DAC Quantization-Noise Cancellation in an Echo-Canceling Transceiver

Acoustic Noise and Echo Canceling with Microphone Array

A novel method of performing acoustic echo cancelling using microphone arrays is presented. The method employs a digital self-calibrating microphone system. The calibration process is a simple indirect on-site calibration that adapts to the particulars of the acoustic environment and the electronic equipment in use. Primarily intended for handsfree telephones in automobiles, the method simultan...

Robust Noise Reduction and Echo Cancellation

Vector Quantization of Speech with Noise Cancellation

This thesis is an investigation of robust vector quantization, with the purpose of providing a system for the application of data compression and speech enhancement. Vector quantization is widely used in data compression systems. However, the performance of these systems will degrade in a noisy environment. The proposed robust vector quantization system solves the problem of optimal quantizatio...

Convergence improvement for oversampled subband adaptive noise and echo cancellation

The convergence rate of the Least Mean Square (LMS) algorithm is dependent on the eigenvalue distribution of the reference input correlation matrix. When adaptive filters are employed in low-delay over-sampled subband structures, colored subband signals considerably decelerate the convergence speed. Here, we propose and implement two promising techniques for improving the convergence rate based...

Quantization Noise Cancellation for FDC-Based Fractional-N PLLs

This paper presents a quantization noise cancellation technique for frequency-to-digital converter-based fractional-N phase-locked loops (FDC-PLLs). The technique cancels quantization noise prior to the loop filter so the PLL bandwidth can be increased without a significant phase noise penalty. The paper also presents an FDC-PLL architecture enhancement that achieves the effect of a charge pump...