unknown if it can be improved beyond 3 dB. Relationship to Hadamard transform Cohn and Lempel showed the relationship of the MLS to the Hadamard transform. This relationship allows the correlation of an MLS to be computed in a fast algorithm similar to the FFT. See also Barker code Complementary sequences Federal Standard 1037C Frequency response Gold code Impulse response Polynomial ring References External links — Short on-line tutorial describing how MLS is used to obtain the impulse response of a linear time-invariant system. Also describes how nonlinearities in the system can show up as spurious spikes in the apparent impulse response. — Paper describing MLS generation. Contains C-code for MLS generation using up to 18-tap-LFSRs and matching Hadamard transform for impulse response extraction. A (binaural) room impulse response database generated by means of maximum length sequences. — Implementing lfsr's in FPGAs includes listing of taps for 3 to 168 bits Pseudorandomness Polynomials Binary sequences