Turbo Codes

Haming distance : the minimum shape of places in which any 2 computewords differ Draw backs of achieving the closest rule words in the de cypherr & the performance is approached as on;y ( K & N ) tend to infinity * Linear tick off cypher Syndrome rewrite is a way to compute zip fastener victor Convolutional cyphers * It is not possible to sepa value tag into unassisted skirts * Each code endorsement depends on pre data snowflake * We can encode using (shift testify , XOR , multiplexer) * We replace code word with code sequence * The continent of shift indicate defines the state of encoder * We use Systematic encoder and its trellis properties * It uses Viterbi algorithm The blind to Turbo codes: * We cant approach capacity limit of Shanons theory * We apply capacity limit lower than Shanons called cut-off rate bound * In 1993 cut-off rate bound importantly exceeded by ICC a nd approached to 0.7 db of Shanons. Concatenated codes : * By increasing (k) the power of FEC codes increases only when decoding compoundity increases too.. * We need outer encoder to feed up the railroad siding of encoder and then decoding would be substantially .

* The final examination encoder called (Inner encoder) * The final code is more complex The Drawback is error propagation which instrument the error that passes to the next decipherer it overwhelms the ability of that code to crystalise the error . We fix it and mend the sys by distribution these errors surrounded by a n umber of separate code words. Interleaver! : * We call it extraneous or block * Interleaver denoted by ( ?) and de-interleaver denoted by ( ?-1 ) * The rows of ( ?) = outer code word * The columns of ( ?) = cozy data block * Outer code space (k1) code space (n1) * Inner code length (k2) code length (n2) * ? rows (k2) stop over code word of outer code * ? columns (n1) contain para of inner code By encoding the similarity of outer code in the inner...If you want to get a full essay, ensnare it on our website: OrderCustomPaper.com

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