A Variety Of Research And Design Of Concatenated Code Error Correction System

Mobile communication is one of the most active and rapid development fields in the communication, it produces great influence on the society development and human life in the new century. However, with the increased number of users and extended operation areas, the contradiction between frequency resource and channels turns more acutely. During this period, the emphases of the mobile communication development is, that beginning the research work with developing new channels, new demonstration methods and using frequency spectrum effectively.Channel code is the key point of the digital mobile communication, it can make the signals withstand influence such as noise and fading more effectively, which can improves the performance of the communication system. The purpose of channel code is to make the SNR reduced, or reduce the BER for the given SNR. For this, we have to expend larger bandwidth.In the article, we introduce the concatenated code, which is used in channel code to improve the system correction ability. First, we make the simulation on four types of codes such as HAMMING code, BCH code, RS code, Convolution code. Second, according to the constitution principle of the concatenated code, we make five different kinds of concatenated codes simulation with interlace and three different ways of modulation such as BPSK, QPSK,π/4-QPSK. The results indicates, compared with the single coding, especially the un-encoding, the concatenated coding acquired much coding plus in the term of given BER, however, the system complexity is not increased. Meanwhile, we get different BER results on different modulation methods. Moreover, based on the characters of the mobile communication system, we also analyses the different performance between different concatenated coding withπ/4-QPSK modulation. The purpose is to split the difference between better BER and better use of frequency spectrum. Above of the simulation experiences provide theory basis for the concatenated coding, which is used in the mobile system, it is meaningful actually.