scispace - formally typeset
Search or ask a question
Journal ArticleDOI

A Robust Multi-Level Design for Dirty-Paper Coding

TL;DR: A robust close-to-capacity dirty-paper coding (DPC) design framework in which multi-level low density parity check (LDPC) codes and trellis coded quantization (TCQ) are employed as the channel and source coding components, respectively is proposed.
Abstract: We propose a robust close-to-capacity dirty-paper coding (DPC) design framework in which multi-level low density parity check (LDPC) codes and trellis coded quantization (TCQ) are employed as the channel and source coding components, respectively. The proposed design framework is robust in the sense that it yields close to capacity solutions in the high-, medium-, and low-rate regimes. This is in contrast to existing practical DPC schemes that perform well only in one or two of these regimes, but not all three. We design codes for transmission rates of 0.5, 1.0, 1.5, and 2.0 bits/sample (b/s) using one, two, three, and four LDPC levels; at a block length of 2×105, the codes perform 0.95, 0.58, 0.55, and 0.54 dB from the corresponding information theoretic limits, respectively. We also propose a low-complexity decoding scheme that does not involve iterative message passing between the source and channel decoders; the low-complexity scheme performs only 1.08, 0.85, and 0.79 dB away from the theoretical limits at transmission rates of 1.0, 1.5, and 2.0 b/s, respectively.
Citations
More filters
Journal ArticleDOI
TL;DR: For a given decoding order strategy in two-user MACs, a suboptimal power control policy based on the average energy arrivals and causal energy and channel information is proposed and shown to achieve performance close to the optimal one.
Abstract: This paper studies the achievable throughput of fading multiple-access channels (MACs) with energy harvesting transmitters subject to statistical quality of service (QoS) constraints in the form of limitations on the buffer overflow probability. Effective capacity, which characterizes the maximum constant arrival rate that a given process can support while satisfying the QoS constraints, is employed as the performance metric. Perfect channel state information (CSI) and energy arrivals are assumed to be available at both the transmitters and the receiver. With the assumption of naive power control scheme, in which the transmission power level is irrespective of the CSI and decided by the instantaneous harvested energy, the effective throughput regions of time division multiple access and superposition coding (SC) with fixed decoding are characterized. In the special case of the same QoS constraints, the optimal decoding order strategy for SC with variable decoding order is obtained. With the assumption that the channel states and harvested energy in all time slots are known at the transmitters, the point-to-point link is first revisited. Then, for a given decoding order strategy in two-user MACs, a suboptimal power control policy based on the average energy arrivals and causal energy and channel information is proposed and shown to achieve performance close to the optimal one.

5 citations


Cites background from "A Robust Multi-Level Design for Dir..."

  • ...It is worth noting that practical superposition coding schemes have been proposed in [29] recently....

    [...]

Journal ArticleDOI
TL;DR: A novel joint decoder is presented and low-density parity-check codes for this set-up are designed to outperform the conventional maximum ratio combining type decoder and the point-to-point optimal codes, respectively.
Abstract: We investigate cognitive interference channels (CICs), a variant of two-user ICs in which one of the transmitters (called the cognitive transmitter) has non-causal knowledge of the other’s (private user’s) message. Prompted by the information theoretical results, we design an explicit coding scheme for CIC in the primary decodes cognitive regime. We present a novel joint decoder and design low-density parity-check codes for this set-up. Simulation results demonstrate that the proposed joint decoder and the designed codes outperform the conventional maximum ratio combining type decoder and the point-to-point optimal codes, respectively.

3 citations


Cites methods from "A Robust Multi-Level Design for Dir..."

  • ...1We choose this generator polynomial owing to its good performance in DPC [9]....

    [...]

