What is echo subtractor and echo estimator ?

[laiza]

Echo Estimator

Hello to all brilliant people!

I want to know what are echo subtractor and echo estimator all about. Does anyone know what these means and how to achieve them? and also I am confuse about the Noise gate as an expander.

 

[mahdithdn]

Echo Estimator

Hi lariza,
an example of need of this systems is as followed.
DSL systems are full duplex links. so both systems transmit data to the other and recieve data from the other simultanously. but they need only one pair of wire for communication (instead of two pair of wire). both systems put their data on the wire by an isolater. so in the recievers there are sum of both signals and reciever know its own transmitted signal so use an echo cancellation method to recover desired signal of the other system.
echo cancellator composed of an echo estimator and then a subtractor.
hope this help.
regards.

 

[laiza]

Re: Echo Estimator

hello,
how to subtract the echo and the desired signal.Is it necessary to have it mimic?

 

[laiza]

Re: Echo Estimator

Hi lariza,
an example of need of this systems is as followed.
DSL systems are full duplex links. so both systems transmit data to the other and recieve data from the other simultanously. but they need only one pair of wire for communication (instead of two pair of wire). both systems put their data on the wire by an isolater. so in the recievers there are sum of both signals and reciever know its own transmitted signal so use an echo cancellation method to recover desired signal of the other system.
echo cancellator composed of an echo estimator and then a subtractor.
hope this help.
regards.

you only said where is echo subtractor and estimator can be found but you did not state what it is all about like to make such?or how to design?pls...pls..reply...

 

[Techietone]

Re: Echo Estimator

In echo canceller (estimator+substractor), Adaptive filter (which adapts according to the surrounding accoustic conditions) are used.

The energy contents of of difference signal betwwn adaptive filter output and actual signal input determines the actual characteristics of the filter.

The adaptation takes place in the absence of near end signal.