In mobile speech communication usually vector quantization (VQ) is employed to ensure high coding efficiency Convolutional coding and softbit speech decoding [1-3] can add a considerable amount of robustness. VQ as we...
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ISBN:
(纸本)0780364163
In mobile speech communication usually vector quantization (VQ) is employed to ensure high coding efficiency Convolutional coding and softbit speech decoding [1-3] can add a considerable amount of robustness. VQ as well as softbit decoding however can be a quite complex task. Under the constraint of a constant gross bit rate and clean channel quality we propose the use of lower dimensional VQ or even scalar quantization (SQ) with a higher bit rate which leaves then fewer redundancy to be added by channel coding. This concept of joint speech/channel coding with its suboptimal speech coder and weaker channel coder can efficiently employ softbit speech decoding yielding a low overall complexity transmission scheme. Cases are shown where its performance is even better as compared to a high dimensional VQ with softbit decoding.
channel coding and modulation are two fundamental building blocks of physical layer wireless communications. We propose a neural network based end-to-end communication system, where both the channel coding and the mod...
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ISBN:
(纸本)9781728154787
channel coding and modulation are two fundamental building blocks of physical layer wireless communications. We propose a neural network based end-to-end communication system, where both the channel coding and the modulation blocks are modeled as neural networks. Our proposed architecture combines Turbo Autoencoder together with feed-forward neural networks for modulation, and hence called TurboAE-MOD. Turbo Autoencoder was introduced in [1] and consists of a neural network based channel encoder (convolutional neural networks with an interleaver) and a neural network based decoder (iterations of convolutional neural networks with interleavers and de-interleavers in between). By allowing joint training of the channel coding and modulation in an end-to-end manner, we demonstrate that TurboAE-MOD performs comparable to modern codes stacked with canonical modulations for moderate block lengths. We also demonstrate that TurboAE-MOD learns interesting modulation patterns that are amenable to meaningful interpretations.
We study the joint source-channel coding (JSCC) error exponent for discrete memoryless source-channel systems with side information which is correlated to the transmitted source. Two cases are considered: (1) the side...
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ISBN:
(纸本)9781424407682
We study the joint source-channel coding (JSCC) error exponent for discrete memoryless source-channel systems with side information which is correlated to the transmitted source. Two cases are considered: (1) the side information is available only at the decoder;(2) the side information is available at both the encoder and decoder. We employ the method of types to establish a lower bound for the JSCC error exponent for each case. As a consequence, a JSCC theorem on the reliable transmissibility of the source over the channel is obtained. It is noted that the same JSCC theorem applies for both cases. For binary sources and symmetric channels, we derive a sufficient condition for which the side information at the decoder can strictly improve the JSCC error exponent. Numerical results show that side information can enlarge the region for reliable transmissibility and increase the JSCC error exponent for a wide class of source-channel parameters.
Past work on cooperative communications has indicated substantial improvement in channel reliability through cooperative transmission strategies. To exploit this benefit for video transmission, we propose to jointly a...
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ISBN:
(纸本)9781424404810
Past work on cooperative communications has indicated substantial improvement in channel reliability through cooperative transmission strategies. To exploit this benefit for video transmission, we propose to jointly allocate bits among video coding, channel coding and cooperation to optimize the decoded video quality. Recognizing that not all source bits are equal, we further propose to protect the more important bits through user cooperation. We simulate and compare four modes of video transmission that differ in their error protection strategy (equal vs. layered, with vs. without cooperation). Our simulation uses the H.263+ video codec and the RCPC channel code over quasi-static Rayleigh fading channels. We show that cooperation can provide significant improvement over no-cooperation when the average channel SNR is in the low to medium range, and that layered cooperation can extend this benefit to the entire range of channel quality.
Saddlepoint approximations of the meta-converse and random-coding union bounds are derived. These bounds accurately characterize the channel coding minimum error probability for symmetric memoryless channels in a wide...
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ISBN:
(纸本)9781538605790
Saddlepoint approximations of the meta-converse and random-coding union bounds are derived. These bounds accurately characterize the channel coding minimum error probability for symmetric memoryless channels in a wide range of system parameters. The proposed approximations are simple to compute and yield a unified analysis of both hypothesis-testing lower bounds and random-coding upper bounds.
