AnsweredAssumed Answered

TX FIR using 16 taps can not transmit signal

Question asked by RobertYJ on Oct 5, 2017
Latest reply on Oct 6, 2017 by DragosB

Hi everyone,

 

when I using the setting below for TX FIR can not transmit signal, I can not observe the signal in Spectrum.

AD9361_TXFIRConfig tx_fir_config = {
3, // tx;
0, // tx_gain; [0,-6]
4, // tx_int;
{-245,0,1348,0,-4739,0,20013,32768,
20013,0,-4739,0,1348,0,-245,0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0}, // tx_coef[128];
16 // tx_coef_size
};

 

But when I using the setting below it can transmit well, why?

AD9361_TXFIRConfig tx_fir_config = {
3, // tx;
0, // tx_gain; [0,-6]
4, // tx_int;
{0,0,1,0,-1,-2,-2,0,
4,5,1,-6,-10,-6,7,18,
16,-4,-27,-32,-7,34,56,30,
-34,-85,-69,17,112,127,25,-127,
-199,-102,113,275,220,-53,-339,-376,
-74,363,560,285,-312,-750,-593,144,
910,1008,197,-987,-1541,-797,899,2233,
1846,-477,-3265,-4037,-921,5858,13701,18937,
18937,13701,5858,-921,-4037,-3265,-477,1846,
2233,899,-797,-1541,-987,197,1008,910,
144,-593,-750,-312,285,560,363,-74,
-376,-339,-53,220,275,113,-102,-199,
-127,25,127,112,17,-69,-85,-34,
30,56,34,-7,-32,-27,-4,16,
18,7,-6,-10,-6,1,5,4,
0,-2,-2,-1,0,1,0,0}, // tx_coef[128];
128 // tx_coef_size
};

 

Whether can not use just 16 taps for setting the FIR?

 

Thanks

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