The Design Of The Data Generation Module Of The UWB And OFDM Signal Simulation Software

Arbitrary waveform generator(AWG) is a kind of signal source in electronic measurement, which can provide stimulus signals for the system under test. AWG’s ability to generate testing signal is not only based on its own hardware, but also depened on its matching waveform editing software.Orthogonal Frequency Division Multiplexing(OFDM) and Utral Wide Band(UWB) are the current hotspots in the wireless communication filed. In order to enable AWG to generate OFDM and UWB testing signal, the data generation modules of OFDM and UWB signal in waveform editing software were studied in this paper. The main contents are as follows:1) Analyzing OFDM modulation scheme. Firstly, the principle of OFDM modulation and its IFFT implementation were discussed. Then the WiMedia UWB physical layer specification was introduced and the application of OFDM in the UWB was analyzed. Finally, after a comprehensive analysis, the use of sampling the OFDM signal expression to implement OFDM modulation was established. Compared with the IFFT method, the proposed scheme can be more flexible to set the sampling rate and sampling points of OFDM signals.2) Designing and implementing OFDM signal data generation module. By analyzing the OFDM signal’s generation process in the communication physical layer, a set of generic OFDM signal data generation module was designed.This module supports user-defined digital baseband signal by using channel coding such as convolutional code and scramble code, and user-defined OFDM modulation process by setting the number of subcarriers, frequency spacing between subcarriers and other parameters. This module also supports user-defined frame structure and adding non-ideal characteristics to OFDM signal, such as carrier frequency offset and phase noise.3) Designing and implementing UWB signal data generation module.In accordance with the WiMedia physical layer specification, the structure of UWB frame was formed firstly, and then UWB baseband signal and radio frequency signal were generated.4) Testing and verifying.The data generation module was tested by different testing cases. Firstly, the generated discrete waveform data was transformed into analog signal by AWG, and then the analog signal was analyzed by oscilloscope and spectrum analyzer.After testing and verifying, the OFDM signal data generation module designed in this paper can generate generic OFDM signal, and the UWB signal data generation module can generate UWB signal which is in accordance with the WiMedia physical layer specification.