Turbo Codes And Its Third-generation Mobile Communications Applications

Mobile communication systems require channel coding techniques that protect digital data form errors in radio environments. Turbo Code ,a channel coding scheme introduced in 1993 has been proposed for third generation mobile communication systems. In this paper ,Turbo Code and its implements in third generation communication system are discussed.First part presents the structure of encoder and decoder of Turbo Code is discussed, emphasizing the performance of various interleavers and decoding algorithms of Turbo Code.In the second part, we provide an overview of standard of CDMA2000 ,one of the standard of the third generation mobile systems, and place emphasis on the frame structure of Reverse Supplemental Channel and Turbo encoder designated in CDMA2000.At last, we analyze the parameters influence on the performance of the Turbo Code in AWGN channel. These parameters include the times of iterative decoding, the length of interleaver and the code rate etc.Then on the circumstance of multipath fading Channel, we simulate the influence of the variant code length and velocity of mobile.The result of the experiments indicate that anti-fading technique is so necessary for fading channel ,and Turbo Code is an effective error correcting coding technique.