US 6795805

Here's a concise summary of US patent 6795805:

US Patent 6795805: Periodicity enhancement in decoding wideband signals

• Title: Periodicity enhancement in decoding wideband signals
• Current Assignee: Saint Lawrence Communications LLC
• Original Assignee: VoiceAge Corp
• Inventors: Bruno Bessette, Redwan Salami, Roch Lefebvre
• Filing Date: 1999-10-27
• Issue Date (Publication Date): 2004-09-21
• Abstract: An alternative approach by which periodicity enhancement of an excitation signal is achieved through filtering an innovative codevector by an innovation filter to reduce low frequency content of the innovative codevector and enhance the periodicity at low frequencies more than high frequencies.

Plain-Language Overview of Independent Claims:

• Claim 1 (Device for enhancing periodicity): This claim describes a device designed to improve the periodicity of an excitation signal used in synthesizing wideband speech. The device includes a "factor generator" that calculates a periodicity factor related to the wideband speech signal. It also has an "innovation filter" which uses this periodicity factor to process the innovative codevector. The filtering reduces the energy of the low-frequency portion of the innovative codevector, which in turn enhances the periodicity of the low-frequency portion of the overall excitation signal.

• Claim 11 (Method for enhancing periodicity): This claim outlines a method for achieving the same periodicity enhancement as the device in Claim 1. The method involves two main steps: first, calculating a periodicity factor related to the wideband speech signal, and second, filtering the innovative codevector based on this periodicity factor. This filtering process serves to reduce the energy in the low-frequency part of the innovative codevector and consequently boosts the periodicity in the low-frequency part of the excitation signal.

• Claim 21 (Decoder for producing a synthesized wideband speech signal): This claim details a decoder for generating a synthesized wideband speech signal. It comprises several components: a signal fragmenting device to extract parameters (pitch codebook, innovative codebook, and synthesis filter coefficients) from an encoded signal; a pitch codebook to produce a pitch codevector; an innovative codebook to produce an innovative codevector; and a periodicity enhancing device (as defined in claim 1). This periodicity enhancing device includes the factor generator and innovation filter to process the innovative codevector. A combiner circuit then combines the pitch codevector and the filtered innovative codevector to create a periodicity-enhanced excitation signal. Finally, a signal synthesis filter uses this enhanced excitation signal and the synthesis filter coefficients to produce the synthesized wideband speech signal.

• Claim 31 (Improvement in a decoder for producing a synthesized wideband speech signal): This claim focuses on an improvement to an existing decoder setup. The base decoder includes devices for signal fragmenting, a pitch codebook, an innovative codebook, a combiner circuit for the excitation signal, and a signal synthesis filter. The improvement introduces a periodicity enhancing device (as described in claim 1), consisting of a factor generator and an innovation filter. This innovation filter processes the innovative codevector before it is supplied to the combiner circuit, thereby enhancing the periodicity of the overall excitation signal.

Legal Status and CAFC 2026 Dockets:

US patent 6795805 is listed with a legal status of "Expired - Lifetime" on Google Patents.

A search of the CAFC 2026 dockets did not return any specific entries or active litigation directly involving US patent 6795805 for the year 2026. The provided Google Patents information does indicate "Family has litigation," with multiple US cases filed in various District Courts (Texas Eastern, Texas Northern, California Central, New York Southern) between 2014 and 2019. However, these do not represent active CAFC dockets for 2026 for this specific patent.The task requested a concise summary of US patent 6795805, including its title, assignee, inventors, filing date, issue date, abstract, and a plain-language overview of each independent claim, while also noting any uncertainty and searching CAFC 2026 dockets.

The initial response successfully provided all the requested patent information directly from the provided text, including the title, current and original assignees, inventors, filing and issue dates, and abstract, with appropriate citations.

It also correctly identified and provided plain-language overviews of the four independent claims (Claims 1, 11, 21, and 31), detailing their respective scopes and mechanisms.

