Dear Sir, <br />
<br />
I am Shashank, fresher to DSP field. Sir I was going through your fixed point echo <br />
cancellation module , here I am not getting the computation of RER in the fixed <br />
point. The lower bound computation for the same in floating point is having the <br />
error energy term but when I tried to solve the same equation for fixed point I <br />
did not get the equation implemented in code, the term used in the LHS of the (b) <br />
if condition is equivalently modified to (RER * See) in fixed point, but I am not <br />
clear with RHS computation of the same in equation equation (f) and the <br />
corresponding comparisons.<br />
<br />
RER = (.0001*Sxx + 3.*MULT16_32_Q15(st->leak_estimate,Syy)) / See; - a<br />
if (RER < Sey*Sey/(1+See*Syy)) ---------------------------------- b<br />
<br />
tmp32 = MULT16_32_Q15(st->leak_estimate,Syy);----------------------- c<br />
tmp32 = ADD32(SHR32(Sxx,13), ADD32(tmp32, SHL32(tmp32,1)));------ d<br />
{<br />
spx_float_t bound = PSEUDOFLOAT(Sey);------------------------- e<br />
bound = FLOAT_DIVU(FLOAT_MULT(bound, bound),<br />
PSEUDOFLOAT(ADD32(1,Syy)));-------- f<br />
if (FLOAT_GT(bound, PSEUDOFLOAT(See)))------------------------ g<br />
tmp32 = See;<br />
<br />
Waiting for your reply...<br />
<br />
Thank You in advance<br />
<br />
With Regards<br />
Shashank V K<br />
<br />
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