In this paper, we investigate problems of communication over physically degraded, state-dependent broadcast channels (BCs) with cooperating decoders. Two different setups are considered, and their capacity regions are...
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In this paper, we investigate problems of communication over physically degraded, state-dependent broadcast channels (BCs) with cooperating decoders. Two different setups are considered, and their capacity regions are characterized. First, we study a setting in which one decoder can use a finite capacity link to send the other decoder information regarding the messages or the channel states. In this scenario, we analyze two cases: one, where noncausal state information, is available to the encoder and the strong decoder, and the other, where state information, is available only to the encoder in a causal manner. Second, we examine a setting in which the cooperation between the decoders is limited to taking place before the outputs of the channel are given. In this case, one decoder, which is informed of the state sequence noncausally, can cooperate only to send the other decoder rate-limited information about the state sequence. The proofs of the capacity regions introduce a new idea of coding for channels with cooperation between different users, where we exploit the link between the decoders for multiple binnings. Finally, we discuss the optimality of using rate-splitting techniques when coding for cooperative BCs. In particular, we show that rate splitting is not necessarily optimal when coding for cooperative BCs by solving an example in which our method of coding outperforms rate splitting.
In this paper, we investigate problems of communication over physically-degraded, state-dependent broadcast channels (BC) with cooperating decoders. Three different setups are considered and their capacity regions are...
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ISBN:
(纸本)9781479934096
In this paper, we investigate problems of communication over physically-degraded, state-dependent broadcast channels (BC) with cooperating decoders. Three different setups are considered and their capacity regions are characterized. First, we study a setting where noncausal state information is available to the encoder and the strong decoder. Furthermore, the strong decoder can use a finite capacity link to send the weak decoder information regarding the messages or the channel state. Second, we examine a setting where the encoder and the strong decoder both have access to noncausal state information, while the weak decoder has access to rate-limited state information. This scenario can be interpreted as a special case, where the strong decoder can only cooperate to send the weak decoder rate-limited information about the state sequence. A third case we consider, is a cooperative setting where state information is available only to the encoder in a causal manner. Finally, we discuss the optimality of using rate-splitting when coding for cooperative BC. In particular, we prove that rate-splitting is not necessarily optimal when coding for cooperative BC and solve an example where a multiple-binning coding scheme outperforms rate-splitting.
In this paper, we investigate problems of communication over physically-degraded, state-dependent broadcast channels (BC) with cooperating decoders. Three different setups are considered and their capacity regions are...
详细信息
ISBN:
(纸本)9781479934119
In this paper, we investigate problems of communication over physically-degraded, state-dependent broadcast channels (BC) with cooperating decoders. Three different setups are considered and their capacity regions are characterized. First, we study a setting where noncausal state information is available to the encoder and the strong decoder. Furthermore, the strong decoder can use a finite capacity link to send the weak decoder information regarding the messages or the channel state. Second, we examine a setting where the encoder and the strong decoder both have access to noncausal state information, while the weak decoder has access to rate-limited state information. This scenario can be interpreted as a special case, where the strong decoder can only cooperate to send the weak decoder rate-limited information about the state sequence. A third case we consider, is a cooperative setting where state information is available only to the encoder in a causal manner. Finally, we discuss the optimality of using rate-splitting when coding for cooperative BC. In particular, we prove that ratesplitting is not necessarily optimal when coding for cooperative BC and solve an example where a multiple-binning coding scheme outperforms rate-splitting.
In this work, coding for channel with partial state information at the decoder is studied. Specifically, the model under consideration assumes that the encoder is provided with full channel state information (CSI) in ...
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In this work, coding for channel with partial state information at the decoder is studied. Specifically, the model under consideration assumes that the encoder is provided with full channel state information (CSI) in a noncausal manner, and the decoder is provided with partial state knowledge, quantified by a rate limit. coding of side information intended for the channel decoder is a Wyner-Ziv like problem, since the channel output depends statistically on the state, thus serving as side information in retrieving the encoded state. Therefore, coding for such a channel involves the simultaneous solution of a Wyner-Ziv problem and a related Gel'fand-Pinsker problem. A single-letter characterization of the capacity of this channel is developed, that involves two rate constraints, in the form of Wyner-Ziv and Gel'fand-Pinsker formulas. Applications are suggested to watermarking problems, where a compressed version of the host signal is present at the decoder. Two main models are examined: the standard watermarking problem, where the decoder is interested only in the embedded information, and the reversible information embedding problem, where the decoder is interested also in exact reproduction of the host. For both problems, single-letter characterizations of the region of all achievable rate-distortion triples (R, R-d, D) are given, where R is the embedding rate, R-d is the rate limit of the compressed host at the decoder, and D is the average distortion between the host and the composite data set (stegotext). For reversible information embedding, two stages of attack are considered, modeled by a degraded broadcast channel, where the weaker (degraded) channel represents the second attack, and both decoders are required to fully reproduce the host.
In this work, coding for the degraded broadcast channel controlled by random parameters is studied. Two main paradigms are considered: where side information on the random parameters is provided to the transmitter in ...
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In this work, coding for the degraded broadcast channel controlled by random parameters is studied. Two main paradigms are considered: where side information on the random parameters is provided to the transmitter in a noncausal manner (termed here noncausal coding), and where side information is provided in a causal manner (termed causal coding). Inner and outer bounds are derived on the capacity region with noncausal coding. For the special case where the nondegraded user is informed about the channel parameters, it is shown that the inner bound is tight, thus deriving the capacity region for that case. For causal coding, a single-letter characterization of the capacity region is derived. This characterization is expressed via auxiliary random variables (RVs), and can also be interpreted by means of Shannon strategies, as the formula for the capacity of the single-user channel with causal coding derived by Shannon. The capacity region of a class of binary broadcast channels with causal coding is computed, as an example. Applications to watermarking are suggested. In particular, the results on noncausal coding can be used to derive the capacity region of a watermarking system where the channel (attacker) is fixed, and the watermark is subject to several stages of attack, or a watermarking system where the encoder is required to encode watermarks for both private and public users.
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