Pub Date : 2022-06-05DOI: 10.1109/cwit55308.2022.9817677
Mahmoud A. Hasabelnaby, A. Chaaban
Most existing works on cloud radio-access networks (C-RANs) investigate the uplink or the downlink transmissions separately. However, joint uplink and downlink design can bring additional advantages, especially in intra-cloud C-RAN commu-nications scenarios. In this paper, a two-way multi-pair computation strategy is proposed, where message source-destination information is taken into account in our design. The achiev-able end-to-end rate of this scheme is derived, optimized, and evaluated numerically under total power and fronthaul capacity constraints. Numerical results reveal that significant improvement in the achievable end-to-end sum-rate can be obtained using the proposed scheme compared to conventional ones.
{"title":"Intra C-RAN Two-Way Multi-Pair Computation under Total Power and Fronthaul Capacity Constraints","authors":"Mahmoud A. Hasabelnaby, A. Chaaban","doi":"10.1109/cwit55308.2022.9817677","DOIUrl":"https://doi.org/10.1109/cwit55308.2022.9817677","url":null,"abstract":"Most existing works on cloud radio-access networks (C-RANs) investigate the uplink or the downlink transmissions separately. However, joint uplink and downlink design can bring additional advantages, especially in intra-cloud C-RAN commu-nications scenarios. In this paper, a two-way multi-pair computation strategy is proposed, where message source-destination information is taken into account in our design. The achiev-able end-to-end rate of this scheme is derived, optimized, and evaluated numerically under total power and fronthaul capacity constraints. Numerical results reveal that significant improvement in the achievable end-to-end sum-rate can be obtained using the proposed scheme compared to conventional ones.","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"100 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120980247","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 : 2022-06-05DOI: 10.1109/cwit55308.2022.9817666
Elhamsadat Anarakifirooz, S. Loyka
Favorable propagation (FP) for massive MIMO with uniform and non-uniform linear arrays is studied. A gap in the existing FP studies of uniform linear arrays is identified, which is related to the existence of grating lobes in the array pattern and which results in the FP condition being violated, even under distinct angles of arrival. A novel analysis and design of non-uniform linear arrays are proposed to cancel grating lobes and to restore favorable propagation for all distinct angles of arrival. This design is based on a sub array structure and fits well with efficient hybrid beamforming structures proposed for 5/6G systems. In addition, we show that the proposed design is robust in the frequency domain and can be used for wideband or ultra-wideband systems.
{"title":"Favorable Propagation for Wideband Massive MIMO with Non-Uniform Linear Arrays","authors":"Elhamsadat Anarakifirooz, S. Loyka","doi":"10.1109/cwit55308.2022.9817666","DOIUrl":"https://doi.org/10.1109/cwit55308.2022.9817666","url":null,"abstract":"Favorable propagation (FP) for massive MIMO with uniform and non-uniform linear arrays is studied. A gap in the existing FP studies of uniform linear arrays is identified, which is related to the existence of grating lobes in the array pattern and which results in the FP condition being violated, even under distinct angles of arrival. A novel analysis and design of non-uniform linear arrays are proposed to cancel grating lobes and to restore favorable propagation for all distinct angles of arrival. This design is based on a sub array structure and fits well with efficient hybrid beamforming structures proposed for 5/6G systems. In addition, we show that the proposed design is robust in the frequency domain and can be used for wideband or ultra-wideband systems.","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133480044","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 : 2022-06-05DOI: 10.48550/arXiv.2206.14329
Ferenc Cole Thierrin, F. Alajaji, T. Linder
The Rényi cross-entropy measure between two distributions, a generalization of the Shannon cross-entropy, was recently used as a loss function for the improved design of deep learning generative adversarial networks. In this work, we examine the properties of this measure and derive closed-form expressions for it when one of the distributions is fixed and when both distributions belong to the exponential family. We also analytically determine a formula for the cross-entropy rate for stationary Gaussian processes and for finite-alphabet Markov sources.
