Pub Date : 2011-04-26DOI: 10.1109/NRSC.2011.5873603
M. Ahmed, A. El-Mahdy, K. El-barbary
The performance of adaptive Hard Decision Parallel Interference Cancellation (HD-APIC) Algorithm in asynchronous Multicarrier Direct Sequence Code Division Multiple Access (MC-DS-CDMA) system has not been studied before. In this study, the performance of HD APIC scheme in asynchronous MC-DS-CDMA is introduced. Receiver under study consists of a bank of matched filters (decorrelator) as a first stage, then, HD-APIC scheme as a second stage. The APIC is used to eliminate the Multiple Access Interference (MAI) of the system. Frequency diversity inherent in the Multicarrier (MC) system is exploited through maximal ratio combining (MRC). Performance analysis of decorrelator, Conventional Parallel Interference Cancellation (CPIC), and HD-APIC schemes of asynchronous MC-DS-CDMA are evaluated. Finally computer simulations are performed to validate the theoretical development.
{"title":"Performance analysis of adaptive Hard Decision Parallel Interference Cancellation receiver in asynchronous Multicarrier DS-CDMA system","authors":"M. Ahmed, A. El-Mahdy, K. El-barbary","doi":"10.1109/NRSC.2011.5873603","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873603","url":null,"abstract":"The performance of adaptive Hard Decision Parallel Interference Cancellation (HD-APIC) Algorithm in asynchronous Multicarrier Direct Sequence Code Division Multiple Access (MC-DS-CDMA) system has not been studied before. In this study, the performance of HD APIC scheme in asynchronous MC-DS-CDMA is introduced. Receiver under study consists of a bank of matched filters (decorrelator) as a first stage, then, HD-APIC scheme as a second stage. The APIC is used to eliminate the Multiple Access Interference (MAI) of the system. Frequency diversity inherent in the Multicarrier (MC) system is exploited through maximal ratio combining (MRC). Performance analysis of decorrelator, Conventional Parallel Interference Cancellation (CPIC), and HD-APIC schemes of asynchronous MC-DS-CDMA are evaluated. Finally computer simulations are performed to validate the theoretical development.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123177638","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873591
M. Iskander
In the last decade, antenna and sensor array processing has attracted considerable interest in the signal processing community, and has been applied to a variety of areas ranging from biomedical applications to telecommunication networks. In telecommunication, the importance of antenna array processing initiates from its ability to cancel the noise and interfering signals, mitigate the multipath and fading due to the environment effects, reduce the total power consumption, and its ability to replace the mechanical scanning arrays. The objective of this work is to improve the performance of adaptive array systems by taking the inter-element coupling effects into account. Many publications discussed the adaptive arrays techniques neglecting the coupling effects, but in practical antennas the elements of the array affect each other through mutual coupling and this reduces the adaptive antenna system performance. In the present work the adaptive array response is considered in two cases, beamforming and Direction of Arrival [DOA] estimation algorithms. To be able to compensate the coupling effects the coupling needs to be calculated. Here, the coupling in Uniform Linear Array (ULA) of MicroStrip (MS) patches is calculated using two Matlab codes and FEKO software based on MOM technique. This small array composed of three MS elements, is considered as a replacement of the single element mobile station antenna. The final numerical simulations for the proposed adaptive array system prove that including coupling effects greatly improve performance of the array.
