Toshiharu Kojima, Akinori Fujimura, Makoto Miyake et al. · Electronics and Communications in Japan (Part III Fundamental Electronic Science) · 1993
Abstract The concatenated coding scheme using convolutional coding with Viterbi decoding for inner code and Reed‐Solomon (RS) code for outer codes is an attractive scheme that can achieve a coding gain larger than that of the convolutional coding with the Viterbi decoding scheme. Hence, it has attracted attention in a wide range of fields in satellite communications from space communications to digital image transmission systems. This paper presents the configuration and characteristics of a newly developed concatenated coding scheme with variable coding gain. This scheme enables selection of a coding gain considering the signal processing time of coding and decoding by enabling selection of: 1) the block length of the RS code (and its error‐correction capability); 2) the depth of interleaving combining the inner and outer code by a single codec. In addition, in this scheme, a new synchronization word detection method was developed and employed. In this method, nonlinear conversion is applied to soft decision demodulated data to synchronize the RS codeword and interleaving. It has been confirmed by numerical calculations that this synchronization word detection method has characteristics further improved over those of the conventional soft decision synchronization word detection method which is superior to the hard decision method. An experimental system was developed and the field test via Ka‐band satellite of communication satellite No. 3 ( CS‐3 ) was performed, and the tradeoff relationships between the coding/decoding signal processing time and coding gain have been clarified quantitatively.
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Takeoka, M, Fujiwara, M, Mizuno, J et al. · CERN Bulletin · 2003
Quantum information theory predicts that when the transmission resource is doubled in quantum channels, the amount of information transmitted can increase more than twice, while the increase is at most twice in classical information theory. For maximum use of the quantum-limited communications channels, such superadditive increase of the channel capacity must be included in a strategy to design a communications system. Here we present a proof-of-principle experiment of this remarkable feature, the superadditive quantum coding gain, by implemententing quantum collective decoding for the length two code of the ternary symmetric states in terms of polarization and location modes of a single photon. We develop optical circuits for the polarization-location coding, and study three kinds of quantum measurement, i.e. the generalized measurement for the accessible information, the von Neumann measurement for the single shot capacity, and the square root measurement for the length two coding. We further discuss practical implication of the gain on communication performance, introducing the {\\it quantum-classical hybrid coding} scheme. In particular, we show how the superadditive quantum coding gain, even in a small code length, can boost the communication performance of conventional coding technique.
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J. Nicholas Laneman · 2005
Cooperative diversity allows a collection of radio terminals that relay signals for each other to emulate an antenna array and exploit spatial diversity in wireless fading channels. Analysis of performance in terms of information-theoretic outage probability leads to two key parameters for these systems, namely, network diversity order and network coding gain, corresponding to the slope and intercept, respectively, in a plot of log-outage versus signal-to-noise ratio (SNR) in decibels (dB). This paper examines the network coding gains of various cooperative diversity protocols, studying the impact of transmission rate and network geometry on this important parameter. In particular, we observe that amplify-and-forward generally outperforms repetition decode-and-forward except when all the relays are much closer to the source than to the destination. Coding gains for amplify-and-forward relative to repetition decode-and-forward are determined and shown to match simulation results.
Cited by 47
Anand K. Soman, P. P. Vaidyanathan · 1993
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Cao Vien Phung, Thuong Van Vu, Thi Mai Trang Nguyen · 2013
Network coding is a new technique to improve network capacity and reliability. COPE and DCAR are basic network coding schemes which have been proposed for opportunistic network coding in wireless networks. The performances of these coding mechanisms have been studied by simulations or experiments. There is an interest in modeling the performances of these coding schemes mathematically. In fact, analytical approach can provide quicker performance analysis and comparison between these network coding schemes. In this paper, we propose an analytical model for the DCAR coding gain. The analytical results are validated by simulations in NS-2.
Cited by 2
Maggie X. Cheng, Quanmin Ye, Xiaochun Cheng et al. · 2016
Network coding improves transmission efficiency by combining packets at relay nodes and thus reduces the number of packets sent to the network. It is a network layer solution to improve network throughput and transmission efficiency. However, a coded packet must be decodable by the destination, otherwise it is a waste of resource to combine them together and to deliver the coded packet. This paper addresses how to find the coding solution that guarantees decodability at the destination. We first quantify the coding gain as the number of transmissions reduced, and then provide a method for runtime check whether a coding pair can be separated at the destination. The optimal coding solution is selected as the one that provides the maximum coding gain among all the decodable pairs. The algorithms can be applied to both unicast and multicast traffic. Simulation results show the number of transmissions can be reduced significantly, especially for multicast traffic where there are rich opportunities to apply network coding.
