Described herein are technologies related to an implementation of a digital-to-time converter (DTC) circuitry that utilizes a first interpolation and a second and finer interpolation to increase interpolation ranges. The DTC circuitry generates a fine-phase modulated signal generating at least two correlated signals, and generating coarse and fine interpolations of the correlated signals.

According to some embodiments, an apparatus for generating multiple variable frequency and phase locked clock signals comprises complex tuners, digital up-samplers, image isolation filters, quadrature modulators, a combiner, a DAC, a local oscillator, and an analog filter. The complex tuners tune multiple digital baseband signals. The up-samplers interpolate the complex tuned digital signals such that one of the up-sampled images of each of the complex tuned digital signals corresponds to a desired frequency. The image isolation filters isolate images corresponding to the desired frequencies. The quadrature modulators convert the isolated images of the complex tuned digital signals into real digital signals. The combiner combines the real digital signals into a combined real digital signal. The DAC, driven by the local oscillator, converts the combined real digital signal into an analog clock signal. The analog filter then filters the analog clock signal to select images located at the desired frequencies.

According to an embodiment, a digital transmitter (1) includes an amplitude modulation amplitude signal generation unit (132) that generates a function f(A(t)) of an amplitude signal A(t) as an amplitude modulation amplitude signal A(t), an amplitude modulation phase signal generation unit (133) that calculates cos.sup.1 {A(t)/f(A(t))} as a phase 1(t) and generates amplitude modulation phase signals P1(t) and P2(t), an individual digital transmission unit (11) that generates an amplified RF-pulse signal based on the signals A(t) and P1(t), an individual digital transmission unit (12) that generates an amplified RF-pulse signal based on the signals A(t) and P2(t), and an RF-synthesizer (16) that combines outputs of the individual digital transmission units (11, 12) with each other.

Systems and methods for demodulating a signal is described. A device can receive a modulated signal that encodes data. The device can sample a voltage of the modulated signal to generate a plurality of samples in digital domain. The device can determine in-phase data and quadrature data of the plurality of samples. The device can determine amplitude data and phase data based on the in-phase data and the quadrature data. The device can decode the amplitude data and phase data into digital symbols that represent the data encoded in the modulated signal.

A wireless transmission system includes: a communication unit for transmission; and a communication unit for reception. The communication units for transmission and reception are housed in a housing of the same electronic apparatus, or the communication unit for transmission is housed in a housing of first electronic apparatus and the communication unit for reception is housed in a housing of second electronic apparatus and a wireless signal transmission path enabling wireless information transmission between the communication units is formed between the communication units when the first and the second electronic apparatus are disposed at given positions to be integrated with each other. The communication unit for transmission includes a first carrier signal generating unit and a first frequency converter, and the communication unit for reception includes a second carrier signal generating unit, and a second frequency converter.

A method for synchronizing a data frame and data symbols in a communication system includes generating a training sequence including a serial sequence of data symbols that are conjugate symmetric, inserting the training sequence in a transmitter-side data frame, converting constituent data symbols of the transmitter-side data frame to communication signals, transmitting the communication signals from a transmitter to a receiver, converting the communication signals to a stream of received data symbols, detecting presence of the training sequence in the stream of received data symbols, and identifying a position of a received data frame from the presence of the training sequence.

A system and method for data communication using amplitude-encoded sinusoids. The method includes encoding the input digital data using a plurality of symbol waveforms where each of the plurality of symbol waveforms occupies a period of a composite encoded waveform and represents at least one bit of the input digital data. A first symbol waveform of the plurality of symbol waveforms is defined by a sinusoid of a first amplitude and a second symbol waveform is defined by a sinusoid of a second amplitude different from the first amplitude. The method includes generating an encoded analog waveform from a representation of the composite encoded waveform.

A method for channel aggregation and single sideband transmission executed in a broad-band communication system is suggested in which only I and Q versions of a purely sinusoidal local oscillator signals are needed, easing the system scaling when large numbers of channels must be aggregated. In addition to that, instead of phase shifting of an intermediate frequency broadband signal rather two intermediate frequency broadband signals are generated, which are phase shifted by +90 or by 90. As a result, the problems of frequency dependent phase shifting explained in the background section is not relevant for the method according to the present disclosure. Also, a corresponding method for image reject reception and channel separation as well as a transmitter and receiver for performing the methods are suggested.

Methods, systems, and devices for wireless communications are described. In some examples, a first device may generate and transmit multiple shaped symbols based on a state for each shaped symbol. To generate each shaped symbol, the first device may normalize the state for each symbol in accordance with a range interval. If the state is outside the range interval, the first device may receive and convert bits from a bit buffer to generate the shaped symbol and normalize the state to be within the range interval. A second device may receive the multiple shaped symbols and generate information bits for each shaped symbol. Once the second device has received all of the shaped symbols of the sequence of shaped symbols, the second device may obtain a deshaped information vector based on the information bits generated for each shaped symbol and a state for a last shaped symbol.