Serial Concatenated Convolutional Codes

The field of forward error correction was greatly influenced by the discovery of turbo codes. This invention led to a great improvement in terms of Bit-Error-Rate (BER). Various schemes have been proposed and are based either on parallel or serial designs of concatenated decoders. These decoders are iterative using SOVA (soft output viterbi) or MAP (maximum a posteriori) algorithms. They introduce superior recovery functions of data which have been transmitted through noisy environments. Actually, these turbo schemes compared to convolutional codes achieve better data recovery with the increase of the constraint length. Considering all previous principles, we designed a new parallel turbo encoder-decoder system. This system was compared to already existing serial and parallel turbo coding schemes and to a convolutional encoder. Performance level was verified through simulations including Additive White Guassian noise. BER analysis exhibited better results compared to all other designs for various numbers of iterations.