[linux-dvb] Values returned by IOCTL: FE_READ_BER, FE_READ_SNR

Menion menion at gmail.com
Wed Oct 31 12:52:54 CET 2007


Tipically SNRdB = 10 * Log10( SNR )
In this case you have around 40dB of SNRdB, assuming that the value of SNR
you got is linear

I can't understand what is the representation of bit error rate

2007/10/31, Roberto Granato <granroby at gmail.com>:
>
> How to interpret the values returned using  FE_READ_BER and FE_READ_SNR
> in a frontend IOCTL?
>
> The definition of BER is (error bit)/(total bit) in a time interval,
> while the definition of SNR is (signal power)/(error power).
>
> In the DVB Frontend API I see that BER is a uint32_t and SNR ia a
> uint16_t.
>
> For example, with a poor signal I got the following values:
>
> Bit error rate: 304146
> Signal strength: 38576
> SNR: 22359
>
> Bit error rate: 316097
> Signal strength: 37912
> SNR: 21588
>
> The interval between two readings is 5 seconds.
>
> Why BER is a (so) big number?
> How to express SNR with dB?
>
> Thanks,
> Roberto Granato
>
>
>
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