Title :
Blind estimation of direct-sequence spread spectrum m-sequence chip codes
Author :
Hill, P.C.J. ; Ridley, M.E.
Author_Institution :
Dept. of Inf. & Simulation, R. Mil. Coll. of Sci., Shrivenham, UK
Abstract :
The Massey (1969) algorithm for breaking cryptographic codes based on linear feedback shift register (LFSR) generators can also be used to detect pseudonoise (PN) chip-code sequences in direct-sequence spread spectrum (DS/SS) signals from short intercepted snapshots in low-noise channels. The algorithmic process has been extended in order to estimate DS/SS m-sequence codes of unknown order by solving for the LFSR tap sets over multiple windows using majority-vote logic. The effects on performance of random chip errors, digital modulation, and multiple code schemes, such as code-division (CDMA) and Gold sequences, have been investigated
Keywords :
codes; m-sequences; majority logic; modulation; multiuser channels; parameter estimation; pseudonoise codes; signal detection; spread spectrum communication; CDMA sequences; DS/SS channels; DS/SS signals; Gold sequences; LFSR generators; LFSR tap sets; Massey algorithm; PN chip-code sequences detection; algorithmic process; blind estimation; cryptographic code breaking; digital modulation; direct-sequence spread spectrum; linear feedback shift register generators; low-noise channels; m-sequence chip codes; majority-vote detection; majority-vote logic; multiple code; pseudonoise chip-code sequences; random chip errors; Cryptography; Equations; Gold; Multiaccess communication; Noise generators; Recursive estimation; Signal generators; Signal processing; Spread spectrum communication; Spread spectrum radar;
Conference_Titel :
Spread Spectrum Techniques and Applications, 2000 IEEE Sixth International Symposium on
Conference_Location :
Parsippany, NJ
Print_ISBN :
0-7803-6560-7
DOI :
10.1109/ISSSTA.2000.878134
