Abstract: A transmitter employing a cryptographic algorithm and key generates and transmits a staggered pulse signal that includes a plurality of high-power pulses that are part of a pseudonoise (PN) code. The high-power pulses are separated by a group of low-power chips and the time interval between the high-power pulses is varied according to the cryptographic algorithm and key. A receiver, employing a corresponding cryptographic algorithm and key receives the signal and correlates it with a locally generated code that is modified according to the cryptographic algorithm and key to detect the phase of the received PN code. The receiver also can include a matched filter configured according to the cryptographic algorithm and key to detect the sequence of high-power pulses in the received signal.

Abstract: A spectral notch modulation technique for encoding information in a signal involves transforming the signal into the frequency domain via a fast Fourier transform (FFT) of length N, such that the signal is represented by N frequency bins, selectively nulling M of the N frequency bins, where nulled combinations of M frequency bins respectively correspond to encoded information bits, transforming the selectively nulled signal to the time domain via an inverse FFT, and transmitting the selectively nulled signal. At the receiving end, the signal is demodulated to recover the encoded information by transforming the signal into the frequency domain via a fast Fourier transform (FFT) of length N, identifying the set of M nulled frequency bins among the N frequency bins, and converting the set of M nulled frequency bins to corresponding information bits.

Abstract: A quadrature multi-frequency ranging system applied to DSSS multipath mitigation problems is described. The QMFR techniques include taking the time-of-arrival measurements on the received signal at a time when the multipath component is at a 90 degree angle to the direct path. Further, the preferred embodiment of the present invention recognizes that when a signal is transmitted at a series of frequencies, and the spread of these frequencies is sufficient, a quadrature or near quadrature condition can be forced to occur, at which the TOA estimation gives the highest certainty of measurement.

Abstract: A quadrature multi-frequency ranging system applied to DSSS multipath mitigation problems is described. The QMFR techniques include taking the time-of-arrival measurements on the received signal at a time when the multipath component is at a 90 degree angle to the direct path. Further, the preferred embodiment of the present invention recognizes that when a signal is transmitted at a series of frequencies, and the spread of these frequencies is sufficient, a quadrature or near quadrature condition can be forced to occur, at which the TOA estimation gives the highest certainty of measurement.

Abstract: Operational parameters for transmitting a signal over a communication channel of a network are selected by first determining RF conditions on the communication channel from a received signal transmitted over the communication channel. An initial set of parameter values is selected for transmitting the signal based on RF conditions determined from the received signal. The initial set of parameter values is used to identify other sets of parameter values as other potential candidates for transmitting the signal. The parameter values in the other sets of parameter values differ from parameter values in the initial set of parameter values by less than a predetermined amount. The expected performance of the candidate sets of parameter values is compared to determine which set of parameter values has the best expected performance among the candidate sets of parameter values. The signal is transmitted on the communication channel using the selected set of parameter values.

Abstract: A transmitter employing a cryptographic algorithm and key generates and transmits a staggered pulse signal that includes a plurality of high-power pulses that are part of a pseudonoise (PN) code. The high-power pulses are separated by a group of low-power chips and the time interval between the high-power pulses is varied according to the cryptographic algorithm and key. A receiver, employing a corresponding cryptographic algorithm and key receives the signal and correlates it with a locally generated code that is modified according to the cryptographic algorithm and key to detect the phase of the received PN code. The receiver also can include a matched filter configured according to the cryptographic algorithm and key to detect the sequence of high-power pulses in the received signal.

Abstract: The Coin and Token Roll Opener facilitates the opening of machine packaged paper rolls of coins and tokens. The Coin and Token Roll Opener consists of top and bottom wings, joined by an eyelet, upon which are mounted rotating, circular cutters. The wings rotate about the eyelet to fit various coin and token roll sizes. For sturdiness that facilitates the opening process, both wings are cast in aluminum and the rotating, circular cutters are constructed from stainless steel. Paper rolls of coins and tokens are opened by gripping the Coin and Token Roll Opener in one hand and inserting the roll of coins or tokens into the opener with the other hand and rotating while squeezing the sides, or wings, of the opener firmly against the roll. The four rotating, circular cutters in the opener cut off the top of the paper roll so that the paper roll can be easily peeled away from the coins or tokens.

Abstract: There is disclosed a high frequency communication system of the type employing a high frequency terminal which terminal can transmit a processed signal in a transmitting mode or process a received signal in a receiving mode which terminal includes a first subsystem for voice processing, including a processor responsive to voice signals to provide a linear predictive coded voice signal at a given data rate which signal is coupled to a data modem subsystem that digitally encrypts said voice signal which data modem subsystem is coupled to a modem processor subsystem capable of processing said encrypted signal for providing frequency hopping, feedback equalization, intersymbol interference cancellation, error correction and interleaving to provide a transmitted signal which is relatively immune to jamming during said transmitting mode which includes a convolutional encoder means included in said modem processor subsystem responsive to said encrypted signal to provide a convoluted signal at a higher data rate than