Turbine code
Using iterative process, the algorithm itself is more complicated. The key of these algorithms is not only to decode each bit, but also to give the reliability information of each bit through decoding. With this information, the iteration can continue. The specific algorithms used in Turbo code decoding are: map (Maximum A Poster).
Maximum logarithmic mapping, logarithmic mapping and SOVA (soft output Viterbi algorithm) algorithm. MAP algorithm is used to decode convolutional codes in 1974, but it needs to be modified to decode Turbo codes. According to the MAP algorithm, Max-Log-MAP and Log-map are greatly improved in calculation. Although the performance is degraded, the decoding complexity of Turbo code is greatly reduced, which is more suitable for practical system applications. Viterbi algorithm is not suitable for decoding Turbo codes because there is no reliability information output per bit. The modified SOVA algorithm with soft information output is just suitable for decoding Turbo codes. These algorithms have some differences in complexity and performance. A systematic understanding of the principles of these algorithms is the basis of studying Turbo codes, and a comparative study of the complexity and performance of these algorithms is also helpful to the application research of Turbo.
The simulation of Turbo codes generally refers to Wu Yufei's classic program.
In addition, in order to successfully use Turbo codes in mobile wireless systems, we should first consider the limitation of the maximum delay in voice transmission. The simulation results in the case of short frames show that short interleaved Turbo codes still have error correction capability close to the channel capacity in AWGN channel and Rayleigh fading, which indicates that Turbo codes have a very broad application prospect in mobile wireless communication systems.
Turbo code (turbo code)
Turbo code is a kind of high-performance error-correcting code, which is applied to satellite communication and other wireless communication applications in outer space. In these applications, designers seek to transmit information to the maximum through communication links with limited bandwidth in the face of data destruction noise. There are two types of Turbo codes, block Turbo codes and convolutional Turbo codes (CTC), which are quite different because they use different component codes, different concatenation schemes and different SISO algorithms.