Journal ArticleDOI
TL;DR: This study investigates multi-layer coding over a dirty-paper channel and demonstrates that superposition coding in such channel still achieves the capacity of interference-free additive white Gaussian noise channel when the transmitter is non-causally aware of interference signal.
Abstract: This study investigates multi-layer coding over a dirty-paper channel First, it is demonstrated that superposition coding in such channel still achieves the capacity of interference-free additive white Gaussian noise channel when the transmitter is non-causally aware of interference signal Then, the problem is extended to the dirty-paper block fading channel, where it is shown that in the lack of channel information at the transmitter, the so-called broadcast approach maximises the average achievable rate of such channel

3 citations

Dissertation
01 Nov 2019
TL;DR: This research considers cognitive interference channels, a variant of classical two-user ICs in which one of the transmitters has non-causal knowledge of the other's (private user's) message, and designs an explicit coding scheme for CIC in the primary decodes cognitive regime.
Abstract: CODE DESIGN FOR INTERFERENCE CHANNELS Mahdi Shakiba Herfeh Ph.D. in Electrical and Electronics Engineering Advisor: Tolga Mete Duman November 2019 As the number of wireless devices dramatically increases, they experience more interference in their communications. As a result, managing interference in wireless networks is an important challenge in future wireless communication systems, which can be tackled in di erent layers of communications. Designing good channel codes, which can enable reliable communication close to the information theoretic limits in the presence of interference, is one of the ways to increase the quality of service. With the above motivation, in this research, we focus on code design for interference channels (ICs). We, rst consider classical two-user fading IC and study implementation of di erent encoding/decoding schemes with low-density paritycheck (LDPC) codes for both quasi-static and fast fading scenarios. We adopt the Han-Kobayashi (HK) type encoding, derive stability conditions on the degree distributions of LDPC code ensembles, and obtain explicit and practical code designs. In order to estimate the decoding thresholds, a modi ed form of the extrinsic information transfer (EXIT) chart analysis based on binary erasure channel (BEC) approximation for the incoming messages from the component LDPC decoders to state nodes is developed. The proposed code design is employed in several examples for both fast and quasi-static fading cases. A comprehensive set of examples demonstrates that the designed codes perform close to the achievable information theoretic limits. Furthermore, multiple antenna transmissions employing the Alamouti scheme for fading ICs are studied; a special receiver structure is developed, and speci c codes are explored. Finally, advantages of the designed codes over point-to-point (P2P) optimal ones are demonstrated via both asymptotic and nite block length simulations. Next, we consider cognitive interference channels (CICs), a variant of classical two-user ICs in which one of the transmitters (cognitive transmitter) has non-causal knowledge of the other's (private user's) message. Prompted by the information theoretical results, we design an explicit coding scheme for CIC in the primary decodes cognitive regime. We present a novel joint decoder and design iii

3 citations


Cites background or methods from "A Robust Multi-Level Design for Dir..."

  • ...In this work, we pick the implementation of [7] due to its e ciency and simplicity, and in the following, we discuss it in detail....

    [...]

  • ...Finally, in [7] the authors utilize an LDPC code and TCQ as the channel and source coding components, respectively....

    [...]

  • ...Also, the proposed technique shows more robustness to inaccuracies in channel state information compared to dirty paper coding (DPC) implemented using LDPC codes and trellis coded quantization as the channel and source coding components [7]....

    [...]

  • ...1 shows (1)We choose this generator polynomial owing to its good performance in DPC [7]....

    [...]

Proceedings ArticleDOI
01 Nov 2015
TL;DR: This work statistically model the errors caused by channel estimation and feedback delay and proposes a flexible low-complexity compensation method for THP with imperfect CSI that can achieve average robustness for various THP implementations with negligible complexity overhead.
Abstract: Tomlinson-Harashima precoding (THP) is an attractive non-linear interference cancellation method for multiple-input multiple-output (MIMO) system with decentralized receivers. Compared to linear methods, it is able to achieve significant performance improvement while introduce negligible computational complexity increase. However, THP is sensitive to inevitable channel state information (CSI) errors at the transmitter in wireless communications. We statistically model the errors caused by channel estimation and feedback delay. By taking this modeling into account, we propose a flexible low-complexity compensation method for THP with imperfect CSI. In contrast to several robust designs optimized for one specific THP implementation, our approach can achieve average robustness for various THP implementations with negligible complexity overhead. Several canonical and emerging preprocessing algorithms, e.g, sorted QR decomposition (SQRD), vertical Bell Laboratories Space Time (V-BLAST) and lattice reduction (LR), are evaluated under a 802.11ac based MIMO OFDM simulation system. The experimental results show that the proposed compensation approach is able to lower the error floors caused by imperfect CSI significantly for various THP implementations.

