Pub Date : 2006-05-14DOI: 10.1109/ICASSP.2006.1660933
Christophe Rouchy, H. Sadjadpour
Space-time convolutional code (STCC) is a technique that combines transmit diversity and coding to improve reliability in wireless fading channels. In this paper, we demonstrate a technique to design MQAM STCCs with high spectral efficiencies utilizing QPSK STCC as component code. The approach is based on a unique construction of M-QAM signal from several QPSK signals. The upper bound on the pairwise block error probability of the new scheme is derived. Simulation result demonstrates that the new technique outperforms existing M-QAM STCC design for M = 16
{"title":"Construction of M-QAM STCC Based on QPSK STCC","authors":"Christophe Rouchy, H. Sadjadpour","doi":"10.1109/ICASSP.2006.1660933","DOIUrl":"https://doi.org/10.1109/ICASSP.2006.1660933","url":null,"abstract":"Space-time convolutional code (STCC) is a technique that combines transmit diversity and coding to improve reliability in wireless fading channels. In this paper, we demonstrate a technique to design MQAM STCCs with high spectral efficiencies utilizing QPSK STCC as component code. The approach is based on a unique construction of M-QAM signal from several QPSK signals. The upper bound on the pairwise block error probability of the new scheme is derived. Simulation result demonstrates that the new technique outperforms existing M-QAM STCC design for M = 16","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127694847","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 : 2005-12-01DOI: 10.1109/ACSSC.2005.1599974
K. W. Forsythe, Daniel W. Bliss
In this paper, waveform optimization for multiple- input multiple-output (MIMO) radar systems is considered. Two types of waveform optimization are studied for static radar envi- ronments. Firstly, image-energy optimization using environmen- tally adaptive waveform design is considered. Secondly, waveform optimization for angle estimation in clutter-free environments is treated using Cramer-Rao bounds.
{"title":"Waveform Correlation and Optimization Issues for MIMO Radar","authors":"K. W. Forsythe, Daniel W. Bliss","doi":"10.1109/ACSSC.2005.1599974","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599974","url":null,"abstract":"In this paper, waveform optimization for multiple- input multiple-output (MIMO) radar systems is considered. Two types of waveform optimization are studied for static radar envi- ronments. Firstly, image-energy optimization using environmen- tally adaptive waveform design is considered. Secondly, waveform optimization for angle estimation in clutter-free environments is treated using Cramer-Rao bounds.","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133426119","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 : 2005-12-01DOI: 10.1109/ACSSC.2005.1600017
Feng Teng, K. Kiasaleh
{"title":"A Joint Precoding and Scheduling Technique for Multiuser MIMO Systems","authors":"Feng Teng, K. Kiasaleh","doi":"10.1109/ACSSC.2005.1600017","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1600017","url":null,"abstract":"","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115423606","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 : 2005-12-01DOI: 10.1109/ACSSC.2005.1599697
K. Ausavapattanakun, Aria Nosratinia
This work analyzes the throughput of selective repeat (SR) protocol in fading wireless channels. Hidden Markov models (HMM) provide a good approximation to the fading wireless channel, hut the calculation of SR throughput has been unavailable for channels characterized by HMM. We use a generalization of Mason's flow graphs with matrix weights for our analysis, leading to the moment generating function of the transmission lime, and thus calculating the throughput. Our methodology is general and can be applied for any finite-state Markov channels. It can also be used to analyze the delay of SR protocol
{"title":"Throughput Analysis of Selective Repeat ARQ in Fading Wireless Channels","authors":"K. Ausavapattanakun, Aria Nosratinia","doi":"10.1109/ACSSC.2005.1599697","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599697","url":null,"abstract":"This work analyzes the throughput of selective repeat (SR) protocol in fading wireless channels. Hidden Markov models (HMM) provide a good approximation to the fading wireless channel, hut the calculation of SR throughput has been unavailable for channels characterized by HMM. We use a generalization of Mason's flow graphs with matrix weights for our analysis, leading to the moment generating function of the transmission lime, and thus calculating the throughput. Our methodology is general and can be applied for any finite-state Markov channels. It can also be used to analyze the delay of SR protocol","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123560065","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 : 2005-12-01DOI: 10.1109/ACSSC.2005.1599928
Lei Feng, W. Namgoong
The acquisition performance of the channel- ized receiver for ultra-wideband (UWB) transmitted reference (TR) system is presented. Instead of sampling the received UWB signal with a single ADC as in a conventional fullband receiver, the channelized receiver digitizes with multiple slow ADCs, each of which samples a partial band of the UWB sig- nal. In this paper, we show that the frequency channelized receiver naturally leads to fast acquisition. In the channelized receiver, the reduced bandwidth in each subband widens the correlation peak, allowing the search increment to be corre- spondingly increased. Consequently, the search space in the channelized receiver is reduced, resulting in significantly faster acquisition time than in a fullband receiver.
