Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487929
P. R., B. Amrutur
Frequency hopping communications, used in the military present significant opportunities for spectrum reuse via the cognitive radio technology. We propose a MAC which incorporates hop instant identification, and supports network discovery and formation, QOS Scheduling and secondary communications. The spectrum sensing algorithm is optimized to deal with the problem of spectral leakage. The algorithms are implemented in a SDR platform based test bed and measurement results are presented.
{"title":"Cognitive radio implementation for a frequency hopping primary signal","authors":"P. R., B. Amrutur","doi":"10.1109/NCC.2013.6487929","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487929","url":null,"abstract":"Frequency hopping communications, used in the military present significant opportunities for spectrum reuse via the cognitive radio technology. We propose a MAC which incorporates hop instant identification, and supports network discovery and formation, QOS Scheduling and secondary communications. The spectrum sensing algorithm is optimized to deal with the problem of spectral leakage. The algorithms are implemented in a SDR platform based test bed and measurement results are presented.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129878328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487982
Gaurav Jyoti Phukan, P. Bora
This paper presents a method for classification of digital modulation schemes in an asynchronous reception scenario. The proposed classification is based on likelihood principles and without prior knowledge of channel response. We propose blind channel estimation in non-cooperative scenario using conventional Decision Directed Least Mean Square algorithm while the signal is subjected to channel distortion and unknown gain. Convergence characteristics of the LMS algorithm is modulation dependent and after choosing the best equalizer, the final decision for Modulation Classification is made by likelihood principles. Experimental results are presented to compare the performance with the optimal classifier. The scope for further improvement is outlined.
{"title":"An algorithm to mitigate channel distortion in blind modulation classification","authors":"Gaurav Jyoti Phukan, P. Bora","doi":"10.1109/NCC.2013.6487982","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487982","url":null,"abstract":"This paper presents a method for classification of digital modulation schemes in an asynchronous reception scenario. The proposed classification is based on likelihood principles and without prior knowledge of channel response. We propose blind channel estimation in non-cooperative scenario using conventional Decision Directed Least Mean Square algorithm while the signal is subjected to channel distortion and unknown gain. Convergence characteristics of the LMS algorithm is modulation dependent and after choosing the best equalizer, the final decision for Modulation Classification is made by likelihood principles. Experimental results are presented to compare the performance with the optimal classifier. The scope for further improvement is outlined.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128429249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487975
A. Karmakar, Utsab Banerjee, R. Ghatak, D. R. Poddar
This paper presents the design and analysis of a planar UWB monopole antenna with impedance steps and fractal slots in the ground plane that contributes to ultra wide band characteristics. Here impedance steps as well as Fractal technique is adopted to improve the bandwidth of the antenna in comparison to its non fractal counterpart. The operating frequency of the proposed antenna is ranging from 2.7GHz to 10.9GHz which provides 120% impedance bandwidth, close to UWB specification. The antenna has omnidirectional radiation characteristics and moderate gain throughout its operating band and can be considered as a good candidate for UWB communications.
{"title":"Design and analysis of fractal based UWB monopole antenna","authors":"A. Karmakar, Utsab Banerjee, R. Ghatak, D. R. Poddar","doi":"10.1109/NCC.2013.6487975","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487975","url":null,"abstract":"This paper presents the design and analysis of a planar UWB monopole antenna with impedance steps and fractal slots in the ground plane that contributes to ultra wide band characteristics. Here impedance steps as well as Fractal technique is adopted to improve the bandwidth of the antenna in comparison to its non fractal counterpart. The operating frequency of the proposed antenna is ranging from 2.7GHz to 10.9GHz which provides 120% impedance bandwidth, close to UWB specification. The antenna has omnidirectional radiation characteristics and moderate gain throughout its operating band and can be considered as a good candidate for UWB communications.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116280237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487968
S. Bhagat, A. Yadav, Vivek Sharma, N. Pathak
This paper reports design, analysis and simulation of QPSK modulator in Ka-band. The modulator is designed at 28GHz frequency in hybrid microwave integrated circuit (HMIC) technology. For feasible high frequency operation, the design is integrated with non-radiative dielectric (NRD) guide using NRD guide to Microstrip line transition. In simulation, the observed value of the maximum phase deviation from the quadrature phase shift is 5°. Error vector magnitude (EVM) of the designed modulator is determined to be 11.9% for 400 Mbps digital data rate, modulated over 28 GHz RF carrier. The effect of amplitude and phase variations is analyzed through a constellation diagram, power spectrum and eye pattern.
