Adaptive Noise Reduction in the new 8000 radios

Trucker

Reading through the 8000 radios hardware manual I found a section stating that the 8000 radios have Adaptive Noise Reduction. Looking at the hardware manual for the 6000 radios there is no mention of what type of noise reduction the 6000 radios use.
I do know that they use Spectral Subtraction as one of the algorithms used in the 6000 radios. And from some limited research, I find that Adaptive Noise Reduction can use Spectral Subtraction along with other algorithms.
Dr Warren Pratt's WDSP library uses Least Mean Square algorithms as well as the new AI trained algorithm for noise reduction which works extremely well. ( for the radios that use Thetis)
My question is, is Adaptive Noise Reduction something new and exclusive to 8000 radios? Or does it exist in the 6000 radios as well?
I have not had the opportunity to hear how well the noise reduction in the new radios work compared to the 6000 radios. I have yet to find a comparison video online.
I hope someone can provide some insight to any differences there are ( if any) between the two series of radios.
James
WD5GWY

km9r.mike

I hope someone can provide some insight to any differences there are ( if any) between the two series of radios.

Hi James,

I have not noticed any difference in NR between my 6700 and 8600, I assumed any upgrade with NR will come with new releases in SSDR. However, your attention to detail appears to have let the future cat out of the bag. I am not certain how much detail FRS would be willing to share about this unknown feature (ANR) that appears to be documented ahead of it's release. Interesting indeed and thanks for sharing.

73,

mike

Trucker

A quick uplate. Dan Quigley posted a reply to my questions on the Flex Radio Facebook page. Basically, he said that currently, both series of radios ( 6000 and 8000) share the same code base for noise reduction and noise blanker. Both use Adaptive Noise Reduction and the same algorithms to process the audio to remove/reduce, noise in a received signal. He did say that as improvements are made in noise reduction and noise blanking, that the differences between the two hardware platforms will make things diverge as the hardware in the 6000 radios will not be capable of doing what the new hardware can do. This should make for some interesting things that might make moving to the new radios more attractive. Whoever wrote the hardware manual for the new radios went a lot further in describing noise reduction and blanking than what was used in the 6000 radios hardware manual. I feel like that is what led me to believe that ANR was a new technology that Flex Radio was using ( or going to use) in the new 8000 radios. It turns out that the new hardware manual was better written and more descriptive than the 6000 hardware manual.

James

WD5GWY

km9r.mike

SSDR v3. user guide agrees that adaptive is not new but labeling NR "ANR" would be

15.5 NOISE REDUCTION (NR)
The Noise Reduction processor (NR) will reduce random (“white”) noise making signals more
readable which are buried in the noise. It is best to adjust the AGC threshold first, and then enable
the Noise Reduction.
The Noise Reduction algorithm uses a correlation based adaptive filter. Noise Reduction increases
correlation between input and output with the assumption that noise is uncorrelated and should be
canceled out. The threshold adjustment controls the adaptation rate of the filter, so in the case of
Noise Reduction, there will be very little audible change while adjusting the threshold unless the
noise is changing rapidly or dramatically. The most aggressive settings of Noise Reduction increase
the signal to noise ratio but will tend to “color” the signal. The slider should be set for the optimal
tradeoff between signal to noise ratio and minimal distortion of the desired signal.