fixed point issue inSRC

Started by srikk March 20, 2007

I am implimenting a SRC for both decimation and interpolation using
polyphase filter implementation.

my question is 

1.i take a sine wave (+1 to -1) of 24 bit and convolving with filter  
  taps of 1.31 format.
2. when i save my result after filtering to 24 bit, i need to truncate the

   result to 24 bit and save it
3. in the above process i found the output sine wave having a maximum 
   value of 1.002 and i am truncating it to 1.000
   because of this i get a error of 0.001 at some point and my final SNR 
   of the resultant signal  is detoriated.
4. when i dont truncate the result i get a proper signal and SNR...

IS there a method to redue the error by some means (dithering, HalfaddUp)
any inputs are helpful...