V.90 Based Modem Technology Study

With the rapid development of Internet, the speed of information transmission becomes more and more important. We must completely make use of the present telephone network resources to reduce the cost of building network. Nowadays digital connection between ISP and Central Office has been established. Application of new communication standard can further increase the data transmission rate. This thesis studies the Recommendation V.90 issued by ITU, analyses and simulates the key theory of 56K Modem. The research has been carried out to study the V.90 protocol and the technology, the key technical algorithm including trellis coded modulation and Viterbi decode, line detect, equalizer, error control etc. It put emphasis on the method of decoding - multi-dimension Viterbi decode. The total technical solution based on V.90 has been pointed out.