Single-ended echo cancellation system and method
OwnerWilliam Christopher Hardyinventor
Life of this patent
Estimating the term…
Abstract
A method of for canceling echos at a first end of a telephone call marks every other byte of a first digital representation of a first analog signal originating at the first end of the call with a signature. A second digital representation of a second analog signal from the second end of the call is received at the first end and split into a stream of odd number bytes and a stream of even number bytes. The streams of bytes are analyzed for the presence of the signature and one of the streams of bytes is converted to a third analog signal if the signature is detected.
Claims22
A method of canceling echos in a telephone call, the telephone call having a first end and a second end, which comprises the steps of:
- marking every other byte of a first digital representation of a first analog signal originating at the first end with a signature;
- receiving at the first end a second digital representation of a second analog signal from the second end;
- splitting the second digital representation of the second analog signal received at the first end into a stream of odd number bytes and a stream of even number bytes;
- and
- analyzing the streams of bytes for the presence of the signature.
A method of canceling echos in a telephone call between a first end and a second end, which comprises the steps of:
- converting a first analog signal to a first digital signal at the first end, the first digital signal including a serial string of bytes;
- replacing every other byte of the serial string of bytes with a fixed value byte, thereby converting the first digital signal into a second digital signal;
- transmitting the second digital signal from the first end to the second end;
- converting the second digital signal to a second analog signal at the second end;
- converting a third analog signal to a third digital signal at the second end, the third digital signal comprising a serial stream of bytes;
- transmitting the third digital signal from the second end to the first end;
- splitting the third digital signal into a stream of even number bytes and a stream of odd number bytes at the first end;
- and
- determining if one of the streams of bytes has a fixed offset.
A system for canceling echos in a telephone call between a first end and a second end, which comprises:
- a first analog-to-digital converter at the first end for converting an analog signal from the first end to a stream of bytes;
- a unit coupled to the first analog-to-digital converter for replacing every other byte of the stream of bytes with a fixed value byte;
- a first digital-to-analog converter at the second end coupled to the unit for converting a stream of bytes received from the first end to an analog signal;
- a second analog-to-digital at the second end converter for converting an analog signal from the second end to a stream of bytes;
- a second unit coupled to the second analog-to-digital converter for separating a stream of bytes received at the first end into a sub-stream of even number bytes and a sub-stream of odd number bytes;
- and
- a third unit coupled to the second unit for determining if the bytes of either of the sub-streams have a fixed offset.
Dependencies are inferred from the claim text.