Abstract: This paper introduces a design method for a general-purpose modulator based on software-defined radio (SDR). The overall design scheme is presented, illustrating the functional division between DSP and FPGA, the system workflow, the hardware implementation methods for key components, and the software design. Measurement results are also provided. Keywords : Software-defined radio, modulator, digital up-converter. Software-defined radio (SDR), which emerged in the 1990s, is based on the idea of ​​constructing an open, standardized, and modular general-purpose hardware platform to implement various functions in software. This novel concept has received widespread attention since its inception. However, research on SDR remains limited in many countries. Since the implementation of SDR requires a high degree of digitization, which current device technology cannot meet, and the lack of unified design standards, the system design can only utilize the SDR concept, adjusting its structure appropriately according to system requirements. This paper employs a design method combining programmable and dedicated devices and a hierarchical design approach to present a design and implementation method for a general-purpose modulator based on SDR, and provides system test results. [b]1 Overall Design Scheme 1.1 Overall Scheme Block Diagram[/b] The overall scheme block diagram of the general modulator is shown in Figure 1. [b][align=center]For details, please click: Design and Implementation of a General Modulator Based on Software Radio[/align][/b]