{"title":"On the Rényi Cross-Entropy","authors":"Ferenc Cole Thierrin, F. Alajaji, T. Linder","doi":"10.48550/arXiv.2206.14329","DOIUrl":"https://doi.org/10.48550/arXiv.2206.14329","url":null,"abstract":"The Rényi cross-entropy measure between two distributions, a generalization of the Shannon cross-entropy, was recently used as a loss function for the improved design of deep learning generative adversarial networks. In this work, we examine the properties of this measure and derive closed-form expressions for it when one of the distributions is fixed and when both distributions belong to the exponential family. We also analytically determine a formula for the cross-entropy rate for stationary Gaussian processes and for finite-alphabet Markov sources.","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133733818","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 : 2022-06-05DOI: 10.1109/cwit55308.2022.9817680
Ehsan Seifi, M. Atamanesh, A. Khandani
The idea of media-based modulation (MBM), introduced in [1] [2], is to embed information in the variations of the transmission media (channel states). This is in contrast to legacy wireless systems which embeds data in a radio frequency (RF) source prior to the transmit antenna. MBM offers several advantages over legacy systems, including “additivity of information over multiple receive antennas” and “inherent diversity over a static fading channel”. MBM is particularly suitable for transmitting high data rates using a single transmit unit and multiple receive antennas (single input multiple output MBM, or SIMO-MBM). Furthermore, layered multiple input multiple output MBM (LMIMO-MBM) [3] addresses hardware and decoding complexity along with training overhead when transmitting high data rates using a single MBM transmit unit. The current article compares the performance of MBM and LMIMO-MBM vs. legacy multiple input multiple output (MIMO) and emerging modulation techniques, spatial modu-lation (SM), and its variants, such as generalized SM (GSM) and quadrature SM (QSM). These comparisons demonstrate considerable performance gains for MBM and LMIMO-MBM vs. these notable schemes.
{"title":"Performance Evaluation of Media-based Modulation in Comparison with Spatial Modulations and Legacy SISO/MIMO","authors":"Ehsan Seifi, M. Atamanesh, A. Khandani","doi":"10.1109/cwit55308.2022.9817680","DOIUrl":"https://doi.org/10.1109/cwit55308.2022.9817680","url":null,"abstract":"The idea of media-based modulation (MBM), introduced in [1] [2], is to embed information in the variations of the transmission media (channel states). This is in contrast to legacy wireless systems which embeds data in a radio frequency (RF) source prior to the transmit antenna. MBM offers several advantages over legacy systems, including “additivity of information over multiple receive antennas” and “inherent diversity over a static fading channel”. MBM is particularly suitable for transmitting high data rates using a single transmit unit and multiple receive antennas (single input multiple output MBM, or SIMO-MBM). Furthermore, layered multiple input multiple output MBM (LMIMO-MBM) [3] addresses hardware and decoding complexity along with training overhead when transmitting high data rates using a single MBM transmit unit. The current article compares the performance of MBM and LMIMO-MBM vs. legacy multiple input multiple output (MIMO) and emerging modulation techniques, spatial modu-lation (SM), and its variants, such as generalized SM (GSM) and quadrature SM (QSM). These comparisons demonstrate considerable performance gains for MBM and LMIMO-MBM vs. these notable schemes.","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"576 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123406399","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 : 2022-06-05DOI: 10.1109/cwit55308.2022.9817661
{"title":"17th Canadian Workshop on Information Theory","authors":"","doi":"10.1109/cwit55308.2022.9817661","DOIUrl":"https://doi.org/10.1109/cwit55308.2022.9817661","url":null,"abstract":"","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121197297","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 : 2022-06-05DOI: 10.1109/cwit55308.2022.9817664
Daniel B. Dermont, Jérémy Nadal, François Leduc-Primeau
Low-density parity-check codes are widely used in communication systems. To meet the high throughput and energy efficiency requirements of current and future systems, it is desirable to further simplify the decoder. Quantized min-sum (MS) decoders are of particular interest for their low implementation complexity, which can be further reduced by computing a single minimum (SM) during check node update, instead of two. However, this simplification can lead to poor decoding performance unless it is carefully incorporated. In this paper, we formalize a general optimization problem for SM decoding, and propose search heuristics to solve it. In addition, we provide density evolution (DE) equations for the first two decoding iterations that properly take into account the lack of extrinsic update rule, and show that this DE result can be used to obtain good solutions to the SM optimization problem with low computational complexity.
