BCJR decoder obtains as estimate of a posteriori LLR by incorporating the trellis of the code:
An iteration of BCJR or MAP decoding algorithm for RSCC requires O(12[OMEGA]([L.
Therefore, together with BCJR algorithm, the proposed iterative decoder requires at most
3) BCJR algorithm, which is based on the Log Likelihood Ratio, is highly adapted to the BPSK signals.
At the receiver side, before going through the traditional turbo decoding process using the BCJR algorithm, pulse position demodulation comes into play to generate the desired BPSK-like soft decision.
In other words, the iterative turbo decoding, irrespective of the decoding algorithm used (whether BCJR algorithm or Soft Output Viterbi Algorithm (SOVA) or any other algorithm), cannot be operated directly on the received PPM symbols.
La literatura propone en la decodificacion SISO (Soft Input Soft Output) algoritmos tales como Algoritmo de Viterbi salida suave (SOVA) y modificaciones del algoritmo (Maximo A Posteriori) o BCJR, donde se presentan versiones como Log MAP Max [7-11].
Do algoritmo BCJR a descodificacao turbo, Portugal, 2004, en linea: http://paginas.