{"title":"Fast Acquisition for Transmitted Reference Ultra-Wideband Systems with Channelized Receiver","authors":"Lei Feng, W. Namgoong","doi":"10.1109/ACSSC.2005.1599928","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599928","url":null,"abstract":"The acquisition performance of the channel- ized receiver for ultra-wideband (UWB) transmitted reference (TR) system is presented. Instead of sampling the received UWB signal with a single ADC as in a conventional fullband receiver, the channelized receiver digitizes with multiple slow ADCs, each of which samples a partial band of the UWB sig- nal. In this paper, we show that the frequency channelized receiver naturally leads to fast acquisition. In the channelized receiver, the reduced bandwidth in each subband widens the correlation peak, allowing the search increment to be corre- spondingly increased. Consequently, the search space in the channelized receiver is reduced, resulting in significantly faster acquisition time than in a fullband receiver.","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126691372","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 : 2005-12-01DOI: 10.1109/ACSSC.2005.1599696
V. Suryavanshi, Aria Nosratinia
In this work we address resilient packet header compression in a setup similar to RFC 3095 (robust header compression - ROHC), where a noisy feedback channel is available. We propose a new predictive hybrid ARQ (HARQ), using a systematic convolutional code with delay-limited interleaving. The compressed packet headers are bit interleaved, encoded, and the parity bits are loaded onto the packets in a manner that is consistent with existing standards. Our HARQ design is distinct from previous ones in that it cannot wait until the end of a codeword for retransmission, rather, ARQ's corresponding to individual packet headers arrive continually during a convolutional codeword and must be processed at that time. In our system, each time a NACK is encountered, the encoder estimates the state of the Viterbi decoder, deciding when a retransmission is necessary. The use of coding in conjunction with a specially designed interleaver, provides a flexible and powerful design methodology that makes it possible to improve the throughput via FEC and interleaving, while strictly limiting the delay to avoid timeout in higher layers. Simulations show that the throughput of the resulting system is superior to ROHC, and the delay is less sensitive to the channel conditions. Furthermore, over a large part of the operating range the delay is comparable to, or smaller than, the delay of RQHC
{"title":"A Hybrid ARQ Scheme for Resilient Packet Header Compression","authors":"V. Suryavanshi, Aria Nosratinia","doi":"10.1109/ACSSC.2005.1599696","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599696","url":null,"abstract":"In this work we address resilient packet header compression in a setup similar to RFC 3095 (robust header compression - ROHC), where a noisy feedback channel is available. We propose a new predictive hybrid ARQ (HARQ), using a systematic convolutional code with delay-limited interleaving. The compressed packet headers are bit interleaved, encoded, and the parity bits are loaded onto the packets in a manner that is consistent with existing standards. Our HARQ design is distinct from previous ones in that it cannot wait until the end of a codeword for retransmission, rather, ARQ's corresponding to individual packet headers arrive continually during a convolutional codeword and must be processed at that time. In our system, each time a NACK is encountered, the encoder estimates the state of the Viterbi decoder, deciding when a retransmission is necessary. The use of coding in conjunction with a specially designed interleaver, provides a flexible and powerful design methodology that makes it possible to improve the throughput via FEC and interleaving, while strictly limiting the delay to avoid timeout in higher layers. Simulations show that the throughput of the resulting system is superior to ROHC, and the delay is less sensitive to the channel conditions. Furthermore, over a large part of the operating range the delay is comparable to, or smaller than, the delay of RQHC","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117251605","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 : 2005-12-01DOI: 10.1109/ACSSC.2005.1599872
