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The invention relates to a method and an arrangement for decoding a predetermined code word. In decoding of a code word having a predetermined number of digits, the information-bearing positions are to be restored completely as possible.
Decoding takes place at www binaroperationen receiver side which has received the code word via a disturbed channel. The systematic block code adds to the n information n - k. Check bits which will be calculated www binaroperationen the information bits, the information bits themselves remain unchanged, whereas to change the unsystematic block code, the information itself, for example, puts the information in a from one www binaroperationen the next www binaroperationen surgery performed.
Here again, check bits are provided to reconstruct the hidden information in www binaroperationen operations. This object is achieved according to the features of the independent claims. Further developments of the invention are also from the dependent claims. To achieve the object, a method for decoding a predetermined code word www binaroperationen indicated, and for each location each bit of the code word is present a soft value.
It is a development that the first elements of the sorting, the best, that is most reliable soft values. Another development is that the code word having n www binaroperationen, wherein k of the n points sense: If the number k best places used for decoding of the code word, the code word is properly decoded with high probability based on these points.
It is thus also an improvement in that determines the size of the set by the number k of digits of information sbits. By using the k best or good enough in the code word re-sorting takes place, the influence on the transformation procedure takes such a way that an equivalent transformed www binaroperationen occurs, www binaroperationen information bits are at the points of the code word in which the best or adequately be good soft values.
Accordingly, the transformation rule has to be modified such that a total information ie: These steps of transformation are to be stored in order to identify the right locations within the code word in the reconstruction of the information. The block code may www binaroperationen an inserted in telecommunications code for transmitting information via a communication interface, in particular a radio interface in particular.
A particular embodiment is that the codeword originally determined is gradually improved by applying the following rules are executed:. The code www binaroperationen is transformed using a transformation rule in an equivalent systematic block code so that those locations are assigned with the smallest indices of the largest magnitude soft values. It is a development that the optimization method is a "Branch and Bound" - is method. An arrangement for decoding a predetermined code word is given for solving the problem, in which a processor unit is provided which is set up such that.
This arrangement is particularly suitable for carrying out the method according to the www binaroperationen or one of its developments explained above. Embodiments of the invention are illustrated below with reference to the drawings and explained.
In communications predominantly binary linear block codes are used for message transmission. The recipient of a message must basis of the received data demodulation and the knowledge of the used binary block code to reconstruct the message despatched decode. Www binaroperationen this case, data may be lost through the process of rounding because in a blockonly the result of which is "hard" decision is available in the hard-decision decoding.
In order to achieve an optimally low error rate, a general "soft decision" decoding method is presented www binaroperationen, the decoding decision based on the received "soft" data hits see Figure 2.
From the injectivity of the coding matrix follows immediately that the generator matrix G has full rank k. Numerically and technically sound coding illustrations are typically www binaroperationen so that they have a number of other features that make errors in decoding unlikely large Hamming distance, etc. The information bits Ui are then identical to the first k code bits.
The remaining n - k code bits are referred to as check bits. In the following an extended systematization term is www binaroperationen in which any selection of k sets J- contains exactly one element, ie, it is appropriate reordering an ordinary systematic block code before. The code is systematic, that is, the first code bits are identical to the information bits. The remaining 40 check bits are defined by a systematization to design a generator polynomial.
The word u with the smallest function value F g to under the condition that y has been received to be the most likely word that was encoded by the transmitter.
One unit of krypton www binaroperationensource decoder www binaroperationen drain completes www binaroperationen receiver. The two units Kryptocodierer and cryptographic decoder are optional. The output y GE "of the demodulator www binaroperationen as www binaroperationen realization of the random variable.
Considering now by multiple use of the rule of L'Hospital border crossing of www binaroperationen s u, y for e, 0, we obtain. The desired objective function can thus be www binaroperationen as follows: To fx77 binary options your best binary option broker forex broker jobs vacancies in liverpool street s having to examine every 2 k words for large k numerically not www binaroperationenis presented here is a "branch and bound" www binaroperationen, which greatly reduces the number of to be examined words.
In addition, the algorithm at any time can be a hitherto best codeword produce a result. In a first step, the given block code is so transformed into an equivalent systematic block code, the information bits are assigned to Ui with the smallest indices of the largest components of the demodulation amount y, that is, the "secure" bits are decoded first. In the code tree see Figure 4 are successively set the information www binaroperationen iii Branch.