{"title":"Single-Minimum LDPC Decoding Offset Optimization Methods","authors":"Daniel B. Dermont, Jérémy Nadal, François Leduc-Primeau","doi":"10.1109/cwit55308.2022.9817664","DOIUrl":"https://doi.org/10.1109/cwit55308.2022.9817664","url":null,"abstract":"Low-density parity-check codes are widely used in communication systems. To meet the high throughput and energy efficiency requirements of current and future systems, it is desirable to further simplify the decoder. Quantized min-sum (MS) decoders are of particular interest for their low implementation complexity, which can be further reduced by computing a single minimum (SM) during check node update, instead of two. However, this simplification can lead to poor decoding performance unless it is carefully incorporated. In this paper, we formalize a general optimization problem for SM decoding, and propose search heuristics to solve it. In addition, we provide density evolution (DE) equations for the first two decoding iterations that properly take into account the lack of extrinsic update rule, and show that this DE result can be used to obtain good solutions to the SM optimization problem with low computational complexity.","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132736223","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 : 2022-06-05DOI: 10.1109/cwit55308.2022.9817660
Milad Dabiri, S. Loyka
Intelligent reflective surface (IRS) has recently emerged as a valuable addition to other key technologies for 5/6G to improve their energy efficiency and achievable rate at low cost. An IRS-assisted single-input multiple-output (SIMO) channel is studied here from an information-theoretic perspective. Its channel capacity includes an optimization over IRS phase shifts, which is not a convex problem and for which no closed-form solutions are known either. A number of closed-form bounds are obtained for the general case, which are tight in some special cases and thus provide a globally-optimal solution to the original problem. Based on a closed-form globally-optimal solution for the single reflector case, a computationally-efficient iterative algorithm is proposed for the general case. Its convergence to a local optimum is rigorously proved and a number of cases are identified where its convergence point is also globally optimal. Numerical experiments show that the algorithm converges fast in practice and its convergence point is close to a global optimum.
{"title":"On The Capacity of IRS-Assisted Gaussian SIMO Channels","authors":"Milad Dabiri, S. Loyka","doi":"10.1109/cwit55308.2022.9817660","DOIUrl":"https://doi.org/10.1109/cwit55308.2022.9817660","url":null,"abstract":"Intelligent reflective surface (IRS) has recently emerged as a valuable addition to other key technologies for 5/6G to improve their energy efficiency and achievable rate at low cost. An IRS-assisted single-input multiple-output (SIMO) channel is studied here from an information-theoretic perspective. Its channel capacity includes an optimization over IRS phase shifts, which is not a convex problem and for which no closed-form solutions are known either. A number of closed-form bounds are obtained for the general case, which are tight in some special cases and thus provide a globally-optimal solution to the original problem. Based on a closed-form globally-optimal solution for the single reflector case, a computationally-efficient iterative algorithm is proposed for the general case. Its convergence to a local optimum is rigorously proved and a number of cases are identified where its convergence point is also globally optimal. Numerical experiments show that the algorithm converges fast in practice and its convergence point is close to a global optimum.","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"47 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124194647","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 : 2022-06-05DOI: 10.1109/cwit55308.2022.9817670
P. Yahampath
Separate source-channel (SSC) coding is known to be sub-optimal for communicating correlated Gaussian sources over fading Gaussian multiple-access channel (GMAC). Consid-ering the two-to-one GMAC with Rayleigh block fading and no transmitter-side channel-state information (CSI), a recent work demonstrated a simple fixed-rate joint source-channel (JSC) coding scheme referred to as source-channel trellis coded vector quantization (SC- TCVQ). This paper presents a new extension to SC- TCVQ which is shown to further improve performance with only a minor increase in encoder complexity. New results are presented which show that this finite block-length JSC coding scheme can beat the asymptotic performance upper bound of SSC coding.
{"title":"An Extension to Source-Channel Coding of Correlated Gaussian Sources for a Fading GMAC Using TCVQ","authors":"P. Yahampath","doi":"10.1109/cwit55308.2022.9817670","DOIUrl":"https://doi.org/10.1109/cwit55308.2022.9817670","url":null,"abstract":"Separate source-channel (SSC) coding is known to be sub-optimal for communicating correlated Gaussian sources over fading Gaussian multiple-access channel (GMAC). Consid-ering the two-to-one GMAC with Rayleigh block fading and no transmitter-side channel-state information (CSI), a recent work demonstrated a simple fixed-rate joint source-channel (JSC) coding scheme referred to as source-channel trellis coded vector quantization (SC- TCVQ). This paper presents a new extension to SC- TCVQ which is shown to further improve performance with only a minor increase in encoder complexity. New results are presented which show that this finite block-length JSC coding scheme can beat the asymptotic performance upper bound of SSC coding.","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129912466","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 : 2022-06-05DOI: 10.1109/cwit55308.2022.9817675
F. Amirzade, Mohammad-Reza Sadeghi, D. Panario
Controlling small size trapping sets and short cycles can result in LDPC codes with large minimum distance $d_{min}$. We prove that short cycles with a chord are the root of several trapping sets and eliminating these cycles increases $d_{min}$. We show that the lower bounds on $d_{min}$ of an LDPC code with chordless short cycles, girth 6 and column weights $gamma$ is $2gamma$. This is a significant improvement compared to the existing bounds $gamma+1$ • Several exponent matrices of protograph-based LDPC codes with chordless short cycles are proposed for any type of pro-tographs, single-edge and multi-edge. These numerical results as well as simulations show that the removal of short cycles with a chord improves previous results in the literature.