{"title":"Design, analysis and simulation of hybrid integrated NRD guide based QPSK modulator for LMDS applications at 28GHz","authors":"S. Bhagat, A. Yadav, Vivek Sharma, N. Pathak","doi":"10.1109/NCC.2013.6487968","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487968","url":null,"abstract":"This paper reports design, analysis and simulation of QPSK modulator in Ka-band. The modulator is designed at 28GHz frequency in hybrid microwave integrated circuit (HMIC) technology. For feasible high frequency operation, the design is integrated with non-radiative dielectric (NRD) guide using NRD guide to Microstrip line transition. In simulation, the observed value of the maximum phase deviation from the quadrature phase shift is 5°. Error vector magnitude (EVM) of the designed modulator is determined to be 11.9% for 400 Mbps digital data rate, modulated over 28 GHz RF carrier. The effect of amplitude and phase variations is analyzed through a constellation diagram, power spectrum and eye pattern.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"174 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114693837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487941
N. Mehta, H. Kaushal, V. Jain, Subrat Kar
In this paper aperture averaging technique is considered to mitigate the effects of turbulence. An experimental study is carried out for different receiver diameters in atmospheric turbulence created in the OTG chamber. Improvement in performance with the increase in receiver aperture diameter is observed.
{"title":"Experimental study on aperture averaging in free space optical communication link","authors":"N. Mehta, H. Kaushal, V. Jain, Subrat Kar","doi":"10.1109/NCC.2013.6487941","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487941","url":null,"abstract":"In this paper aperture averaging technique is considered to mitigate the effects of turbulence. An experimental study is carried out for different receiver diameters in atmospheric turbulence created in the OTG chamber. Improvement in performance with the increase in receiver aperture diameter is observed.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114752833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6488004
P. Sarath Kumar, B. Sai Kiran, A. P. Kannu, S. Bhashyam
In this paper, we consider change detection in a sensor network where an unknown subset of sensor nodes are affected by the change. We consider two models for the channel between the sensors and the fusion center: (1) parallel non-interfering channels, and (2) physical layer fusion. For both these models, we propose quantized transmission schemes for the sensors and corresponding fusion rules at the fusion center. The proposed fusion rules are based on an adaptive version of CUSUM. The detection delay performance of the proposed schemes is studied as a function of the number of affected sensors for a given false alarm constraint. Simulation results show that the proposed schemes can work well for a wide range of the fraction of affected sensors.
{"title":"Algorithms for change detection with unknown number of affected sensors","authors":"P. Sarath Kumar, B. Sai Kiran, A. P. Kannu, S. Bhashyam","doi":"10.1109/NCC.2013.6488004","DOIUrl":"https://doi.org/10.1109/NCC.2013.6488004","url":null,"abstract":"In this paper, we consider change detection in a sensor network where an unknown subset of sensor nodes are affected by the change. We consider two models for the channel between the sensors and the fusion center: (1) parallel non-interfering channels, and (2) physical layer fusion. For both these models, we propose quantized transmission schemes for the sensors and corresponding fusion rules at the fusion center. The proposed fusion rules are based on an adaptive version of CUSUM. The detection delay performance of the proposed schemes is studied as a function of the number of affected sensors for a given false alarm constraint. Simulation results show that the proposed schemes can work well for a wide range of the fraction of affected sensors.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128173038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487981
B. K. Das, R. Das, M. Chakraborty
Adaptive identification of sparse systems is one of the popular adaptive signal processing topics due to its application in acoustic and network echo cancellation, adaptive channel estimation and several other areas. It has been observed that sometimes the amount of sparseness in the identifiable system impulse response can vary greatly depending on the nonstationary nature of the system. The compressive sensing based sparsity-aware adaptive algorithm performs satisfactorily in strongly sparse environment, but is shown to perform worse than the conventional ones when sparseness of the impulse response decreases. We propose an algorithm which works well both in sparse and non-sparse circumstances, and adapts dynamically to the level of sparseness using a dual stage adaptive filtering approach using an affine combination of the outputs of two single stage adaptive filters using two different algorithms. The proposed algorithm is supported by simulation results that show its robustness against variable sparsity.
