Correction of Insertions and Deletions in Selective Watermarking

Schlauweg, Mathias; Pröfrock, Dima; Müller, Erika

doi:10.1109/sitis.2008.26

Cited by 5 publications

(10 citation statements)

References 6 publications

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“…Clearly, the AMVs serve the same function as the use of different encodings in TVB codes. In contrast to a random distributed marker sequence, the use of AMVs does Table I A (7,8,4) TVB CODE C = (C 0 , . .…”

Section: B Representation Of Previous Schemes As Tvb Codesmentioning

confidence: 99%

“…On the other hand, the fixed marker bits improve the determination of codeword boundaries, and the random use of different marker bits creates the necessary diversity to improve performance in poorer channel conditions. To illustrate the difference in performance between the various designs, consider encodings of size (n, q) = (7,8) with N = 666 (same size as codes C and H in [4]). A (7,8,4) TVB code where each constituent code has the best possible Levenshtein distance spectrum with d lmin = 3, found through an exhaustive search, is given in Table I.…”

Section: B Representation Of Previous Schemes As Tvb Codesmentioning

confidence: 99%

“…Comparison of Inner Codes with (n,q) = (7,8) and N =666 (7,8) sparse + random marker 3 data bits + 4 marker bits (7,8,3) SEC code with 8 AMVs (7,8,4) TVB code Figure 1. Comparison of inner code designs of size (n, q) = (7, 8) with N = 666: a sparse code with random distributed marker from [4], a marker code with 0011/1100 marker bits similar to [5], a SEC code with randomlysequenced AMVs from [15], and the TVB code of Table I. to a drift |S t | ≤ x max , where x max was chosen to be 'several times larger' than the standard deviation of the synchronization drift over one block length, assuming this takes a Gaussian distribution.…”

Section: Symbol Error Ratementioning

confidence: 99%

“…These codes are designed to operate under channel conditions P i , P d from 10 −3 to above 10 −1 . Evaluating (8) under these conditions, one encounters very large values for the two binomial coefficients and very small values for the power term. For example, consider evaluating (8) at m = 0 for T = 6000 and P i = P d = 10 −3 .…”

Section: B Avoiding Numerical Issuesmentioning

confidence: 99%

“…We start by investigating the effect of stream decoding on the ability of the MAP decoder to track codeword boundaries. We consider a (6,8,12) TVB code, which is the inner code for the concatenated system N2b of Table III. We simulate…”

Section: A Stream Decoding With Map Decodermentioning

confidence: 99%

See 4 more Smart Citations

Time‐varying block codes for synchronisation errors: maximum a posteriori decoder and practical issues

Briffa

Buttigieg

Wesemeyer

2014

J. eng.

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In this paper we consider Time-Varying Block (TVB) codes, which generalize a number of previous synchronization error-correcting codes. We also consider various practical issues related to MAP decoding of these codes. Specifically, we give an expression for the expected distribution of drift between transmitter and receiver due to synchronization errors. We determine an appropriate choice for state space limits based on the drift probability distribution. In turn, we obtain an expression for the decoder complexity under given channel conditions in terms of the state space limits used. For a given state space, we also give a number of optimizations that reduce the algorithm complexity with no further loss of decoder performance. We also show how the MAP decoder can be used in the absence of known frame boundaries, and demonstrate that an appropriate choice of decoder parameters allows the decoder to approach the performance when frame boundaries are known, at the expense of some increase in complexity. Finally, we express some existing constructions as TVB codes, comparing performance with published results, and showing that improved performance is possible by taking advantage of the flexibility of TVB codes.

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Section: B Representation Of Previous Schemes As Tvb Codesmentioning

confidence: 99%