| 摘要 |
PCT No. PCT/IB95/00912 Sec. 371 Date Jun. 25, 1996 Sec. 102(e) Date Jun. 25, 1996 PCT Filed Oct. 24, 1995 PCT Pub. No. WO96/13105 PCT Pub. Date May 2, 1996A variant of the symbol-by-symbol MAP algorithm only stores the backwards state metric in each Lth step, thereby reducing the memory requirement for the backward metric by a factor of L, where L is the influence length of the convolutional code. The results can be transferred to a sub-optimum algorithm which utilizes log-likelihood ratios. In that case, it is possible to have a further saving of memory and computational effort when soft-output values are only needed for selected bits. The soft-output algorithm may then be restricted to the number of soft-output bits, and the conventional Viterbi algorithm is used for the remaining bits.
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