Ofdm Test System Based On Spectrum Aggregation Fpga Implementation Technology Research

Nowadays, with the development of wireless and mobile communicationtechnology, the speed of data transmission has become higher and higher, orthogonalfrequency division multiplexing (OFDM) gets widespread attention and application,because of its advantages such as high transmission rate, high spectrum efficiency etc.And with the development of the wireless communication, the amount of the wirelessusers is growing, but the wireless spectrum resources become very scarce. For thepurpose of full use of the spectrum resources, spectrum aggregation has been proposed,which can improve the spectrum resources usage and the system capacity effectively byaggregating discontinuous spectrum fragment. HF radio communications has a widerange of practical applications in the military and civilian fields. In this dissertation, twokey technologies, i.e. OFDM and spectrum aggregation, have been researched andapplied to the short-wave communications and implemented in hardware testbed. Byusing this testbed, we can study, implement and validate the related research of OFDM,spectrum aggregation and short-wave communication in this system.Based on a common software-defined radio platform (mainly consists of an FPGAchip and two DSP chips), this dissertation focuses on and sets up an OFDM wirelesscommunication system of spectrum aggregation.Based on the principle of hardware implementation and using less hardwareresources, this dissertation gives the principle of the test system, the overall program aswell as the complexity of the system interface solutions.This dissertation provides theprinciple of system design and the programming details with an emphasize on interfacedesign.This dissertation has designed, implemented and validated six externalcommunication interface modules about FPGA chip in this wireless communicationsystem. An interface module between the FPGA and high-speed RS232serial and theinterface modules between the FPGA and DSP chips are researched and implementedtoo. All interface modules have been tested and verified in the actual experiment.The timing module in this wireless communication system is designed, implemented and validated in this dissertation. The timing module provides the timesynchronization benchmark for the whole system. And this dissertation has alsodesigned, implemented and validated the Digital Down Converter module and DigitalUp Converter module.In order to test the overall system performance, this dissertation also conducts anindoor wired testing for the system. The channel simulator is used to simulate the realwireless environment such as Gaussian channel and fading channel. The tests can provethat this wireless communication system is feasible and correct.