A Soft-Input Soft-Output Maximum A Posteriori (MAP) Module to Decode Parallel and Serial Concatenated Codes
نویسنده
چکیده
Concatenated coding schemes with interleavers consist of a combination of two simple constituent encoders and an interleaver. The parallel concatenation known as “turbo code” has been shown to yield remarkable coding gains close to theoretical limits, yet admitting a relatively simple iterative decoding technique. The recently proposed serial concatenation of interleaved codes may offer performance superior to that of turbo codes. In both coding schemes, the core of the iterative decoding structure is a soft-input soft-output (SISO) module. In this article, we describe the SISO module in a form that continuously updates the maximum a posteriori (MAP) probabilities of input and output code symbols and show how to embed it into iterative decoders for parallel and serially concatenated codes. Results are focused on codes yielding very high coding gain for space applications.
منابع مشابه
Performance of parallel and serial concatenated codes on fading channels
The performance of parallel and serial concatenated codes on frequency-nonselective fading channels is considered. The analytical average upper bounds of the code performance over the Rician channels with independent fading are derived. Furthermore, the log-likelihood ratios and extrinsic information for maximum a posteriori (MAP) probability and soft-output Viterbi algorithm (SOVA) decoding me...
متن کاملSoft-input soft-output modules for the construction and distributed iterative decoding of code networks
Soft-input soft-output building blocks (modules) are presented to construct and iteratively decode in a distributed fashion code networks, a new concept that includes, and generalizes, various forms of concatenated coding schemes. Among the modules, a central role is played by the SISO module (and the underlying algorithm): it consists of a four-port device performing a processing of the sequen...
متن کامل[Article] Soft-input soft-output modules for the construction and distributed iterative decoding of code networks
Soft input soft output building blocks modules are presented to construct and iteratively decode in a distributed fashion code networks a new concept that includes and generalizes various forms of concatenated coding schemes Among the modules a central role is played by the SISO module and the underlying algorithm it consists of a four port device performing a processing of the sequences of two...
متن کاملutput Decoding Algorithms for Continuous Decoding of Parallel Concatenated Convolutional Codes
I n this paper we propose new decoding algorithms to be embedded in the iterative decoding strategy of parallel concatenated convolutional codes. They are derived f rom the optimum maximum-a-posteriori algorithm and permit a continuous decoding of the coded sequence without requiring trellis termination of the constituent codes. Two basic versions of the continuous algorithm and their suboptimu...
متن کاملSoft-Output Decoding Algorithms in Iterative Decoding of Turbo Codes
In this article, we present two versions of a simplified maximum a posteriori decoding algorithm. The algorithms work in a sliding window form, like the Viterbi algorithm, and can thus be used to decode continuously transmitted sequences obtained by parallel concatenated codes, without requiring code trellis termination. A heuristic explanation is also given of how to embed the maximum a poster...
متن کامل