Cascaded biquad infinite impulse response filter
US6845135B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 22, 2001 |
| Grant date | Jan 18, 2005 |
| Priority date | — |
| Expiry date | Feb 2, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H17/04
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved cascaded biquad infinite impulse response (IIR) filter structure is provided. The IIR filter of the invention may be implemented in a digital signal processor (DSP) such as a very long instruction word (VLIW) type DSP, as well as other processing circuitry, e.g., an integrated circuit. The new filter structure, among other advantages, overcomes the bottleneck condition known to occur in the updating operation of the w2(n−1) state of a conventional cascaded biquad IIR filter. In one illustrative implementation of the invention, this is accomplished by adding a single 32-bit intermediate state thus providing a cascaded biquad IIR filter structure such that the w2(n−1) state may be updated one clock cycle earlier. Thus, in a StarCore SC140 DSP example where a corresponding conventional cascaded biquad IIR filter structure executes at seven cycles per input sample, the improved cascaded biquad IIR filter structure of the present invention executes at six cycles per input sample. Therefore, without losing any precision, the kernel cycle count associated with the improved cascaded biquad IIR filter structure is advantageously reduced by 14 percent. Such a reduction in kernel …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.