Touch Programmable High-order Modulation Signal Generator Based On UCGui Graphic Interface

With the development of modern satellite communication blind equalization technology, blind equalization system has entered the stage of industrialization. In order to test the blind equalization system, building a complete electronic measurement system is very necessary. The complete electronic measurement system of satellite communication blind equalization technology is composed of signal source, channel simulator and blind equalization receiver. This thesis is devoted to designing the front end vector signal source. High-end vector modulation signal generator on the market is expensive and poorly portable. Besides,the disadvatages of low-end vector modulation signal generator are single function, low precision and low frequency bandwith. To solve these problems, a special and low cost vector source is designed. Paper's main contents are as follows:1) Comparing with the scheme of traditional modulation signal generation, the structure of FPGA + digital orthogonal up-conversion chip AD9957 is used to generate modulation signal. The baseband generation module is built by FPGA internal digital logic units. AD9957 can generate maximum 200MHz carrier to orthogonally upconvert signal.2) 7-inch capacitive screen is used to achieve man-machine friendly user interface.The Nios soft-core system is implemented in FPGA to build embedded platform for the operating system and graphics library.Then,baseband control IP is designed based on Avalon bus rulers and display control IP is designed based on timing sequence rulers. As a result, the system achieves vast transplantability.3) The timing closure of FPGA is designed and AD9957 parallel output interface timing is constrained. The results show that the FPGA baseband generation module maximum operating frequency is 100MHz. To ensure the system work stably,the IQ path matching is analyzed.4) In baseband generation module, on the one hand, variable parameter pulse shaping filter and single sideband Hilbert filter are designed. On the other hand, the function of 2/4/8/16ASK modulation,4/16/64/256QAM modulation,DPSK modulation and FSK/MSK modulation is achieved.5) The software part of high-order modulation signal generator is designed.Based on Nios SBT for Eclipse, uC/OS ? operating system is built and uC/GUI graphics interface is transplanted. Finally, the main control interface is implemented.6) A system test platform is built to prove that the high-order modulation signal generator can correctly generate all kinds of modulation signals and can achieve the goals of desired design.