“`html
Scholars from MIT and other institutions have crafted an innovative transmitter chip that greatly enhances the energy efficiency of wireless communication, potentially extending the range and battery longevity of connected devices.
Their methodology utilizes a distinctive modulation technique to encode digital information into a wireless signal, which minimizes errors during transmission and results in more dependable communication.
This compact and adaptable system could be integrated into current internet-of-things gadgets to offer immediate improvements while also aligning with the stricter efficiency standards expected in future 6G technologies.
The chip’s flexibility may render it ideal for various applications requiring precise energy management for communications, such as industrial sensors that continuously assess factory environments and smart appliances providing instant updates.
“By adopting an unconventional perspective, we developed a more efficient, intelligent circuit for next-gen devices that exceeds the capabilities of existing legacy systems. This illustrates how embracing a modular framework for adaptability can stimulate innovation at all levels,” states Muriel Médard, the NEC Professor of Software Science and Engineering at the School of Science and co-author of a publication on the novel transmitter.
Médard’s collaborators include Timur Zirtiloglu, the primary author and a graduate student at Boston University; Arman Tan, another graduate student at BU; Basak Ozaydin, an MIT graduate student in EECS; Ken Duffy, a professor at Northeastern University; and Rabia Tugce Yazicigil, associate professor of electrical and computer engineering at BU. The research was recently unveiled at the IEEE Radio Frequency Circuits Symposium.
Enhancing transmissions
In wireless devices, a transmitter transforms digital information into an electromagnetic signal dispatched over airwaves to a receiver. It accomplishes this by assigning digital bits to symbols that depict the amplitude and phase of the electromagnetic signal, a process known as modulation.
Conventional systems send signals that are evenly spaced by generating a uniform sequence of symbols, which helps prevent interference. However, this standardized arrangement lacks flexibility and can be inefficient, as wireless channel conditions are often dynamic and change rapidly.
In contrast, optimal modulation schemes adopt a non-uniform pattern that can adapt to fluctuating channel conditions, maximizing data transmission while minimizing energy consumption.
Yet, while optimal modulation can enhance energy efficiency, it is also more vulnerable to errors, particularly in crowded wireless spaces. When the signals lack uniform length, it becomes challenging for the receiver to differentiate between symbols and noise that may interfere with the transmission.
To address this issue, the MIT transmitter incorporates a small amount of padding, in the form of additional bits between symbols, ensuring each transmission maintains a consistent length.
This facilitates the receiver’s ability to recognize the start and end of each transmission, averting misinterpretation of the message. At the same time, the device benefits from the energy efficiency advantages of using a non-uniform, optimal modulation scheme.
This strategy is effective due to a technique the researchers previously pioneered known as GRAND, which serves as a universal decoding algorithm capable of deciphering any code by estimating the noise impacting the transmission.
In this context, they utilize a GRAND-inspired algorithm to modify the length of the received transmission by estimating the additional bits added. This allows the receiver to reconstruct the original message accurately.
“Thanks to GRAND, we now possess a transmitter capable of executing these more efficient transmissions with non-uniform data constellations, and we are witnessing the advantages,” Médard remarks.
An adaptable circuit
The new chip has a compact design that enables researchers to integrate additional methods that enhance efficiency, resulting in transmissions with only about a quarter of the signal error compared to methods employing optimal modulation.
Unexpectedly, the device also demonstrated significantly lower error rates than transmitters using traditional modulation techniques.
“The traditional method has become so entrenched that it was difficult to resist reverting to the status quo, particularly since we were modifying aspects we often take for granted and concepts we’ve been teaching for decades,” Médard notes.
This groundbreaking architecture could enhance the energy efficiency and reliability of existing wireless communication devices while also providing the versatility to be integrated into future devices utilizing optimal modulation.
Looking ahead, the researchers aim to refine their approach by incorporating additional techniques to further increase efficiency and lower error rates in wireless transmissions.
“This optimal modulation transmitter radio frequency integrated circuit represents a revolutionary advancement over traditional RF signal modulation. It is poised to play a crucial role in the next generation of wireless connectivity, including 6G and Wi-Fi,” states Rocco Tam, NXP Fellow for Wireless Connectivity SoC Research and Development at NXP Semiconductors, who did not participate in this research.
This endeavor is supported, in part, by the U.S. Defense Advanced Research Projects Agency (DARPA), the National Science Foundation (NSF), and the Texas Analog Center for Excellence.
“`