Design And Implementation Of All-digital And High Speed 128QAM Modulation And Demodulation

In recent years, along with rapid development of the Modern Communication Technology, it is an important change that people have more demand than past in Communication. The requirements in service of communication are shown in three aspects:firstly data traffic of high velocity, secondly the information reliability, the last is the validity of information.Now days, It is a very important topic for people that we must find a new way to solve the problem of improve spectrum utilization. There is less and less resource in frequency day and day, but people have more and more higher velocity of data.QAM (Quadrature and Amplitude Modulation) is regard as one kind of highly effective technology of modulation, because it high frequency spectrum band utilization ratio and it is widely used in more and more many widespread applications. There is message of baseband in phase and amplitude of carrier signals.This article is based on FPGA(Field Programmable Gate Array) and has described the design and the confirmation of the entire digital high speed 128QAM modulation and the demodulation. The first chapter described principle theory of QAM, the second chapter comprehensively described the basic process of hardware circuit design and the characteristic of important components in circuits; the third and the fourth chapter particularly described algorithm research and implementation of 128QAM modulation and demodulation; the last made a summary and analysis of the entire article.In the design process ? used the graph and the VHDL language.With the CMOS processing and microelectronic technology development, the FPGA resources and scale becomes more and more wide, which has provided the enough hardware condition for complex algorithm realization. Therefore it is a great advantage for the most design engineers who uses the FPGA in process of designing circuit, ? selected the chip EP4CE115F484I7 which belongs to is Altera Corporation's cyclone ? devices. Its development environment is Quartus ? software.