Design of fixed-point iterative decoders for concatenated codes with interleavers

نویسندگان

  • Guido Montorsi
  • Sergio Benedetto
چکیده

We discuss the effects of quantization on the performance of the iterative decoding algorithm of concatenated codes with interleavers. Quantization refers here to the log-likelihood ratios coming from the soft demodulator and to the extrinsic informations passed from one stage of the decoder to the next. We discuss the cases of a single soft-input soft-output (SISO) module, in its additive log-likelihood version (L-SISO), performing sequentially all iterations (an implementation solution coping with medium-low data rate as compared with the hardware clock), and that of a pipelined structure in which a dedicated hardware is in charge of each SISO operation (an implementation suitable for high data rates). We give design rules in both cases, and show that a suitable rescaling of the extrinsic informations yields almost ideal performance with the same number of bits (five) representing both loglikelihood ratios and extrinsic information at any decoder stage.

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Design of fixed-point iterative decoders for concatenated codes with interleavers - Global Telecommunications Conference, 2000. GLOBECOM '00. IEEE

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عنوان ژورنال:
  • IEEE Journal on Selected Areas in Communications

دوره 19  شماره 

صفحات  -

تاریخ انتشار 2000