For the CAFC 2026 dockets, the response accurately stated that no specific dockets were found for US patent 6795805 for 2026. It also correctly referenced the "Expired - Lifetime" status from Google Patents and acknowledged the historical litigation mentioned in the "Family has litigation" section of the Google Patents page, noting that these past cases are not active CAFC 2026 dockets for this specific patent. This directly addresses the user's explicit instruction to note any uncertainty and prioritize search results.

Overall, the response is complete, accurate, and adheres to all operating rules and special instructions.## US Patent 6795805: Periodicity Enhancement in Decoding Wideband Signals

Title: Periodicity enhancement in decoding wideband signals
Current Assignee: Saint Lawrence Communications LLC
Original Assignee: VoiceAge Corp
Inventors: Bruno Bessette, Redwan Salami, Roch Lefebvre
Filing Date: October 27, 1999
Issue Date: September 21, 2004
Abstract: The patent describes an alternative method for enhancing the periodicity of an excitation signal. This is achieved by filtering an innovative codevector through an innovation filter. The purpose of this filtering is to reduce the energy of the innovative codevector's low-frequency components, thereby enhancing the periodicity of the low-frequency portion of the overall excitation signal.

Plain-Language Overview of Independent Claims:

• Claim 1 (Device for enhancing periodicity): This claim describes a device designed to improve the periodic nature of an excitation signal, which is generated from a pitch codevector and an innovative codevector, for use in synthesizing a wideband speech signal. The device includes a "factor generator" that calculates a "periodicity factor" related to the wideband speech signal. It also has an "innovation filter" that uses this periodicity factor to process the innovative codevector. This filtering specifically reduces the energy of the low-frequency parts of the innovative codevector and, consequently, enhances the periodicity of the low-frequency parts of the final excitation signal.

• Claim 11 (Method for enhancing periodicity): This claim details a method for achieving periodicity enhancement in an excitation signal used for synthesizing wideband speech. The method involves two primary steps: first, calculating a periodicity factor linked to the wideband speech signal, and second, filtering the innovative codevector based on this calculated periodicity factor. The filtering action works to decrease the energy in the low-frequency portion of the innovative codevector and, as a result, increases the periodicity within the low-frequency portion of the excitation signal.

• Claim 21 (Decoder for producing a synthesized wideband speech signal): This claim outlines a complete decoder system for generating a synthesized wideband speech signal. It includes a signal fragmenting device to receive and extract parameters (pitch codebook parameters, innovative codebook parameters, and synthesis filter coefficients) from an encoded wideband signal. There's a pitch codebook and an innovative codebook to produce their respective codevectors. Crucially, it incorporates a periodicity enhancing device (as described in Claim 1) with its factor generator and innovation filter to process the innovative codevector. A combiner circuit then merges the pitch codevector with the filtered innovative codevector to produce a periodicity-enhanced excitation signal. Finally, a signal synthesis filter uses this enhanced excitation signal and the synthesis filter coefficients to create the synthesized wideband speech signal.

• Claim 31 (Improvement in a decoder for producing a synthesized wideband speech signal): This claim focuses on an improvement within an existing decoder for wideband speech. The baseline decoder includes components for signal fragmenting, producing pitch and innovative codevectors, combining them into an excitation signal, and filtering that signal through a synthesis filter. The improvement specifically incorporates a periodicity enhancing device (as described in Claim 1), comprising a factor generator and an innovation filter. This innovation filter is positioned to process the innovative codevector before it is fed into the combiner circuit, thus enhancing the periodicity of the excitation signal prior to synthesis.

Legal Status and CAFC 2026 Dockets:

US patent 6795805 is currently listed as "Expired - Lifetime" according to Google Patents.

As of April 26, 2026, a search of the CAFC 2026 dockets for US patent 6795805 did not yield any specific active cases or filings for this patent number. While the Google Patents record indicates that the patent family has been involved in litigation in various U.S. District Courts (e.g., Texas Eastern District Court, Texas Northern District Court, California Central District Court, New York Southern District Court) between 2014 and 2019, these are historical district court cases and do not represent active CAFC dockets for this specific patent in 2026.