Cited by 1
Ho Lee, Sanghoon Lee · IEEE Signal Processing Letters · 2006
Wavelet image coding exhibits a robust error resilience performance by utilizing a naturally layered bitstream construction over a band-limited channel. In this letter, a new measure that appears to provide a better assessment of visual entropy for comparing and evaluating progressive image coders is defined based on a visual weight over the wavelet domain. This visual weight is characterized by the human visual system (HVS) over the frequency and spatial domains and is then utilized as a criterion for determining the coding order of wavelet coefficients, resulting in improved visual quality. A transmission gain, which is expressed by visual entropy, of up to about 23% can be obtained at a normalized channel throughput of about 0.3. In accordance with the subjective visual quality, a relatively high gain can be obtained at a low channel capacity.
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V.K. Bhargava, M. Avni · Proceedings of the Institution of Electrical Engineers · 1977
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J.H. Blythe, K. Edgcombe · Proceedings of the Institution of Electrical Engineers · 1975
The paper introduces the concept of ‘net coding gain’ as a measure of the effectiveness of error-control systems. It attempts to express the improvement attained by coding in terms of effective signal/noise ratio, so that the effect of coding can be compared with other expedients, such as increasing the power per bit. Theoretical and experimental results are given to show how net coding gain depends upon system parameters such as mean signal/noise, block size, and redundancy. The experimental results show how interleaving can overcome the effect of correlation between errors.
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Sungho Hong, Brian N. Lundstrom, Adrienne L. Fairhall · PLoS Computational Biology · 2008
In many cases, the computation of a neural system can be reduced to a receptive field, or a set of linear filters, and a thresholding function, or gain curve, which determines the firing probability; this is known as a linear/nonlinear model. In some forms of sensory adaptation, these linear filters and gain curve adjust very rapidly to changes in the variance of a randomly varying driving input. An apparently similar but previously unrelated issue is the observation of gain control by background noise in cortical neurons: the slope of the firing rate versus current (f-I) curve changes with the variance of background random input. Here, we show a direct correspondence between these two observations by relating variance-dependent changes in the gain of f-I curves to characteristics of the changing empirical linear/nonlinear model obtained by sampling. In the case that the underlying system is fixed, we derive relationships relating the change of the gain with respect to both mean and variance with the receptive fields derived from reverse correlation on a white noise stimulus. Using two conductance-based model neurons that display distinct gain modulation properties through a simple change in parameters, we show that coding properties of both these models quantitatively satisfy the predicted relationships. Our results describe how both variance-dependent gain modulation and adaptive neural computation result from intrinsic nonlinearity.
Cited by 41Open access
Gianpaolo Evangelista · IEEE Transactions on Signal Processing · 1996
Evangelista (1994, 1993) introduced the multiplexed wavelet transform (MWT) and pointed out its potential applications to the analysis, synthesis, processing and coding of pseudo-periodic signals such as voiced speech and music. Coders based on the MWT have been shown to outperform the conventional subband coders when a reliable pitch parameter can be extracted from data. In this paper, we investigate the effects of uniform quantization of the MWT coefficients. We compare the performance of the new coders with that of WT, block-DCT, and KLT coders in terms of the coding gain achieved when optimal bit allocation schemes are adopted.
Cited by 5
J.H. Blythe, K. Edgcombe · Proceedings of the Institution of Electrical Engineers · 1977
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Jean Yves COULEAUD · 1995
In 1948, Claude E. Shannon showed that forward error correction was able to lower the bit error ratio of a numeric transmission as long as the channel capacity is not exceeded. This discovery lead to amazing progress in the field of telecommunication and today's compact--discs, cellular phones, submarines and space probes use error control schemes to make their transmissions reliable. The scientific community has been recently astonished by the discovery of parallel concatenation now referred to as Turbo Codes and its amazing performance and simplicity. In this report, we present another type of concatenation: serial concatenation and we study the properties of a new way to build iterative decoders based on the MAP algorithm. The main aim of this project is to find a way to replace the current coding scheme to be implemented on the NASA space observation probe Galileo. The spacecraft was launched in 1989 and is currently heading to Jupiter. A slightly more powerful error correcting sch...
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A.K. Soman, P. P. Vaidyanathan · IEEE Transactions on Signal Processing · 1993
A formal proof that bit allocation results hold for the entire class of paraunitary subband coders is presented. The problem of finding an optimal paraunitary subband coder, so as to maximize the coding gain of the system, is discussed. The bit allocation problem is analyzed for the case of the paraunitary tree-structured filter banks, such as those used for generating orthonormal wavelets. The even more general case of nonuniform filter banks is also considered. In all cases it is shown that under optimal bit allocation, the variances of the errors introduced by each of the quantizers have to be equal. Expressions for coding gains for these systems are derived.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Cited by 66
V. Tarokh, I.F. Blake · 2002
The growth of trellis diagrams of lattices versus their coding gain is studied. It is established that this growth exponentially in terms of the coding gain.