{"title":"Mitigation of mutual coupling effects in microstrip adaptive arrays for portable devices","authors":"M. Iskander","doi":"10.1109/NRSC.2011.5873591","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873591","url":null,"abstract":"In the last decade, antenna and sensor array processing has attracted considerable interest in the signal processing community, and has been applied to a variety of areas ranging from biomedical applications to telecommunication networks. In telecommunication, the importance of antenna array processing initiates from its ability to cancel the noise and interfering signals, mitigate the multipath and fading due to the environment effects, reduce the total power consumption, and its ability to replace the mechanical scanning arrays. The objective of this work is to improve the performance of adaptive array systems by taking the inter-element coupling effects into account. Many publications discussed the adaptive arrays techniques neglecting the coupling effects, but in practical antennas the elements of the array affect each other through mutual coupling and this reduces the adaptive antenna system performance. In the present work the adaptive array response is considered in two cases, beamforming and Direction of Arrival [DOA] estimation algorithms. To be able to compensate the coupling effects the coupling needs to be calculated. Here, the coupling in Uniform Linear Array (ULA) of MicroStrip (MS) patches is calculated using two Matlab codes and FEKO software based on MOM technique. This small array composed of three MS elements, is considered as a replacement of the single element mobile station antenna. The final numerical simulations for the proposed adaptive array system prove that including coupling effects greatly improve performance of the array.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127422672","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873578
Z. Houaneb, H. Zairi, A. Gharsallah, H. Baudrand
In this paper, a simple and novel circular patch with annular slits loaded monopole antenna fed by a annular source is proposed for operating at PCS band. A TM02-mode circular patch loaded with annular slits antenna for the application of radio LAN's is reported. An theoretical prototype operating at 5.2GHz is designed and simulated. The antenna pattern is omni-directional in azimuth and has a notch in the normal direction. A 7.4% bandwidth of VSWR < 2 and 5.1dB antenna gain was simulated.
{"title":"Study of new annular multi-slits antenna for radio LAN's by an iterative method","authors":"Z. Houaneb, H. Zairi, A. Gharsallah, H. Baudrand","doi":"10.1109/NRSC.2011.5873578","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873578","url":null,"abstract":"In this paper, a simple and novel circular patch with annular slits loaded monopole antenna fed by a annular source is proposed for operating at PCS band. A TM02-mode circular patch loaded with annular slits antenna for the application of radio LAN's is reported. An theoretical prototype operating at 5.2GHz is designed and simulated. The antenna pattern is omni-directional in azimuth and has a notch in the normal direction. A 7.4% bandwidth of VSWR < 2 and 5.1dB antenna gain was simulated.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129886713","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873592
M. Abdalla, Zhi Run, H. Hamza
This paper presents the verification of left handed propagation in planar left handed transmission lines implemented using only periodic shunt inductive load. In other words, the implemented left handed transmission line was designed with no series capacitive load. The left handed transmission line was designed on a ferrite substrate in coplanar waveguide configuration. The ferrite substrate is horizontally magnetized which has small demagnetization factor and hence it requires small external DC magnetic bias. The equivalent negative permeability was obtained thanks to the ferrite negative permeability according to the ferrite magnetic properties and the applied DC magnetic bias. The design concepts for this kind of transmission lines have been explained theoretically. The left handed transmission propagation verification along the transmission line has been done using both the transmission characteristics and electric field profile. The transmission characteristics results, for different DC magnetic bias values, confirms that the transmission coefficient (S21) gains up to 15 dB increase in its value within the frequency band of ferrite negative permeability. Also, the electric field profile emphasize illustrates the negative phase associated with left-handed propagation
{"title":"Propagation verification of left handed transmission line implemented without series capacitive load","authors":"M. Abdalla, Zhi Run, H. Hamza","doi":"10.1109/NRSC.2011.5873592","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873592","url":null,"abstract":"This paper presents the verification of left handed propagation in planar left handed transmission lines implemented using only periodic shunt inductive load. In other words, the implemented left handed transmission line was designed with no series capacitive load. The left handed transmission line was designed on a ferrite substrate in coplanar waveguide configuration. The ferrite substrate is horizontally magnetized which has small demagnetization factor and hence it requires small external DC magnetic bias. The equivalent negative permeability was obtained thanks to the ferrite negative permeability according to the ferrite magnetic properties and the applied DC magnetic bias. The design concepts for this kind of transmission lines have been explained theoretically. The left handed transmission propagation verification along the transmission line has been done using both the transmission characteristics and electric field profile. The transmission characteristics results, for different DC magnetic bias values, confirms that the transmission coefficient (S21) gains up to 15 dB increase in its value within the frequency band of ferrite negative permeability. Also, the electric field profile emphasize illustrates the negative phase associated with left-handed propagation","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126408733","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873628
G. Attia, I. El Dokany, A. Mohamed
Of all kinds of multiple access techniques, optical code division multiple access (OCDMA) is considered the strongest candidates to challenge the rapid evolution of optical communication systems to support multimedia. However, the harmful multiple access interference (MAI) and all forms of noise such as optical amplified spontaneous emission (ASE) noise, electronic receiver noise and photodiode (PD) shot noise are the limiting factors for the system capacity. The current paper, presents an advanced modulation scheme to enhance the capacity of OCDMA networks using hybrid frequency-polarization shift keying, where the polarization can be utilized to double the communication channel. Moreover, we will adopt the direct detection scheme rather than coherent detection to fulfill (i) the system simplicity, (ii) cost effectiveness, (iii) high immunity to laser noise and (iv) insensitivity to self and cross phase modulations caused by fiber nonlinearity. The simulated computer results for the proposed scheme indicate the substantial enhancement in the performance of the system in terms of ȁcapacity enhancement”. Where, the proposed scheme could mitigate the effect of MAI, and all forms of noise in the network. Moreover, approved its power efficient and provides secure communication.
