Pulse or digital communications – Spread spectrum – Direct sequence
Patent
1997-06-20
2000-07-25
Chin, Stephen
Pulse or digital communications
Spread spectrum
Direct sequence
375142, 332103, 329304, H04K 100, H03C 300, H03D 300
Patent
active
060944501
ABSTRACT:
A modulation/demodulation system and method comprising transmitting structure having first and second PN generators which produce distinct, synchronized, first and second PN sequences. A tapped delay line generates a plurality of symbols from the second PN sequence, each symbol corresponding to an offset of the second PN sequence by one or more chips from the epoch of the first PN sequence. A plurality of output taps are associated with the tapped delay line, with each tap corresponding to one of the symbols. A symbol selection device associated with the output taps selects from amongst the symbols based upon one or more message signal bits. The selected symbols and first PN sequence are applied to separate channels of a modulator to modulate a carrier signal. At a destination, first and second local PN generators generate first and second PN sequences which correspond to the first and second PN sequences in the transmitting structure. A tapped delay line connected to the second local PN generator generates a plurality of symbols which correspond to the symbols in the transmitting structure. An analog baseband signal is recovered from the modulated carrier signal and sampled, and each sample is multiplied by the symbols from the tapped delay line. The resulting products are filtered, summed and compared to a predetermined threshold, and the sum which exceeds the threshold is converted to a bit pattern. Consecutive bit patterns are combined to produce a serial data stream which corresponds to the message signal.
REFERENCES:
patent: 4217586 (1980-08-01), McGuffin
patent: 4583231 (1986-04-01), Puckette
patent: 4933952 (1990-06-01), Albrieux et al.
patent: 4998261 (1991-03-01), van Driest et al.
patent: 5020075 (1991-05-01), Tachita
patent: 5166951 (1992-11-01), Schilling
patent: 5243622 (1993-09-01), Lux et al.
patent: 5257282 (1993-10-01), Adkisson et al.
patent: 5313457 (1994-05-01), Hostetter et al.
patent: 5383220 (1995-01-01), Murai
patent: 5414728 (1995-05-01), Zehavi
patent: 5454005 (1995-09-01), O'Clock et al.
patent: 5499265 (1996-03-01), Dixon et al.
patent: 5712869 (1998-01-01), Lee et al.
Chin Stephen
Cincinnati Electronics Corporation
Park Albert
LandOfFree
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