Pub Date : 2011-05-17DOI: 10.1109/CWIT.2011.5872155
M. Tehrani, M. Uysal
In this paper, we consider the shared used model in the context of IEEE 802.22 cognitive and investigate spectrum trading via auction approach. We consider two different scenarios in which the dominant risk is either associated with imperfect spectrum sensing or the uncertainties in the environment. Taking into account these risks, we propose a bidding strategy for sealed-bid first-price auction. Our numerical results demonstrate significant revenue increases in comparison to the conventional auction methods in risky environments.
{"title":"Spectrum trading for risky environments in IEEE 802.22 cognitive networks","authors":"M. Tehrani, M. Uysal","doi":"10.1109/CWIT.2011.5872155","DOIUrl":"https://doi.org/10.1109/CWIT.2011.5872155","url":null,"abstract":"In this paper, we consider the shared used model in the context of IEEE 802.22 cognitive and investigate spectrum trading via auction approach. We consider two different scenarios in which the dominant risk is either associated with imperfect spectrum sensing or the uncertainties in the environment. Taking into account these risks, we propose a bidding strategy for sealed-bid first-price auction. Our numerical results demonstrate significant revenue increases in comparison to the conventional auction methods in risky environments.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121830906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-17DOI: 10.1109/CWIT.2011.5872122
F. Shayegh, M. Soleymani
We derive and analyze an algorithm for collaborative decoding of heterogeneous Interleaved Reed-Solomon (IRS) codes. In order to generate IRS codes, several codewords from different RS codes with the same length over the same Galois field are interleaved. The basis of the decoding algorithm is similar to the Guruswami-Sudan (GS) decoding method. However, here multivariate interpolation is used in order to decode all the codewords of the interleaved scheme simultaneously. In the presence of burst errors, it is shown that the error correction capability of this algorithm is larger than that of independent decoding of each codeword using the standard GS method. In the latter case, the error correction capability is equal to the decoding radius of the GS algorithm for the RS code with the largest dimension.
{"title":"Multivariate interpolation decoding of heterogeneous Interleaved Reed-Solomon codes","authors":"F. Shayegh, M. Soleymani","doi":"10.1109/CWIT.2011.5872122","DOIUrl":"https://doi.org/10.1109/CWIT.2011.5872122","url":null,"abstract":"We derive and analyze an algorithm for collaborative decoding of heterogeneous Interleaved Reed-Solomon (IRS) codes. In order to generate IRS codes, several codewords from different RS codes with the same length over the same Galois field are interleaved. The basis of the decoding algorithm is similar to the Guruswami-Sudan (GS) decoding method. However, here multivariate interpolation is used in order to decode all the codewords of the interleaved scheme simultaneously. In the presence of burst errors, it is shown that the error correction capability of this algorithm is larger than that of independent decoding of each codeword using the standard GS method. In the latter case, the error correction capability is equal to the decoding radius of the GS algorithm for the RS code with the largest dimension.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"78 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127183523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-17DOI: 10.1109/CWIT.2011.5872151
M. Mirmohseni, Bahareh Akhbari, M. Aref
In this paper, we analyze the capacity region of a communication network where a Multiple Access Channel (MAC) and a point-to-point channel share a same medium and interfere with each other, where the transmitter of the point-to-point channel has cognitive capabilities. We introduce Multiple Access-Cognitive Interference Channel (MA-CIFC), with a two-user MAC as a primary network and a cognitive transmitter-receiver pair in which the cognitive transmitter knows the message being sent by all of the transmitters in a non-causal manner. We obtain an inner bound on the capacity region of MA-CIFC and derive two sets of strong interference conditions under which we establish the capacity regions. We also consider the Gaussian case and find capacity results for Gaussian MA-CIFC. Some numerical examples are also provided.
