Pub Date : 2008-07-06DOI: 10.1109/SPAWC.2008.4641579
A. Alsawah, I. Fijalkow
We address the problem of resource allocation on an OFDMA downlink under fairness constraints with limited channel state information (CSI). Target QoS corresponds to a minimum user data rate, a target bit-error rate and a maximum outage probability. The only available CSI is the channel average gain of each user. This partial CSI can be viewed as a shadowed pathloss that yields a modified user distribution on which resource allocation is based. Under these constraints, we provide the optimal resource allocation that maximizes the user rate. Compared to full-CSI-based allocation schemes, our solution offers a significant complexity and feedback reduction as well as a good robustness to CSI estimation errors.
{"title":"Fair service provision in OFDMA with partial channel-state information","authors":"A. Alsawah, I. Fijalkow","doi":"10.1109/SPAWC.2008.4641579","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641579","url":null,"abstract":"We address the problem of resource allocation on an OFDMA downlink under fairness constraints with limited channel state information (CSI). Target QoS corresponds to a minimum user data rate, a target bit-error rate and a maximum outage probability. The only available CSI is the channel average gain of each user. This partial CSI can be viewed as a shadowed pathloss that yields a modified user distribution on which resource allocation is based. Under these constraints, we provide the optimal resource allocation that maximizes the user rate. Compared to full-CSI-based allocation schemes, our solution offers a significant complexity and feedback reduction as well as a good robustness to CSI estimation errors.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129406391","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641624
A. Das, J. Ng
32-amplitude and phase-shift-keying (32APSK) is one of the modulation schemes proposed in the 2nd generation digital video broadcasting over satellite (DVB-S2) standard. This paper presents a non-data-aided (NDA) SNR estimation scheme for 32APSK using the expectation-maximization (EM) algorithm. Two variants of the EM algorithm are presented, first with an arbitrary initialization and a second version that is initialized by modifying an existing (sub-optimal) SNR estimation technique. We demonstrate a significantly faster convergence with the latter form of initialization. We compare the performance of this estimator to the Cramer-Rao lower bound (CRLB) of NDA SNR estimation and show that the estimator performs very close to the CRLB over all SNRs of practical interest even for block sizes of 100 symbols. The estimator has also been implemented on FPGAs and we show that the fixed point implementation also performs very close to the theoretical limit.
{"title":"NDA SNR estimation for 32APSK in AWGN","authors":"A. Das, J. Ng","doi":"10.1109/SPAWC.2008.4641624","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641624","url":null,"abstract":"32-amplitude and phase-shift-keying (32APSK) is one of the modulation schemes proposed in the 2nd generation digital video broadcasting over satellite (DVB-S2) standard. This paper presents a non-data-aided (NDA) SNR estimation scheme for 32APSK using the expectation-maximization (EM) algorithm. Two variants of the EM algorithm are presented, first with an arbitrary initialization and a second version that is initialized by modifying an existing (sub-optimal) SNR estimation technique. We demonstrate a significantly faster convergence with the latter form of initialization. We compare the performance of this estimator to the Cramer-Rao lower bound (CRLB) of NDA SNR estimation and show that the estimator performs very close to the CRLB over all SNRs of practical interest even for block sizes of 100 symbols. The estimator has also been implemented on FPGAs and we show that the fixed point implementation also performs very close to the theoretical limit.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132996094","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641676
A. Kammoun, M. Kharouf, W. Hachem, J. Najim
Consider the linear Wiener receiver for multidimensional signals. Such a receiver is frequently encountered in wireless communications and in array processing, and the Signal to noise ratio (SNR) at its output is a popular performance index. The SNR can be modeled as a random quadratic form and in order to study this quadratic form, one can rely on well-know results in Random Matrix Theory, if one assumes that the dimension of the received and transmitted signals go to infinity, their ratio remaining constant. In this paper, we study the asymptotic behavior of the SNR for a large class of multidimensional signals (MIMO, CDMA, MC-CDMA transmissions). More precisely, we provide a deterministic approximation of the SNR, that depends on the system parameters; furthermore, the fluctuations of the SNR around this deterministic approximation are shown to be Gaussian, with variance decreasing as 1/K, where K is the dimension of the transmitted signal.
