James Douglas McDonald

Title: Innovations of James Douglas McDonald

Introduction

James Douglas McDonald is a notable inventor based in Champaign, IL (US). He has made significant contributions to the field of digital communications, particularly in adaptive equalization techniques. With a total of 3 patents, McDonald has developed innovative solutions that enhance the quality of signal reception in various communication systems.

Latest Patents

One of McDonald's latest patents is titled "Adaptive equalization of digital modulating signal recovered from amplitude-modulated signal subject to multipath." This invention focuses on an adaptive equalizer for amplitude-modulation (AM) signals received via over-the-air radio transmission. The system employs feed-forward finite-impulse-response (FIR) filtering along with infinite-impulse-response (IIR) filtering for decision feedback. The method measures the echo content of the baseband signal to initially determine the reception channel impulse response (CIR) in the time-domain, which is then updated through decision feedback. The strengths of longer-delay post-echoes are utilized to determine the weighting coefficients for IIR filtering, effectively suppressing these echoes.

Another significant patent is "Digital modulation signal receiver with adaptive channel equalization employing discrete Fourier transforms." This invention describes techniques for calculating the system characteristics of adaptive filtering used for equalization and echo suppression in digital communications receivers. The system characteristics are derived from the discrete Fourier transform of successive portions of the input signal and the corresponding portions of the transmitted signal. Various receiver implementations for these techniques are also disclosed.

Career Highlights

Throughout his career, McDonald has demonstrated a commitment to advancing communication technologies. His work has been instrumental in improving the reliability and clarity of digital signal reception. His innovative approaches have garnered attention in the field, making him a respected figure among his peers.

Collaborations

James Douglas McDonald has collaborated with notable individuals such as Allen Le Roy Limberg and Chandrakant Bhailalbhai Patel. These collaborations have contributed to the development of his patents and have fostered advancements in the field of digital communications.

Conclusion

James Douglas McDonald is a distinguished inventor whose work in adaptive equalization and digital communications has made a lasting impact. His innovative patents continue to influence the way signals are processed and received in modern communication systems.