{"title":"Strong interference conditions for Multiple Access-Cognitive Interference Channel","authors":"M. Mirmohseni, Bahareh Akhbari, M. Aref","doi":"10.1109/CWIT.2011.5872151","DOIUrl":"https://doi.org/10.1109/CWIT.2011.5872151","url":null,"abstract":"In this paper, we analyze the capacity region of a communication network where a Multiple Access Channel (MAC) and a point-to-point channel share a same medium and interfere with each other, where the transmitter of the point-to-point channel has cognitive capabilities. We introduce Multiple Access-Cognitive Interference Channel (MA-CIFC), with a two-user MAC as a primary network and a cognitive transmitter-receiver pair in which the cognitive transmitter knows the message being sent by all of the transmitters in a non-causal manner. We obtain an inner bound on the capacity region of MA-CIFC and derive two sets of strong interference conditions under which we establish the capacity regions. We also consider the Gaussian case and find capacity results for Gaussian MA-CIFC. Some numerical examples are also provided.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122946539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-17DOI: 10.1109/CWIT.2011.5872144
D. Lui, Ahmed Badr, A. Khisti
A sender and receiver are connected by two links, which both pass through a burst erasure channel. The channel induces an erasure burst of length B onto both links, but the bursts are separated by d time units. Source packets arrive at the sender, and are encoded with a streaming code such that the receiver can decode with a delay T. If source packet s[t] arrives at the sender at time t, then the receiver must be able to decode s[t] by time t+T from its received packets. Given the parameters B, T and d, we find the upper bound for the rate of the streaming code, and also discover codes that can operate at capacity for certain parameter values. The code constructions also internally make use of SCo codes. Finally, we find that by exploiting the dependence of the burst erasure locations on either link, we can achieve a higher rate than if we simply used single-link SCo codes on each link.
{"title":"Streaming codes for a double-link burst erasure channel","authors":"D. Lui, Ahmed Badr, A. Khisti","doi":"10.1109/CWIT.2011.5872144","DOIUrl":"https://doi.org/10.1109/CWIT.2011.5872144","url":null,"abstract":"A sender and receiver are connected by two links, which both pass through a burst erasure channel. The channel induces an erasure burst of length B onto both links, but the bursts are separated by d time units. Source packets arrive at the sender, and are encoded with a streaming code such that the receiver can decode with a delay T. If source packet s[t] arrives at the sender at time t, then the receiver must be able to decode s[t] by time t+T from its received packets. Given the parameters B, T and d, we find the upper bound for the rate of the streaming code, and also discover codes that can operate at capacity for certain parameter values. The code constructions also internally make use of SCo codes. Finally, we find that by exploiting the dependence of the burst erasure locations on either link, we can achieve a higher rate than if we simply used single-link SCo codes on each link.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130523344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-17DOI: 10.1109/CWIT.2011.5872132
N. Zlatanov, R. Schober, Z. Hadzi-Velkov, G. Karagiannidis
In this paper, assuming transmission with fixed rate and fixed power, we derive the average duration of capacity outage and non-outage events of selective decode-and-forward relaying with repetition coding over slow Rayleigh fading channels. Furthermore, we develop high signal-to-noise ratio (SNR) approximations for both durations which provide significant insight into the impact of various system and channel parameters. For high SNR, on a double logarithmic scale, both the average outage duration (AOD) and the average non-outage duration (ANOD) become straight lines when plotted as functions of the SNR. However, while the slope of the ANOD improves with increasing diversity order, the slope of the AOD is −1/2 independent of the diversity order.
{"title":"Average outage and non-outage duration of selective decode-and-forward relaying","authors":"N. Zlatanov, R. Schober, Z. Hadzi-Velkov, G. Karagiannidis","doi":"10.1109/CWIT.2011.5872132","DOIUrl":"https://doi.org/10.1109/CWIT.2011.5872132","url":null,"abstract":"In this paper, assuming transmission with fixed rate and fixed power, we derive the average duration of capacity outage and non-outage events of selective decode-and-forward relaying with repetition coding over slow Rayleigh fading channels. Furthermore, we develop high signal-to-noise ratio (SNR) approximations for both durations which provide significant insight into the impact of various system and channel parameters. For high SNR, on a double logarithmic scale, both the average outage duration (AOD) and the average non-outage duration (ANOD) become straight lines when plotted as functions of the SNR. However, while the slope of the ANOD improves with increasing diversity order, the slope of the AOD is −1/2 independent of the diversity order.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114732583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-17DOI: 10.1109/CWIT.2011.5872150
W. Chou, R. Adve
This paper investigates the performance enhancements using radio-frequency (RF) beamforming on closely spaced antennas in multiple-input multiple-output (MIMO) communication system. Of specific interest is the case of a array of extremely closely spaced antennas with complexity constraints, here implemented being restricted to a single RF chain. Our system model is developed in context of closely spaced metamaterial antennas that have low mutual coupling. Even without mutual coupling, the physical location of the antennas still contributes to strong spatial correlation. We also re-derive the mutual information equation for both RF and digital beamforming techniques under the assumption that the transmitter has no information regards to the channel. Further, by comparing the capacity improvement between different receiver combining techniques, this paper suggests that in a closely spaced antenna system with only one RF-chain and transmitter, selection across beams provides higher capacity than using the traditional approach of element-selection. Furthermore, beamforming based MIMO processing is more robust to different scattering environments.
