Abstract: A High-Order PSK Signaling (HOPS) communications system which adapts sequence-based spread spectrum signaling techniques to the needs of low-power commercial standards. A HOPS signal generation apparatus incudes a seed calculator configured to calculate a series of seed vectors in response to a plurality of time-evolving key values wherein each of the seed vectors includes a plurality of index values calculated based upon the current key values. A sequence generator is configured to generate a series of time-evolving spreading sequences using the series of seed vectors. A modulator is operative to generate the communications signal by spreading the data signal using the spreading sequences. A transmitter transmits an analog version of the communications signal.

Abstract: A High-Order PSK Signaling (HOPS) communications system which adapts sequence-based spread spectrum signaling techniques to the needs of low-power commercial standards. A HOPS signal generation apparatus incudes a seed calculator configured to calculate a series of seed vectors in response to a plurality of time-evolving key values wherein each of the seed vectors includes a plurality of index values calculated based upon the current key values. A sequence generator is configured to generate a series of time-evolving spreading sequences using the series of seed vectors. A modulator is operative to generate the communications signal by spreading the data signal using the spreading sequences. A transmitter transmits an analog version of the communications signal.

Abstract: A correlation apparatus including a sequence generator configured to generate a non-repeating preamble sequence which changes during each of a plurality of time epochs. The correlation apparatus includes a fallthrough correlator having a tapped delay line for receiving a set of complex-valued samples of a received signal. Each of a plurality of complex multipliers of the correlator is coupled to one of the delay line taps. Each multiplier multiplies, during one of the plurality of time epochs, one of the complex-valued samples of the received signal by one of a plurality of matched filter coefficients corresponding to the preamble sequence. A summation module includes a plurality of adders where a last of the plurality of adders outputs a correlation signal. A peak value of the correlation signals exceeds a threshold value when a sufficient correlation exists between the received signal and the values of the preamble sequence.

Abstract: A signal receiver for receiving a HOPS-based communications signal includes a seed calculator configured to produce a series of seed vectors generated from a corresponding series of sets of key values. A sequence generator provides a series of internally generated sequences using the series of seed vectors. A fallthrough correlator produces a series of correlation values by correlating samples of a received signal and samples of the internally generated sequences. The spreading sequences are used by a transmitter to generate a transmit signal subsequently received as the received signal. A peak detector is configured to generate a trigger signal upon determining that at least one of the correlation values exceeds a threshold value. At least one of a plurality of demodulator chains is selected in response to the trigger signal and used to demodulate the received signal in order to recover data values carried by the received signal.

Abstract: A candidate arbitrary-phase spread spectrum modulation technique that offers similar performance to spread continuous phase modulation (CPM) waveforms and additional capabilities for programming a chosen frequency domain spectra into the resulting spread spectrum signal. The proposed chaotic-FSK waveform is derived from high-order sequence-based spread spectrum signals, with multi-bit resolution chaos-based sequences defining incremental phase words, enabling real-time efficient generation of practically non-repeating waveforms. A result of the C-FSK formulation is a parameterized hybrid modulation capable of acting like a traditional sequence-based spread spectrum signal or a traditional frequency shift keying signal depending on chosen parameters. As such, adaptation in this modulation may be easily implemented as a time-varying evolution, increasing the security of the waveform while retaining many efficiently implementable receiver design characteristics of traditional PSK modulations.

Abstract: A signal receiver for receiving a HOPS-based communications signal includes a seed calculator configured to produce a series of seed vectors generated from a corresponding series of sets of key values. A sequence generator provides a series of internally generated sequences using the series of seed vectors. A fallthrough correlator produces a series of correlation values by correlating samples of a received signal and samples of the internally generated sequences. The spreading sequences are used by a transmitter to generate a transmit signal subsequently received as the received signal. A peak detector is configured to generate a trigger signal upon determining that at least one of the correlation values exceeds a threshold value. At least one of a plurality of demodulator chains is selected in response to the trigger signal and used to demodulate the received signal in order to recover data values carried by the received signal.

Abstract: A correlation apparatus including a sequence generator configured to generate a non-repeating preamble sequence which changes during each of a plurality of time epochs. The correlation apparatus includes a fallthrough correlator having a tapped delay line for receiving a set of complex-valued samples of a received signal. Each of a plurality of complex multipliers of the correlator is coupled to one of the delay line taps. Each multiplier multiplies, during one of the plurality of time epochs, one of the complex-valued samples of the received signal by one of a plurality of matched filter coefficients corresponding to the preamble sequence. A summation module includes a plurality of adders where a last of the plurality of adders outputs a correlation signal. A peak value of the correlation signals exceeds a threshold value when a sufficient correlation exists between the received signal and the values of the preamble sequence.

Abstract: A candidate arbitrary-phase spread spectrum modulation technique that offers similar performance to spread continuous phase modulation (CPM) waveforms and additional capabilities for programming a chosen frequency domain spectra into the resulting spread spectrum signal. The proposed chaotic-FSK waveform is derived from high-order sequence-based spread spectrum signals, with multi-bit resolution chaos-based sequences defining incremental phase words, enabling real-time efficient generation of practically non-repeating waveforms. A result of the C-FSK formulation is a parameterized hybrid modulation capable of acting like a traditional sequence-based spread spectrum signal or a traditional frequency shift keying signal depending on chosen parameters. As such, adaptation in this modulation may be easily implemented as a time-varying evolution, increasing the security of the waveform while retaining many efficiently implementable receiver design characteristics of traditional PSK modulations.