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Comparison of viewpoint-invariant template matchings 比较视点不变模板匹配
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6947982
Guillermo Angel Perez Lopez, H. Y. Kim
{"title":"Comparison of viewpoint-invariant template matchings","authors":"Guillermo Angel Perez Lopez, H. Y. Kim","doi":"10.1109/ITS.2014.6947982","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947982","url":null,"abstract":"SIFT, Forapro and Ciratefi are three rotation and scale invariant template matching (or keypoint matching) algorithms. They can become viewpoint-invariant using the view simulation technique, compensating the perspective deformation by simulated affine transformations, yielding the algorithms named ASIFT (Affine-invariant SIFT), Aforapro and Aciratefi. We compare the three algorithms, evaluating their performances in different situations. We focus our attention especially to situations with illumination changes and in the presence of repetitive similar patterns. The results show that all the three algorithms have strengths and weaknesses and the user should choose the best suited algorithm according to the intended application.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117275315","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}
引用次数: 3
A theoretical analysis of frequency/time quantization noise in polar transmitters 极性发射机频率/时间量化噪声的理论分析
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6947962
Mohamed Ibrahim, Bin Yang
{"title":"A theoretical analysis of frequency/time quantization noise in polar transmitters","authors":"Mohamed Ibrahim, Bin Yang","doi":"10.1109/ITS.2014.6947962","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947962","url":null,"abstract":"The polar transmitter is an increasingly interesting architecture for building up transmitters. One of the most important components of the polar transmitter is the Digitally Controlled Oscillator (DCO). This component takes digital codewords representing instantaneous frequencies as input and produces either square waves or cosine waves with periods corresponding to the instantaneous frequencies. Therefore, it suffers from frequency quantization noise. There are a lot of works in literature which analyze the effect of amplitude quantization. However, no works have been done on analyzing the effect of frequency quantization. In this paper, we perform an analytical study of the frequency quantization in polar transmitters. The analysis helps hardware designers to understand the frequency quantization noise behavior as well as to evaluate the hardware by comparing measurements to theory.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125098088","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}
引用次数: 2
Bufferbloat systematic analysis Bufferbloat系统分析
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6947975
Thiago B. Cardozo, A. P. C. da Silva, A. Vieira, A. Ziviani
{"title":"Bufferbloat systematic analysis","authors":"Thiago B. Cardozo, A. P. C. da Silva, A. Vieira, A. Ziviani","doi":"10.1109/ITS.2014.6947975","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947975","url":null,"abstract":"There is a recent interest in the bufferbloat phenomenon as a possible explanation for the increased network latency observed in the Internet. The bufferbloat phenomenon is related to the excessive packet queuing in over-sized buffers inside the network that may lead to network performance degradation. In this context, we observe a lack of experimental results considering the practical aspects of off-the-shelf network devices. Therefore, in this paper, we present a systematic analysis of the bufferbloat phenomenon considering the microscopic view of the insides in the buffer architecture of typical network devices. Our experimental results show that bufferbloat might not be a significant problem in practice. First, the phenomenon is only observed in specific cases. Second, changes made to the queues under the control of the operating system have negligible effects. Finally, recent versions of the Linux kernel avoid bufferbloat, even in the specific cases in which it was observed.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126502704","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}
引用次数: 6
Choosing coherent times of flight for improved acoustic sensor localization 选择相干飞行时间改进声传感器定位
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6947978
D. B. Haddad, W. Martins, L. Biscainho, M. D. V. M. da Costa, Kyu-Han Kim