1 citations


Cites background from "A Robust Multi-Level Design for Dir..."

  • ...However, DPC is much involved [2] [3] and is generally deemed impractical for real implementation....

    [...]

References
More filters
Journal ArticleDOI
Max Costa1
TL;DR: It is shown that the optimal transmitter adapts its signal to the state S rather than attempting to cancel it, which is also the capacity of a standard Gaussian channel with signal-to-noise power ratio P/N.
Abstract: A channel with output Y = X + S + Z is examined, The state S \sim N(0, QI) and the noise Z \sim N(0, NI) are multivariate Gaussian random variables ( I is the identity matrix.). The input X \in R^{n} satisfies the power constraint (l/n) \sum_{i=1}^{n}X_{i}^{2} \leq P . If S is unknown to both transmitter and receiver then the capacity is \frac{1}{2} \ln (1 + P/( N + Q)) nats per channel use. However, if the state S is known to the encoder, the capacity is shown to be C^{\ast} =\frac{1}{2} \ln (1 + P/N) , independent of Q . This is also the capacity of a standard Gaussian channel with signal-to-noise power ratio P/N . Therefore, the state S does not affect the capacity of the channel, even though S is unknown to the receiver. It is shown that the optimal transmitter adapts its signal to the state S rather than attempting to cancel it.

4,130 citations


"A Robust Multi-Level Design for Dir..." refers background in this paper

  • ...On the other hand, additional levels are obviously beneficial at high SNRs....

    [...]

  • ...6, we show the EXIT curves corresponding to the set of shifts optimized for the simplified decoding as well as for normal decoding for T = 2 levels and an SNR of 5.2 dB....

    [...]

  • ...However, as we will see in the following, having the reverse for our DPC design results in a 4An inconsistency might appear at somewhat larger SNRs, where the gap to capacity starts increasing with increasing SNR....

    [...]

  • ...The capacity of this channel is given by C = 12 log2 (1 + SNR) [1], the same as the case with no interference....

    [...]

  • ...The input to be quantized is V = αS+D [14], where α is Costa’s mean-square error (MSE) scaling factor [1] given by α = SNR 1+SNR , S is the interference/side-information sequence, and D is the random dither shared by the encoder and the decoder....

    [...]

Journal ArticleDOI
TL;DR: This work designs low-density parity-check codes that perform at rates extremely close to the Shannon capacity and proves a stability condition which implies an upper bound on the fraction of errors that a belief-propagation decoder can correct when applied to a code induced from a bipartite graph with a given degree distribution.
Abstract: We design low-density parity-check (LDPC) codes that perform at rates extremely close to the Shannon capacity. The codes are built from highly irregular bipartite graphs with carefully chosen degree patterns on both sides. Our theoretical analysis of the codes is based on the work of Richardson and Urbanke (see ibid., vol.47, no.2, p.599-618, 2000). Assuming that the underlying communication channel is symmetric, we prove that the probability densities at the message nodes of the graph possess a certain symmetry. Using this symmetry property we then show that, under the assumption of no cycles, the message densities always converge as the number of iterations tends to infinity. Furthermore, we prove a stability condition which implies an upper bound on the fraction of errors that a belief-propagation decoder can correct when applied to a code induced from a bipartite graph with a given degree distribution. Our codes are found by optimizing the degree structure of the underlying graphs. We develop several strategies to perform this optimization. We also present some simulation results for the codes found which show that the performance of the codes is very close to the asymptotic theoretical bounds.