Wanlun Zhao, Renqiu Wang, G. Giannakis
A convolutionally coded multiple-input multiple-output system equipped with CRC error detection is considered. For each convolutional code, the list Viterbi algorithm (LVA) is employed to find a list of promising codewords. CRC code is used not only to select a correct one from this list; but also to control the switching between hard-decision feedback and soft interference cancellation. Further, bit-level soft information is generated with low complexity, albeit approximately, using the same codeword list returned by LVA. Simulations confirm that this hybrid hard/soft interference cancellation scheme achieves enhanced error performance relative to existing hard-decision approaches at a comparable complexity
{"title":"Hybrid Hard/Soft Interference Cancellation Based on List Viterbi Decoding","authors":"Wanlun Zhao, Renqiu Wang, G. Giannakis","doi":"10.1109/ACSSC.2005.1599872","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599872","url":null,"abstract":"A convolutionally coded multiple-input multiple-output system equipped with CRC error detection is considered. For each convolutional code, the list Viterbi algorithm (LVA) is employed to find a list of promising codewords. CRC code is used not only to select a correct one from this list; but also to control the switching between hard-decision feedback and soft interference cancellation. Further, bit-level soft information is generated with low complexity, albeit approximately, using the same codeword list returned by LVA. Simulations confirm that this hybrid hard/soft interference cancellation scheme achieves enhanced error performance relative to existing hard-decision approaches at a comparable complexity","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129863711","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 : 2005-12-01DOI: 10.1109/ACSSC.2005.1599963
Q. Ma, C. Tepedelenlioğlu
This paper studies the performance of antenna selection (AS) for space-time (ST) coded systems with noisy channel estimates. For coherent AS systems over Rayleigh flat fading channels, we derive the pairwise error probability (PEP) in the presence of imperfect channel estimation, where the channel is estimated using training insertion and minimum mean square error (MMSE) estimation. Multiplexed training is employed, where the antennas are multiplexed to the small number of RF chains available in the AS system. AS is performed only at the receiver, using the maximum estimated channel power selection rule. Both the maximum likelihood (ML) decoder taking into account the channel estimation error, and the minimum distance decoder are considered, and full diversity gain is shown to be preserved for both cases. Based on the derived training-based PEP, the effective SNR and the coding gain loss due to training are quantified for square unitary and orthogonal codes. The optimal power allocation between the training and data symbols is obtained by minimizing the PEP. For AS systems employing orthogonal designs, we further derive the exact PEP expression in closed-form. We also show that when square unitary training is employed, AS using the norm of MMSE channel estimates is equivalent to AS using the norm (power) of the received signal. Exploiting this fact, we propose an alternate training scheme which avoids multiplexing, has higher spectral efficiency, and better performance compared to the multiplexed training scheme. Simulations are shown to validate our analysis.
