A groundbreaking interference management technique for wireless communications, developed at Imperial College London, is set to revolutionise the future of mobile connectivity. The technique, known as Rate Splitting Multiple Access…
A groundbreaking interference management technique for wireless communications, developed at Imperial College London, is set to revolutionise the future of mobile connectivity. The technique, known as Rate Splitting Multiple Access (RSMA), was invented by Professor Bruno Clerckx from the Department of Electrical and Electronic Engineering.
The research has shown a remarkable potential to outperform existing methods, paving the way for its use in 6G networks. It has other real world applications like supporting massive Internet of Things deployments, and improving the efficiency and capacity of satellite communication systems. It can also enhance the communication capabilities of Unmanned Aerial Vehicles (UAVs), allowing for better coordination and data exchange in applications such as surveillance, delivery, and disaster response.
The primary challenge in modern wireless communication systems, such as 5G, is the multiple access problem: how to simultaneously serve as many users as possible to meet the enormous demand for mobile connectivity. Effective multiple access requires overcoming the interference caused by signals intended for other users. In 5G, this is achieved using multiple antennas at each cell tower through a signal processing technique called Space Division Multiple Access (SDMA), which reduces the power of interfering signals to the low thermal noise levels inherent in all electronic devices. However, SDMA becomes less effective as the number of users increases.
At high interference levels, an alternative technique known as Non-Orthogonal Multiple Access (NOMA) attempts to decipher and subtract the interfering signals to extract the desired message. However, NOMA’s effectiveness is limited to single-antenna networks, unlike today’s multi-antenna networks like 5G.
RSMA bridges the gap between NOMA and SDMA by partially deciphering and subtracting interference (like NOMA) and suppressing the remaining interference power (like SDMA). This unique interference management strategy allows RSMA to achieve higher data rates for users than what is possible with 5G’s SDMA. Recent publications from Professor Clerckx’s lab have experimentally demonstrated that RSMA can indeed achieve higher data rates than both SDMA and NOMA, making it a promising technology for future wireless networks like 6G. This success builds on other milestones, such as a best paper award and the establishment of an IEEE special interest group devoted to RSMA.
On the prospects of RSMA for 6G, Professor Clerckx stated, “RSMA has already been submitted for 6G standardisation by companies like Viavi and BBC. It is also a key topic in recent EU funding calls for 6G R&D. Our experimental validation of RSMA’s long-theorised superiority over SDMA and NOMA is a timely achievement that should attract many more industry stakeholders in 6G.” But this is only the beginning. In addition to higher data rates, RSMA has also been shown, in theory, to benefit over 40 different use cases in 6G, such as integrated (radar) sensing and communications, and joint unicast (one-to-one communications) and multicast (one-to-many communications). “Going forward, we intend to experimentally validate RSMA’s versatility in supporting several of these use cases using our prototype. This would, of course, build more momentum towards RSMA’s inclusion in the 6G standards,” Clerckx said.
The research is a part of TITAN Lighthouse Project 2: User-Centric Service-Aware Radio Access Control, Integration and Optimisation. The Lighthouse Project 2 (LP2) focuses on user-centric service-aware radio access control, integration and optimisation. The work’s outcomes will support broader societal goals.
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If you have any questions about the research discussed in this article, please contact titan-enquiries@eng.cam.ac.uk.
