Pub Date : 1998-09-02DOI: 10.1109/ISSSTA.1998.722520
M. Eric, A. Zejak, M. Obradovic
In this paper we propose an approach to type II ambiguity analysis of arbitrary volume antenna array. This approach is interesting especially from the point of in designing of volume antenna arrays for mobile communications. We define and propose a type II ambiguity function and show that the proposed function is very effective tool for type II ambiguity characterization of volume antenna arrays.
{"title":"Ambiguity characterization of arbitrary antenna array: type II ambiguity","authors":"M. Eric, A. Zejak, M. Obradovic","doi":"10.1109/ISSSTA.1998.722520","DOIUrl":"https://doi.org/10.1109/ISSSTA.1998.722520","url":null,"abstract":"In this paper we propose an approach to type II ambiguity analysis of arbitrary volume antenna array. This approach is interesting especially from the point of in designing of volume antenna arrays for mobile communications. We define and propose a type II ambiguity function and show that the proposed function is very effective tool for type II ambiguity characterization of volume antenna arrays.","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125720885","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 : 1998-09-02DOI: 10.1109/ISSSTA.1998.723833
X. Gui, T. S. Ng
The bit error rate (BER) performance of an asynchronous multi-carrier code division multiple access (MC-CDMA) system for the uplink of the mobile communication system with equal gain combining and maximum ratio combining are obtained. Given a fixed bandwidth frequency selective channel, performance of MC-CDMA is compared with that of conventional CDMA and MC-DS-CDMA in numerical results.
{"title":"Performance comparison of asynchronous orthogonal multi-carrier CDMA in frequency selective channel","authors":"X. Gui, T. S. Ng","doi":"10.1109/ISSSTA.1998.723833","DOIUrl":"https://doi.org/10.1109/ISSSTA.1998.723833","url":null,"abstract":"The bit error rate (BER) performance of an asynchronous multi-carrier code division multiple access (MC-CDMA) system for the uplink of the mobile communication system with equal gain combining and maximum ratio combining are obtained. Given a fixed bandwidth frequency selective channel, performance of MC-CDMA is compared with that of conventional CDMA and MC-DS-CDMA in numerical results.","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125771568","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 : 1998-09-02DOI: 10.1109/ISSSTA.1998.726225
L. Tomba, W. Krzymień
Multicarrier (MC) modulation combined with code division multiple access (CDMA) has gained considerable attention in the last years because of its many advantageous features. However, while downlink design is possible even with M-QAM modulation schemes, a similar solution is much more difficult on the uplink because its asynchronous character complicates the channel identification. Indeed, performance of M-QAM schemes depends strongly on the accuracy of the channel estimation, as well as the adopted equalization techniques. We propose an uplink architecture based on chip-level differential encoding. This choice is motivated by the need to simplify the hardware structure and the channel estimation algorithms as well as to reduce the sensitivity to possible phase noise in the frequency down-conversion circuit. The numerical results of this work are preliminary and they are based on simulations.
{"title":"Comparison of encoding/detection techniques for the reverse link of an MC-CDMA multiple access scheme","authors":"L. Tomba, W. Krzymień","doi":"10.1109/ISSSTA.1998.726225","DOIUrl":"https://doi.org/10.1109/ISSSTA.1998.726225","url":null,"abstract":"Multicarrier (MC) modulation combined with code division multiple access (CDMA) has gained considerable attention in the last years because of its many advantageous features. However, while downlink design is possible even with M-QAM modulation schemes, a similar solution is much more difficult on the uplink because its asynchronous character complicates the channel identification. Indeed, performance of M-QAM schemes depends strongly on the accuracy of the channel estimation, as well as the adopted equalization techniques. We propose an uplink architecture based on chip-level differential encoding. This choice is motivated by the need to simplify the hardware structure and the channel estimation algorithms as well as to reduce the sensitivity to possible phase noise in the frequency down-conversion circuit. The numerical results of this work are preliminary and they are based on simulations.","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132423840","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 : 1998-09-02DOI: 10.1109/ISSSTA.1998.726232
K. Takeo, S. Sato
Non-uniform traffic could cause the disparity in communications quality among base stations (BSs) and lower system efficiency in CDMA systems. We have proposed a cell design algorithm to minimize the difference in communications quality between BSs at system introduction. The algorithm designs cell areas according to predicted traffic distribution with non-uniformity. In this paper, the proposed cell design algorithm is applied to an operating system in order to cope with change in traffic situations. The algorithm operates using measured SIR and reduces the difference in SIR between BSs.