{"title":"Capacity and security enhancement in optical CDMA systems","authors":"G. Attia, I. El Dokany, A. Mohamed","doi":"10.1109/NRSC.2011.5873628","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873628","url":null,"abstract":"Of all kinds of multiple access techniques, optical code division multiple access (OCDMA) is considered the strongest candidates to challenge the rapid evolution of optical communication systems to support multimedia. However, the harmful multiple access interference (MAI) and all forms of noise such as optical amplified spontaneous emission (ASE) noise, electronic receiver noise and photodiode (PD) shot noise are the limiting factors for the system capacity. The current paper, presents an advanced modulation scheme to enhance the capacity of OCDMA networks using hybrid frequency-polarization shift keying, where the polarization can be utilized to double the communication channel. Moreover, we will adopt the direct detection scheme rather than coherent detection to fulfill (i) the system simplicity, (ii) cost effectiveness, (iii) high immunity to laser noise and (iv) insensitivity to self and cross phase modulations caused by fiber nonlinearity. The simulated computer results for the proposed scheme indicate the substantial enhancement in the performance of the system in terms of ȁcapacity enhancement”. Where, the proposed scheme could mitigate the effect of MAI, and all forms of noise in the network. Moreover, approved its power efficient and provides secure communication.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125263090","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 : 2011-04-26DOI: 10.1109/NRSC.2011.5873620
Ramy M. Bahy, G. Salama, T. Mahmoud
This paper presents a new partition fusion technique for multi-focus images based on a no-reference blur metric. The no-reference blur metric is used to evaluate the amount of blur in images whereby, in many practical applications the original images are not available. The proposed algorithm is considered as a region based fusion technique, in which each of the input images are divided into a set of blocks and then the no-reference blur metric is used to evaluate the amount of blur in each block. Finally the less blurred block (sub-image) is selected as a part of the output fused image. In this paper the input images are considered registered whereas; our paper put a focus on image fusion field. The proposed technique considers the presence of overlapped blurred regions in input images; however previous related works didn't consider this assumption. Experimental results show that image fusion based on the selected no-reference blur metric give better performance against other algorithms based on traditional blur measurements.
{"title":"A no-reference blur metric guided fusion technique for multi-focus images","authors":"Ramy M. Bahy, G. Salama, T. Mahmoud","doi":"10.1109/NRSC.2011.5873620","DOIUrl":"https://doi.org/10.1109/NRSC.2011.5873620","url":null,"abstract":"This paper presents a new partition fusion technique for multi-focus images based on a no-reference blur metric. The no-reference blur metric is used to evaluate the amount of blur in images whereby, in many practical applications the original images are not available. The proposed algorithm is considered as a region based fusion technique, in which each of the input images are divided into a set of blocks and then the no-reference blur metric is used to evaluate the amount of blur in each block. Finally the less blurred block (sub-image) is selected as a part of the output fused image. In this paper the input images are considered registered whereas; our paper put a focus on image fusion field. The proposed technique considers the presence of overlapped blurred regions in input images; however previous related works didn't consider this assumption. Experimental results show that image fusion based on the selected no-reference blur metric give better performance against other algorithms based on traditional blur measurements.","PeriodicalId":438638,"journal":{"name":"2011 28th National Radio Science Conference (NRSC)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125531951","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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