Area Efficient of Max Log Map Algorithm Using SB/DB Methods for Turbo Decoder

The convolutional turbo code (CTC) has been widely adopted as one of forward error correcting (FEC) schemes of wireless standards to have a reliable transmission over noisy channels. A soft-input-soft-output (SISO) equalizer can be combined with a SISO decoder to form a turbo equalizer. Turbo decoders are composed of two or more constituent SISO decoders, which correspond to the component codes, employed in the transmitter, and an interconnection of these constituent the decoders through an interleaver/deinterleaver. The decoding Algorithm employed in the constituent decoders is the maximum a posteriori probability (MAP) algorithm. The MAP algorithm provides a reliability metric, known as the log-likelihood ratio (LLR), on the transmitted code symbols.