The Application Of HARQ In The Cross Layer Design

As the opening and reform policy has been carried out in china, the standard of living has improved greatly. The wireless mobile communication has become an indispensable part in people's everyday life. And the higher requirements of the service in mobile communication are demanded which are more various kinds of service and the higher quality. The ultimate goal of the mobile communication research is: anybody at anywhere at anytime could achieve high quality and various kinds of communication. As a result, the requirements of the society and the goal of the research agree with each other, which push the communication research forward. But the communication researchers are facing the contradiction between the going short of the wireless communication resources and the higher requirements of the services of the communication. So they proposed the concept of cross layer design, break the traditional seven layers protocol communication framework, and consider the parameters of different layers together to make full use of the system resources, in order to provide better services for the users.The reliability and the validity of the communication are two goals of the communication research. Because of the time-varying character of the mobile communication channel, the channel code alone could not satisfy the reliability of the mobile communication. So we apply the hybrid automatic repeat request techniques in the communication system framework, under the QoS requirements of the system, to achieve the higher reliability and validity at the same time. This is the essence of the hybrid automatic repeat request.The work has been done in my thesis are:1. Do research on the basic principle of the type-I, II, III HARQ, and use the convolutional code to realize three different types of HARQ. Analyze the performances of different parameters. Summarize the application conditions of type-I, H,III HARQ. 2. Obtain the principle and the performance of the automatic modulation and coding technique. The convolutinal code is used in this part.3. Combine the automatic modulation at the physical layer and the hybrid automatic repeat request at the data link layer to do the cross layer design. Under the prescribed QoS requirements at the data link layer, combine the HARQ and the AMC together to design the system and improve the system average spectral frequency. Analysis the performance of the system and figure out the mathematic expression of the system performance.