{"title":"The proposal of CDMA cell design scheme considering change in traffic distributions","authors":"K. Takeo, S. Sato","doi":"10.1109/ISSSTA.1998.726232","DOIUrl":"https://doi.org/10.1109/ISSSTA.1998.726232","url":null,"abstract":"Non-uniform traffic could cause the disparity in communications quality among base stations (BSs) and lower system efficiency in CDMA systems. We have proposed a cell design algorithm to minimize the difference in communications quality between BSs at system introduction. The algorithm designs cell areas according to predicted traffic distribution with non-uniformity. In this paper, the proposed cell design algorithm is applied to an operating system in order to cope with change in traffic situations. The algorithm operates using measured SIR and reduces the difference in SIR between BSs.","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133382218","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 : 1998-09-02DOI: 10.1109/ISSSTA.1998.726250
M. Raitola, H. Holma
The performance of wideband CDMA packet data with soft combining of packets is analysed. First, the main parameters of W-CDMA (wideband CDMA) are presented. W-CDMA refers to the air interface that was decided by the ETSI to be standardised for the UMTS air interface for paired bands. Secondly, the W-CDMA packet transmission scheme with soft combining of packets is introduced. Soft combining indicates the combining of the soft values of the unsuccessful transmission with the retransmission before feeding them to the channel decoder. The performance of soft combining is compared to the performance of noncombining packet solution. The results show that soft combining can increase the capacity and extend the cell range up to 2 dB against Gaussian noise if no fast power control is used. With fast power control the gain is 0.3-2.0 dB. Soft combining can also be used to decrease the maximum packet delays. It is also shown that using slow power control instead of fast power control can increase the packet data capacity in the downlink.
{"title":"Wideband CDMA packet data with hybrid ARQ","authors":"M. Raitola, H. Holma","doi":"10.1109/ISSSTA.1998.726250","DOIUrl":"https://doi.org/10.1109/ISSSTA.1998.726250","url":null,"abstract":"The performance of wideband CDMA packet data with soft combining of packets is analysed. First, the main parameters of W-CDMA (wideband CDMA) are presented. W-CDMA refers to the air interface that was decided by the ETSI to be standardised for the UMTS air interface for paired bands. Secondly, the W-CDMA packet transmission scheme with soft combining of packets is introduced. Soft combining indicates the combining of the soft values of the unsuccessful transmission with the retransmission before feeding them to the channel decoder. The performance of soft combining is compared to the performance of noncombining packet solution. The results show that soft combining can increase the capacity and extend the cell range up to 2 dB against Gaussian noise if no fast power control is used. With fast power control the gain is 0.3-2.0 dB. Soft combining can also be used to decrease the maximum packet delays. It is also shown that using slow power control instead of fast power control can increase the packet data capacity in the downlink.","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133392176","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 : 1998-09-02DOI: 10.1109/ISSSTA.1998.722529
J. Detlefsen, E. Schmidhammer, T. Troll
The paper reports on the system concept, design and realization of an experimental radar using PN-codes for ranging and wavefront reconstruction for angular discrimination. The road evaluation of the system has confirmed the specifications regarding essential system parameters such as radial and longitudinal resolution, sensitivity and velocity discrimination. Simulative studies have shown that by choosing suitable parameters for the PN-code, the system is not limited by the influence of the Doppler effect. The memory readout concept for PN-codes enables the expected fast access to radially separated range gates and allows on-line tracking of several objects. The overall performance with respect to ranging, angular resolution and velocity discrimination obtained from an evaluation process demonstrates the usefulness of the principles, making them potential candidates for an implementation into second generation autonomous cruise control (ACC) or collision warning systems.
{"title":"Spread spectrum ranging for an ACC-radar","authors":"J. Detlefsen, E. Schmidhammer, T. Troll","doi":"10.1109/ISSSTA.1998.722529","DOIUrl":"https://doi.org/10.1109/ISSSTA.1998.722529","url":null,"abstract":"The paper reports on the system concept, design and realization of an experimental radar using PN-codes for ranging and wavefront reconstruction for angular discrimination. The road evaluation of the system has confirmed the specifications regarding essential system parameters such as radial and longitudinal resolution, sensitivity and velocity discrimination. Simulative studies have shown that by choosing suitable parameters for the PN-code, the system is not limited by the influence of the Doppler effect. The memory readout concept for PN-codes enables the expected fast access to radially separated range gates and allows on-line tracking of several objects. The overall performance with respect to ranging, angular resolution and velocity discrimination obtained from an evaluation process demonstrates the usefulness of the principles, making them potential candidates for an implementation into second generation autonomous cruise control (ACC) or collision warning systems.","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115053964","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 : 1998-09-02DOI: 10.1109/ISSSTA.1998.726241
A. Giovanard, G. Mazzini
Through the definition of traffic scenarios for the characterization of inter and intra LAN communications, we propose a time division duplex scheme for wireless access. The system is based on a centralized polling approach and implements an ARQ strategy, allowing to consider the actual impact of the propagation channel on the performance. The analysis is performed by means of a theoretical investigation and some numerical results have been reported to show the system parameters impact. Furthermore, the role of users positions is taken into account by testing circular scenarios with two different users distributions.
