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Altera_Forum
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14 years ago

Quantization Problem...Help Please

Hi i'm working on a 2 Channel QMF perfect reconstruction Filter bank using a tutorial in Matlab and i'm trying to implement the design on a Cyclone II FPGA board. after setting everything up i notice...
Altera_Forum's avatar
Altera_Forum
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14 years ago

The specific problem is i dont know why im not getting the output to be the same as the input, when the simulation shows that it should be...ive taken some of the things you've said into consideration like the bit growth of the filters, but i dont get why it cant represent an 11 bit magnitude as a 34 bit magnitude. also i'm not sure if the word length of the coefficients affect this bit growth.

The input Range should be the highest signed 11 bit number which is +-1025, and the output range should be the same. theres a high pass decimator and low pass decimator, with a 10 bits to represent their coefficients. same for the interpolators. the decimators and interpolators are halfband filters.