M-sequence

M-sequence（Maximum length sequence、MLS、最大長度序列）是在基本的通訊電路設計中，所經常被利用到的一個虛擬隨機數位訊號《Pseudo Random Sequence》，其主要的方式是利用第一位與其他位暫存器的輸出值做ex-or來設計其第一位暫存器的輸入值。

參考文獻

• Golomb, Solomon W.; Guang Gong. Signal Design for Good Correlation: For Wireless Communication, Cryptography, and Radar. Cambridge University Press. 2005. ISBN 978-0-521-82104-9. 

外部連結

• Bristow-Johnson, Robert. A Little MLS Tutorial. —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.
• Hee, Jens. Impulse response measurement using MLS (PDF).  —Paper describing MLS generation. Contains C-code for MLS generation using up to 18-tap-LFSRs and matching Hadamard transform for impulse response extraction.
• Kerr, Wesley. Creation of M-Sequences. Geoffrey Aguirre Lab. University of Pennsylvania.  ]
• Linear Feedback Shift Registers. New Wave Instruments. 2005. —Properties of maximal length sequences, and comprehensive feedback tables for maximal lengths from 7 to 16,777,215 (3 to 24 stages), and partial tables for lengths up to 4,294,967,295 (25 to 32 stages).
• Schäfer, Magnus. Aachen Impulse Response Database. Institute of Communication Systems and Data Processing, RWTH Aachen University. October 2012. V1.4.  A（binaural）room impulse response database generated by means of maximum length sequences]
• Efficient Shift Registers, LFSR Counters, and Long Pseudo-Random Sequence Generators—Obsolete (PDF). Xilinx. July 1996. XAPP052 v1.1. —Implementing lfsr's in FPGAs includes listing of taps for 3 to 168 bits