Analysis Of Wireless Image Transmission System Over Rayleigh Fading Channels And Cross-Layering Design

With the continuous development of mobile cellular networks, in the next generation network, it needs to achieve higher bandwidth support and more strict quality assurance to assure the integration of data, voice, audio and video business on the wireless link. It is required to support a variety of business types and quality of service requirements. It must support the complex changes of the network topology. The ideology of cross-layering design is to make useful information be provided and used between the arbitrary two layers, and realize the adaptive mechanisms. This paper deals with it and gives an example.In the 3rd mobile communication system, the space-time coding technique is the latest coding method that has resistance to the channel fading and can increase the system's capacity. Researches show that the space-time coding can make the spectrum utilization significantly improved. Because in the broadband system it can achieve a very high data transmission rate, it is increasingly being applied to the businesses of improving the data transmission rate and mobile computing in the broadband wireless channel.In this paper the image extraction is simulated by taking a colored picture as an example; the signal transmission in the Rayleigh fading channels is modeled and simulated, and its error rate curve is given out; the space-time coding is studied and applied to the wireless image transmission and enhances the signal's resistance ability to the fading. By modeling and simulating the system, the conclusion is: with the same SNR, the system's error rate has been greatly improved. Information from images is classified, and the transmission of different signals is controlled by setting the Rayleigh fading coefficient. The images obtained through the simulation are closer to the original image than not using this method. In this paper the corresponding examples are given out to explain certain theories vividly.To sum up, in this paper, by modeling, simulating and analyzing the Rayleigh fading channels based on PSK modulation and space-time coding technique, wireless image transmission is combined with the method of setting up the Rayleigh fading coefficient. And another method of wireless image transmission to get more high-quality images is realized.