A Review of Spectrum Sensing Techniques for Cognitive Radio Environment
Abstract: This paper focuses on the physical layer of cognitive radio networks (CR), that is, techniques that are used to detect the presence or absence of licensed users in different bands of the electromagnetic spectrum. The techniques presented, with their advantages and disadvantages, are organized hierarchically as: fundamental techniques (energy detection, adapted filter and cyclostationary characteristics), techniques based on fundamentals or evolution (waveform detection, identification of radio transmitter, detection of the leakage power at the receiver) and typical alternative techniques of image analysis (Hough and Wavelet transform). Additionally, the main challenges in the detection of licensed users are described along with the different dimensions in which opportunities for efficient spectral use by cognitive radio devices can be found.

Authors: Pallavi Garg, Shiva Bhatnagar

File Name: Pallavi_50900-17-103.pdf
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Performance Evaluation of Energy Detection based Blind Spectrum Sensing
Abstract: Cognitive radio (CR) emerges as a novel wireless communications technology with the potential to change the inefficient way in which the radio spectrum is currently used. The techniques of dynamic access to the spectrum are a key element in the implementation of radio cognitive technology. This paper implements a blind spectrum sensing framework in cognitive radio networks using Energy Detection technique in Rician fading channel

Authors: Pragya Lodhi, Shivangini Saxena

File Name: Pragya_50900-17-101.pdf
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BER Performance of WiMAX System using Discrete Cosine Transform
Abstract: This paper presents simulation of the OFDM Physical layer specification of IEEE 802.16. Performance analysis of higher data rate is analysed with changing the different modulation techniques using Discrete Cosine Transform (DCT). Forward error correction codes (Reed Solomon and Convolution code) are implemented to improve the BER under higher data rate. The performance analysis is recorded based on the simulation results of Bit-Error-Rate (BER) and Signal-to-Noise Ratio (SNR). The simulation of above-mentioned system is done by MATLAB 2014a.

Authors: Sheena S Mary, Rahul Gedam

File Name: Sheena_51000-17-202.pdf
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BER Evaluation of OFDM under Multipath Fading using SVD and MMSE
Abstract: This paper presents a simulation model based on 802.16 OFDM-PHY baseband and demonstrated in different simulation scenarios with different modulation techniques; BPSK and QPSK to find out the best performance of physical layer for WiMAX Mobile. The relay multipath fading and AWGN channel model under varying parameters are taken for the wireless channel in the simulation. The performance is recorded based on BER, and SNR output through MATLAB simulation.

Authors: Surbhi Vyas, Pankaj Rathi

File Name: Surbhi_51000-17-204.pdf
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BER Performance of Alamouti STBC and Precoded Alamouti in ZF and MMSE Equalization Techniques
Abstract: Alamouti code is a simple space-time code that can be used for transmit diversity systems. This is a class of easily decoded space-time codes that achieve full diversity order in Rayleigh fading channels. Alamouti exist only for certain numbers of transmit antennas and do not provide array gain like diversity techniques that exploit transmit channel information. When channel state information (CSI) is available at the transmitter, though, precoding the space-time codeword can be used to support different numbers of transmit antennas. The objective of this paper is to design a method of precoders which shows comparison of bit error rate (BER) performance of Alamouti STBC and Precoded Alamouti in Zero Forcing and MMSE equalization techniques. The Rayleigh fading channel is used as modulation channel.

Authors: Rupinder Roop, Pallavi Chandel

File Name: Rupinder_50900-17-106.pdf
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