{"title":"Fluctuations of the SNR at the wiener filter output for large dimensional signals","authors":"A. Kammoun, M. Kharouf, W. Hachem, J. Najim","doi":"10.1109/SPAWC.2008.4641676","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641676","url":null,"abstract":"Consider the linear Wiener receiver for multidimensional signals. Such a receiver is frequently encountered in wireless communications and in array processing, and the Signal to noise ratio (SNR) at its output is a popular performance index. The SNR can be modeled as a random quadratic form and in order to study this quadratic form, one can rely on well-know results in Random Matrix Theory, if one assumes that the dimension of the received and transmitted signals go to infinity, their ratio remaining constant. In this paper, we study the asymptotic behavior of the SNR for a large class of multidimensional signals (MIMO, CDMA, MC-CDMA transmissions). More precisely, we provide a deterministic approximation of the SNR, that depends on the system parameters; furthermore, the fluctuations of the SNR around this deterministic approximation are shown to be Gaussian, with variance decreasing as 1/K, where K is the dimension of the transmitted signal.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133228552","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641566
J. Haghighat, H. Behroozi, D. Plant
An iterative joint decoding algorithm for data gathering wireless sensor networks is proposed in where the correlation between sensorspsila data is considered as a global code and iterative decoding is performed by concatenating the global decoder with the decoder of error correcting code applied to encode sensors observations. We apply this algorithm for sensor networks with binary CEO model where sensors observe different noisy versions of a single source, located away from sensors. This calls for employing more powerful error correcting codes, therefore we apply convolutional codes (Hamming codes and single parity check codes are applied in). We use the concept of iterative horizontal-vertical decoding for concatenated block codes to formulate the update rules for L-values for the considered binary CEO model. Our simulations confirm that the iterative joint decoding scheme substantially decreases the bit error rate compared with the separate decoding scheme, and reaches the minimum achievable distortion for channels with significantly higher noise levels.
{"title":"Iterative joint decoding for sensor networks with binary CEO model","authors":"J. Haghighat, H. Behroozi, D. Plant","doi":"10.1109/SPAWC.2008.4641566","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641566","url":null,"abstract":"An iterative joint decoding algorithm for data gathering wireless sensor networks is proposed in where the correlation between sensorspsila data is considered as a global code and iterative decoding is performed by concatenating the global decoder with the decoder of error correcting code applied to encode sensors observations. We apply this algorithm for sensor networks with binary CEO model where sensors observe different noisy versions of a single source, located away from sensors. This calls for employing more powerful error correcting codes, therefore we apply convolutional codes (Hamming codes and single parity check codes are applied in). We use the concept of iterative horizontal-vertical decoding for concatenated block codes to formulate the update rules for L-values for the considered binary CEO model. Our simulations confirm that the iterative joint decoding scheme substantially decreases the bit error rate compared with the separate decoding scheme, and reaches the minimum achievable distortion for channels with significantly higher noise levels.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122244227","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641628
C. Pimentel, F. Alajaji
This paper considers the transmission of a Reed-Solomon (RS) code over a binary modulated time-correlated flat Rician fading channel with hard-decision demodulation. We define a binary packet (symbol) error sequence that indicates whether or not an RS symbol is transmitted successfully across the discrete channel whose input enters the modulator and whose output exits the demodulator. We then approximate the discrete channelpsilas packet error sequence using an Mth order Markov queue-based channel (QBC). In other words, the QBC is used to model the discrete channel at the packet level. Modeling accuracy is evaluated by comparing the simulated probability of codeword error (PCE) for the discrete channel with the numerically evaluated PCE for the QBC. Modeling results identify accurate low-order QBCs for a wide range of fading conditions and reveal that modeling the discrete channel at the packet level is an efficient tool for non-binary coding performance evaluation over channels with memory.
