Decoding of punctured turbo codes using dual codes

In this paper we show how to construct trellis of the dual code for punctured systematic recursive convolutional code. Such codes are often applied as constituent codes of turbo codes. Since they are used in wireless communication standards their efficient decoding has practical applications. It has been long known that decoding of high rate codes is more efficient in dual space than in normal space. For decoding in dual space one needs to generate the trellis of the dual code. In this paper we show how to generate it by finding dual code for the sections of the initial code. The generated dual decoder performance is tested by simulations against logMAP and maxlogMAP algorithms in normal code space.