[Discuss-gnuradio] Re: Calculate SNR

[Neal Becker]

Brian Padalino wrote:

> On 11/9/07, Meenaktchi Venkatachalam <address@hidden> wrote:
>> Hi,
>>
>> I was wondering how to calculate SNR. Is there function already a
>> function that I can use to find SNR?
> 
> If you know where your constellation symbols are, and you know where
> the IQ symbol really ended up after equalization - calculating the
> amount of noise should be straight forward.
> 
> I don't know if there is a block which takes in a constellation
> mapping along with a stream of IQ datapoints and calculates SNR.
> 
> Brian

You can compute mse between received points and hard decisions, but this
will be a biased estimate at low s/n.