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Demodulator with CINR Estimation

Question asked by yuyang339 on Apr 27, 2010
Latest reply on Apr 27, 2010 by CraigG

Hi,

 

I am using the API Reference for the Analog Devices 802.16 OFDMA Software Library for the TigerSHARC Processor, release 1.7.

 

I've got a problem when i read the source code of 'qam16_demodulator_cinr' in the library.

 

Q1: Can anyone tell me what the meaning of these values A0, A1, A2 and how can i derive these values?

Q2: How can I derive this equation cinr = (A2 * cinr + A1) * cinr + A0 ?

 

#define A0 -16.9853
#define A1 3.0092
#define A2 -0.0588

 

cinr = 10.0 * log10(MSE_recip);

    if (cinr <= 15.0) {

        cinr = (A2 * cinr + A1) * cinr + A0;

    }

 

Regards,

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