Observing Random Jitter in HackRF One in High Bandwidth with High Carrier Modulation

Yet i work on DVB-T in HackRF one, in TX we can send DVB-T and we receive it with a hardware dongle DVB-T. but for receiving with SDR Based we had error: see this link for our older work or this link.

DVBT project receiver probelm OOrestart aquisition d_freq_offset: -5 Od_freq_offset: -5

So for examine my problem i created a new issue on hackrfone github project see this link, every thing i found i will update there. In older our post we define jitter error , for more info you can see this link.

Fig1:Jitter error diagram description

  • So we start examine that how we observed HackRF One has Random jitter errors??

my reason why HackRF One has random jitter error, In protocol like gr-dvbt,gr-ofdm,gr-atsc that they are ofdm based modulation, we had not any response in receiver mode in dvb-t we had famous error: but frequency offset instantly from -5,3,2,7,….

restart aquisition d_freq_offset: -5 Od_freq_offset: -5

So we  had a error in uncertianly frequency and other hand it is random, so we had radom jitter errror.for more info see this link.

  • reason of causing HackRF  One has Jitter error?
  • Low Resolution ADC:

after some search i concluded that one of reason for random jitter error in HackRFOne is low resolution ADC, it has 8 bit ADC,please see this link that describe how low resolution ADC can create jitter errors .

  •     Low SNR in  HackRF One:

For problem long switch diode stage in RF HackRF One it is more noisy vs USRP. So it use long way RF, it should edited in newer version.

you can see in below image and link that how bad SNR and low ADC resolution can caused jitter errros.

for more info please see this link.

 

jitterADC

Fig2:low resolution ADC can cause jitter errors

 

So we saw that HackRF One in OFDM based modulation and high carrier or in high bandwidth it sucks and it has random jitter errors, so we should ask myself that we need new design opensource hardware SDR hardware?

But some question is need to answered??

why is mention HackRFOne has bandwidth 20 MSPS…..??
we should define bandwidth and sps in high carrier modulation
it has problem in high carrier modulation?.So really HackRF One have Bandwidth more than 2 MSPS?

but what's solution?


  • using a external clock for hackrf one???

  • design a new hardware………?

i liked hackrfone for reason that is opensource and hardware, but with this condition i concluded that
we should think a new way for future sdr hardware opensource?

best regards stackprogramer

Fig3:HackRFOne a opensource hardware SDR hardware

 

 

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