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

In Turbo decoding the design of Log MAP algorithm is more complicated with the exponential sum. In this paper a mathematical model is designed with a jacobian logarithm which consists of a max function along with the exponential correction function. The complexity of the jacobian logarithm is also reduced by the Max Log Map algorithm by eliminating the correction term. The MAP decoder is recursive and complex, which makes high-speed implementations. The block-interleaved pipelining (BIP) as a new high-throughput technique for MAP decoders. An area-efficient symbol-based BIP MAP decoder architecture is proposed by combining BIP with the well-known look-ahead computation. Due to the powerful error correcting performance, the turbo codes have been adopted in many wireless communication standards. The optimum decoding procedure for turbo codes is the maximum a posteriori (MAP) algorithm. It is very difficult to design high-speed MAP Decoder, because of its recursive computations. The MAP decoding algorithm has equipped to output soft-decision bits that turbo decoding requires. We propose maximum a posteriori algorithm (MAP) which can support both single-binary (SB) and double-binary (DB) CTC decoding It gives a mathematical description of the MLMAP algorithm for Single Binary and Double Binary turbo decoders.