A method for determining a noise shaped quantized parameter contributing to generation of an output signal comprises estimating an error within the output signal using a quantization of the parameter and a quantization of a further parameter contributing to generation of the output signal. The quantization of the parameter is used as the noise shaped quantized parameter according to a selection criterion.

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.

The present invention relates to a modulator for a digital amplifier and a device comprising such a modulator and a digital amplifier.

The modulator (100) comprises a pulse shaper (110) and a control unit (120) for controlling the pulse shaper (110) to convert an input signal into a bit stream (130) configured for a digital amplifier which encodes an amplitude value per clock of a carrier signal. The pulse shaper (110) can represent a respective amplitude value of the input signal with different bit patterns. The bit pattern respectively used by the pulse shaper is determined by the control unit (120) by means of a corresponding, associated control command. The modulator (100) is characterized in that in the control unit (120) an assignment (160) of the control commands to associated amplitude values resulting from amplification of the associated bit patterns with the digital amplifier (400) is stored or at least is provided in that the control unit (120) selects a control command per clock by means of the assignment (160) and the amplitude value of the input signal and drives the pulse shaper (110) accordingly.

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.

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.

A multi-zone analog-to-digital converter (ADC) is provided that includes a track-and-hold (T/H) stage having a bandwidth of L Hertz (Hz) to accept an analog input signal, a clock input to accept a clock signal with a clock frequency of P Hz, and N deinterleaved signal outputs with a combined bandwidth of M Hz. N(P/2)=M, L>QM, and Q is an integer >1. The T/H stage is able to sample an analog input signal in the Qth Nyquist Zone, where Q is an integer. A quantizer stage has N interleaved signal inputs connected to corresponding T/H stage signal outputs, a clock input to accept the clock signal, and an output to supply a digital output signal having a bandwidth of M Hz. A packaging interface typically connects the T/H stage to the quantizer stage, and has a bandwidth less than the clock frequency.

A method for determining a noise shaped quantized parameter contributing to generation of an output signal comprises estimating an error within the output signal using a quantization of the parameter and a quantization of a further parameter contributing to generation of the output signal. The quantization of the parameter is used as the noise shaped quantized parameter according to a selection criterion.

A multi-zone analog-to-digital converter (ADC) is provided that includes a track-and-hold (T/H) stage having a bandwidth of L Hertz (Hz) to accept an analog input signal, a clock input to accept a clock signal with a clock frequency of P Hz, and N deinterleaved signal outputs with a combined bandwidth of M Hz. N(P/2)=M, L>QM, and Q is an integer >1. The T/H stage is able to sample an analog input signal in the Qth Nyquist Zone, where Q is an integer. A quantizer stage has N interleaved signal inputs connected to corresponding T/H stage signal outputs, a clock input to accept the clock signal, and an output to supply a digital output signal having a bandwidth of M Hz. A packaging interface typically connects the T/H stage to the quantizer stage, and has a bandwidth less than the clock frequency.

The present invention describes an orthogonal frequency-division multiplexing, OFDM, transmitter and a method for embedding phase reference symbols into an OFDM symbol. The invention comprises a single-carrier pre-processing unit arranged to receive phase reference symbols and provide pre-processed phase reference samples as output and an OFDM modulator arranged to receive data symbols and the pre-processed phase reference samples as input and map the data symbols to sub-carriers and embed the single-carrier samples into a frequency sub-band of the OFDM symbol. While the invention particularly relates to an OFDM communication system, it should be noted that it could be applicable to any type of multicarrier communication system.

The transmission circuit includes a comparator that converts a phase-modulated signal from an orthogonal modulator into a pulse signal so as to use the pulse signal as the sampling clock of the a delta-sigma modulator, and an asynchronous clock transfer unit and an interpolating circuit, disposed between a circuit operating based on the baseband clock and the delta-sigma modulator. The asynchronous clock transfer unit converts the amplitude component signal synchronized with the baseband clock, into an amplitude component signal synchronized with an N-frequency divided clock obtained by dividing the frequency of the sampling clock by N. The interpolating circuit interpolates the output signal from the asynchronous clock transfer unit so that the amount of change of one sample in the N-frequency divided clock becomes equal to the amount of change of one sample in the sampling clock.