Amrit Mukherjee

Spectrum Sensing for Cognitive Radio Using Blind Source Separation and Hidden Markov Model

Most of the radio frequency spectrum is not being utilized efficiently. The utilization can be improved by including unlicensed users to exploit the radio frequency spectrum by not creating any interference to the primary users. For Cognitive Radio, the main issue is to sense and then identify all spectrum holes present in the environment. In this paper, we are proposing the Blind Source Separation (BSS) sensing which is applied through the Hidden Markov Model (HMM). It does not need any kind of synchronizing signals from the Primary user as well as with the secondary transmitter in a working condition. Simulation results by the proposed method for BSS by the activity of Primary User (PU) have been presented.

Advanced Energy Sensing Techniques Implemented Through Source Number Detection for Spectrum Sensing in Cognitive Radio

The world of wireless technology is been one of the most progressive and challenging aspects for the users and providers. It deals with the wireless spectrum whose efficient use is of foremost concern. These are improved by the cognitive radio users for their noninterference communication with the licensed users. Spectrum holes detection and sensing is a dynamic time variant function which is been modified using the proposed source number detection and energy detection. Energy detection technique is implemented so as to compare the thresholds of the channels dynamically, and source detection method is used for predicting the number of channels where the energy detection is to be performed. The simulation results show the optimization and reduced probability of miss detection considering the change in threshold.

Modal analysis and design a planar elliptical shaped UWB antenna with triple band notch characteristics

A Planer CPW fed UWB monopole antenna with triple band notch characteristics is presented in this paper. Modal analysis of band-notched UWB antennas illustrates the existence of resonant modes linked to the embedded narrowband slot structure (slot modes), whose location within the planar geometry of the monopole determines the effect over the rest of the radiating modes of the wideband structure, and consequently, over the behavior of the antenna. The proposed antenna could potentially minimize frequency interference from many underlying technologies i.e. WLAN, WiMAX and Aeronautical mobile bands. The U slot that is etched out from the radiator results in creating band notch centered at 3.5GHz and 10.5 GHz. The band notch centered at 5.5GHz is obtained by L shape slots etched from the ground plane. The dimensions of proposed antenna are 45 mm × 41 mm × 0.762 mm and the proposed antenna is realized on Taconic substrate with εr= 2.2. The impedance bandwidth of the proposed antenna covers the frequency range from 2.8 GHz to 12 GHz. The simulated gain is 4.93dBi.

Optimization of sensing and detection in cognitive radio using energy based algorithm and quantized data fusion

With the evolution of cognitive radio, there are continuously an ongoing development to make it more efficient. More stress is given on the Sensing and Management of cognitive radio as these plays an important role for the allocation and managing of secondary users in different channels. For Cognitive Radio, the main issue is to sense and then identify all spectrum holes present in the environment. In this paper, we have studied the behavior of primary signals and its corresponding detection in secondary nodes and improving the error rate performance with varying threshold. In the proposed method, the false alarm probability is compared and made it improved by using energy based algorithm which were used in radar detection techniques.

TEEN — V: A solution for intra-cluster cooperative communication in wireless sensor network

Wireless Sensor Network (WSN) has amassed as a promising tool in various research applications. Since the sensors are constrained by battery power, so lifetime of the network and the energy efficiency becomes a challenging for WSN. To solve this problem many clusters-based routing protocols are proposed like LEACH, TEEN, SEP. This paper deals with Threshold Sensitive Energy Efficient Network Protocol (TEEN) which is a reactive cluster based protocol. It is specially designed for critical application of time. As multiple nodes are required for cooperative communication, TEEN Protocol is used for cluster formation. Further Vector Quantization (VQ) is used for analysis of low energy path for the nodes and clusters respectively. The main issue of inter cluster node communication is carried out in earlier work using TEEN protocol. The proposed technique illustrates the TEEN-Vector Quantization (TEEN-V) protocol, for intra-cluster communication in a cooperative communication network. As per the application point of view, TEEN-V performs the lowest energy path for intra cluster communication. TEEN provides the optimum cluster size and their cluster head and using VQ, the minimum distance is calculated using Euclidean distance between the multiple cluster heads which creates the shortest path results in energy efficient technique. Further the spectral distortion of the proposed technique has been analysed for practical implementation.

Spectrum sensing for cognitive radio using quantized data fusion and Hidden Markov model

Most of the radio frequency spectrum is not being utilized efficiently. The utilization can be improved by including unlicensed users to exploit the radio frequency spectrum by not creating any interference to the primary users. For Cognitive Radio, the main issue is to sense and then identify all spectrum holes present in the environment. In this paper, we are proposing the Quantized data fusion sensing which is applied through the Hidden Markov Model (HMM). It does not need any kind of synchronizing signals from the Primary user as well as with the secondary transmitter in a working condition. Simulation results with error rates are improved by the activity of Primary User (PU) and have been presented.

Design of a compact ultra wide band microstrip patch antenna

This paper deals with a new compact, ultrawideband (UWB) antenna using a coaxial probe feed technique by introducing some slots in the square patch of 20mm × 20 mm. The proposed antenna is designed to operate from 1.82 to 3.72 GHz with the center frequency at 2.20 GHz. Size reduction of 83% is also presented in this paper. The antenna has nearly good Omni-directional radiation pattern and peak gain of 3.65 dBi. The group delay profile of the proposed antenna lies within 1ns. The areas of applications are medical imaging, wireless communication, and vehicular radar. Theoretical investigations have been done by An soft designer software.

Design of a Novel Shaped Ultra Wideband Co-Axial Feed Microstrip Patch Antenna

In this paper the antenna designing is shown for a compact nature and co-axial fed for Ultra Wide Band (UWB) applications. The antenna has been designed by introducing some slots on the radiating patch and some slots on the ground plane. FR4 substrate has been used here with a dielectric constant of 3.4. The ultra wide band of the antenna ranges from 2.70 GHz to 6.40 GHz (Bandwidth of 3.70 GHz). The minimum return loss observed here is -37.05 dB in the resonating frequency of 3.30 GHz. So the percentage bandwidth is 112%. The maximum gain achieved here is 4.0 dBi at 5.80 GHz.

Error analysis for high data rate applications using Welch's power spectral by Cognitive radio users

In this paper the Bit Error Rate (BER) is considered for Cognitive radio users using spectrum sensing algorithms. The proposed modified algorithm shows a substantial improvement in BER for high data rate applications of CR. The algorithms are exclusively made for Cognitive transmitters. All the simulations are been performes using real time signal using NI-USRP 2920. The energy is beinf found using Welches power spectral density and Probability of detection and probability of false alarm are being compared using FFT/NFFT conventional Periodogram and then the BER is compared with the Welchs Periodogram which is modified. The BER performance analysis has been evaluated and compared with standard error function for binary FSK. Simulation results show that the substantial improve in bit error rate for high data rate cognitive radio users.

Near field to far field transformation by asymptotic evaluation of aperture radiation field

An alternate technique for the analysis of far field antenna patterns from near field measurements. This technique uses near field information to determine the far field using Fourier transform. Radiation from a planar aperture using asymptotic evaluation of aperture radiation field and Fourier transform is done. Sampling method is discussed at length to optimize the near zone data points. Exact far field has been computed and was compared to the transformed field of the near zone data.