The Design And Implementation Of Communication Signal Simulator Based On FPGA

Nowadays,whether research and development of the military communications equipment or that of the civilian communications equipment require the acceptance testing of these equipment to ensure that the indicators of these equipment are correct and reasonable.For the testing of these devices,a specific signal source is usually required as a stimulus signal for testing.Especially for some tactical frequency hopping stations,it is usually necessary to use the frequency hopping signal as a test source.Therefore,in view of the requirements above,this paper has conducted a research and design about a portable communication signal simulator which can not only generate general signals but also generate frequency hopping signals.The main research contents of this paper are as follows:1.Aiming at the design index and requirements of this communication signal simulator,this paper proposes a communication signal generation scheme based on tablet computer+FPGA architecture.The tablet computer is mainly used to set the communication signal parameters,while FPGA is mainly used to generate the communication signals.By setting up the communication signal parameter through the tablet computer,it can control FPGA to produce the generate general signals or frequency hopping signals that the user needs.2.Research channel coding techniques,mainly focusing on convolutional codes,RS codes,and TCM coding.By studying their coding principle and encoder structure,these codes are implemented in FPGA.Since TCM coding is a new coding technique for coding and modulation cascades,this paper mainly implements TCM8 PSK coding modulation.In order to implement the simulator to control the channel coding type,this paper proposes a channel coding switchable design scheme.3.The QPSK modulation,8PSK modulation,16 QAM modulation,32 QAM modulation and GMSK modulation involved in the simulation are studied and implemented.According to the design requirements,a general signal generation scheme in which the modulation scheme can be switched freely is proposed.By studying the basic principles and key parameters of frequency hopping communication,this paper proposes a frequency hopping signal generation scheme with adjustable frequency hopping rate,setable frequency hopping points,controllable hopping frequency range,and preconfigurable frequency hopping control code.4.Research digital up-conversion techniques,including pulse shaping techniques,interpolation principles,and polyphase filtering techniques.By studying the pulse shaping technology,a signal bandwidth control scheme based on FIR filtering is proposed.By studying the interpolation principle and polyphase filtering technology,and combining the design index,a digital up-conversion scheme based on polyphase filtering is proposed.The test results show that the communication signal simulator in this design has the function of controllable communication parameters,and can generate general communication signals or frequency-hopping communication signals,which can be used for index detection,performance evaluation and tactical training of communication equipment.