{"title":"Packet-based Markov modeling of Reed-Solomon block coded correlated fading channels","authors":"C. Pimentel, F. Alajaji","doi":"10.1109/SPAWC.2008.4641628","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641628","url":null,"abstract":"This paper considers the transmission of a Reed-Solomon (RS) code over a binary modulated time-correlated flat Rician fading channel with hard-decision demodulation. We define a binary packet (symbol) error sequence that indicates whether or not an RS symbol is transmitted successfully across the discrete channel whose input enters the modulator and whose output exits the demodulator. We then approximate the discrete channelpsilas packet error sequence using an Mth order Markov queue-based channel (QBC). In other words, the QBC is used to model the discrete channel at the packet level. Modeling accuracy is evaluated by comparing the simulated probability of codeword error (PCE) for the discrete channel with the numerically evaluated PCE for the QBC. Modeling results identify accurate low-order QBCs for a wide range of fading conditions and reveal that modeling the discrete channel at the packet level is an efficient tool for non-binary coding performance evaluation over channels with memory.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115125295","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641647
A. Lalos, A. Rontogiannis, K. Berberidis
In this work we present efficient channel estimation algorithms for wideband amplify-and-forward (AF) based relay networks which utilize a recently proposed transmission model. It is shown that all channels in the network from the source through the relays to the destination/receiver node can be blindly estimated up to a phase ambiguities vector which contains the phases of the direct source to destination channel frequency response. Hence, by employing a small number of pilot symbols, phase ambiguities can be effectively resolved. As verified by computer simulations, the proposed methods exhibit high estimation accuracy even for a short training sequence, and outperform direct training-based channel estimation. A performance study of the proposed schemes in high SNR conditions is also presented and verified through computer simulations.
{"title":"Channel estimation techniques in amplify and forward relay networks","authors":"A. Lalos, A. Rontogiannis, K. Berberidis","doi":"10.1109/SPAWC.2008.4641647","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641647","url":null,"abstract":"In this work we present efficient channel estimation algorithms for wideband amplify-and-forward (AF) based relay networks which utilize a recently proposed transmission model. It is shown that all channels in the network from the source through the relays to the destination/receiver node can be blindly estimated up to a phase ambiguities vector which contains the phases of the direct source to destination channel frequency response. Hence, by employing a small number of pilot symbols, phase ambiguities can be effectively resolved. As verified by computer simulations, the proposed methods exhibit high estimation accuracy even for a short training sequence, and outperform direct training-based channel estimation. A performance study of the proposed schemes in high SNR conditions is also presented and verified through computer simulations.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120962320","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641683
L. Mendo, J. M. Hernando
This paper considers the uniformly minimum variance unbiased estimator of a probability p based on inverse binomial sampling. It is shown that the confidence associated to intervals of the form [p/mu2, pmu1], mu1, mu2 > 1 has an asymptotic value as p rarr 0. Furthermore, the confidence for p isin (0, 1) arbitrary is guaranteed to exceed this asymptotic value if mu1, mu2 satisfy certain conditions. The derived conditions cover a wide range of practical situations.
{"title":"Unbiased Monte Carlo estimator with guaranteed confidence","authors":"L. Mendo, J. M. Hernando","doi":"10.1109/SPAWC.2008.4641683","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641683","url":null,"abstract":"This paper considers the uniformly minimum variance unbiased estimator of a probability p based on inverse binomial sampling. It is shown that the confidence associated to intervals of the form [p/mu<sub>2</sub>, pmu<sub>1</sub>], mu<sub>1</sub>, mu<sub>2</sub> > 1 has an asymptotic value as p rarr 0. Furthermore, the confidence for p isin (0, 1) arbitrary is guaranteed to exceed this asymptotic value if mu<sub>1</sub>, mu<sub>2</sub> satisfy certain conditions. The derived conditions cover a wide range of practical situations.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133706933","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641587
V. Venkateswaran, A.-J. van der Veen
In this paper, we consider a receiver setup with fewer analog to digital convertors (ADCpsilas) than antennas. An analog preprocessing network (APN) is placed before the ADCpsilas to reduce power consumption in the receiver. A set of low resolution beamformers is used to design the APN and cancel contributions of interfering users. Simulation results show that introduction of such APN design algorithms for a narrowband channel with 3 to 4 interfering users, 6 antennas and 3 ADCs results in a reduction of the total consumed receiver power by 15%.
