Researchers from the Indian Institute of Technology Mandi have developed a cutting-edge solution for telecommunications – a cooperative spectrum sensor that improves the reusability of the radio frequency spectrum, which will help improve data communication for future wireless communication applications .
The results of their work have recently been published in the Institute of Electrical and Electronics Engineers (IEEE) Transactions on Consumer Electronics and other IEEE journals. These articles were written by Dr. Rahul Shrestha, Assistant Professor (School of Computer Science and Electrical Engineering – IIT Mandi), and his PhD student, Mr. Rohit B Chaurasiya.
Dr Shrestha said that radio frequency waves, or “spectrum” as they are known in the telecommunications field, are used for wireless communications and that the wireless radio frequency spectrum is a limited resource allocated by the government to companies. telecommunications through a licensing process. The rapid growth in wireless communication technology seen in recent years and the exponential increase predicted due to the mass adoption of technologies such as the new fifth-generation radio (5G-NR) and the Internet of Things (IoT ) should drive demand for the spectrum bands, he added.
Highlighting the need for research in the area of spectrum optimization, he said: “Given the fixed spectrum allocation policy of many governments around the world, including ours, it becomes important to use intelligently the available spectrum. Cognitive radio technology is considered one of the best ways to optimize spectrum usage.
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Not all parts of the spectrum band licensed to a telecommunications company (known as a primary user or UP) are permanently used by the UP. Cognitive Radio Technology’s idea is that a wireless device such as a cell phone, used by the Secondary User (SU) can be fitted with a special sensor that can detect “spectrum holes” (parts of the spectrum that are not used by the PU) and use them when the main channel is unavailable or congested, Dr Shrestha said. “This forms the basis of a dynamic spectrum access policy that can overcome shortages of spectrum available at any given time. The in-device spectrum hole detection sensor of the SU is called a stand-alone spectrum sensor (SSSR),” he added.
Discussing the relevance of the team’s research, Dr Shrestha said: ‘The detection capability of SSSR is often less than satisfactory due to various issues such as signal-to-noise ratio (SNR) wall issues. This leads to unreliable performance when SSSR is used in real time.
“The team’s research aims to circumvent the above problem. The technology is one where instead of equipping the SU’s wireless device with an SSSR, the received parts are transmitted from the spectrum band to a Data Fusion Center (DFC). The DFC then digitizes these parts and processes them using a single cooperative spectrum sensor (CSR),” he said.
Mr. Rohit B. Chaurasiya, further explained the issue: “We have proposed easy-to-implement algorithms for cooperative spectrum sensing with lower computational complexity and also developed several new hardware architectures for CSR and their submodules.”
This digital CSR ASIC chip developed by IIT Mandi provides excellent PU detection reliability in real channel scenarios with best hardware efficiency and fast detection time. The CSR chip can be used with any portable wireless mobile communication device to access unused spectrum. Specifically, it can be used in future 5G and 6G wireless communication technologies to improve spectral efficiency, he added.
He said further, it will enable mass deployment of IoT-based networks where many connected devices can use gaps in spectrum for uninterrupted communication. The specific uses of cooperative spectrum sensing technology in India cannot be underestimated and will help establish broadband services in remote and rural parts of the country.