Signal and system is a core field in modern engineering disciplines, widely used in various fields such as communication, control, electronics, healthcare, audio and video processing, etc. Signals typically represent the form of information transmission, while systems are the tools for processing and transmitting these signals. In the study of signals and systems, how to effectively analyze and process various signals, understand the characteristics of the system, and predict the response of the system is the key to solving practical engineering problems. One of the fundamental tasks of signals and systems is to model, process, and analyze signals. Common signals include continuous time signals and discrete-time signals, while systems can be either continuous time or discrete-time systems. Signals can take various forms, such as periodic signals, non periodic signals, analog signals, or digital signals. Systems include linear systems, time invariant systems, causal systems, etc. By mathematically modeling signals and systems, tools such as Fourier transform, Laplace transform, and Z-transform can be used for frequency domain analysis to better understand the spectral characteristics of signals and the frequency response of the system. In recent years, with the development of digital signal processing technology, the study of discrete-time signals and discrete-time systems has become an important component of signal and system theory. Especially in applications such as digital communication, image processing, and audio processing, discrete signal processing methods have made significant progress. On the other hand, with the development of artificial intelligence and machine learning technologies, the theoretical basis of signals and systems has also been applied to a wider range of fields, such as speech recognition, image classification, and natural language processing. This paper aims to explore some key theories and applications in signals and systems, and analyze how to improve system performance and solve practical engineering problems through reasonable system design and signal processing methods, based on the latest research results and technological advances.

Jia Jianguo, Mao Fangdi, Chen Jiangbo, Zhang Yuting, Zhu Qinyang, Cai Weiling, Zhong Weihong, Ma Xie, Yu Bibo, Lin Qinxi. The Application of Signals in Monitoring and Transmission. International Journal of Big Data Intelligent Technology (2025), Vol. 6, Issue 1: 75-81. https://doi.org/10.38007/IJBDIT.2025.060107.

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