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MATLAB Filter Design Wizard for AD9361

Question asked by OnurOguz on May 6, 2016
Latest reply on May 11, 2016 by tlili

Hello,

 

I'am trying to use the MATLAB Filter Design Wizard for AD9361, to obtain the Tx settings for a 20 MHz Wlan system.

 

In summarry I'd like to is:

1: feed the "Programmable TX FIR" with a baseband wlan signal, that is (created) sampled at 20 MHz

2: Interpolate this baseband signal by 4 (or any other interpolation factor greater than 4) using a valid cascade of FIR, HB1, HB2 and/or HB3

3: Apply a LowPass filter to comply with the spectrum mask (cf IEEE 802.11a WLAN Spectral Masks @ WLAN IEEE 802.11a 802.11b 802.11g Spectral Mask - RF Cafe ). That is 9 MHz pass band and 11 MHz stop frequency.

 

Unfortunately no matter how I try, I always get errors both using the Filter Design Wizard APP, or using MATLAB Functions "design_filter(input)".

 

Could you please point me what I am doing wrong?

 

Here is my input struct:

 

wlan20.Rdata = 20000000;

wlan20.FIR = 4;

wlan20.PLL_mult = 8;

wlan20.Fpass = 9000000;

wlan20.Fstop = 11000000;

wlan20.Apass = 0.125;

wlan20.Astop = 45;

wlan20.FIRdBmin = 0;

wlan20.phEQ = -1;

wlan20.int_FIR = 1;

wlan20.wnom = 9500000;

wlan20.RxTx = 'Tx';

wlan20.HB1      = 1;

wlan20.HB2      = 1;

wlan20.HB3      =1;

wlan20.DAC_div  = 1;

 

output = design_filter(wlan20)

 

Here is the error from "design_filter"

---------------------------------------------------------------------------------

Error using  .*

Matrix dimensions must agree.

 

Error in internal_design_filter (line 360)

    wg1 = abs(freqz(dfilter,omega(Gpass+2:end),input.converter_rate).*analogresp('Tx',omega(Gpass+2:end),input.converter_rate,b1,a1,b2,a2));

 

Error in design_filter (line 56)

output = clean_filter_fields(internal_design_filter(input));

---------------------------------------------------------------------------------

Thanks in advance for your time.

 

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