New Radio Resource Development Technology Opens the Era of Dream Data Speed 6G

UNIST Professor Eunmi Choi's Team Develops and Experimentally Verifies Fundamental Method for OAM Wave Resource Degrees of Freedom

Data Transmission Increases by Multiples of Degrees of Freedom Using OAM, Securing Fundamental 6G Technology

Conceptual diagram of wireless backhaul communication using OAM transmission mode.

[Asia Economy Yeongnam Reporting Headquarters Reporter Kim Yong-woo] A new radio resource development technology has emerged in preparation for the future dream data speed 6G era.

This technology, developed by domestic researchers, is gaining attention at a time when the amount of data is exploding and data transmission volume is increasing exponentially as we enter a hyper-connected society.

For the commercialization of 6G technology, which is expected to increase data transmission rates by more than 50 times compared to 5G, new radio resource development and technology to quantify it were needed.

The research team led by Professor Choi Eun-mi of the Department of Electrical and Electronic Engineering at Ulsan National Institute of Science and Technology (UNIST, President Lee Yong-hoon) established a channel capacity prediction formula for wireless communication applying the new concept radio resource called Orbital Angular Momentum (OAM).

Using this formula, it is possible to predict the maximum data transmission volume that can be sent at once when applying OAM. The research team succeeded in experimentally verifying this.

Supported by the Samsung Future Technology Development Project, this research was first published online in the authoritative wireless communication journal IEEE Wireless Communications Magazine and is scheduled to be published in the February issue.

OAM mode used for experimental verification.

OAM wireless communication utilizes the characteristics of OAM waves that twist and move like a spiral staircase. Even waves of the same frequency (wavelength) can have different numbers of twists (OAM modes) within the same wavelength, maximizing the utilization efficiency of limited frequency resources.

The ‘degree of freedom analysis method’ proposed by Professor Choi’s research team is a technology that can determine ‘how many modes (twists) can be maximally increased’ by considering the size and distance of transmitting and receiving antennas in an actual wireless communication environment.

If the number of twists can be increased up to three times, the data transmission volume increases threefold. This is because modes twisted once, twice, and three times can each be used as separate channels to transmit data simultaneously.

This degree of freedom analysis method can be applied to the terahertz frequency range, which is emerging as a frequency resource to open the 6G era.

The existing OAM mode degree of freedom analysis method is limited to the RF (Radio Frequency) range commonly used in current wireless communications.

The terahertz range is a short-wavelength region close to visible light, requiring consideration of both optical properties and radio frequency (RF) characteristics.

Professor Eunmi Choi of UNIST (front row, right) and her research team.

Professor Choi explained, “We were able to solve the problem based on the mode orthogonality, a non-interfering property of the quantized physical quantity OAM, and paraxiality, the property of electromagnetic waves concentrated along the propagation axis.”

The research team not only theoretically proposed the channel capacity analysis method for OAM degrees of freedom but also completed experimental verification of the theory developed at 81-86 GHz (gigahertz, E-band frequency range).

Using a metasurface produced by 3D printing techniques, they experimentally generated OAM modes and measured the OAM mode channel capacity, confirming that the results matched the theory.

Professor Choi Eun-mi said, “OAM wave modes can be used in future 6G communication technologies such as wireless backhaul communication that wirelessly connects base stations and top-level networks,” adding, “This research predicting the degrees of freedom of OAM wave modes is meaningful in that it discovered new radio resources to increase channel capacity in 6G communication and quantitatively evaluated their advantages and disadvantages.”