Pub Date : 2012-04-03DOI: 10.1109/NCC.2012.6176816
A. Singh, M. Bhatnagar, R. K. Mallik
In this paper, we consider a cooperative cognitive network containing two cognitive radios (CRs) and one primary user. Cooperation between the CRs is achieved through a fusion center (FC). The CRs forward energy estimates to the FC by using finite number of received data samples. The FC utilizes an optimized global threshold based on local thresholds of the CRs for determining presence or absence of the primary signal. We derive average probability of error of detecting the primary user in this set-up. An optimized global threshold in the FC is obtained by minimizing the average probability of error in detection of a spectrum hole. The average probability of error is assumed to be the sum of the probability of false alarm and missed detection in the FC.
{"title":"Threshold optimization of finite sample based cognitive radio network","authors":"A. Singh, M. Bhatnagar, R. K. Mallik","doi":"10.1109/NCC.2012.6176816","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176816","url":null,"abstract":"In this paper, we consider a cooperative cognitive network containing two cognitive radios (CRs) and one primary user. Cooperation between the CRs is achieved through a fusion center (FC). The CRs forward energy estimates to the FC by using finite number of received data samples. The FC utilizes an optimized global threshold based on local thresholds of the CRs for determining presence or absence of the primary signal. We derive average probability of error of detecting the primary user in this set-up. An optimized global threshold in the FC is obtained by minimizing the average probability of error in detection of a spectrum hole. The average probability of error is assumed to be the sum of the probability of false alarm and missed detection in the FC.","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134645945","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 : 2012-04-03DOI: 10.1109/NCC.2012.6176912
Manjunath Kashyap Jataprolu, R. D. Koilpillai, S. Bhashyam
Cognitive radio based systems rely on spectrum sensing techniques to detect whitespaces to exploit. For the sake of ease of implementation, simple schemes such as energy detector have been proposed and studied widely. However, such simple schemes perform far from optimally, thereby affecting the performance of the underlying system. On the other hand sophisticated detectors are difficult to implement, giving rise to a trade-off. This paper explores the idea of using spectral estimates for detection. The case of HDTV based cognitive radio is explored and an optimal detection scheme following multi taper estimation is proposed and studied.
{"title":"Optimal MTM spectral estimation based detection for cognitive radio in HDTV","authors":"Manjunath Kashyap Jataprolu, R. D. Koilpillai, S. Bhashyam","doi":"10.1109/NCC.2012.6176912","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176912","url":null,"abstract":"Cognitive radio based systems rely on spectrum sensing techniques to detect whitespaces to exploit. For the sake of ease of implementation, simple schemes such as energy detector have been proposed and studied widely. However, such simple schemes perform far from optimally, thereby affecting the performance of the underlying system. On the other hand sophisticated detectors are difficult to implement, giving rise to a trade-off. This paper explores the idea of using spectral estimates for detection. The case of HDTV based cognitive radio is explored and an optimal detection scheme following multi taper estimation is proposed and studied.","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125604116","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 : 2012-04-03DOI: 10.1109/NCC.2012.6176888
V. Upadhya, D. Jalihal
Design of robust test statistics which mitigate the channel and noise uncertainties are the essential requirement of detection applications. Covariance absolute value (CAV) detection is one of the non-parametric detection methods which claims robustness [1]. Achieving the theoretical probability of detection performance depends on the accuracy in calculating the thresholding parameter, which in turn depends on the distribution of the test statistic under the null hypothesis. Since the exact analysis of distribution is cumbersome, approximation techniques are used. We present approximation techniques which achieve performance very close to the one obtained from exact distribution of the test statistic (using Monte-Carlo simulation). Further, an equivalent test statistic compared to CAV is proposed which uses the Bartlett decomposition of the sample covariance matrix and its performance is compared with CAV. The robustness of the proposed test statistic is verified for the noise uncertainty model assumed [2].
