International Journal of Engineering Research and Development (IJERD)
Turbo codes are used for error protection, especially in wireless systems (e.g., in the cdma2000 standard) and in joint source-channel coding. An example of joint source-channel coding is the use of turbo codes in conjunction with JPEG2000 for image communication over noisy channels. A turbo encoder consists of two recursive systematic convolutional component encoders connected in parallel and separated by a random interleaver. Different iterative decoding algorithms like the Iterative MAP, the Iterative Log-Map and the Iterative Soft Output Viterbi Algorithm (SOVA) are used to decode the turbo codes. The complexity of the iterative SOVA is much lower than the MAP and the Log-MAP algorithms.