Pub Date : 2000-09-24DOI: 10.1109/VETECF.2000.887080
T. Nakagawa, K. Araki
The effect of phase noise on RF communication signals is investigated using a new parameter, the symbol rate normalized to the phase-lock loop (PLL) bandwidth of local oscillators. Using this parameter, we estimate the phase noise effect on the bit error rates (BER) error vector magnitude (EVM), and adjacent channel signals. These treatments generalize the phase noise effect on communication signals having various symbol rates and various phase noise characteristics.
{"title":"Effect of phase noise on RF communication signals","authors":"T. Nakagawa, K. Araki","doi":"10.1109/VETECF.2000.887080","DOIUrl":"https://doi.org/10.1109/VETECF.2000.887080","url":null,"abstract":"The effect of phase noise on RF communication signals is investigated using a new parameter, the symbol rate normalized to the phase-lock loop (PLL) bandwidth of local oscillators. Using this parameter, we estimate the phase noise effect on the bit error rates (BER) error vector magnitude (EVM), and adjacent channel signals. These treatments generalize the phase noise effect on communication signals having various symbol rates and various phase noise characteristics.","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116007534","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 : 2000-09-24DOI: 10.1109/VETECF.2000.886294
J. Yi, Jae-Hyok Lee
An adaptive RAKE receiver with diversity combining is proposed for a DS-CDMA system in multipath fading channels. The proposed adaptive RAKE receiver exploits antenna diversity and adaptive interference cancellation (AIC) to mitigate the effect of both multipath fading and multiple-access interference (MAI). The LMS algorithm with variable step-size is used to update the tap-weight vector of AICs. The performance of the proposed receiver is evaluated by computer simulation for the various numbers of antennas and RAKE fingers. It is shown that the proposed receiver achieves significant performance improvement over a conventional RAKE receiver.
{"title":"RAKE receiver with adaptive interference cancellers for a DS-CDMA system in multipath fading channels","authors":"J. Yi, Jae-Hyok Lee","doi":"10.1109/VETECF.2000.886294","DOIUrl":"https://doi.org/10.1109/VETECF.2000.886294","url":null,"abstract":"An adaptive RAKE receiver with diversity combining is proposed for a DS-CDMA system in multipath fading channels. The proposed adaptive RAKE receiver exploits antenna diversity and adaptive interference cancellation (AIC) to mitigate the effect of both multipath fading and multiple-access interference (MAI). The LMS algorithm with variable step-size is used to update the tap-weight vector of AICs. The performance of the proposed receiver is evaluated by computer simulation for the various numbers of antennas and RAKE fingers. It is shown that the proposed receiver achieves significant performance improvement over a conventional RAKE receiver.","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116576866","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 : 2000-09-24DOI: 10.1109/VETECF.2000.886328
Y.M. Jang, Jeehwan Ahn
This paper proposes a transient connection admission control (CAC) scheme using the transient quality of service (QoS) measure for CDMA systems. We derive the transient outage probability as the QoS measure using the fluid-flow approximation model. Based on the outage measures, we compare transient outage performance against steady-state outage performance. The predictive CAC is a promising approach for the hierarchical CDMA systems.
{"title":"A connection admission control using transient outage probability in CDMA systems","authors":"Y.M. Jang, Jeehwan Ahn","doi":"10.1109/VETECF.2000.886328","DOIUrl":"https://doi.org/10.1109/VETECF.2000.886328","url":null,"abstract":"This paper proposes a transient connection admission control (CAC) scheme using the transient quality of service (QoS) measure for CDMA systems. We derive the transient outage probability as the QoS measure using the fluid-flow approximation model. Based on the outage measures, we compare transient outage performance against steady-state outage performance. The predictive CAC is a promising approach for the hierarchical CDMA systems.","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114471044","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 : 2000-09-24DOI: 10.1109/VETECF.2000.886858
A. Wiesler, O. Muller, F. Jondral
The international mobile communication system IMT2000 will enable very flexible communication, which means variable data rates from 8 kbit/s speech up to 2 Mbit/s for data transmission. In November 1999 five modes of IMT2000 have been specified. In several modes turbo codes are proposed to enable bit error rates (BER) as low as 10/sup -6/ for high quality data services. Usually for this type of channel coding two MAP-algorithms, based on the maximum a posteriori criterion, are used for decoding. The MAP-algorithm utilizes soft input information and produces soft output information. The practical implementation of the MAP-algorithm, respectively its computational reduced version log-MAP and max-log-MAP, is investigated.