{"title":"Time division token based WLANs: a proposal and analysis","authors":"A. Giovanard, G. Mazzini","doi":"10.1109/ISSSTA.1998.726241","DOIUrl":"https://doi.org/10.1109/ISSSTA.1998.726241","url":null,"abstract":"Through the definition of traffic scenarios for the characterization of inter and intra LAN communications, we propose a time division duplex scheme for wireless access. The system is based on a centralized polling approach and implements an ARQ strategy, allowing to consider the actual impact of the propagation channel on the performance. The analysis is performed by means of a theoretical investigation and some numerical results have been reported to show the system parameters impact. Furthermore, the role of users positions is taken into account by testing circular scenarios with two different users distributions.","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116994943","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 : 1998-09-02DOI: 10.1109/ISSSTA.1998.722528
I. Simic, A. Zejak, B. Zrnic, A. Petrovic
We present a radar ambiguity function that accurately describes the operation of the compressive receiver. The most important benefit of this approach is the possibility of the application of radar signal design methods for ambiguity function shaping in the field of compressive receivers. Results in ambiguity function shaping are also presented. We successfully designed a compression filter which suppresses sidelobes without significant degradation of the receiver resolution.
{"title":"Compressive receiver sidelobes suppression based on mismatching algorithms","authors":"I. Simic, A. Zejak, B. Zrnic, A. Petrovic","doi":"10.1109/ISSSTA.1998.722528","DOIUrl":"https://doi.org/10.1109/ISSSTA.1998.722528","url":null,"abstract":"We present a radar ambiguity function that accurately describes the operation of the compressive receiver. The most important benefit of this approach is the possibility of the application of radar signal design methods for ambiguity function shaping in the field of compressive receivers. Results in ambiguity function shaping are also presented. We successfully designed a compression filter which suppresses sidelobes without significant degradation of the receiver resolution.","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117221544","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 : 1998-09-02DOI: 10.1109/ISSSTA.1998.722517
N. R. Patel, Timothy O'Farrell
Conventional matched-filter detection (MFD) in a DS/CDMA system is sub-optimal when the channel noise is dominated by multiple access interference (MAI). MAI is a limiting factor to the bit error rate performance. Multi-user detector schemes have been proposed to combat MAI but these schemes have a high degree of complexity. The optimum single-user detector (OSD) considerably reduces the complexity while maintaining an improvement in the BER performance over the MFD. The first realisation of this detector (OSD-1) was proposed by O'Farrel (1989). A new interpretation of this detector architecture (OSD-2) is presented which can completely cancel MAI. A comparison of the OSD-2 with OSD-1 and the MFD is presented.
{"title":"Optimum single-user detection for DS/CDMA systems achieving complete MAI cancellation","authors":"N. R. Patel, Timothy O'Farrell","doi":"10.1109/ISSSTA.1998.722517","DOIUrl":"https://doi.org/10.1109/ISSSTA.1998.722517","url":null,"abstract":"Conventional matched-filter detection (MFD) in a DS/CDMA system is sub-optimal when the channel noise is dominated by multiple access interference (MAI). MAI is a limiting factor to the bit error rate performance. Multi-user detector schemes have been proposed to combat MAI but these schemes have a high degree of complexity. The optimum single-user detector (OSD) considerably reduces the complexity while maintaining an improvement in the BER performance over the MFD. The first realisation of this detector (OSD-1) was proposed by O'Farrel (1989). A new interpretation of this detector architecture (OSD-2) is presented which can completely cancel MAI. A comparison of the OSD-2 with OSD-1 and the MFD is presented.","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117247641","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 : 1998-09-02DOI: 10.1007/978-1-4615-5103-4_9
P. Jung
{"title":"Turbo-codes for future mobile radio applications","authors":"P. Jung","doi":"10.1007/978-1-4615-5103-4_9","DOIUrl":"https://doi.org/10.1007/978-1-4615-5103-4_9","url":null,"abstract":"","PeriodicalId":116377,"journal":{"name":"1988 IEEE 5th International Symposium on Spread Spectrum Techniques and Applications - Proceedings. Spread Technology to Africa (Cat. No.98TH8333)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128159725","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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