Abstract: In simulating communication transmission systems, there exists a principal problem to develop efficient models and algorithms. Four sections in this paper are provided to discuss it. How to estimate the bit-error-rate of communication systems in Monte-Carlo simulation is shown in section one.The micro-interfence simulation method is one of the most efficient methods to handle the non-linear memory systems. In section two different approaches to develop the models of linear or non-linear channels are outlined. Moreover, some of modelings and techniques used in continuous systems to increase simulation efficiency may be extended to digital coded and decoded systems. In section three different algorithms to simulate signals through linear systems are summarized, and it is emphasized that fast convolution algorithm will play a more and more roles in speeding up simulation and making the real-time simulation possible. Finally, the additional efforts on simulation techniques of communication transmission systems are presented.

Key words: Monte-Carlo method, computer simulation, communication systems