{"title":"Almost exact threshold calculations for covariance absolute value detection algorithm","authors":"V. Upadhya, D. Jalihal","doi":"10.1109/NCC.2012.6176888","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176888","url":null,"abstract":"Design of robust test statistics which mitigate the channel and noise uncertainties are the essential requirement of detection applications. Covariance absolute value (CAV) detection is one of the non-parametric detection methods which claims robustness [1]. Achieving the theoretical probability of detection performance depends on the accuracy in calculating the thresholding parameter, which in turn depends on the distribution of the test statistic under the null hypothesis. Since the exact analysis of distribution is cumbersome, approximation techniques are used. We present approximation techniques which achieve performance very close to the one obtained from exact distribution of the test statistic (using Monte-Carlo simulation). Further, an equivalent test statistic compared to CAV is proposed which uses the Bartlett decomposition of the sample covariance matrix and its performance is compared with CAV. The robustness of the proposed test statistic is verified for the noise uncertainty model assumed [2].","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133831169","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 : 2012-04-03DOI: 10.1109/NCC.2012.6176916
B. C. Haris, R. Sinha
In this work, we explore the use of sparse representation of GMM mean shifted supervectors over a learned dictionary for the speaker verification (SV) task. In this method the dictionaries are learned using the KSVD algorithm unlike the recently proposed SV methods employing the sparse representation classification (SRC) over exemplar dictionaries. The proposed approach with learned dictionary results in an equal error rate of 1.56 % on NIST 2003 SRE dataset, which is found to be better than those of the state-of-the-art i-vector based approach and the exemplar based SRC approaches using either GMM mean shifted supervectors or i-vectors, with appropriate session/channel variability compensation techniques applied.
{"title":"Speaker verification using sparse representation over KSVD learned dictionary","authors":"B. C. Haris, R. Sinha","doi":"10.1109/NCC.2012.6176916","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176916","url":null,"abstract":"In this work, we explore the use of sparse representation of GMM mean shifted supervectors over a learned dictionary for the speaker verification (SV) task. In this method the dictionaries are learned using the KSVD algorithm unlike the recently proposed SV methods employing the sparse representation classification (SRC) over exemplar dictionaries. The proposed approach with learned dictionary results in an equal error rate of 1.56 % on NIST 2003 SRE dataset, which is found to be better than those of the state-of-the-art i-vector based approach and the exemplar based SRC approaches using either GMM mean shifted supervectors or i-vectors, with appropriate session/channel variability compensation techniques applied.","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122866189","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 : 2012-04-03DOI: 10.1109/NCC.2012.6176811
S. Sarkar, R. Datta
In this paper, we propose a mobility factor based path selection scheme in Mobile Ad-hoc Network (MANET). In MANET, Nodal mobility is one of the important issues to determine the potential capacity of ad hoc networks. Various mobility metrics have been proposed in the literature as measurement of topological changes in networks. All such metrics describe the link or path stability to allow adaptive routing in MANET based on predicted link behaviour. We investigate and find that a path can become reliable and the average throughput of the network can increase if we select a route considering the mobility of the network nodes. Our proposed scheme selects the nodes to construct a path based on their mobility. In our work a trust value is generated by a trust module that calculates and compares mobility of the concerned nodes. Simulation results show that our proposed scheme performs better than pure Ad hoc On-Demand Distance Vector (AODV) and Dynamic Source Routing (DSR) protocols.
{"title":"A mobility factor based path selection scheme for Mobile Ad-hoc Networks","authors":"S. Sarkar, R. Datta","doi":"10.1109/NCC.2012.6176811","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176811","url":null,"abstract":"In this paper, we propose a mobility factor based path selection scheme in Mobile Ad-hoc Network (MANET). In MANET, Nodal mobility is one of the important issues to determine the potential capacity of ad hoc networks. Various mobility metrics have been proposed in the literature as measurement of topological changes in networks. All such metrics describe the link or path stability to allow adaptive routing in MANET based on predicted link behaviour. We investigate and find that a path can become reliable and the average throughput of the network can increase if we select a route considering the mobility of the network nodes. Our proposed scheme selects the nodes to construct a path based on their mobility. In our work a trust value is generated by a trust module that calculates and compares mobility of the concerned nodes. Simulation results show that our proposed scheme performs better than pure Ad hoc On-Demand Distance Vector (AODV) and Dynamic Source Routing (DSR) protocols.","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127676636","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 : 2012-04-03DOI: 10.1109/NCC.2012.6176807
S. K. Basha, P. C. Pandey
An electrolarynx, a vibrator held against the neck tissue, is used by laryngectomy patients to provide excitation to the vocal tract as a substitute to that provided by the glottis. The quality and intelligibility of electrolaryngeal speech is generally poor because of the presence of background noise caused by leakage of acoustic energy from the vibrator and vibrator-tissue interface. This noise can be suppressed by pitch-synchronous application of spectral subtraction. The paper presents a real-time implementation of the spectral subtraction for enhancement of electrolaryngeal speech, using a 16-bit fixed-point DSP board. Electrolaryngeal speech is continuously acquired at 12 kHz using codec and DMA into the input buffers. It is processed using 256-point FFT, 3-frame 4-stage cascaded median-based dynamic estimation of noise, spectral subtraction, and IFFT, using two-pitch period window with 50 % overlap. The resynthesized speech is output using DMA and codec.
