A Design And Realization Technology Of Digital Communication Signal Simulator

This paper uses AD9958DDS chip of the AD Inc as the core chip, ARMdevelopment board as the host computer, DSP processor of the AD Inc as the main chipto control DDS, FPGA chip of ALTERA company as the DDS chip timing controlcircuit, to develop a good performance digital communication signal simulator, whichcan generate multi-hex and binary FSK, ASK, PSK signals of which the band is15MHz-85MHz.The main work of this article is as this:First of all, this paper introduces the working principle of DDS, derives amathematical expression, and analyzes the spectrum of the DDS in the ideal case. Basedon the principle of the DDS, it deduces Time-domain expressions of the outputsignal.Then, this paper gives mathematical modeling of typical digital communicationsignal, introduces expression of time-domain signal and analyzes characteristics of thesignal in the time domain and frequency domain, and we simulates the digitalcommunication signal with matlab in time-domain simulation andfrequency-domain.Then, this article introduces the communication signal simulatorsystem design, hardware design, and software design based on DDS chip.Finally, thisarticle describes the functional testing of the entire system, and we give some typicalsignal test results and analysis.