{"title":"RF beamforming with closely spaced antennas","authors":"W. Chou, R. Adve","doi":"10.1109/CWIT.2011.5872150","DOIUrl":"https://doi.org/10.1109/CWIT.2011.5872150","url":null,"abstract":"This paper investigates the performance enhancements using radio-frequency (RF) beamforming on closely spaced antennas in multiple-input multiple-output (MIMO) communication system. Of specific interest is the case of a array of extremely closely spaced antennas with complexity constraints, here implemented being restricted to a single RF chain. Our system model is developed in context of closely spaced metamaterial antennas that have low mutual coupling. Even without mutual coupling, the physical location of the antennas still contributes to strong spatial correlation. We also re-derive the mutual information equation for both RF and digital beamforming techniques under the assumption that the transmitter has no information regards to the channel. Further, by comparing the capacity improvement between different receiver combining techniques, this paper suggests that in a closely spaced antenna system with only one RF-chain and transmitter, selection across beams provides higher capacity than using the traditional approach of element-selection. Furthermore, beamforming based MIMO processing is more robust to different scattering environments.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133013744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-17DOI: 10.1109/cwit.2011.5872129
Lei Zhou, Wei Yu
Noisy network coding, which elegantly combines the conventional compress-and-forward relaying strategy and ideas from network coding, has recently drawn much attention for its simplicity and optimality in achieving to within constant gap of the capacity of the multisource multicast Gaussian network. The constant-gap result, however, applies only to Gaussian relay networks with independent noises. This paper investigates the application of noisy network coding to networks with correlated noises. By focusing on a four-node Gaussian relay chain network with a particular noise correlation structure, it is shown that noisy network coding can no longer achieve to within constant gap to capacity with the choice of Gaussian inputs and Gaussian quantization. The cut-set bound of the relay chain network in this particular case, however, can be achieved to within half a bit by a simple concatenation of a correlation-aware noisy network coding strategy and a decode-and-forward scheme.
{"title":"On noisy network coding for a Gaussian relay chain network with correlated noises","authors":"Lei Zhou, Wei Yu","doi":"10.1109/cwit.2011.5872129","DOIUrl":"https://doi.org/10.1109/cwit.2011.5872129","url":null,"abstract":"Noisy network coding, which elegantly combines the conventional compress-and-forward relaying strategy and ideas from network coding, has recently drawn much attention for its simplicity and optimality in achieving to within constant gap of the capacity of the multisource multicast Gaussian network. The constant-gap result, however, applies only to Gaussian relay networks with independent noises. This paper investigates the application of noisy network coding to networks with correlated noises. By focusing on a four-node Gaussian relay chain network with a particular noise correlation structure, it is shown that noisy network coding can no longer achieve to within constant gap to capacity with the choice of Gaussian inputs and Gaussian quantization. The cut-set bound of the relay chain network in this particular case, however, can be achieved to within half a bit by a simple concatenation of a correlation-aware noisy network coding strategy and a decode-and-forward scheme.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133400490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-17DOI: 10.1109/CWIT.2011.5872149
Chao Zheng, R. Yazdani, M. Ardakani
Log-likelihood ratios (LLRs) are efficient metrics used in the decoding of modern channel codes such as low-density parity-check and turbo codes. LLR calculation, however, can be a complex task since LLRs are usually complicated nonlinear functions of the channel output. In multi-input multioutput (MIMO) channels, the complexity of the calculation increases exponentially with the number of antennas. In this paper, an LLR approximation method is proposed for MIMO-BICM systems. In particular, piecewise linear approximation functions are introduced and an accuracy measure is provided to optimize the parameters. Simulations verify that the performance of the optimized approximate LLRs is better than the existing approximation method and quite close to that of true LLRs.
