Design And Implementation Of A Rate Adaptive Low Order Modulation

In recent years the development of wireless communication technology with each passing day, along with the rapid development of microwave technology, various related industries and areas of communications technology and the corresponding demand of broadband access business communication is growing fast, and the increase of demand makes the frequency spectrum resource is more and more scarce, but spectrum can't unlimited increase, spectrum resources increasingly cannot meet the demand of the market, This contradiction has become increasingly prominent. Therefore, how to greatly improve the utilization rate of spectrum, has always been the main task of the research in the field of wireless communications. The rate adaptive system is one of the important topics. Rate adaptive, that is, in a communication system, according to the real time state in the current communication channel, By changing the rate of sending data in real time, to improve the transmission of communication system, also improve the utilization rate of the spectrum. In the wireless communication system, the research of the rate adaptive modem is of great significance.This thesis based on the theory of adaptive modulation demodulation, proposes a rate adaptive modem which based on the FPGA implementation. The design and implementation of the related hardware circuit and software of the FPGA platform to achieve has made the detailed introduction, and the simulation and actual test results is given.