{"title":"Real-time enhancement of electrolaryngeal speech by spectral subtraction","authors":"S. K. Basha, P. C. Pandey","doi":"10.1109/NCC.2012.6176807","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176807","url":null,"abstract":"An electrolarynx, a vibrator held against the neck tissue, is used by laryngectomy patients to provide excitation to the vocal tract as a substitute to that provided by the glottis. The quality and intelligibility of electrolaryngeal speech is generally poor because of the presence of background noise caused by leakage of acoustic energy from the vibrator and vibrator-tissue interface. This noise can be suppressed by pitch-synchronous application of spectral subtraction. The paper presents a real-time implementation of the spectral subtraction for enhancement of electrolaryngeal speech, using a 16-bit fixed-point DSP board. Electrolaryngeal speech is continuously acquired at 12 kHz using codec and DMA into the input buffers. It is processed using 256-point FFT, 3-frame 4-stage cascaded median-based dynamic estimation of noise, spectral subtraction, and IFFT, using two-pitch period window with 50 % overlap. The resynthesized speech is output using DMA and codec.","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127315489","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 : 2012-04-03DOI: 10.1109/NCC.2012.6176765
S. Bhatlawande, J. Mukhopadhyay, M. Mahadevappa
This paper presents an electronic navigation system for visually impaired and blind people (subject). This system understands obstacles around the subject up to 500 cm in front, left and right direction using a network of ultrasonic sensors. It effectively calculates distance of the detected object from the subject and prepares navigation path accordingly avoiding obstacles. It uses speech feedback to aware the subject about the detected obstacle and its distance. This proposed system uses AT89S52 microcontroller based embedded system to process real time data collected using ultrasonic sensor network. Based on direction and distance of detected obstacle, relevant pre-recorded speech message stored in APR9600 flash memory is invoked. Such speech messages are conveyed to the subject using earphone.
{"title":"Ultrasonic spectacles and waist-belt for visually impaired and blind person","authors":"S. Bhatlawande, J. Mukhopadhyay, M. Mahadevappa","doi":"10.1109/NCC.2012.6176765","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176765","url":null,"abstract":"This paper presents an electronic navigation system for visually impaired and blind people (subject). This system understands obstacles around the subject up to 500 cm in front, left and right direction using a network of ultrasonic sensors. It effectively calculates distance of the detected object from the subject and prepares navigation path accordingly avoiding obstacles. It uses speech feedback to aware the subject about the detected obstacle and its distance. This proposed system uses AT89S52 microcontroller based embedded system to process real time data collected using ultrasonic sensor network. Based on direction and distance of detected obstacle, relevant pre-recorded speech message stored in APR9600 flash memory is invoked. Such speech messages are conveyed to the subject using earphone.","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126221788","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 : 2012-04-03DOI: 10.1109/NCC.2012.6176853
R. Mukherjee, W. H. Prasad, P. Dheeraj, I. Chakrabarti, S. Sengupta
The H.264 standard uses integer transform block in its encoder. In this paper, a pipelined architecture of fast 2-D forward integer transform is proposed. For video compression applications such as Television Studio Broadcast or Surveillance Videos, where throughput is of prime importance for real-time encoding, we propose an efficient realization of the forward integer transform unit. Using Xilinx Virtex-5 technology, the proposed architecture gives an excellent throughput of 5383 Mpixels/sec, where the critical path delay is 2.97 ns and the maximum operating frequency is of 336 MHz.