{"title":"Low complexity piecewise linear LLR calculation for MIMO-BICM systems","authors":"Chao Zheng, R. Yazdani, M. Ardakani","doi":"10.1109/CWIT.2011.5872149","DOIUrl":"https://doi.org/10.1109/CWIT.2011.5872149","url":null,"abstract":"Log-likelihood ratios (LLRs) are efficient metrics used in the decoding of modern channel codes such as low-density parity-check and turbo codes. LLR calculation, however, can be a complex task since LLRs are usually complicated nonlinear functions of the channel output. In multi-input multioutput (MIMO) channels, the complexity of the calculation increases exponentially with the number of antennas. In this paper, an LLR approximation method is proposed for MIMO-BICM systems. In particular, piecewise linear approximation functions are introduced and an accuracy measure is provided to optimize the parameters. Simulations verify that the performance of the optimized approximate LLRs is better than the existing approximation method and quite close to that of true LLRs.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133402568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-17DOI: 10.1109/CWIT.2011.5872156
E. Karamad, R. Adve
We consider a network utility maximization (NUM) framework to allocate resources in a cooperative network comprising multiple sources, dedicated relays and a single destination. The allocation is designed to ensure the average queue length at each source is below a chosen demand. The optimization is over power allocation at all nodes, relay selection and relaying strategy. We formulate the NUM problem and propose a solution to achieve the optimal allocation scheme. The two main contributions here are the formulation including queue length and an efficient solution that has only linear complexity in the number of source nodes. Furthermore, unlike previous works, it avoids a brute-force search over rates.
{"title":"Resource allocation to achieve cross-layer metrics in cooperative networks","authors":"E. Karamad, R. Adve","doi":"10.1109/CWIT.2011.5872156","DOIUrl":"https://doi.org/10.1109/CWIT.2011.5872156","url":null,"abstract":"We consider a network utility maximization (NUM) framework to allocate resources in a cooperative network comprising multiple sources, dedicated relays and a single destination. The allocation is designed to ensure the average queue length at each source is below a chosen demand. The optimization is over power allocation at all nodes, relay selection and relaying strategy. We formulate the NUM problem and propose a solution to achieve the optimal allocation scheme. The two main contributions here are the formulation including queue length and an efficient solution that has only linear complexity in the number of source nodes. Furthermore, unlike previous works, it avoids a brute-force search over rates.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"54 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132238337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-05-17DOI: 10.1109/CWIT.2011.5872124
Jing Wang, Xiang Yu, Dake He
In this paper, a quantization scheme based on hard-decision partition and adaptive reconstruction levels is proposed for High Efficiency Video Coding (HEVC), the video coding standard currently under development, which has demonstrated approximately 40% bit saving compared to H.264/AVC. For each video frame, the residual signal after motion estimation is transformed and then quantized by a hard-decision scalar quantizer. The reconstruction levels of the quantization outputs are adaptively computed based on the statistics of the residual signals of previously coded frames, and are selectively transmitted to the decoder. Compared with the rate-distortion optimized quantization (RDOQ) method in HEVC, which is attempting optimal among all encoder-side quantization techniques, the proposed scheme addresses the decoder-side reconstruction problem and achieves further rate reduction in the low-delay low-complexity setting while the encoding computational complexity is significantly reduced, and the decoder complexity remains almost the same.
{"title":"Hard-decision quantization with adaptive reconstruction levels for High Efficiency Video Coding","authors":"Jing Wang, Xiang Yu, Dake He","doi":"10.1109/CWIT.2011.5872124","DOIUrl":"https://doi.org/10.1109/CWIT.2011.5872124","url":null,"abstract":"In this paper, a quantization scheme based on hard-decision partition and adaptive reconstruction levels is proposed for High Efficiency Video Coding (HEVC), the video coding standard currently under development, which has demonstrated approximately 40% bit saving compared to H.264/AVC. For each video frame, the residual signal after motion estimation is transformed and then quantized by a hard-decision scalar quantizer. The reconstruction levels of the quantization outputs are adaptively computed based on the statistics of the residual signals of previously coded frames, and are selectively transmitted to the decoder. Compared with the rate-distortion optimized quantization (RDOQ) method in HEVC, which is attempting optimal among all encoder-side quantization techniques, the proposed scheme addresses the decoder-side reconstruction problem and achieves further rate reduction in the low-delay low-complexity setting while the encoding computational complexity is significantly reduced, and the decoder complexity remains almost the same.","PeriodicalId":250626,"journal":{"name":"2011 12th Canadian Workshop on Information Theory","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117290774","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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