Researchers at the Indian Institute of Technology Mandi have created a cutting-edge telecommunications solution: a cooperative spectrum sensor (CSR) that improves the reusability of the radiofrequency spectrum, allowing for better data communication for future wireless communication applications.
The results of their research have recently been published in IEEE Transactions on Consumer Electronics and other IEEE journals. Dr Rahul Shrestha, Assistant Professor (School of Computing and Electrical Engineering – IIT Mandi), and Mr Rohit B Chaurasiya, his PhD student, co-authored these works.
The current rapid rise in wireless communication technology, as well as the forecasted exponential increase owing to mass adoption of technologies such as fifth-generation new-radio (5G-NR) and the Internet of Things (IoT), are expected to result in a large demand for spectrum bands. Dr Shrestha said, “Given the fixed-spectrum allocation policy of many governments around the world, including ours, it becomes important to use the available spectrum intelligently. Cognitive Radio Technology is considered one of the best ways to optimise spectrum use.”
The spectrum band licenced to a telecom operator (known as the primary user or PU) is not always used by the PU. According to Dr Shrestha, the idea behind Cognitive Radio Technology is that a secondary user’s (SU) wireless device, such as a cell phone, can be fitted with a special sensor that can detect “spectrum holes” (spectrum parts not used by the PU) and use them when the main channel is unavailable or crowded.
“This forms the basis of a dynamic-spectrum access policy that can overcome shortages of available spectrum at a given time. The spectrum-hole detecting sensor that is built into the SU’s device is called a Stand-Alone Spectrum Sensor (SSSR),” he added. “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 Centre (DFC). The DFC then digitises these parts and processes them using a single cooperative spectrum sensor (CSR)” he said.
Mr Rohit B. Chaurasiya, elucidated on the matter further, “We have proposed implementation-friendly algorithms for cooperative spectrum sensing with lower computational complexity and have also developed multiple new hardware architectures for CSR and their submodules.”
For accessing the unused spectrum, the CSR chip can be utilised with any portable mobile wireless communication device. It can be utilised to improve spectral efficiency in future 5G and 6G wireless communication technologies, he added. Furthermore, this will enable widespread deployment of IoT-based networks in which multiple connected devices can leverage spectrum holes for fail-safe communication. The importance of cooperative spectrum-sensing technology in India cannot be overstated, as it will aid in the establishment of broadband services in the country’s remote and rural areas.
