.vhf / Uhf Multipath Mobile Channel Model Study

With rapid development of wireless communications, muitipath radio channel simulation has become an indispensable means of evaluating radio links. Transmission of information over muitipath fading radio channel, such as the land-mobile HF or VHP channel has received much attention during the last three decades. Such channels are generally characterized by a number of muitipath rays with distinct propagation delays. This number may range from very few path (e.g., five or fewer HF ionospheric or rural-area land-mobile propagation paths) to a multitude paths (occurring, e.g., for some land mobile channel conditions).in mis paper the muitipath radio channel's characters were discussed in detail, they include the multipath number distribution, the muftipafh time delay distribution and the muitipath small scale fading distribution. Their distribution taws were theoretically derived by new ideas and were simulated in computer, the results were weM proved according with the actual tests published in IEEE papers. Some discusses have been made in application of this distribution to the analysis of muitipath delay and the simulation of mobile radio channel. At the same time we derived some good conclusions from the discussions that can explain the relevant wkeless communication phenomenon. Furthermore, the paper tried a new frame of digital fitter simulator and compared with an advanced product that were successfully used in a simuiation project of countercommunication.The researches start from the theory of radio scatter, highly generalized the communication terrain and other conditions in some parameters. The digital simulator frame has many distinct advantages such as programmable, various fading model and channel type that can be design freely by user.