{"title":"MAP-algorithm with fixed-point representation for software radios","authors":"A. Wiesler, O. Muller, F. Jondral","doi":"10.1109/VETECF.2000.886858","DOIUrl":"https://doi.org/10.1109/VETECF.2000.886858","url":null,"abstract":"The international mobile communication system IMT2000 will enable very flexible communication, which means variable data rates from 8 kbit/s speech up to 2 Mbit/s for data transmission. In November 1999 five modes of IMT2000 have been specified. In several modes turbo codes are proposed to enable bit error rates (BER) as low as 10/sup -6/ for high quality data services. Usually for this type of channel coding two MAP-algorithms, based on the maximum a posteriori criterion, are used for decoding. The MAP-algorithm utilizes soft input information and produces soft output information. The practical implementation of the MAP-algorithm, respectively its computational reduced version log-MAP and max-log-MAP, is investigated.","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122156432","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 : 2000-09-24DOI: 10.1109/VETECF.2000.886870
M. Sugita, K. Uehara, S. Kubota
We summarize the security necessary for software defined radio (SDR) systems, and propose a flexible structure for security systems on SDR. We introduce a new electronic commerce scheme for SDR that utilizes the ability of SDR to switch between different security algorithms for electronic commerce. We evaluate the performance of the cryptographic algorithms used in electronic commerce on various platforms including SDR systems, as basic research toward the implementation of SDR.
{"title":"Flexible security systems and a new structure for electronic commerce on software radio","authors":"M. Sugita, K. Uehara, S. Kubota","doi":"10.1109/VETECF.2000.886870","DOIUrl":"https://doi.org/10.1109/VETECF.2000.886870","url":null,"abstract":"We summarize the security necessary for software defined radio (SDR) systems, and propose a flexible structure for security systems on SDR. We introduce a new electronic commerce scheme for SDR that utilizes the ability of SDR to switch between different security algorithms for electronic commerce. We evaluate the performance of the cryptographic algorithms used in electronic commerce on various platforms including SDR systems, as basic research toward the implementation of SDR.","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129723838","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 : 2000-09-24DOI: 10.1109/VETECF.2000.886314
G. Lehmann, C. Gessner, M. Haardt
For third generation mobile radio systems like the TD-CDMA based UTRA TDD mode the use of smart antenna technology promises a substantial performance improvement on the up- and the downlink. The third generation mobile radio system UTRA with the TDD mode, which utilizes a combined CDMA and TDMA multiple access scheme, has been specified in the Third Generation Partnership Project (3GPP). The use of smart antennas at the base station reduces interference in two ways: on the uplink the intercell interference can be suppressed. The estimated spatial information about the users and interferers can then be used for beamforming on the downlink, which significantly reduces the interference also in this direction. Especially for terminals with a RAKE-receiver-structure a major performance improvement can be observed because of the intracell interference reduction. These performance improvements are expressed in concrete results derived from link-level simulations using the described technology and simulation environment.
{"title":"Evaluation of link-level performance improvements by using smart antennas for the TD-CDMA based UTRA TDD mobile radio system","authors":"G. Lehmann, C. Gessner, M. Haardt","doi":"10.1109/VETECF.2000.886314","DOIUrl":"https://doi.org/10.1109/VETECF.2000.886314","url":null,"abstract":"For third generation mobile radio systems like the TD-CDMA based UTRA TDD mode the use of smart antenna technology promises a substantial performance improvement on the up- and the downlink. The third generation mobile radio system UTRA with the TDD mode, which utilizes a combined CDMA and TDMA multiple access scheme, has been specified in the Third Generation Partnership Project (3GPP). The use of smart antennas at the base station reduces interference in two ways: on the uplink the intercell interference can be suppressed. The estimated spatial information about the users and interferers can then be used for beamforming on the downlink, which significantly reduces the interference also in this direction. Especially for terminals with a RAKE-receiver-structure a major performance improvement can be observed because of the intracell interference reduction. These performance improvements are expressed in concrete results derived from link-level simulations using the described technology and simulation environment.","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128536794","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 : 2000-09-24DOI: 10.1109/VETECF.2000.886324
H. Kobayashi
This paper proposes a novel coherent demodulation method for orthogonal frequency division multiplexing (OFDM) systems with multi-level quadrature amplitude modulation (M-QAM) that are operating in a burst mode such as wireless LAN communications systems. The salient feature of the proposed method is that two training symbols placing at the start of every burst frame are used both for the synchronization of received burst signal and the estimation of channel frequency response under frequency selective fading environments. Furthermore, this paper proposes a simple phase tracking method for compensating the phase rotation of signal constellation points due to the residual frequency offset as the result of frequency offset estimation method of using two training symbols. The coherent demodulator including the phase tracking method proposed in this paper offers excellent C/N performance even under severe frequency selective fading environments without any assistance of the pilot tones which is usually employed in the conventional coherent demodulation for the M-QAM OFDM signal.
