Signal processing structure
US10972123B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 2019 |
| Grant date | Apr 6, 2021 |
| Priority date | — |
| Expiry date | May 9, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2460/01
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A signal processing structure and method are presented. A first digital filter operates on received sigma-delta modulated (SDM) input signals. A second pre-processing digital filter receives a SDM input signal, directly low pass filter the SDM input signal and provides an output SDM signal. The output sigma-delta modulated signal is provided as an input for said first digital filter. In standard digital systems operating with digital microphones, filtering of the microphones' output signal requires to first convert the signal into pulse code modulation (PCM), then filter and finally convert back to pulse density modulation (PDM). This approach increases the latency of the system because decimation and interpolation must be performed in order to pass from PDM to PCM. By using filters that operate directly on the oversampled PDM output of the digital microphones it is possible to reduce the latency of the system and minimize the hardware area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.