Help with FPGA correlator

Thanks all who has replied my thread. Much appreciate.

To OrchestraDirector: yeah, I've read the altmult_accum document, understand how it works, but still have no idea how many multiplier-accumulator is required in my design, did you mean 1 ? (1 mult_accum ---> 1 multiplier, right?), then I don't know how could I replace my 66 multipliers by just 1 mult_accum circuit, because most of the time, more than one multiplication needs to be carried out at one moment... Anyway, your suggestion gave me a brand new idea about correlator design. Thank you very much.

To parrado: yes, I stop thinking about the FFT. However, I don't understand "Transpose Structure", googled it but so few found related result. Could you please provide me some links or documents ? That would be excellent.

The FPGA correlator is used in a sound velocity sensor device, it correlates a 66 points reference signal (which can be transfered from the ROM of a microprocessor) with signals coming in from an ADC (I'm not sure about the A-D sampling fre, the layout said the A-D clock is 40Mhz, so I assumed the sampling frequency is 40Mhz)

Thank you