{"title":"A novel coherent demodulation for M-QAM OFDM signal operating in the burst mode","authors":"H. Kobayashi","doi":"10.1109/VETECF.2000.886324","DOIUrl":"https://doi.org/10.1109/VETECF.2000.886324","url":null,"abstract":"This paper proposes a novel coherent demodulation method for orthogonal frequency division multiplexing (OFDM) systems with multi-level quadrature amplitude modulation (M-QAM) that are operating in a burst mode such as wireless LAN communications systems. The salient feature of the proposed method is that two training symbols placing at the start of every burst frame are used both for the synchronization of received burst signal and the estimation of channel frequency response under frequency selective fading environments. Furthermore, this paper proposes a simple phase tracking method for compensating the phase rotation of signal constellation points due to the residual frequency offset as the result of frequency offset estimation method of using two training symbols. The coherent demodulator including the phase tracking method proposed in this paper offers excellent C/N performance even under severe frequency selective fading environments without any assistance of the pilot tones which is usually employed in the conventional coherent demodulation for the M-QAM OFDM signal.","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129162226","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 : 2000-09-24DOI: 10.1109/VETECF.2000.886859
J. Lariviere, R. Goubran
A noise-reduction (NR) enhancement to the generalized multi-delay frequency domain algorithm, suitable for automatic speech recognition (ASR) and acoustic echo cancellation (AEC) is presented. Findings are presented on the ability of the algorithm to suppress car noise from the microphone signal in hands-free mobile telephony in terms of an improvement in echo return loss enhancement (ERLE) and error rates of a digit recognizer from a commercial ASR engine. Minimal computations are involved in the enhancement, e.g. for an additional 11 N/P real multiplies and 8 N/P real additions per output sample, where N is the block size and P is the number of output samples per GMDF iteration, results show an average increase in ERLE of 9dB and an improvement of 15% in digit error recognition rates at low SNR (-5dB).
{"title":"Noise-reduced GMDF for acoustic echo cancellation and speech recognition in mobile environments","authors":"J. Lariviere, R. Goubran","doi":"10.1109/VETECF.2000.886859","DOIUrl":"https://doi.org/10.1109/VETECF.2000.886859","url":null,"abstract":"A noise-reduction (NR) enhancement to the generalized multi-delay frequency domain algorithm, suitable for automatic speech recognition (ASR) and acoustic echo cancellation (AEC) is presented. Findings are presented on the ability of the algorithm to suppress car noise from the microphone signal in hands-free mobile telephony in terms of an improvement in echo return loss enhancement (ERLE) and error rates of a digit recognizer from a commercial ASR engine. Minimal computations are involved in the enhancement, e.g. for an additional 11 N/P real multiplies and 8 N/P real additions per output sample, where N is the block size and P is the number of output samples per GMDF iteration, results show an average increase in ERLE of 9dB and an improvement of 15% in digit error recognition rates at low SNR (-5dB).","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124573277","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 : 2000-09-24DOI: 10.1109/VETECF.2000.886682
H. Benjamin, B. Kamali
The catalog of Reed-Solomon (RS) codes is a rather long one. To select a proper code for a given application, the system designer is compelled to deal with numerous tables, graphs and equations. We have reported our result of designing an artificial neural network (NN) from which one can select the most "efficient" unmodified RS code for a specific application. In this article we present the continuation of our work, in development of an artificial NN database for selection of shortened RS codes for a given application. A student version of the MATLAB Neural Networks Toolbox is used for NN simulation. The Levenberg-Marquardt learning algorithm is used to train the NN. The resultant NN has five inputs, nine units in the hidden layer, and two units in the output layer. The outputs are the shortened "n" and "k". The test data results show the accuracy of selecting the correct code length and code dimension is 84.4% for shortened codes.
{"title":"Selection of the most \"efficient\" shortened Reed-Solomon code from a neural network database","authors":"H. Benjamin, B. Kamali","doi":"10.1109/VETECF.2000.886682","DOIUrl":"https://doi.org/10.1109/VETECF.2000.886682","url":null,"abstract":"The catalog of Reed-Solomon (RS) codes is a rather long one. To select a proper code for a given application, the system designer is compelled to deal with numerous tables, graphs and equations. We have reported our result of designing an artificial neural network (NN) from which one can select the most \"efficient\" unmodified RS code for a specific application. In this article we present the continuation of our work, in development of an artificial NN database for selection of shortened RS codes for a given application. A student version of the MATLAB Neural Networks Toolbox is used for NN simulation. The Levenberg-Marquardt learning algorithm is used to train the NN. The resultant NN has five inputs, nine units in the hidden layer, and two units in the output layer. The outputs are the shortened \"n\" and \"k\". The test data results show the accuracy of selecting the correct code length and code dimension is 84.4% for shortened codes.","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"490 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129492014","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 : 2000-09-24DOI: 10.1109/VETECF.2000.886335
J. Bakker, F. Schoute
A stack of protocols and methods enabling high speed wireless communications has been developed. This paper discusses the design and implementation of a wireless research platform that allows experiments with this and other protocol stacks. A comparison is made with other experimental platforms. A performance estimation of the LART (Linux Advanced Radio Terminal) platform is presented.
{"title":"LART: design and implementation of an experimental wireless platform","authors":"J. Bakker, F. Schoute","doi":"10.1109/VETECF.2000.886335","DOIUrl":"https://doi.org/10.1109/VETECF.2000.886335","url":null,"abstract":"A stack of protocols and methods enabling high speed wireless communications has been developed. This paper discusses the design and implementation of a wireless research platform that allows experiments with this and other protocol stacks. A comparison is made with other experimental platforms. A performance estimation of the LART (Linux Advanced Radio Terminal) platform is presented.","PeriodicalId":186198,"journal":{"name":"Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130284679","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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