{"title":"Antenna Selection for Space-Time Coded Systems with Imperfect Channel Estimation","authors":"Q. Ma, C. Tepedelenlioğlu","doi":"10.1109/ACSSC.2005.1599963","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599963","url":null,"abstract":"This paper studies the performance of antenna selection (AS) for space-time (ST) coded systems with noisy channel estimates. For coherent AS systems over Rayleigh flat fading channels, we derive the pairwise error probability (PEP) in the presence of imperfect channel estimation, where the channel is estimated using training insertion and minimum mean square error (MMSE) estimation. Multiplexed training is employed, where the antennas are multiplexed to the small number of RF chains available in the AS system. AS is performed only at the receiver, using the maximum estimated channel power selection rule. Both the maximum likelihood (ML) decoder taking into account the channel estimation error, and the minimum distance decoder are considered, and full diversity gain is shown to be preserved for both cases. Based on the derived training-based PEP, the effective SNR and the coding gain loss due to training are quantified for square unitary and orthogonal codes. The optimal power allocation between the training and data symbols is obtained by minimizing the PEP. For AS systems employing orthogonal designs, we further derive the exact PEP expression in closed-form. We also show that when square unitary training is employed, AS using the norm of MMSE channel estimates is equivalent to AS using the norm (power) of the received signal. Exploiting this fact, we propose an alternate training scheme which avoids multiplexing, has higher spectral efficiency, and better performance compared to the multiplexed training scheme. Simulations are shown to validate our analysis.","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124099217","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 : 2005-12-01DOI: 10.1109/ACSSC.2005.1599949
Heumpil Cho, E. Swartzlander
Quantum-dot cellular automata (QCA) is a novel nanotechnology for electronic circuits. The QCA cell is a funda- mental building block. QCA circuits are different from transistor circuits mainly because the basic computational gate is a majority gate and interconnections consume time and area. It's easy to design a pipelined circuit and coplanar wire crossings for a two dimensional structure, but complex designs consume more time due to the wire. The estimation of timing is difficult until the layout is finished. This paper proposes a pipelined carry lookahead adder design in QCA. Using the QCADesigner, 4, 16, and 64 bit carry lookahead adders are designed and simulated. Those designs are compared with ripple carry adders according to the complexity, area, and timing. The final layouts show modular designs and small delays for the carry lookahead adder.
{"title":"Pipelined Carry Lookahead Adder Design in Quantum-dot Cellular Automata","authors":"Heumpil Cho, E. Swartzlander","doi":"10.1109/ACSSC.2005.1599949","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599949","url":null,"abstract":"Quantum-dot cellular automata (QCA) is a novel nanotechnology for electronic circuits. The QCA cell is a funda- mental building block. QCA circuits are different from transistor circuits mainly because the basic computational gate is a majority gate and interconnections consume time and area. It's easy to design a pipelined circuit and coplanar wire crossings for a two dimensional structure, but complex designs consume more time due to the wire. The estimation of timing is difficult until the layout is finished. This paper proposes a pipelined carry lookahead adder design in QCA. Using the QCADesigner, 4, 16, and 64 bit carry lookahead adders are designed and simulated. Those designs are compared with ripple carry adders according to the complexity, area, and timing. The final layouts show modular designs and small delays for the carry lookahead adder.","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128004647","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 : 2005-12-01DOI: 10.1109/ACSSC.2005.1599767
Chao Cheng, K. Parhi
In this paper, we present two parallel LMS adaptive filtering algorithms with low hardware. The proposed parallel algorithm 1 doesn't alter the input-output behavior and saves large amount of hardware cost of previous designs, especially when the parallelism level is high. For example, it saves 68.4% of the multiplications and 4.7% of the additions, of those of prior fast parallel adaptive filtering algorithms when parallelism level is 72 and the filter length N is large. The proposed parallel algorithm 2, while maintaining the same performance, can further save 5.56% to 12.5% of the multipliers and 8.54% to 24.9% of the additions when the level of parallelism varies from 3 to 72
{"title":"Low Cost Parallel Adaptive Filter Structures","authors":"Chao Cheng, K. Parhi","doi":"10.1109/ACSSC.2005.1599767","DOIUrl":"https://doi.org/10.1109/ACSSC.2005.1599767","url":null,"abstract":"In this paper, we present two parallel LMS adaptive filtering algorithms with low hardware. The proposed parallel algorithm 1 doesn't alter the input-output behavior and saves large amount of hardware cost of previous designs, especially when the parallelism level is high. For example, it saves 68.4% of the multiplications and 4.7% of the additions, of those of prior fast parallel adaptive filtering algorithms when parallelism level is 72 and the filter length N is large. The proposed parallel algorithm 2, while maintaining the same performance, can further save 5.56% to 12.5% of the multipliers and 8.54% to 24.9% of the additions when the level of parallelism varies from 3 to 72","PeriodicalId":326489,"journal":{"name":"Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005.","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116960767","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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