{"title":"High throughput pipelined architecture for fast 2-D 4×4 forward integer transform of H.264","authors":"R. Mukherjee, W. H. Prasad, P. Dheeraj, I. Chakrabarti, S. Sengupta","doi":"10.1109/NCC.2012.6176853","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176853","url":null,"abstract":"The H.264 standard uses integer transform block in its encoder. In this paper, a pipelined architecture of fast 2-D forward integer transform is proposed. For video compression applications such as Television Studio Broadcast or Surveillance Videos, where throughput is of prime importance for real-time encoding, we propose an efficient realization of the forward integer transform unit. Using Xilinx Virtex-5 technology, the proposed architecture gives an excellent throughput of 5383 Mpixels/sec, where the critical path delay is 2.97 ns and the maximum operating frequency is of 336 MHz.","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128042110","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 : 2012-04-03DOI: 10.1109/NCC.2012.6176809
M. Yargholi, A. P. Tarighat
A CMOS low noise amplifier with Out-of-band rejection for radio ultra-wide band receivers is designed and implemented in TSMC RF CMOS 0.18μm technology. Received power signal in UWB is smaller than narrow band interferences that are located near it, Thus we proposed a resistive feedback LNA that includes; input matching network, cascoded structure, RC feedback loop, LC load, output matching network and dual band notch filter with low power active inductor to improve the out-of-band rejection. Power gain of 16.03 and minimum noise figure of 2.4 dB at frequency of 3.76GHZ can be measured; maximum rejection of 20.3dB and 44.18 dB be achieved at 2.4GHz and 5.2GHZ respectively. The power dissipation of designed LNA with dual band notch filter is 15.75mW from 1.5V supply, while it was 13.5mW without notch filter.
{"title":"Resistive feedback LNA with dual band notch filter for suppressing WLAN signals in UWB receivers","authors":"M. Yargholi, A. P. Tarighat","doi":"10.1109/NCC.2012.6176809","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176809","url":null,"abstract":"A CMOS low noise amplifier with Out-of-band rejection for radio ultra-wide band receivers is designed and implemented in TSMC RF CMOS 0.18μm technology. Received power signal in UWB is smaller than narrow band interferences that are located near it, Thus we proposed a resistive feedback LNA that includes; input matching network, cascoded structure, RC feedback loop, LC load, output matching network and dual band notch filter with low power active inductor to improve the out-of-band rejection. Power gain of 16.03 and minimum noise figure of 2.4 dB at frequency of 3.76GHZ can be measured; maximum rejection of 20.3dB and 44.18 dB be achieved at 2.4GHz and 5.2GHZ respectively. The power dissipation of designed LNA with dual band notch filter is 15.75mW from 1.5V supply, while it was 13.5mW without notch filter.","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128187063","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 : 2012-04-03DOI: 10.1109/NCC.2012.6176766
M. Suma, S. Narasimhan, B. Kanmani
This paper proposes a new OFDM systems based on A Discrete Cosine Harmonic Wavelet (DCHWT), for BPSK and QPSK signals. This has been realized by proposing new separate structures for BPSK and QPSK signals. This enables to utilize the energy compaction of DCT and the computational simplicity of DCHWT for OFDM systems. The proposed OFDM systems provide improved performance in terms of BER and PAPR compared to those of conventional OFDM based on DFT /DCT with Cyclic prefix. The new OFDMs have a better or equal performance compared to those of some of the existing wavelet based OFDMS.
{"title":"The OFDM system based on Discrete Cosine Harmonic Wavelet transform","authors":"M. Suma, S. Narasimhan, B. Kanmani","doi":"10.1109/NCC.2012.6176766","DOIUrl":"https://doi.org/10.1109/NCC.2012.6176766","url":null,"abstract":"This paper proposes a new OFDM systems based on A Discrete Cosine Harmonic Wavelet (DCHWT), for BPSK and QPSK signals. This has been realized by proposing new separate structures for BPSK and QPSK signals. This enables to utilize the energy compaction of DCT and the computational simplicity of DCHWT for OFDM systems. The proposed OFDM systems provide improved performance in terms of BER and PAPR compared to those of conventional OFDM based on DFT /DCT with Cyclic prefix. The new OFDMs have a better or equal performance compared to those of some of the existing wavelet based OFDMS.","PeriodicalId":178278,"journal":{"name":"2012 National Conference on Communications (NCC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125881108","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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