In this paper, we prove the separation of source-network coding and channel coding in wireline networks. For the purposes of this paper, a wireline network is any network of independent, memoryless, point-to-point, an...
详细信息
In this paper, we prove the separation of source-network coding and channel coding in wireline networks. For the purposes of this paper, a wireline network is any network of independent, memoryless, point-to-point, and finite-alphabet channels used to transmit dependent sources either losslessly or subject to a distortion constraint. In deriving this result, we also prove that in a general memoryless network with dependent sources, lossless, and zero-distortion reconstruction are equivalent provided that the conditional entropy of each source given the other sources is nonzero. Furthermore, we extend the separation result to the case of continuous-alphabet and point-to-point channels, such as additive white Gaussian noise channels.
Distributed source coding techniques enable distributed receivers to independently compress samples to a rate above the Slepian-Wolf bound, by leveraging statistical correlations between different receivers observatio...
详细信息
ISBN:
(纸本)9781467385770
Distributed source coding techniques enable distributed receivers to independently compress samples to a rate above the Slepian-Wolf bound, by leveraging statistical correlations between different receivers observations. The wireless channel can impose many compression challenges, such as unknown or dynamic compression bounds due to time-varying fading and mobility. This work derives a novel rate adaptive non-binary distributed source coding scheme which is motivated by these challenges. Applications are derived for distributed detection and distributed multiple-input multiple-output (MIMO) reception. Results demonstrate strong performance with these applications along with near-bound compression at various SNR levels and channel realizations.
We study secure source-coding with causal disclosure, under the Gaussian distribution. The optimality of Gaussian auxiliary random variables is shown in various scenarios. We explicitly characterize the tradeoff betwe...
详细信息
We study secure source-coding with causal disclosure, under the Gaussian distribution. The optimality of Gaussian auxiliary random variables is shown in various scenarios. We explicitly characterize the tradeoff between the rates of communication and secret key. This tradeoff is the result of a mutual information optimization under Markov constraints. As a corollary, we deduce a general formula for Wyner's Common Information in the Gaussian setting.
This paper deals with a fixed-length lossy source coding problem with some excess distortion probability called the source coding problem with ε-fidelity criterion. In this problem, the rate-distortion function and t...
详细信息
This paper deals with a fixed-length lossy source coding problem with some excess distortion probability called the source coding problem with ε-fidelity criterion. In this problem, the rate-distortion function and the distortion-rate function have already been characterized for i.i.d. sources with an additive distortion measure in the sense of first-order and second-order coding rates. However, general formulas for these functions have not been revealed up to present. Hence, in this paper we derive general formulas for the rate-distortion function and the distortion-rate function with the ε-fidelity criterion in both of the first-order and second-order cases. A relationship between our general formulas and previous results are also discussed.
Wireless communication systems beyond 3G are characterized by variety of applications which have the requirement of simultaneous transmission/reception of low data rate voice and high data rate video streaming content...
详细信息
Wireless communication systems beyond 3G are characterized by variety of applications which have the requirement of simultaneous transmission/reception of low data rate voice and high data rate video streaming content. Wireless applications such as live video chat requires more bandwidth for transmitting/receiving with high quality. The civilian/COTS cellular wireless systems are very promising and prospective communications systems, but they have several drawbacks from military point of view. Increase in communication range and data security are the major. To increase the range increasing receiver sensitivity is very important. Furthermore, to accommodate uninterrupted voice channel in parallel to video transmission reducing the bandwidth occupancy of voice channel is crucial. To reduce the bandwidth occupancy, several source coding techniques exists. CVSD is one of the best source coding technique for reducing the occupied bandwidth as well as improving receiver sensitivity at baseband level. In this paper, hardware efficient voice communication module with bandwidth efficient CVSD source coding is implemented on FPGA. This module has been integrated in wireless LAN as an additional feature for voice calls without disturbing the video/ data transfer. Improvement in receiver sensitivity for voice channel by using this technique has been observed.
Polar codes are proven to achieve the rate distortion bound of Gaussian sources under the condition that the size of reconstruction alphabet and code length grow to infinity. However, this condition cannot be satisfie...
