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This version (18 May 2021 09:00) was approved by Nikhin Shetty.

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NLMS Filter



Description

This implementation of NLMS is a block based implementation. The weight update happens at the end of every processing block.

Variants

  1. NLMSFilter
  2. FxNLMSFilter

Targets Supported

Name ADSP-214xx ADSP-215xx/SC5xx ADAU145x/146x
—————————— ——————-- ——————————-- —————————-
NLMSFilter B B S
FxNLMSFilter NA NA S


Pins

Input

NameTypeDescription
———————- ———————— —————————————————————————————
Input0AudioInput Channel 0
Desired Signal Audio The desired audio output signal (Applicable for NLMSFilter)
Error Signal Audio The error signal would be the difference between the desired response and the output of the FxLMS filter.(Applicable for FxNLMSFilter)
Ref Signal Audio The Reference input will be the reference to the noise to be cancelled (Applicable for FxNLMSFilter)
Adapt On/Off Control Signal which indicates whether FIR filter weights are to be updated or not

Output

NameTypeDescription
———————- ————-- ———————-
Output0AudioFiltered output
ErrorSignal Control Error Signal - Difference signal between desired signal and the filtered output (Applicable for NLMSFilter)


Configurable Parameters

GUI Parameter NameDefault ValueRangeFunction Description
—————————————- ———————- —————— —————————————-
Alpha 0.10 to 1Filter learning rate
NumberOfTaps 2568 to 3200Number of Filter Taps
Leakage 0.01 0.01 to 1 Leakage factor is used as forgetting factor


DSP Parameters

Parameter Name Description ADSP-214xx/SC5xx/215xx ADAU145x/146x
—————————————- ——————————————————————————-- —————————————- —————————-
Alpha Filter learning rate Float FixPoint8d24
leakage_factor Filter Leakage factor NA FixPoint8d24


resources/tools-software/sigmastudiov2/modules/filters/nlmsfilter.txt · Last modified: 13 May 2021 09:24 by Nikhin Shetty