Interference is processed in a waveform received at a device in a wireless network, the received interference comprising non-linear products of at least a first signal (C.sub.1) at a first carrier frequency and a second signal (C.sub.2) at a second carrier frequency. A complex composite baseband signal is generated comprising at least the first and second signal at baseband, occupying a respective first and second frequency range within a composite baseband frequency range and not overlapping in frequency. The complex composite baseband signal is processed by applying at least a first non-linear function (74a) to generate simulated interference comprising at least one simulated non-linear product. The received interference is then processed in dependence on the simulated interference.

One of the embodiments of the present invention relates to a method for modulation. The method comprises: providing a first bit sequence of continuous bits “1” or continuous bits “0” generating a second bit sequence by replacing, in each of a plurality of modulation intervals with a predetermined bit number, at least one bit of the first bit sequence at least one fixed position of the respective modulation interval with one information bit from an information bit sequence; and modulating the second bit sequence so as to generate a positioning packet with a modulated continuous wave signal for transmission. The embodiments further relate to a method for demodulation. Embodiments of the present invention also provide corresponding apparatuses and computer program products.

An envelope signal time delay adjustment apparatus includes a negative group delay unit for converting an envelope signal input from a signal generator into an envelope signal having a group delay of a negative value whose frequency increases from a predetermined frequency band; an envelope-tracking modulator for power-amplifying and outputting the envelope signal output from the negative group delay unit; and a frequency limiting unit for limiting a bandwidth of the envelope-tracking modulator to be lower than an original bandwidth of the envelope-tracking modulator.

The present invention provides an amplifier including a DAC, an analog signal processing circuit, a digital signal processing circuit, a signal detector and a driving stage is disclosed. The DAC is configured to perform a digital-to-analog conversion operation on a digital input signal to generate an analog input signal. The analog signal processing circuit is configured to generate a first processed signal according to the analog input signal and a feedback signal. The digital signal processing circuit is configured to process the digital input signal to generate a second processed signal. The signal detector is configured to detect strength of the digital input signal to generate a mode selection signal. The driving stage is configured to refer to the mode selection signal to receive one of the first processed signal and the second processed signal to generate an output signal, wherein the feedback signal is generated by the output signal.

Communication systems and methods in accordance with various embodiments of the invention utilize modulation on zeros. Carrier frequency offsets (CFO) can result in an unknown rotation of all zeros of a received signal's z-transform. Therefore, a binary MOCZ scheme (BMOCZ) can be utilized in which the modulated binary data is encoded using a cycling register code (e.g. CPC or ACPC), enabling receivers to determine cyclic shifts in the BMOCZ symbol resulting from a CFO. Receivers in accordance with several embodiments of the invention include decoders capable of decoding information bits from received discrete-time baseband signals by: estimating a timing offset for the received signal; determining a plurality of zeros of a z-transform of the received symbol; identifying zeros from the plurality of zeros that encode received bits by correcting fractional rotations resulting from the CFO; and decoding information bits based upon the received bits using a cycling register code.

The invention discloses a modulator, a demodulator and a wireless communication system. The wireless communication system comprises a modulator and a demodulator. The modulator is suitable for generating a target linear frequency modulation signal, wherein the target linear frequency modulation signal is a signal of which the frequency is varied linearly over time, wherein the phase of the target linear frequency modulation signal is determined by an initial frequency and a frequency stepping of the target linear frequency modulation signal, and the frequency stepping is determined by the bandwidth of the target linear frequency modulation signal and the spreading factor of the target linear frequency modulation signal. The demodulator is suitable for demodulating the target linear frequency modulation signal. According to the scheme, power consumption can be reduced while long-distance signal transmission is realized.

A wireless transceiver system includes a transmitter and a receiver. The transmitter includes a digital processor and a self-correction modulator coupled to the digital processor, wherein based upon a calibration correction assessment of an in-phase (I) signal and a quadrature (Q) signal received from the digital processor, the self-correction modulator generates a calibrated modulated signal. The self-correction modulator includes a core modulator and a calibration correction unit. The calibration correction unit is configured to correct an output of the core modulator based upon the calibration correction assessment. The calibration correction unit includes a calibration processing unit and a calibration modulator, wherein the calibration processing unit provides correction quantities that are used to program the calibration modulator to provide the self-corrected modulated signal.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for communicating signals using a multi-dimensional symbol constellation. In one example, a process for modulating a carrier signal includes the actions of mapping data to symbols of a multi-dimensional symbol constellation that includes at least three dimensions, each dimension of the constellation represented by a respective modulation signal. The dimensions of the constellation include first and second dimensions each of which are represented by respective in-phase modulation values and quadrature phase modulation values of a quadrature amplitude modulation (QAM) signal, and a third dimension represented by a transpositional modulation (TM) signal. The method further includes modulating a carrier signal with the TM signal and the QAM signal.

Vector modulation is illustrated. A method includes receiving an input signal. The input signal is split into a first 0° output and a 90° output. The first 0° output is split into a second 0° output and a first 180° output using a continuous transmission line. The 90° output is split into a third 0° output and a second 180° output using a continuous transmission line. The second 0° output, the first 180° output, the third 0° output, and the second 180° output are modulated. The modulated second 0° output, the first 180° output, the third 0° output, and the second 180° output are recombined to produce an output signal, where all four of the modulated second 0° output, the first 180° output, the third 0° output, and the second 180° output are used to create the output signal.

Communication systems and methods in accordance with various embodiments of the invention utilize modulation on zeros. Carrier frequency offsets (CFO) can result in an unknown rotation of all zeros of a received signal's z-transform. Therefore, a binary MOCZ scheme (BMOCZ) can be utilized in which the modulated binary data is encoded using a cycling register code (e.g. CPC or ACPC), enabling receivers to determine cyclic shifts in the BMOCZ symbol resulting from a CFO. Receivers in accordance with several embodiments of the invention include decoders capable of decoding information bits from received discrete-time baseband signals by: estimating a timing offset for the received signal; determining a plurality of zeros of a z-transform of the received symbol; identifying zeros from the plurality of zeros that encode received bits by correcting fractional rotations resulting from the CFO; and decoding information bits based upon the received bits using a cycling register code.