Testing Digital Filter

Started by Abdul in comp.dsp15 years ago 2 replies

Hello, I am using Linear feedback shift register(LFSR) to test Digital filter(DF) because LFSR generate white noise and has a flat...

Hello, I am using Linear feedback shift register(LFSR) to test Digital filter(DF) because LFSR generate white noise and has a flat like spectrum. Can anynody suggest when I pass white noise in DF, on what citeria should I judge the filter (Device Under Test) is pass or fail ?? my filter is 3rd order polyphase comb decimation filter with decimation factor of 256. ...


Regarding Acoustic Echo Cancellation with subbanding

Started by Aparna Ram in comp.dsp12 years ago

Dear Sir, I am working on Acoustic Echo Cancellation. I have implemented both AEC without subbanding and AEC with subbanding in...

Dear Sir, I am working on Acoustic Echo Cancellation. I have implemented both AEC without subbanding and AEC with subbanding in C+ +. For subbanding of AEC I used Polyphase IIR filter(with 70dB attenuation). AEC without subbanding is working fine. But in the outputs of AEC with subbanding there exists some slight disturbance(but echo is cancelling for all recorded...


ripple/Noise floor after decimation

Started by yogesh_gharote in comp.dsp8 years ago 9 replies

I have a ADC system which samples at 160 MHz . I am passing the data through a narrowband FIR filter of bandwidth 2.5 MHz . This also amounts...

I have a ADC system which samples at 160 MHz . I am passing the data through a narrowband FIR filter of bandwidth 2.5 MHz . This also amounts to saying that i can filter & decimate the data sequence (to the input of the filter) by a factor of 32 (80/2.5 = 32) . The FIR is implemented as a polyphase structure. Filter specs are as follows: Input data rate : 160 MHz (160 mega samples...


Digital Filter testing with LFSR

Started by Abdul in comp.dsp15 years ago 1 reply

Hi guys, It is a known fact that LFSR generate flat spectrum, I choosed LFSR to test my 3rd order polyphase comb decimation...

Hi guys, It is a known fact that LFSR generate flat spectrum, I choosed LFSR to test my 3rd order polyphase comb decimation filter with decimation factor of 256. I am wondering what would be the lenght of LFSR ? it should be 4 bit or 8 bit or 10 bit ?? All generate flat spectrum. What characteristics help me in choosing the lenght of LFSR ??. I have read few technical...


Efficient Polyphase FIR Decimators and Interpolators

Started by angeleye in comp.dsp4 years ago

How to design Decimator with the extra filter A(z) at the output and Interpolator with the extra filter A(z) at the input. .. x(n) is the...

How to design Decimator with the extra filter A(z) at the output and Interpolator with the extra filter A(z) at the input. .. x(n) is the input Fs = 24 in the input sampling rate M= 6 is the number of subfilter In case decimator A(z) is operated at output sample rate . as Fs/M ..where M is 6 .Fs is the input sampling rate. In case Interpolator A(z) is placed at the input and operates at in...