Home
Modems
Telephony
Audio
Utilities
Consultancy
Glossary
Index
Contact us

Noise Generator DSP C Code

Description: this routine generates signed random noise samples having a Gaussian distribution. The code is based on a pseudo-random generator which repeats every ~2x10^9 samples. The generator output is converted into samples having Gausssian Probability Density Function (PDF) and Cumulative Distribution Function (CDF) distributions. The crest factor, i.e. the peak signal sample relative to the Root-Mean-Square (RMS) value, is 6.15. Thus for a set RMS value (by assembler equate) of 4096 decimal, the peak signal obtainable is ~±25,000.
         The C code is suitable for any processor with an ANSI-compliant C compiler. It is designed especially for efficient operation on low-cost fixed-point DSP- and general-purpose micro-processors. All data memory is specified as 16-bit integer words. Multiplies are integer 16x16-bit with 32-bit products.
         The software is in the form of two callable subroutines, one for start-up initialisation and one for generation of each sample. Successive calls of the main routine generate successive noise samples that are uncorrelated. The code is re-entrant.

Performance: (values measured over complete pseudo random cycle)

Full performance results are available.

Processor Load:

- #example figures from compiling for the TI TMS320C5000(C55x) DSP processor at 8kHz sampling

Availability: NOW - sale is under licence - integration support offered