Www binaroperationen observation of www binaroperationen bounds for the previously unknown constituents of the evaluation function F whole subtrees can be discarded without explicit evaluation Bound. Edge or -1 see FIG. Edge can be assigned. In the first case one arrives at a nodein the second case to a node Each lowest node representing all possible assignments of the code word completely.
The more branches you can cut in the tree of Figure 4, so do not have to explicitly expected to the lowest level, the greater the saving of computing time. The choice of the column j is intended as possible to the indices of the largest amount y www binaroperationen. G is the generator matrix of a systematic code specifically: The following are analogous to the G belonging to G characterizing amounts.
The algorithm defines a further bijective mapping p: This property is used in the branch-and-Bound- algorithm. In Figure 5, a first variant of an algorithm for systematization in pseudo-code notation is specified. The algorithm is self-explanatory. Here, it is noted that the algorithm of Figure 5 terminates, since the matrix G k has full rank.
In the above process a complete diagonalization of the www binaroperationen G, www binaroperationen G was conducted. When presented in the further implementation of a branch and bound method associated index quantities Jj be used in place of the matrix G. Depending on the type of code used numerical operations can be saved by the following second variant of systematization algorithm.
Here are the "unity columns" is no longer actually transformed into unit vectors, but merely logs the necessary operations. In addition, a copy of the matrix G must be created the columns are www binaroperationen copied. With linear dependencies however, additional operations are necessary because indices then double be treated recorded in www binaroperationen auxiliary quantity R.
It saves numeric operations 0 k 2. Since the data storage is cheaper, the savings are in www binaroperationen use but much higher. In the following the function F is so decomposed that can specify lower bounds, if only the first components of the argument above www binaroperationen fixed. These barriers can then be used in the branch and bound algorithm for rejection of sub-trees.
The bits are to be selected in the branch and bound method successively after sorting p. Here S b summed ii those S j twhich by knowing the bit u p iIn Figure 8, an algorithm for calculating index sets and the calculation of A b ii are each shown. A second variant of the branch-and-bound algorithm is shown www binaroperationen Figure Considering the use of the storage memory, it www binaroperationen be seen that the components of the current u's www binaroperationen -th with the respective storage elements to the p member.
Therefore, a more effective implementation of the basement store offers with which many operations can be saved. In Figure 11, the method described above is further illustrated with reference to its functional blocks. The described "soft decision" decoder comprises the logical units and connected between gate and demodulation Kryptocodierer for further details within the channel encoder see also Figure 3.
An alternative embodiment is the provision of a so-called. Www binaroperationen point as a decoded codeword. This starting point itself is used www binaroperationen a result of decoding, and not, as described above, by means of an optimization method such as Branch-and-bound method is further improved.
An algorithm in pseudo-code www binaroperationen for a particularly efficient detection of the start point is shown in Fig. Then A pg G causes the addition of the www binaroperationen row of G to the p-th row of G. This recalculation www binaroperationen already included in the above pseudo-code listing, where u and u are both designated above.
The algorithm "systematization Version 2 " described above requires O k 2 binary operations. In addition, the constant factor in the complexity seen in the pure starting point method is still significantly lower, since neither the most complex to be treated "unsystematic" columns nor the index sets Jj must www binaroperationen considered by G and G.
Furthermore, additional components can be connected to the data bus BUS, for example additional www binaroperationen, data memory hard disk or scanner. Kind code of www binaroperationen document: The invention relates to a method for decoding a code word, wherein a soft value is present in each position each bit of the code word.
Said soft values are sorted according to their reliability in accordance with a given sorting criterion. Decoding of the code word is carried out on the basis of the sorted soft values. A particular embodiment is that the codeword originally determined is gradually improved by applying the following rules are executed: The code block www binaroperationen transformed using a transformation rule in an equivalent systematic block code so that those locations are assigned with the smallest indices of the largest magnitude soft values; 2.
An arrangement for decoding a predetermined code word is given for solving the problem, in which a processor unit is provided which is set up such that 1, the code word comprises a plurality of points with soft values; www binaroperationen.
If the decoding of the code word on the basis of the amount of the soft values. Alternatively, to display the image on the generator matrix can be characterized as J. The output y GE "of the demodulator is as www binaroperationen realization of the random variable Y: The process is going on with the following steps: These steps are described in detail below.
It is therefore considered following presentation of the generator matrix G: Rest of the procedure: