Cincinnati Electronics Corporation

Bruce Edward Shockey

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.

Spread spectrum chip shift keying modulation/demodulation system and

A system and method for transmitting one or more range safety commands to a launch vehicle which includes transmitting structure having a pilot code generator and at least one additional code generator for generating at least one transmitter command code corresponding to a range safety command. A PN clock continuously locks the one or more transmitter command codes with the transmitter pilot code. Sequence selection structure selectively applies the one or more transmitter command codes to a modulator which combines the transmitter pilot code and the applied transmitter command codes with a carrier signal, and transmits the pilot and command codes through a relay satellite to the vehicle. Receiving structure in the vehicle recovers the pilot and command codes, and aligns a locally generated pilot code with the recovered pilot code. At least one local command code generator, which is synchronized to the local pilot code, is included in the receiving structure for generating one or more local command codes which correspond to the transmitter command codes. The local command codes and recovered transmitter command codes are sampled, and the samples compared over an acquisition period. If at the end of an acquisition period any set of samples exceeds a predetermined level of correspondence, then a hit detect signal is transmitted to decision logic in the vehicle. If all of the hit detect signals for a command are detected by the decision logic within a predetermined time interval, then the decision logic activates the command.

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Mason, OH, United States of America

Bruce Edward Shockey