ECE Graduate Seminar Lecture
Science / Technology - Lecture/Discussion - WPI Only
Thursday, March 28, 2013
11:00 AM-11:50 AM
Spectrally Modulated Spectrally Encoded Based Cognitive Radio Over Non-contiguous Frequency Bands in Mobile Environment Via Software Defined Radio
Assistant Professor, ECE Department
Western New England University
With the emergence of increasing number of wireless devices and demands for higher data rates, spectrum congestion increases. However, recent studies indicate that the spectrum congestion is mainly due to inefficient spectrum usage rather than spectrum scarcity. To exploit under-used spectrum and utilize the spectrum efficiently in dynamically changing environment, a new technology is needed. Cognitive Radio (CR) arises to be a possible solution to solve the spectral congestion problem by introducing opportunistic usage of frequency bands that are not heavily occupied by licensed users. All multi-carrier transmissions, such as OFDM, MC-CDMA, and CI/MC-CDMA, are collectively classified as spectrally modulated spectrally encoded (SMSE) since data modulation and encoding are applied in the spectral domain. We design, implement, and demonstrate an autonomous CR system in mobile environment. Specifically, we employ the SMSE framework to generate multi-carrier transmission waveforms over non-contiguous frequency bands for the cognitive radio. Combined with a spectrum sensing engine, the cognitive radio detects the availability of each and every subcarrier in the operational bandwidth. By turning off those subcarriers occupied by the primary users, the cognitive radio implements a non-contiguous SMSE transmission. In highly mobile environment, the inter-carrier interference (ICI) caused by Doppler shift can be eliminated by our Total ICI Cancellation scheme. There are a few unique features of SMSE cognitive radio implementation: (1) we have demonstrated real-time seamless video transmission without interference from/to primary users; (2) our cognitive radio is capable of taking advantage of multiple spectrum holes and operating over multiple non-contiguous spectrum bands; (3) the cognitive radio dynamically adjusts which subcarriers to turn off according to the primary users transmission; (4) the cognitive radio can also adjust other parameters such as the total number of subcarriers, center frequency, and bandwidth of each subcarrier; (5) the cognitive radio maintains all the features even in high mobility environment, making it a portable, flexible, agile, and robust cognitive radio node in mobile communication system.
Dr. Ruolin Zhou joins Western New England University as an assistant professor since August 2012. She received her M.S. in 2007 and Ph.D. in 2012 from Wright State University, all in Electrical Engineering. Her research interests include FPGA based and Software Defined Radio based Cognitive Radio and Wireless Communications, Signal Processing, and Digital System Design. She has published twenty-six papers in journals and conferences. She was the recipient of the Best Demo Award of the flagship conference of IEEE Communication Society, IEEE Globecom, in December of 2010. She has served on technical program committee for the 7th International Conference on Cognitive Radio Oriented Wireless Networks (CROWNCOM2012) and IEEE 78th Vehicular Technology Conference (VTC2013). She also served as session chair of IEEE Globecom 2012.
Host: Professor Alexander Wyglinski
Suggested Audiences: College
Last Modified: March 21, 2013 at 10:31 AM