Yohtaro Yatsuzuka

Title: The Innovations of Yohtaro Yatsuzuka

Introduction

Yohtaro Yatsuzuka is a prominent inventor based in Yokohama, Japan. He has made significant contributions to the field of technology, holding a total of nine patents. His work primarily focuses on advanced systems for signal processing and speech coding.

Latest Patents

One of Yatsuzuka's latest patents is the "Adaptive Phase Lock Loop System." This innovative system includes a phase detector, a loop filter, a digital voltage-controlled oscillator (VCO), an initial phase difference calculator, a center frequency difference calculator, and an input buffer memory. During the initial training mode, the system searches for the optimum initial phase and center frequency of the VCO to achieve a lock-in state for the input signal stored in the buffer memory. The system estimates the initial phase difference and center frequency difference through repetitive calculations, ensuring optimal performance. In the normal operation mode, the PLL functions as a conventional PLL, executing a phase lock operation between the VCO output and the input signal.

Another notable patent is the "Speech Coding/Decoding System with Reduced Quantization Noise." This system encodes an input speech signal using an adaptive quantizer device. The quantizer processes the predicted residual signal by removing correlations from the digital input signal. A coefficient, known as leakage, is adaptively adjusted based on the prediction gain, which indicates the accuracy of the prediction. The leakage value varies between 0 and 1, depending on whether the speech signal is voiced or unvoiced.

Career Highlights

Yatsuzuka has worked with notable companies, including Kokusai Denshin Denwa Co., Ltd. and Kokusai Denshin Denwa Kabushiki Kaisha. His experience in these organizations has contributed to his expertise in developing innovative technologies.

Collaborations

Throughout his career, Yatsuzuka has collaborated with esteemed colleagues such as Norio Seki and Haruo Sakaguchi. These partnerships have fostered a creative environment that has led to groundbreaking advancements in his field.

Conclusion

Yohtaro Yatsuzuka's contributions to technology through his patents and collaborations highlight his role as a significant inventor. His work continues to influence advancements in signal processing and speech coding, showcasing the importance of innovation in today's technological landscape.