Yoshiaki Doi

Title: Yoshiaki Doi: Innovator in Distortion Compensation and Amplification Technologies

Introduction

Yoshiaki Doi is a prominent inventor based in Tokyo, Japan. He has made significant contributions to the fields of distortion compensation and amplification technologies. With a total of 10 patents to his name, Doi's work has had a substantial impact on the industry.

Latest Patents

Among his latest patents is a distortion compensation apparatus and method. This technology includes a polynomial structure that features a pseudo-interpolation and sub-sample shift processing unit. This unit operates at a sampling rate for sampling an input signal that has not been upsampled in a previous stage. It pseudo-interpolates a sample point between sample points of the input signal and shifts the pseudo-interpolated sample point by a sub-sample. Additionally, a multiplexer is configured to select a combination of a sub-sample shift amount. An FIR filter is also included in the subsequent stage of the polynomial structure, which delays a sample point of the input signal by a sub-sample. This distortion compensation apparatus effectively compensates for distortion due to both sample points and sub-sample points of the input signal.

Another notable patent is an amplification apparatus and method. This apparatus features a combining unit that combines the output signals of two amplifiers provided at different branches. A non-linearity compensation unit multiplies an input baseband signal by a non-linearity compensation coefficient. This coefficient compensates for the non-linearity of the entire apparatus. Furthermore, first and second deviation compensation units multiply their respective branch signals by coefficients that compensate for inter-branch deviations. A compensation coefficient calculation unit is responsible for calculating these coefficients based on the input baseband signal and a feedback baseband signal.

Career Highlights

Yoshiaki Doi has worked with notable companies such as NEC Corporation and Hitachi Kokusai Electric Inc. His experience in these organizations has allowed him to develop and refine his innovative technologies.

Collaborations

Doi has collaborated with esteemed colleagues, including Takashi Okazaki and Hirotaka Sato. Their combined expertise has contributed to the advancement of their respective fields.

Conclusion

Yoshiaki Doi is a distinguished inventor whose work in distortion compensation and amplification technologies has led to significant advancements in the industry. His numerous patents reflect his dedication to innovation and excellence.