{"title":"Multi stage adaptive filter for identification of the systems with variable sparsity","authors":"B. K. Das, R. Das, M. Chakraborty","doi":"10.1109/NCC.2013.6487981","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487981","url":null,"abstract":"Adaptive identification of sparse systems is one of the popular adaptive signal processing topics due to its application in acoustic and network echo cancellation, adaptive channel estimation and several other areas. It has been observed that sometimes the amount of sparseness in the identifiable system impulse response can vary greatly depending on the nonstationary nature of the system. The compressive sensing based sparsity-aware adaptive algorithm performs satisfactorily in strongly sparse environment, but is shown to perform worse than the conventional ones when sparseness of the impulse response decreases. We propose an algorithm which works well both in sparse and non-sparse circumstances, and adapts dynamically to the level of sparseness using a dual stage adaptive filtering approach using an affine combination of the outputs of two single stage adaptive filters using two different algorithms. The proposed algorithm is supported by simulation results that show its robustness against variable sparsity.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132398379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487955
Sreejith Sreekumar
We consider a two user slow fading Gaussian MAC where each transmitter knows only its own channel fading coefficient prior to transmission and where the receiver knows the fading coefficients of both users. The slow fading channel is modeled as a block fading channel. Each user performs block by block encoding for communication with the common receiver. The receiver decodes the messages of both users from the received signal, also on a block by block basis. Each user has its own fixed average power constraint in each block. A useful metric to measure the throughput performance in such a scenario is the adaptive sum capacity which is the maximum expected sum throughput that can be achieved. The adaptive sum capacity in such a setting was derived by the authors in [4]. We show that the adaptive sum capacity can be achieved by an asymptotically optimal rate-splitting scheme with low complexity single-user decoding. This eliminates the need for joint decoding of the two users which, although optimal, has a high complexity.
{"title":"Achieving Adaptive sum-capacity of fading MACs with distributed CSI and non-identical links by rate-splitting","authors":"Sreejith Sreekumar","doi":"10.1109/NCC.2013.6487955","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487955","url":null,"abstract":"We consider a two user slow fading Gaussian MAC where each transmitter knows only its own channel fading coefficient prior to transmission and where the receiver knows the fading coefficients of both users. The slow fading channel is modeled as a block fading channel. Each user performs block by block encoding for communication with the common receiver. The receiver decodes the messages of both users from the received signal, also on a block by block basis. Each user has its own fixed average power constraint in each block. A useful metric to measure the throughput performance in such a scenario is the adaptive sum capacity which is the maximum expected sum throughput that can be achieved. The adaptive sum capacity in such a setting was derived by the authors in [4]. We show that the adaptive sum capacity can be achieved by an asymptotically optimal rate-splitting scheme with low complexity single-user decoding. This eliminates the need for joint decoding of the two users which, although optimal, has a high complexity.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131257555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487930
S. Boddu, A. Mukhopadhyay, Bigi Varghese Philip, Suvra Shekhar Das
This paper analyses Fractional Frequency Reuse (FFR) for Real Time (RT) traffic in an OFDMA cellular networks such as Long Term Evolution (LTE) and Worldwide interoperability for Microwave Access (WiMAX). In these networks, frequency reuse factor of unity is usually considered. In the forward link i.e., in downlink, although frequency reuse one provides higher capacity than other reuse factors, yet it severely affects the Signal to Interference plus Noise Ratio (SINR) of the users at the cell edge. This leads to very poor throughput for cell edge users. To enhance the cell edge performance, FFR is one of the methods being considered. The impact of SINR threshold and bandwidth partitioning ratio on the successful deployment of FFR is presented in this work. Analytical and simulation results show that the proposed Grade of Service (GoS) fair method performs better and is good choice for Real Time traffic.
