coding technique is a widely adopted approach to improve single-to-noise ratio in systems based on the principle of optical time-domain reflectometry. The performance enhancement is characterized by the coding gain wh...
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coding technique is a widely adopted approach to improve single-to-noise ratio in systems based on the principle of optical time-domain reflectometry. The performance enhancement is characterized by the coding gain which is directly associated to the coding length of the optical pulse train. In this work, we find out that the coding gain in coded Brillouin optical time-domain reflectrometry (BOTDR) based on spontaneous Brillouin scattering is very different from the conventional definition, and it needs to be corrected due to the spectral measurement nature of the coded BOTDR. The physical principle of this phenomenon is different from that in coded Brillouin optical time-domain analysis which is based on stimulated Brillouin scattering. Moreover, we investigate in details the coding gain dependence on the duty cycle of the pulse train. We conduct experiments using both the Simplex code and Golay code to confirm our analysis and conclusions, indicating that the performance enhancement of the coded BOTDR should be adjusted from the conventional expectation.
We investigate the performance of Hamming and BCH block codes for the case of ASE noise as the dominating impairment. Numerical results obtained by Monte-Carlo simulations show excellent agreement with theoretical con...
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ISBN:
(纸本)0780378164
We investigate the performance of Hamming and BCH block codes for the case of ASE noise as the dominating impairment. Numerical results obtained by Monte-Carlo simulations show excellent agreement with theoretical considerations.
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 ...
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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.
This paper analytically formulates both the optimal quantization noise allocation ratio and the coding gain of the two-dimensional morphological Haar wavelet transform. The two-dimensional morphological Haar wavelet t...
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This paper analytically formulates both the optimal quantization noise allocation ratio and the coding gain of the two-dimensional morphological Haar wavelet transform. The two-dimensional morphological Haar wavelet transform has been proposed as a nonlinear wavelet transform. It has been anticipated for application to nonlinear transform coding. To utilize a transformation to transform coding, both the optimal quantization noise allocation ratio and the coding gain of the transformation should be derived beforehand regardless of whether the transformation is linear or nonlinear. The derivation is crucial for progress of nonlinear transform image coding with nonlinear wavelet because the two-dimensional morphological Haar wavelet is the most basic nonlinear wavelet. We derive both the optimal quantization noise allocation ratio and the coding gain of the two-dimensional morphological Haar wavelet transform by introducing appropriate approximations to handle the cumbersome nonlinear operator included in the transformation. Numerical experiments confirmed the validity of formulations.
For an arbitrary rational lattice L with gain gamma, the average number of states (respectively, branches) in any given trellis diagram of L is bounded below by a function of gamma, It is proved that this function gro...
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For an arbitrary rational lattice L with gain gamma, the average number of states (respectively, branches) in any given trellis diagram of L is bounded below by a function of gamma, It is proved that this function grows exponentially in gamma, In the reverse direction, it is proved that given epsilon > 0, for arbitrarily large values of gamma, there exist lattices of gain gamma with an average number of branches and states less than exp (gamma((1+epsilon))).
We experimentally confirm recent theoretical predictions, suggesting that return-to-zero (RZ) signals generated by means of a pulse carver or separate pulse source (Tape 1) perform better in the presence of finite dat...
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We experimentally confirm recent theoretical predictions, suggesting that return-to-zero (RZ) signals generated by means of a pulse carver or separate pulse source (Tape 1) perform better in the presence of finite data modulator extinction than RZ signals riding on a pedestal of constant optical power (Type 11). As a consequence, the usually observed receiver sensitivity gain of RZ over nonreturn-to-zero is reduced (or even turned negative) for Type II RZ signals with poor data extinction. For Type I RZ signals, the RZ coding gain is largely unaffected by data modulator extinction.
This paper presents analytical model on motion-compensated predictive processing of the video signals. Multihypothesis prediction extends motion compensation with one prediction signal to the linear superposition of s...
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This paper presents analytical model on motion-compensated predictive processing of the video signals. Multihypothesis prediction extends motion compensation with one prediction signal to the linear superposition of several motion-compensated prediction signals with the result of increased coding efficiency. The prediction error variances of the multihypothesis pictures are derived and minimized in this paper in order to find optimal bit allocations. Then, coding gains of the multihypothesis structures are calculated and compared, which is based on traditional prediction theories. Also, the corresponding rate-distortion functions are obtained in the closed form. Some experimental results show that more multihypotheses bring the smaller distortion of signals and hence improve the efficiency of video coding. (C) 2014 Elsevier GmbH. All rights reserved.
The best possible tradeoff between the coding gain and trellis complexity for lattices is studied, Three trellis complexity functions are defined for lattices as a measure of minimum trellis decoding complexity per di...
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The best possible tradeoff between the coding gain and trellis complexity for lattices is studied, Three trellis complexity functions are defined for lattices as a measure of minimum trellis decoding complexity per dimension required for achieving a coding gain gamma. The properties of these functions are studied from an analytic perspective, It is also shown that the trellis decoding complexity per dimension is lower-bounded by an explicit power of gamma.
Sufficient conditions are derived under which M-ary partial- and full-response continuous phase modulation (CPM) space-time (ST) codes will attain both full spatial diversity and optimal coding gain. General code cons...
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Sufficient conditions are derived under which M-ary partial- and full-response continuous phase modulation (CPM) space-time (ST) codes will attain both full spatial diversity and optimal coding gain. General code construction rules are desirable due to the nonlinearity and inherent memory of the CPM signals which makes manual design or computer search difficult. Using a linear decomposition of CPM signals with tilted phase, we identify a rank criterion for M-ary partial- and full-response CPM that specifies the set of allowable modulation indices. We also propose a coding gain design criterion. Optimization of the coding gain for CPM ST codes is shown to depend on the CPM frequency/phase shaping pulse, modulation index, and codewords. The modulation indices and phase shaping functions that improve the coding gain are specified. Finally, optimization of coding gain for ST-CPM and orthogonal ST-CPM codewords is discussed.
Principal Component Filter Bank (PCFB) is considered optimal in terms of coding gain for specific conditions. P P Vaidyanathan stated that coding gain does not necessarily always increase with the increase in the numb...
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Principal Component Filter Bank (PCFB) is considered optimal in terms of coding gain for specific conditions. P P Vaidyanathan stated that coding gain does not necessarily always increase with the increase in the number of bands. However, very few attempts are made in the literature to go beyond the confines of work done by P P Vaidyanathan. We present the analytic proofs for the monotonicity of specific shapes of PSDs. This papers also derives properties of coding gain of PCFBs, which brings the new insights on the coding gain of Principal Component Filter Banks.
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