAAJ&sortby=pubdate&citation_for_view=YHMetUUAAAAJ:RGFaLdJalmkC(s’ouvre dans une nouvelle fenêtre)
These findings constitute a complete chain of understanding propagation channels and further exploiting the knowledge for real system design. This also facilitates our further investigation, with new funding and Ph.D. students coming.
1. A switched array-based millimeter wave channel sounder has been developed. It can measure 128*256 dual-polarized massive MIMO channels in several hundred milliseconds at 28 GHz. This is a world-class channel sounder with such advanced capabilities. The link to the publication is https://scholar.google.com/citations?view_op=view_citation&hl=zh-CN&user=YHMetUUAAAAJ&sortby=pubdate&citation_for_view=YHMetUUAAAAJ:iH-uZ7U-co4C(s’ouvre dans une nouvelle fenêtre)
2. We have successfully developed and verified the mirror-based channel-sounding technique for the THz band. The conference paper about the mirror setup has been awarded the Best Student Paper in VTC-Fall 2024. This concept will change of the way of high-frequency channel sounding within the propagation research community. The link to the publication is https://scholar.google.com/citations?view_op=view_citation&hl=zh-CN&user=YHMetUUAAAAJ&sortby=pubdate&citation_for_view=YHMetUUAAAAJ:g5m5HwL7SMYC(s’ouvre dans une nouvelle fenêtre)
3. We have investigated the propagation mechanisms of the propagation channels within buildings. Physical interacting points were identified and investigated. This is good work for channel modeling with explainable physics. The link to the publication is https://scholar.google.com/citations?view_op=view_citation&hl=zh-CN&user=YHMetUUAAAAJ&sortby=pubdate&citation_for_view=YHMetUUAAAAJ:J_g5lzvAfSwC(s’ouvre dans une nouvelle fenêtre)
4. Furthermore, based on the deep understanding of the propagation channels, we proposed a new simultaneous localization and mapping algorithm, by exploiting different map features within the environments. In this case, we can localize the device and distinguish between point scatterers and virtual anchors of the environment map. The link to the publication is https://scholar.google.com/citations?view_op=view_citation&hl=zh-CN&user=YHMetUUAAAAJ&sortby=pubdate&citation_for_view=YHMetUUAAAAJ:RGFaLdJalmkC(s’ouvre dans une nouvelle fenêtre)
These findings constitute a complete chain of understanding propagation channels and further exploiting the knowledge for real system design. This also facilitates our further investigation, with new funding and Ph.D. students coming.