Interleaver for turbo decoder

An interleaver for a concatenated convolutional (Turbo) code, comprising:

• a storage unit configured to store a plurality of (K) elements for a data packet at locations representative of a two-dimensional array, wherein the elements are stored into the storage unit in a first order and provided from the storage unit in a second order;
• a first set of at least one table configured to store a first set of sequences of values used to perform row permutation of the two-dimensional array to map from the first order to the second order;
• a second set of at least one table configured to store a second set of sequences of values used to perform column permutation of the two-dimensional array to map from the first order to the second order;
• and
• an address generator coupled to the storage unit and the first and second sets of tables and configured to receive a first address for the first order and generate a corresponding second address for the second order based in part on the sequences stored in the first and second sets of tables.

An address generator operable to generate addresses for a storage unit configured to store data for a concatenated convolutional (Turbo) code, wherein a plurality of (K) elements for a data packet are stored at locations in the storage unit representative of a two-dimensional array, and wherein the elements are stored into the storage unit in a first order and provided from the storage unit in a second order, the address generator comprising:

• a first unit configured to provide an input row number and an input column number for the two-dimensional array corresponding to a first address for the first order;
• a row mapping unit coupled to the first unit and configured to receive the input row number and provide a corresponding permutated row number;
• a column mapping unit coupled to the first unit and configured to receive at least the input column number and provide a corresponding permutated column number;
• a combiner unit coupled to the row and column mapping units and configured to receive and combine the permutated row and column numbers to generate a second address for the second order;
• and
• a first set of at least one table configured to store a first set of sequences of values used to perform row permutation of the two-dimensional array to map from the first order to the second order and a second;
• and
• a second set of at least one table configured to store a second set of sequences of values used to perform column permutation of the two-dimensional array to map from the first order to the second order, and
• wherein the permutated row and column numbers are derived based on values retrieved from the first and second set of tables.

The Turbo decoder comprising:

• a constituent decoder configured to receive and decode coded bits in accordance with a particular constituent code to generate intermediate results;
• a storage unit coupled to the constituent decoder and configured to store the intermediate results at locations representative of a two-dimensional array, wherein the intermediate results are stored into the storage unit a first order and provided from the storage unit in a second order;
• and
• an address generator coupled to the storage unit and configured to receive a first address for the first order and generate a second address for the second order based in part on sequences of values stored in a set of tables, wherein the sequences are used to perform row and column permutation of the two-dimensional array to map from the first order to the second order.

A method for generating addresses for a concatenated convolutional (Turbo) code, wherein a plurality of (K) elements for a data packet are stored at locations in a storage unit representative of a two-dimensional array, and wherein the elements are stored into the storage unit in a first order and provided from the storage unit in a second order, the method comprising:

• determining an input row number and an input column number for the two-dimensional array corresponding to a first address for the first order;
• accessing a first set of at least one table to retrieve a first set of at least one sequence of values used to perform row permutation of the two-dimensional array to map from the first order to the second order;
• mapping the input row number to a permutated row number based on the retrieved first set of at least one sequence;
• accessing a second set of at least one table to retrieve a second set of at least one sequence of values used to perform column permutation of the two-dimensional array to map from the first order to the second order;
• mapping the input column number to a permutated column number based on the retrieved second set of at least one sequence;
• and
• combining the permutated row and column numbers to generate a second address for the second order.