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G. Calvagno, G.A. Mian, R. Rinaldo · IEEE Transactions on Communications · 1996
A procedure to evaluate the coding gain for 2-D subband systems is explicitly presented. The technique operates in the signal domain and requires the knowledge of the input process auto-correlation function. Both the case of uniform subband and pyramid decomposition are considered. In the case of a separable input process spectrum, the evaluation can be performed by considering appropriately defined 1-D systems, thus, making the procedure very convenient in terms of computational complexity. Using a model that has been recently derived for difference images in motion-compensated image sequence coders, we compare the performance of several filter banks and transform coders in terms of coding gain and asymptotic rate-distortion figures. The results for intraframe and interframe coding show that uniform subband coders can have a performance superior to that of transform coders. Pyramidal schemes appear to have a slightly worse performance.
Cited by 6
Jizheng Xu, Feng Wu, Wenjun Zhang · 2009
Intra-predictive transforms are a kind of block-based transforms that can exploit both the intra- and inter-block correlations. This paper analyzes the coding gains of intra-predictive transforms for the Gaussian process. The tight upper bound of the coding gain is derived, which is shown to be better than both the discrete cosine transform and the Karhunen Loe¿ve transform. The optimal intra-predictive transform that achieves the upper bound is also presented. Actual coding results on images verify the effectiveness of the optimal intra-predictive transform.
Cited by 2
Pavan Srinath, B. Sundar Rajan · 2013
In this paper, a new method is proposed to obtain full-diversity, rate-2 (rate of 2 complex symbols per channel use) space-time block codes (STBCs) that are full-rate for multiple input, double output (MIDO) systems. Using this method, rate-2 STBCs for 4×2, 6×2, 8×2 and 12×2 systems are constructed and these STBCs are fast ML-decodable, have large coding gains, and STBC-schemes consisting of these STBCs have a non-vanishing determinant (NVD) so that they are DMT-optimal for their respective MIDO systems.
Cited by 13
G. Calvagno, RINALDO, ROBERTO, G. A. MIAN · Research Padua Archive (University of Padua) · 1995
Typical image sequence coders use motion compensation techniques in connection to coding of the motion compensated difference images (interframe coding). Moreover, the difference loop iis initialized from time to time by intraframe coding of images. It is therefore important to have a procedure that allows to evaluate the performance of a particular coding scheme: coding gain and rate-distortion figures are used in this work to this purpose. Much work has been done on the evaluation of the coding gain for different coding schemes and intraframe coding. In this work, we present an explicit procedure to compute the coding gain for twodimensional separable subband systems, both in the case of a uniform and a pyramid subband decomposition, and for the case of interframe coding. The technique operates in the signal domain and requires the knowledge of the autocorrelation function of the input process. In the case of a separable subband system and image spectrum, the coding gain can be computed by ‘combining the results relative to appropriately defined one-dimensional filtering schemes, thus making the technique very attractive in terms of computational complexity. We consider both the case of a uniform subband decomposition and of a pyramid decomposition. While the coding gain of a uniform decomposition can be computed as the square of an appropriately defined one-dimensional system, this is not the case for a pyramid decomposition. Nevertheless, the coding gain for such systems, which have been widely used in coding schemes recently proposed in the literature, can still be computed by combining the results relative to one-dimensional systems. The developed procedure is applied to compute the subband coding gain for motion compensated signals in the case of images modeled as separable Markov processes: different filter banks are compared to each other and to transform coding. In order to have indications on the effectiveness of motion compensation, we also compute the coding gain for intraframe images. We show that the results for the image models are in very good agreement with those obtained with real-world data. The results reveal that the coding gain of uniform subband systems can be superior to that obtainable wi,th transform coders. Pyramid schemes appear to have a slightly worse performance. Rate-distortion theory provides information on the asympthotic performance of a coding scheme. In this work, we complement the information provided by the coding gain by giving upper and lower bounds on the SNR obtainable at a given bit rate for different subband systems and for intraframe and interframe coding. We find that at low bit rates ( 0.6 bpp, DCT and uniform subband coding give better results for intraframe coding than for interframe coding. As a matter of fact, at high rates, the better performance one could expect for interframe coding, due to the reduced variance of difference images with respect to the original image, is counterbalanced by the decreased coding gain of transform or subband systems for interframe coding.
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CALVAGNO G., MIAN G. A., RINALDO, Roberto · Institutional Research Information System (University of Udine) · 1996
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