"基于MATLAB的FM调制解调电路设计与仿真分析"

本文主要介绍了基于MATLAB的FM调制与解调电路设计。FM在通信系统中应用广泛，包括高保真音乐广播、电视伴音信号的传输、卫星通信和蜂窝电话系统等。本设计利用MATLAB集成环境下的M文件，编写程序来实现FM调制与解调过程，并分别绘制出基带信号、载波信号、已调信号的时域波形。进一步分别绘制出对已调信号叠加噪声后信号、相干解调后信号和解调基带信号的时域波形。最后绘出FM基带信号通过上述信道和调制解调系统后的误码率与信噪比的关系，并通过与理论结果波形对比，来分析该仿真调制与解调系统的正确性及噪声对信号解调的影响。本设计的系统开发平台为Windows Vista，使用工具软件为MATLAB 7.0。通过该平台运行程序完成了对FM调制和解调以及对叠加噪声后解调结果的观察。通过本设计，达到了实现FM信号通过噪声信道，调制和解调系统的仿真目的。关键词：FM、调制、解调、MATLAB 7.0、噪声。 Overall, this article presents a detailed description of the design of an FM modulation and demodulation circuit based on MATLAB. The use of FM in communication systems is widespread, with applications in high-fidelity music broadcasting, television companion audio signal transmission, satellite communication, and cellular telephone systems. The design utilizes MATLAB's integrated environment to write programs that implement the FM modulation and demodulation process, and then plots the time-domain waveform of the baseband signal, the carrier signal, and the modulated signal. Furthermore, it also plots the time-domain waveform of the signal with added noise, the coherent demodulated signal, and the demodulated baseband signal. Lastly, it plots the relationship between the bit error rate and signal-to-noise ratio of the FM baseband signal after passing through the aforementioned channels and modulation/demodulation systems, and analyzes the correctness of this simulated modulation and demodulation system and the impact of noise on signal demodulation by comparing it with theoretical waveform results. The design uses Windows Vista as the system development platform and MATLAB 7.0 as the tool software. By running the programs on this platform, the design achieves the simulation of FM signals through noisy channels and modulation/demodulation systems. Key words: FM, modulation, demodulation, MATLAB 7.0, noise.