{"title":"Bandwidth partitioning And SINR threshold design analysis of Fractional Frequency Reuse","authors":"S. Boddu, A. Mukhopadhyay, Bigi Varghese Philip, Suvra Shekhar Das","doi":"10.1109/NCC.2013.6487930","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487930","url":null,"abstract":"This paper analyses Fractional Frequency Reuse (FFR) for Real Time (RT) traffic in an OFDMA cellular networks such as Long Term Evolution (LTE) and Worldwide interoperability for Microwave Access (WiMAX). In these networks, frequency reuse factor of unity is usually considered. In the forward link i.e., in downlink, although frequency reuse one provides higher capacity than other reuse factors, yet it severely affects the Signal to Interference plus Noise Ratio (SINR) of the users at the cell edge. This leads to very poor throughput for cell edge users. To enhance the cell edge performance, FFR is one of the methods being considered. The impact of SINR threshold and bandwidth partitioning ratio on the successful deployment of FFR is presented in this work. Analytical and simulation results show that the proposed Grade of Service (GoS) fair method performs better and is good choice for Real Time traffic.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131896345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-28DOI: 10.1109/NCC.2013.6487979
Chinmay. V. Marathe, V. Gadre
Volume Rendering is the process of computing the 2D projections of a given 3D data along a specified viewing direction for visualizing it on a 2D screen. Rendering of medical data (MRI, CT etc ) requires discrete evaluation of the X-ray transform which involves computing the line integrals of the 3D data along a specified viewing direction. Frequency domain methods which are based on the Fourier Projection Slice Theorem are very popular due to their low computational complexity. However these suffer from various drawbacks like high interpolation cost, high memory requirement and appearing of ghosting artefacts. In this paper we present a new frequency domain volume rendering algorithm which overcomes these drawbacks to a great extent. The proposed algorithm is based on iteratively computing the inverse Fourier transform with an L1 regularization constraint on the Wavelet coefficients of the final image. The results of our algorithm have significantly fewer ghosting artefacts as compared to the results of conventional frequency domain volume rendering.
{"title":"Wavelet regularization for frequency domain volume rendering","authors":"Chinmay. V. Marathe, V. Gadre","doi":"10.1109/NCC.2013.6487979","DOIUrl":"https://doi.org/10.1109/NCC.2013.6487979","url":null,"abstract":"Volume Rendering is the process of computing the 2D projections of a given 3D data along a specified viewing direction for visualizing it on a 2D screen. Rendering of medical data (MRI, CT etc ) requires discrete evaluation of the X-ray transform which involves computing the line integrals of the 3D data along a specified viewing direction. Frequency domain methods which are based on the Fourier Projection Slice Theorem are very popular due to their low computational complexity. However these suffer from various drawbacks like high interpolation cost, high memory requirement and appearing of ghosting artefacts. In this paper we present a new frequency domain volume rendering algorithm which overcomes these drawbacks to a great extent. The proposed algorithm is based on iteratively computing the inverse Fourier transform with an L1 regularization constraint on the Wavelet coefficients of the final image. The results of our algorithm have significantly fewer ghosting artefacts as compared to the results of conventional frequency domain volume rendering.","PeriodicalId":202526,"journal":{"name":"2013 National Conference on Communications (NCC)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115242256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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