GESMA's (Groupe d'Etudes Sous-Marines de l'Atlantique) objective is to develop a sufficiently robust acoustic link allowing the transmission of different information (text, images ... ). A real-time platfo...
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ISBN:
(纸本)9781424426195
GESMA's (Groupe d'Etudes Sous-Marines de l'Atlantique) objective is to develop a sufficiently robust acoustic link allowing the transmission of different information (text, images ... ). A real-time platform named TRIDENT (TRansmission d'Images et de Donnes EN Temps reel) was designed at TELECOM Bretagne. A blind spatio-temporal equalizer is used to reduce the various perturbations caused by the underwater acoustic channel (UWA). The acoustic link performance was evaluated and its robustness for transmission shown in a strongly disturbed channel. GESMA also wants to increase the link reliability. In order to do so, a channel coding was added to the system. Different kinds of error correcting schemes were tested including Convolutional Codes (CC) and Reed Solomon (RS) block code. Correlation strategies are used to solve both phase ambiguity and frame synchronization before channel decoding.
It is known that, as opposed to point-to-point channel, separate source and channel coding is not optimal in general for sending correlated sources over multiuser channels. In some works joint source-channel coding ha...
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ISBN:
(纸本)9781467378529
It is known that, as opposed to point-to-point channel, separate source and channel coding is not optimal in general for sending correlated sources over multiuser channels. In some works joint source-channel coding has been investigated for some certain multiuser channels, e.g., multiple access channel (MAC) and broadcast channel (BC). In this paper, we obtain a sufficient condition for transmitting arbitrarily correlated sources over a discrete memoryless BC with cooperating receivers, where the receivers are allowed to exchange messages via a pair of noisy cooperative links. It is seen that our result is a general form of previous ones and includes them as its special cases.
We study the zero-delay joint source-channel coding problem of transmitting a Gaussian source over a Gaussian channel in the presence of side information known only to the receiver. To achieve zero-delay, after applyi...
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ISBN:
(纸本)9781457705953
We study the zero-delay joint source-channel coding problem of transmitting a Gaussian source over a Gaussian channel in the presence of side information known only to the receiver. To achieve zero-delay, after applying scalar quantization to the source, the properly scaled analog information, namely the quantization error, is superimposed on the scaled digital information, i.e., the quantized source, and then transmitted. At the decoder, two decoding schemes are proposed, both of which estimate digital component first, followed by the analog component. It is shown that both schemes, when optimized over all related parameters, are superior to pure analog transmission for high enough correlation between source and side information. The robustness of one of the proposed HDA schemes against varying channel and side information conditions is also compared with that of the purely analog scheme.
In wireless scenarios an effective protocol to increase the reliability for time-varying channels is the hybrid automatic repeat request (H-ARQ). The H-ARQ scheme with cross-packet channel coding (CPC) is a recently p...
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ISBN:
(纸本)9781424480166
In wireless scenarios an effective protocol to increase the reliability for time-varying channels is the hybrid automatic repeat request (H-ARQ). The H-ARQ scheme with cross-packet channel coding (CPC) is a recently published extension of H-ARQ with several advantages. No full-diversity low-density parity-check (LDPC) code design for the whole range of coding rates yielding full-diversity has been published. In this paper the authors provide a new outage behavior analysis and a new structured LDPC code ensemble achieving full-diversity for H-ARQ with CPC by exploiting the rootcheck principle. Simulation results show that the new code design outperforms the previous approaches, providing full-diversity and good coding gain, also at high coding rates.
In this paper, a quantum version of Feinstein's Theorem is developed. This is then used to give a completely self-contained proof of the direct channel coding theorem, for transmission of classical information thr...
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ISBN:
(纸本)9781424405053
In this paper, a quantum version of Feinstein's Theorem is developed. This is then used to give a completely self-contained proof of the direct channel coding theorem, for transmission of classical information through a quantum channel with Markovian correlated noise. Our proof does not rely on the Holevo-Schumacher-Westmoreland (HSW) Theorem. In addition, for the case of memoryless channels, our method yields an alternative proof of the HSW Theorem.
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