This blog post explores how digital signal processing technology is driving innovation in daily life and various industries, and what impact it will have on future technologies.
These days, wherever you go, you can do everything with your smartphone. You constantly exchange messages with friends, listen to music through earphones while browsing internet news or searching for trending videos. All these things we now take for granted were unimaginable just 20 years ago. Back then, typewriters were used for typing, CD players for listening to music, and television was the only way to watch videos. Now, a single small device in our hands can do all these things, and sometimes even multiple tasks simultaneously. This is the power of digital signal processing technology.
Digital signal processing refers to converting signals occurring in nature into electrical signals. The natural scenery we see while strolling through a park, the sounds we hear in a cafe – all are types of signals. Since machines cannot directly use these signals, digital signal processing converts them into electrical signals composed of current and voltage, making them easy for machines to process and manipulate. The ability of Apple’s Siri or Samsung’s Bixby to understand human speech and perform tasks is also made possible by this digital signal processing technology.
Why is digital signal processing technology necessary? To answer this question, we must first understand the concepts of analog signals and digital signals. An analog signal refers to a signal with a continuous distribution, like light or sound. Because the signal persists continuously as a single large entity, it is difficult for users to arbitrarily process segments of the signal. Since the signal is used as-is without manipulation, the processing system varies depending on the signal type. Consequently, its application scope is limited, and system design becomes complex. In contrast, a digital signal is a signal with a discrete distribution, composed of 0s and 1s. Because the signal is discrete, users can process it in various ways. Since all digital signals are integrated and processed as sequences of 0s and 1s, they can be managed within a single system regardless of signal type—be it data, video, or audio. However, most signals encountered in daily life are analog. This necessitates digital signal processing technology to convert analog signals into digital form for processing according to our objectives.
Digital signal processing consists of five stages: preprocessing filtering, Analog-to-Digital conversion (A/D conversion), digital signal processing, Digital-to-Analog conversion (D/A conversion), and postprocessing filtering. Let’s examine a simple example. You are holding a mobile phone and talking to a friend. The voice coming from your mouth is an analog signal with a continuous frequency distribution. The preprocessing filter limits the frequency range of the analog signal entering the input, thereby maximizing the prevention of noise other than the human voice from entering the phone’s interior. The A/D conversion then transforms this incoming signal into a digital signal so it can be processed inside the mobile phone. Your voice is now inside the phone, transformed into a combination of countless 0s and 1s. During the digital signal processing stage, any remaining noise in the converted signal is removed. Depending on the situation, volume may be amplified or sound quality enhanced. This processed signal then undergoes D/A conversion again, transforming it back into an analog voice signal that the user on the other end of the phone can understand. Through post-processing filtering, the signal is refined once more into a cleaner form before being transmitted to the other party.
Such digital signal processing systems extend far beyond merely converting voice or video. Digital signal processing has become an essential element in our daily lives, serving as the foundational technology for all modern information and communication systems. For instance, the GPS systems we use daily employ digital signal processing to calculate location information by digitally converting received satellite signals. Furthermore, in the medical field, imaging equipment like MRI and CT scanners generate high-resolution images through digital signal processing, enabling accurate diagnoses.
Advancements in digital signal processing technology have brought significant changes across multiple fields. In particular, cutting-edge technologies like autonomous vehicles and smart homes can analyze data in real-time and make context-appropriate decisions through digital signal processing. This goes beyond mere technological progress, playing a crucial role in enhancing our quality of life. Thus, digital signal processing technology continues to evolve in diverse fields such as information and communications, healthcare, and transportation, and will continue to significantly impact our daily lives.
Through digital signal processing systems, we have gained great convenience in processing and integrating signals by freely converting between analog and digital signals. However, digital signal processing also has several drawbacks. These include the potential loss of some information during the conversion of analog signals to digital, or the distortion of information in the original signal. The phenomenon of voices cutting out during phone calls or perceived deterioration in sound quality exemplifies these drawbacks of digital signal processing. Nevertheless, the advantages far outweigh these disadvantages, making digital signal processing technology widely adopted across diverse fields, including information and communications. Moreover, recent rapid advancements in signal processing technology now deliver performance levels so close to the original analog signal that it is difficult to distinguish with human sensory organs.
In the coming future, digital signal processing technology will remain a powerful tool for realizing artificial intelligence’s natural language understanding, ubiquitous computing, and the Internet of Things. Furthermore, this technology will play a pivotal role in advancing global network infrastructure and building more efficient and faster information processing systems. The potential of this technology, which turns human imagination into reality, is limitless, and we will continue to discover new possibilities within its evolution.