{"title":"Partial beamforming to reduce ADC power consumption in antenna array systems","authors":"V. Venkateswaran, A.-J. van der Veen","doi":"10.1109/SPAWC.2008.4641587","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641587","url":null,"abstract":"In this paper, we consider a receiver setup with fewer analog to digital convertors (ADCpsilas) than antennas. An analog preprocessing network (APN) is placed before the ADCpsilas to reduce power consumption in the receiver. A set of low resolution beamformers is used to design the APN and cancel contributions of interfering users. Simulation results show that introduction of such APN design algorithms for a narrowband channel with 3 to 4 interfering users, 6 antennas and 3 ADCs results in a reduction of the total consumed receiver power by 15%.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129351838","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641560
Rodrigue Imad, S. Houcke
In this paper, we present a new algorithm of blind frame synchronization and phase offset estimation that can be applied to any digital transmission scheme using a channel coding with a binary phase shift keying (BPSK) modulation. The estimator is based on the calculation of the syndrome elements of a received codeword obtained using the parity check matrix of the code. After presenting the proposed method, we evaluate its performance by applying it to some low density parity check (LDPC) codes and convolutional codes. This performance is measured by plotting the probability of false frame synchronization and the mean squared estimation error (MSEE) versus the signal to noise ratio (Eb/N0).
{"title":"Blind frame synchronization and phase offset estimation for coded systems","authors":"Rodrigue Imad, S. Houcke","doi":"10.1109/SPAWC.2008.4641560","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641560","url":null,"abstract":"In this paper, we present a new algorithm of blind frame synchronization and phase offset estimation that can be applied to any digital transmission scheme using a channel coding with a binary phase shift keying (BPSK) modulation. The estimator is based on the calculation of the syndrome elements of a received codeword obtained using the parity check matrix of the code. After presenting the proposed method, we evaluate its performance by applying it to some low density parity check (LDPC) codes and convolutional codes. This performance is measured by plotting the probability of false frame synchronization and the mean squared estimation error (MSEE) versus the signal to noise ratio (Eb/N0).","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131212014","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 : 2008-07-06DOI: 10.1109/SPAWC.2008.4641648
J. Gómez-Vilardebó, A. Pérez-Neira
We address the energy efficiency analysis for the two-sources cooperative multi-access channel and investigate the impact of usual practical constraints. Specifically, we take into account constraints on the transmission/reception duplexing and on the synchronization between sources. Assuming a total network energy, we define and compute the maximum rate-per-energy region (RPE) with decode-and-forward relaying and joint coding of own and relayed data. It is shown that while synchronism provides gains on the maximum RPE region, duplexity does not. To see the gain by duplexing, the slope region of the spectral efficiency is also derived.
{"title":"Duplexing and synchronism for energy efficient source cooperation communications","authors":"J. Gómez-Vilardebó, A. Pérez-Neira","doi":"10.1109/SPAWC.2008.4641648","DOIUrl":"https://doi.org/10.1109/SPAWC.2008.4641648","url":null,"abstract":"We address the energy efficiency analysis for the two-sources cooperative multi-access channel and investigate the impact of usual practical constraints. Specifically, we take into account constraints on the transmission/reception duplexing and on the synchronization between sources. Assuming a total network energy, we define and compute the maximum rate-per-energy region (RPE) with decode-and-forward relaying and joint coding of own and relayed data. It is shown that while synchronism provides gains on the maximum RPE region, duplexity does not. To see the gain by duplexing, the slope region of the spectral efficiency is also derived.","PeriodicalId":197154,"journal":{"name":"2008 IEEE 9th Workshop on Signal Processing Advances in Wireless Communications","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115811569","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：