please help signal processing " daptive filter"

[Ganzales]

help signal

good-morning for all
I have project of amplification a High frequency signal x(t) with frequency f that I received from antenna, next after transpose RF/IF and after filtering the intermediate frequency by pass-band filter center in IF I will amplify the signal in high level and transpose to IF/RF level and next a transmit the signal with the same frequency that I received, but the problem is after applying these operations next the new received signal from antenna is: x(t)+x(t+ β) *(β:is the time delay of operations applied ) *
the new component signal appear in the spectrum as noise or in other word echo, then my object now is to eliminate the signal x(t+ β) after a long search, i have find that to eliminate this signal by applying a adaptive filter anyone can help me to how to putting such type of solution!! and or propose me other solution please a need help.
thank's

 

[RegUser_2]

gsm repeteur

What means you need an "echo canceller", what is standard feature of any DSL modem.

Here is a MATLAB example ->

https://www.mathworks.com/matlabcentral/fileexchange/18403

By the way, LEARN TO SEARCH THE WEB. Very powerfull tool to avoid rediscovering the wheel

 

[Ganzales]

Re: please help signal processing " daptive filter&quot

in fact echo canceler it mean a process to eliminate the signal x(t+β) that return via a feedback "space"in the receiver

 

[ishtiaq]

Re: please help signal processing " daptive filter&quot

If you are using MATLAB along with the Signal Processing Toolbox, then use filtering with the "filtfilt" command. This command performs true "Zero Phase" (i.e. no delay) filtering by using a forward-reverse filtering implementation.

It works with any filter like FIR, IIR, linear phase, etc.

Alternatively, you can pad the data at the ends with intelligently selected values and then take the sections of the filtered output which correspond to your input.

 

[Ganzales]

Re: please help signal processing " daptive filter&quot

Mr ishtiaq
In fact a have a signal time varying exactly "GSM " a search a filter to performe the filtering the echo compenent form amplified signal GSM REPETEUR ISO FREQUENCY
Thanks for reply.


<---------------x(t+B)----------------------------------------------------
\ / \ /
|| ----|RF\FI|----|A\D|----|filtering|----|D\A|----|Amplifying|---|fi\RF|----||
Rx Tx
Note : x(t) and x(t+B) is the same signal with the delay reflexion from echo path