3,520 citations

Journal ArticleDOI
01 Jul 1999
TL;DR: An overview of the information-hiding techniques field is given, of what the authors know, what works, what does not, and what are the interesting topics for research.
Abstract: Information-hiding techniques have recently become important in a number of application areas. Digital audio, video, and pictures are increasingly furnished with distinguishing but imperceptible marks, which may contain a hidden copyright notice or serial number or even help to prevent unauthorized copying directly. Military communications systems make increasing use of traffic security techniques which, rather than merely concealing the content of a message using encryption, seek to conceal its sender, its receiver, or its very existence. Similar techniques are used in some mobile phone systems and schemes proposed for digital elections. Criminals try to use whatever traffic security properties are provided intentionally or otherwise in the available communications systems, and police forces try to restrict their use. However, many of the techniques proposed in this young and rapidly evolving field can trace their history back to antiquity, and many of them are surprisingly easy to circumvent. In this article, we try to give an overview of the field, of what we know, what works, what does not, and what are the interesting topics for research.

2,561 citations


"A Robust Multi-Level Design for Dir..." refers methods in this paper

  • ...Motivated by applications of DPC to multiple-input multiple-output (MIMO) broadcast channels [3], cooperative diversity schemes [4], [5], cognitive radio channels [6], [7], and digital watermarking [8], [9], several research groups have focused on designing practical DPC schemes....

    [...]

Journal ArticleDOI
S. ten Brink1
TL;DR: A code search based on the EXIT chart technique has been performed yielding new recursive systematic convolutional constituent codes exhibiting turbo cliffs at lower signal-to-noise ratios than attainable by previously known constituent codes.
Abstract: Mutual information transfer characteristics of soft in/soft out decoders are proposed as a tool to better understand the convergence behavior of iterative decoding schemes. The exchange of extrinsic information is visualized as a decoding trajectory in the extrinsic information transfer chart (EXIT chart). This allows the prediction of turbo cliff position and bit error rate after an arbitrary number of iterations. The influence of code memory, code polynomials as well as different constituent codes on the convergence behavior is studied for parallel concatenated codes. A code search based on the EXIT chart technique has been performed yielding new recursive systematic convolutional constituent codes exhibiting turbo cliffs at lower signal-to-noise ratios than attainable by previously known constituent codes.

2,498 citations


"A Robust Multi-Level Design for Dir..." refers background or methods in this paper

  • ...Then the degree distribution optimization problem can be written as [21]...

    [...]

  • ...For the channel codes, one can then use standard techniques [21]–[24] to design the degree distributions with the a-priori channel informations set equal to the Y-intercepts of the BCJR EXIT curves....

    [...]

  • ...Consequently, one can simply optimize the degree distributions for these cases using well established techniques for the point to point AWGN channel [21]–[24]....

    [...]

MonographDOI
17 Mar 2008
TL;DR: This summary of the state-of-the-art in iterative coding makes this decision more straightforward, with emphasis on the underlying theory, techniques to analyse and design practical iterative codes systems.
Abstract: Having trouble deciding which coding scheme to employ, how to design a new scheme, or how to improve an existing system? This summary of the state-of-the-art in iterative coding makes this decision more straightforward. With emphasis on the underlying theory, techniques to analyse and design practical iterative coding systems are presented. Using Gallager's original ensemble of LDPC codes, the basic concepts are extended for several general codes, including the practically important class of turbo codes. The simplicity of the binary erasure channel is exploited to develop analytical techniques and intuition, which are then applied to general channel models. A chapter on factor graphs helps to unify the important topics of information theory, coding and communication theory. Covering the most recent advances, this text is ideal for graduate students in electrical engineering and computer science, and practitioners. Additional resources, including instructor's solutions and figures, available online: www.cambridge.org/9780521852296.

2,100 citations