Maximal length sequences are also the base of sets of sequences with good correlation properties. An example of this system identification is provided. This 'impulsive' autocorrelation function allows one to quickly determine the impulse response of a linear time invariant (LTI) system. Some of these LFSR sequences have special properties a maximal length sequence (MLS or m-sequence) has a large autocorrelation at zero lag, with near zero autocorrelation elsewhere. A equivalent mex file is included, which runs approximately 100 times faster than the m file. The code is written for a 32 bit LFSR, but minor alterations allow for 8-64 bit versions.
The LFSR code provided is very unrestricted, allowing for any feedback polynomial, initial state or decimation factor. Linear feedback shift registers (LFSR) are a simple method of generating sequences, including pseudorandom number sequences.
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