{"title":"Protograph-based LDPC codes with chordless short cycles and large minimum distance","authors":"F. Amirzade, Mohammad-Reza Sadeghi, D. Panario","doi":"10.1109/cwit55308.2022.9817675","DOIUrl":"https://doi.org/10.1109/cwit55308.2022.9817675","url":null,"abstract":"Controlling small size trapping sets and short cycles can result in LDPC codes with large minimum distance $d_{min}$. We prove that short cycles with a chord are the root of several trapping sets and eliminating these cycles increases $d_{min}$. We show that the lower bounds on $d_{min}$ of an LDPC code with chordless short cycles, girth 6 and column weights $gamma$ is $2gamma$. This is a significant improvement compared to the existing bounds $gamma+1$ • Several exponent matrices of protograph-based LDPC codes with chordless short cycles are proposed for any type of pro-tographs, single-edge and multi-edge. These numerical results as well as simulations show that the removal of short cycles with a chord improves previous results in the literature.","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"323 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113998007","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 : 2022-06-05DOI: 10.1109/cwit55308.2022.9817663
S. Asoodeh
We investigate the problem of distribution simu-lation under local differential privacy: Alice and Bob observe sequences $X^{n}$ and $Y^{n}$ respectively, where $Y^{n}$ is generated by a non-interactive $varepsilon$ -Iocally differentially private (LDP) mechanism from $X^{n}$. The goal is for Alice and Bob to output $U$ and $V$ from a joint distribution that is close in total variation distance to a target distribution $P_{UV}$. As the main result, we show that such task is impossible if the hynercontractivity coefficient of $P_{UV}$ is strictly bigger than $left(frac{e^{varepsilon}-1}{e^{varepsilon}+1}right)^{2}$ . The proof of this result also leads to a new operational interpretation of LDP mechanisms: if $Y$ is an output of an $varepsilon$ -LDP mechanism with input $X$, then the probability of correctly guessing $f(X)$ given $Y$ is bigger than the probability of blind guessing only by $frac{e^{varepsilon}-1}{e^{varepsilon}+1}$, for any deterministic finitely-supported function $f$ • If $f(X)$ is continuous, then a similar result holds for the minimum mean-squared error in estimating $f(X)$ given $Y$.
{"title":"Distribution Simulation Under Local Differential Privacy","authors":"S. Asoodeh","doi":"10.1109/cwit55308.2022.9817663","DOIUrl":"https://doi.org/10.1109/cwit55308.2022.9817663","url":null,"abstract":"We investigate the problem of distribution simu-lation under local differential privacy: Alice and Bob observe sequences <tex>$X^{n}$</tex> and <tex>$Y^{n}$</tex> respectively, where <tex>$Y^{n}$</tex> is generated by a non-interactive <tex>$varepsilon$</tex> -Iocally differentially private (LDP) mechanism from <tex>$X^{n}$</tex>. The goal is for Alice and Bob to output <tex>$U$</tex> and <tex>$V$</tex> from a joint distribution that is close in total variation distance to a target distribution <tex>$P_{UV}$</tex>. As the main result, we show that such task is impossible if the hynercontractivity coefficient of <tex>$P_{UV}$</tex> is strictly bigger than <tex>$left(frac{e^{varepsilon}-1}{e^{varepsilon}+1}right)^{2}$</tex> . The proof of this result also leads to a new operational interpretation of LDP mechanisms: if <tex>$Y$</tex> is an output of an <tex>$varepsilon$</tex> -LDP mechanism with input <tex>$X$</tex>, then the probability of correctly guessing <tex>$f(X)$</tex> given <tex>$Y$</tex> is bigger than the probability of blind guessing only by <tex>$frac{e^{varepsilon}-1}{e^{varepsilon}+1}$</tex>, for any deterministic finitely-supported function <tex>$f$</tex> • If <tex>$f(X)$</tex> is continuous, then a similar result holds for the minimum mean-squared error in estimating <tex>$f(X)$</tex> given <tex>$Y$</tex>.","PeriodicalId":401562,"journal":{"name":"2022 17th Canadian Workshop on Information Theory (CWIT)","volume":"205 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122886901","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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