详细信息
ISBN:
(纸本)9781479984077
Polar codes are proven to achieve the rate distortion bound of Gaussian sources under the condition that the size of reconstruction alphabet and code length grow to infinity. However, this condition cannot be satisfied in practice. In this paper, we propose a practical source coding scheme based on multilevel polar codes, called polar coded quantization (PCQ). In this scheme, extended reconstruction alphabet, set-partition (SP) labeling and successive cancellation (SC) (or its improved) encoding algorithm are combined to approach the rate distortion bound. Furthermore, an efficient upper bound of encoding rate for a given distortion is derived to guide the practical design of PCQ. Simulation results show that PCQ provides a flexible and constructive framework to efficiently approximate the rate distortion bound of Gaussian sources.
With the boom of big data, traditional source coding techniques face the common obstacle to decode only a small portion of information efficiently. In this paper, we aim to resolve this difficulty by introducing a spe...
详细信息
ISBN:
(纸本)9781467364300
With the boom of big data, traditional source coding techniques face the common obstacle to decode only a small portion of information efficiently. In this paper, we aim to resolve this difficulty by introducing a specific type of source coding scheme called locally decodable source coding (LDSC). Rigorously, LDSC is capable of recovering an arbitrary bit of the unencoded message from its encoded version, by only feeding a small number of the encoded message to the decoder, and we call the decoder t-local if only t encoded symbols are required. We consider both almost lossless (block error) and lossy (bit error) cases for LDSC. First, we show that using linear encoder and a decoder with bounded locality, the reliable compress rate can not be less than one. More importantly, we show that even with a general encoder and 2-local decoders (t = 2), the rate of LDSC is still one. On the contrary, the achievability bounds for almost lossless and lossy compressions with excess distortion suggest that optimal compression rate is achievable when O(log n) encoded symbols is queried by the decoder with block-length n. We also show that, rate distortion is achievable when the number of queries is scaled over n with a bound on the rate in finite-length regime. Although the achievability bounds are simply based on the concatenation of code blocks, they outperform the existing bounds in succinct data structures literature.
The rate-distortion regions of cooperative and interactive source coding is studied and characterized in several important special cases. For the general cooperative and interactive three node source coding problem, w...
详细信息
ISBN:
(纸本)9781467377058
The rate-distortion regions of cooperative and interactive source coding is studied and characterized in several important special cases. For the general cooperative and interactive three node source coding problem, we present an improved inner bound with respect to the bound derived in [1]. This inner bound is used to characterize the optimal rate-distortion regions of several special cases of three terminal information sharing protocols.
We consider a system in which two nodes take correlated measurements of a random source with time-varying and unknown statistics. The observations of the source at the first node are to be losslessly replicated with a...
详细信息
We consider a system in which two nodes take correlated measurements of a random source with time-varying and unknown statistics. The observations of the source at the first node are to be losslessly replicated with a given probability of outage at the second node, which receives data from the first node over a constant-rate channel. We develop a system and associated strategies for joint distributed source coding (encoding and decoding) and transmission control in order to achieve low end-to-end delay. Slepian-Wolf coding in its traditional form cannot be applied in our scenario, since the encoder requires the joint statistics of the observations and the associated decoding delay is very high. We analytically evaluate the performance of our strategies and show that the delay achieved by them are order optimal, as the conditional entropy of the source approaches to the channel rate. We also evaluate the performance of our algorithms based on real-world experiments using two cameras recording videos of a scene at different angles. Having realized our schemes, we demonstrated that, even with a very low-complexity quantizer, a compression ratio of approximately 50% is achievable for lossless replication at the decoder, at an average delay of a few seconds.
In this paper, the problem of lossy source coding with side information at the decoder is considered when the dependency between the source and the side information (SI) is quasi-stationary and unknown to the encoder....
详细信息
In this paper, the problem of lossy source coding with side information at the decoder is considered when the dependency between the source and the side information (SI) is quasi-stationary and unknown to the encoder. This dependency is modeled using a (virtual) block fading channel. In order to help the decoder estimate the dependency, a part of the transmitted source in each block is coded at high rate (disregarding the SI) to be decoded error-free at the decoder. The estimate of the virtual block fading channel is imperfect and its quality depends on the length of the estimation block. The decoder's estimate is then quantized and communicated back to the encoder using a limited rate feedback. The encoder encodes the rest of the source block with this knowledge of the SI dependency model. A source coding scheme that uses the estimated dependency structure is proposed and the appropriate length of the source assigned for the estimation phase is characterized so as to minimize the mean distortion. The effect of the feedback rate, the quantization step size and the dependency estimation error are also investigated.
暂无评论