Gaussian Random Number Generator¶
Gaussian Random Number Generator)
This is a low foot-print Gaussian noise source for testing CASPER based hardware designs during development. It contains a pair of uncorrelated noise and each noise data is available as four parallel output streams, which are directly compatible to the iADC outputs.
|Reset signal to initialize the noise sources. Reset is synchronous active high signal.
|Noise_Out11 to Noise_Out14
|Four uncorrelated streams of noise samples.
|Noise_Out21 to Noise_Out24
|Four uncorrelated streams of noise samples. These are also uncorrelated with respect to Noise_Out11 to Noise_Out14 signals.
The noise source blocks do not use any specific resources like BRAMs, multipliers etc. The Kurtosis value of these sources is around 2.9 to 2.93. Both of these sources can be used as individual noise source or collectively as uncorrelated noise sources. The resource utilization is around 2 to 3 % for a single noise source on Virtex-5 SX95 FPGA.
Note: The seeds of the individual noise sources can be changed. But the seeds need to be mutually uncorrelated for a particular source i.e. considering only one source say Noise Source -1 ,all the fourteen seeds within that source have to mutually uncorrelated.
Test was carried out by integrating these uncorrelated sources with a pocket correlator design running at 600MHz ADC clock and having 1 second integration time, implemented on ROACH. The results show a flat spectrum across all the FFT channels and a normalized cross-correlation of about 0.001.