SciPy

scipy.signal.max_len_seq

scipy.signal.max_len_seq(nbits, state=None, length=None, taps=None)[source]

Maximum length sequence (MLS) generator.

Parameters:

nbits : int

Number of bits to use. Length of the resulting sequence will be (2**nbits) - 1. Note that generating long sequences (e.g., greater than nbits == 16) can take a long time.

state : array_like, optional

If array, must be of length nbits, and will be cast to binary (bool) representation. If None, a seed of ones will be used, producing a repeatable representation. If state is all zeros, an error is raised as this is invalid. Default: None.

length : int | None, optional

Number of samples to compute. If None, the entire length (2**nbits) - 1 is computed.

taps : array_like, optional

Polynomial taps to use (e.g., [7, 6, 1] for an 8-bit sequence). If None, taps will be automatically selected (for up to nbits == 32).

Returns:

seq : array

Resulting MLS sequence of 0’s and 1’s.

state : array

The final state of the shift register.

Notes

The algorithm for MLS generation is generically described in:

The default values for taps are specifically taken from the first option listed for each value of nbits in:

http://www.newwaveinstruments.com/resources/articles/
m_sequence_linear_feedback_shift_register_lfsr.htm

New in version 0.15.0.