{"title":"Choosing coherent times of flight for improved acoustic sensor localization","authors":"D. B. Haddad, W. Martins, L. Biscainho, M. D. V. M. da Costa, Kyu-Han Kim","doi":"10.1109/ITS.2014.6947978","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947978","url":null,"abstract":"Acoustic sensor localization is able to provide mobile users with contextual information without requiring additional hardware components. The location of a mobile device indoors can be computed based on its estimated distances from loudspeakers whose positions and emitted signals are previously known. The spatial information can be inferred from estimated times of flight (TOFs) and the speed of sound. In real environments, however, reverberation and line-of-sight obstructions impose considerable challenges to TOF estimation, with potential to significantly degrade the localization performance. This paper proposes a volumetric-search method that guarantees the use of coherent TOF information by discarding erroneous TOFs. In a simulated realistic scenario, the proposed method achieves localization errors of a few tenths of centimeters.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133242062","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}
引用次数: 1
Outage analysis of AF OFDM relaying systems with power amplifier nonlinearity 功率放大器非线性的AF OFDM继电系统的停电分析
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6948029
Silas L. Silva, C. Fernandes
{"title":"Outage analysis of AF OFDM relaying systems with power amplifier nonlinearity","authors":"Silas L. Silva, C. Fernandes","doi":"10.1109/ITS.2014.6948029","DOIUrl":"https://doi.org/10.1109/ITS.2014.6948029","url":null,"abstract":"The high peak-to-average power ratio (PAPR) is one of the main problems of orthogonal frequency division multiplexing (OFDM), which may cause the introduction of intercarrier interference (ICI) due to the presence of nonlinear power amplifiers (PAs). On the other hand, cooperative diversity is a very promising technology for the future wireless network. In this paper, a performance analysis of an amplify-and-forward (AF) cooperative OFDM systems accounting for nonlinear distortions introduced by a nonlinear power amplifier (PA) is developed. In particular, a close-form expression for a tight lower-bound of the outage probability is presented and validated through computer simulations. Our analysis is based on the sum of the mutual information of all the subcarriers, contrarily to previous works that have analyzed the performance of the nonlinear cooperative OFDM systems based on a single subcarrier. Our analysis shows in what situations the PA nonlinearity affects significantly the outage probability.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116392116","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}
引用次数: 6
Estimating direction of arrival of long range gunshot signals 估计远程射击信号的到达方向
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6947995
Angelo M. C. R. Borzino, J. A. Apolinário, M. D. De Campos
{"title":"Estimating direction of arrival of long range gunshot signals","authors":"Angelo M. C. R. Borzino, J. A. Apolinário, M. D. De Campos","doi":"10.1109/ITS.2014.6947995","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947995","url":null,"abstract":"Information obtained from recorded gunshot signals can be useful for law enforcement agencies and defense forces. Direction of arrival estimation of a gunshot is an important issue in shooter localization. As the distance between the firing position and the sensor increases, signal to noise ratio decreases and this estimation degrades. In that case, some sort of pre-processing of the firing acoustic signal before the application of direction of arrival estimation algorithms becomes necessary. This paper shows that applying spectral subtraction to enhance the signal improves the results. Moreover, it is shown that further improvement is attained when employing a recently proposed data selection algorithm. The tests were carried out with simulated directions by delaying copies of a real gunshot signal and also with real gunshot signals recorded by a microphone array.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129492539","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}
引用次数: 13
Convergence analysis of iterative Interference Alignment algorithms 迭代干涉对准算法的收敛性分析
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6947983
D. C. Moreira, Y. Silva, Khaled Ardah, W. Freitas, F. Cavalcanti
{"title":"Convergence analysis of iterative Interference Alignment algorithms","authors":"D. C. Moreira, Y. Silva, Khaled Ardah, W. Freitas, F. Cavalcanti","doi":"10.1109/ITS.2014.6947983","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947983","url":null,"abstract":"Interference Alignment (IA) is more appropriated for the high Signal-to-Noise Ratio (SNR) regime and it is considered suboptimal for low to middle SNR values, where mixed criteria algorithms that also take the direct channel into consideration are expected to be better. In this paper we investigate the performance of some of the most well known iterative algorithms for IA in the low and high SNR regimes, the Min Leakage algorithm, which is a pure IA algorithm, and the Max Signal-to-Interference-plus-Noise Ratio (SINR) and Minimum Mean-Square Error (MMSE) algorithms, which also take the direct channel into account. We illustrate that although the Max SINR and MMSE algorithms can find solutions close to IA at the high SNR regime, they are not as stable in that regime and a pure IA algorithm might perform better. To obtain good performance in both low and high SNR regimes we propose to initialize the mixed criteria algorithms with a pure IA solution, which does not degrade performance at low SNR values but increases stability and performance at the high SNR regime.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121221143","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}
