Patent classifications
H04L2203/00
HIGH-ORDER PSK SIGNALING (HOPS) TECHNIQUES FOR LOW-POWER SPREAD SPECTRUM COMMUNICATIONS
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.
High-order PSK signaling (HOPS) techniques for low-power spread spectrum communications
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.
High-order PSK signaling (HOPS) techniques for low-power spread spectrum communications
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.
Systems and methods for up-sampling a polar amplitude sample stream in a polar modulator
Systems and methods for up-sampling a polar amplitude sample stream in a polar modulator are disclosed. In some embodiments, a process includes receiving, at a polar modulator, an in-phase sample stream and a quadrature sample stream which together characterize a data signal in an IQ plane. The process includes generating a polar amplitude sample stream and a polar phase sample stream. The process includes generating an up-sampled polar amplitude sample stream by (i) identifying an origin crossing of the data signal in the IQ plane, (ii) responsively adjusting an inversion trigger, (iii) selectively applying an inversion to the polar amplitude sample stream based on the inversion trigger, (iv) interpolating the selectively inverted polar amplitude sample stream, and (v) removing the inversion from the interpolated selectively inverted polar amplitude sample stream. The process includes modulating a carrier signal using the up-sampled polar amplitude stream and the polar phase sample stream.
SYSTEMS AND METHODS FOR UP-SAMPLING A POLAR AMPLITUDE SAMPLE STREAM IN A POLAR MODULATOR
Systems and methods for up-sampling a polar amplitude sample stream in a polar modulator are disclosed. In some embodiments, a process includes receiving, at a polar modulator, an in-phase sample stream and a quadrature sample stream which together characterize a data signal in an IQ plane. The process includes generating a polar amplitude sample stream and a polar phase sample stream. The process includes generating an up-sampled polar amplitude sample stream by (i) identifying an origin crossing of the data signal in the IQ plane, (ii) responsively adjusting an inversion trigger, (iii) selectively applying an inversion to the polar amplitude sample stream based on the inversion trigger, (iv) interpolating the selectively inverted polar amplitude sample stream, and (v) removing the inversion from the interpolated selectively inverted polar amplitude sample stream. The process includes modulating a carrier signal using the up-sampled polar amplitude stream and the polar phase sample stream.
Systems and methods for up-sampling a polar amplitude sample stream in a polar modulator
Systems and methods for up-sampling a polar amplitude sample stream in a polar modulator are disclosed. In some embodiments, a process includes receiving, at a polar modulator, an in-phase sample stream and a quadrature sample stream which together characterize a data signal in an IQ plane. The process includes generating a polar amplitude sample stream and a polar phase sample stream. The process includes generating an up-sampled polar amplitude sample stream by (i) identifying an origin crossing of the data signal in the IQ plane, (ii) responsively adjusting an inversion trigger, (iii) selectively applying an inversion to the polar amplitude sample stream based on the inversion trigger, (iv) interpolating the selectively inverted polar amplitude sample stream, and (v) removing the inversion from the interpolated selectively inverted polar amplitude sample stream. The process includes modulating a carrier signal using the up-sampled polar amplitude stream and the polar phase sample stream.
FALLTHROUGH CORRELATION TECHNIQUES FOR ARBITRARY-PHASE SPREAD SPECTRUM WAVEFORMS
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.
HIGH-ORDER PSK SIGNALING (HOPS) TECHNIQUES FOR LOW-POWER SPREAD SPECTRUM COMMUNICATIONS
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.
RADIO COMMUNICATION APPARATUS CAPABLE OF SWITCHING MODULATION SCHEMES
A radio communication apparatus includes a QPSK modulator that modulates transmission data to produce a QPSK modulation signal and a 64QAM modulator that modulates transmission data to produce a 64QAM modulation signal. A radio transmitter receives the QPSK modulation signal and the 64QAM modulation signal and outputs a transmission signal. An average transmission power of the QPSK modulation signal and the 64QAM modulation signal are within a predetermined output power range.
Radio communication apparatus capable of switching modulation schemes
A transmitting apparatus, includes a signal generator that generates a modulation signal by modulating transmission data using one of a plurality of modulation schemes, a first modulation scheme having a higher m-ary modulation value than other modulation schemes and a pilot signal generator generates a pilot signal. An orthogonal frequency division multiplexing (OFDM) signal generator generates an OFDM signal by selecting the modulation signal and the pilot signal according to the frame timing signal. The OFDM signal is converted to a radio signal, is amplified and is transmitted to an antenna. The pilot signal is inserted in the OFDM signal per a predetermined OFDM symbol and per a predetermined subcarrier and has a lower amplitude than a maximum amplitude of the first modulation scheme in an in-phase-quadrature (IQ) plane.