引用次数: 2
New interpolator and data detector for full digital BPSK demodulator 全数字BPSK解调器的新插值器和数据检测器
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6948019
Caio Gomes de Figueredo, Antonio Macilio Pereira de Lucena, J. Mota
{"title":"New interpolator and data detector for full digital BPSK demodulator","authors":"Caio Gomes de Figueredo, Antonio Macilio Pereira de Lucena, J. Mota","doi":"10.1109/ITS.2014.6948019","DOIUrl":"https://doi.org/10.1109/ITS.2014.6948019","url":null,"abstract":"This work presents a new structure for an all-digital BPSK demodulator developed for space communications that performs simultaneously the sampling and down conversion from intermediate frequency signal to the baseband signal. A new interpolator is proposed in order to simplify the demodulator implementation. This interpolator correlates the samples of the output signal in such way that it was necessary to design a new data detector appropriate to process the samples corrupted by gaussian and colored noise. The effects of the new interpolation at the noise are analyzed as well as the way it affects the whole demodulator performance. Simulations were performed and the results are presented to confirm theoretical analysis.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125747797","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}
引用次数: 2
Comparison between eigenvalue fusion and decision fusion for spectrum sensing of OFDMA signals under errors in the control channel 控制信道误差下OFDMA信号频谱感知的特征值融合与决策融合比较
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6947981
D. Guimarães, Lucas dos Santos Costa, Rausley Adriano Amaral de Souza
{"title":"Comparison between eigenvalue fusion and decision fusion for spectrum sensing of OFDMA signals under errors in the control channel","authors":"D. Guimarães, Lucas dos Santos Costa, Rausley Adriano Amaral de Souza","doi":"10.1109/ITS.2014.6947981","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947981","url":null,"abstract":"Recently, an eigenvalue fusion approach for detecting idle subchannels of OFDMA signals in the context of centralized cooperative spectrum sensing for cognitive radio (CR) was proposed. Four detection techniques were analyzed, and it was concluded that the eigenvalue fusion outperforms the decision fusion scheme, in spite of the larger volume of data sent to the fusion center (FC) in the eigenvalue fusion. Nevertheless, it was conjectured that bit errors in the reporting channel could be more disastrous to the data representing CR decisions than to the data carrying eigenvalues, masking a potential advantage of the eigenvalue combining also in terms of the volume of data sent to the FC. In this paper we investigate this conjecture and conclude that it is partially true: CR decisions are indeed more sensitive to channel errors, but the amount of redundancy inserted to protect the decisions so as to equate the performances of the two fusion schemes does not always leads to a larger number of bits in the decision fusion. Then, one needs to trade performance and amount of data in the reporting channel to decide upon which fusion scheme must be adopted, in a case by case analysis.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121619042","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}
引用次数: 8
Coded cooperation with single parity-check turbo-product codes over fast fading channels 快速衰落信道上与单奇偶校验涡轮积码的编码合作
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-08-01 DOI: 10.1109/ITS.2014.6947979
D. Guimarães, Geraldo Gil Ramundo Gomes, Guilherme Varela Barbosa, Bartolomeu Ferreira Uchoa-Filho
{"title":"Coded cooperation with single parity-check turbo-product codes over fast fading channels","authors":"D. Guimarães, Geraldo Gil Ramundo Gomes, Guilherme Varela Barbosa, Bartolomeu Ferreira Uchoa-Filho","doi":"10.1109/ITS.2014.6947979","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947979","url":null,"abstract":"This paper describes a new coded cooperation scheme based on single parity-check turbo-product codes. The channel soft-information from the source and the relays are also combined in a novel way at the destination. The scheme has simple encoding and decoding, and unveils potential for large cooperation gains in fast fading channels.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122088024","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}
引用次数: 1
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