The disclosure is directed to a method and system for generating a pilot tone for an optical signal with an optical telecommunications system. The pilot tone is generated in the digital domain by modulating the data to be transmitted to a destination node within the optical telecommunications network. The modulation of the data introduces occurrence modulation to the optical signal.

A diversity receiver synchronizes and mixes multiple input signals. In one embodiment, the receiver demodulates the multiple input signals prior to synchronizing, converts the demodulated multiple input signals from analog signals to digital signals, synchronizes the demodulated digital signals, converts the synchronized demodulated digital signals to analog signals and mixes the synchronized demodulated analog signals based on a characteristic of the input signals existing prior to the demodulating.

A receiver circuit comprising: an input terminal configured to receive an input-signal; a feedforward-ADC configured to provide a feedforward-digital-signal based on the input-signal; a feedforward-DAC configured to provide a feedforward-analogue-signal based on the feedforward-digital-signal; a feedforward-subtractor configured to provide an error-signal based on the difference between the feedforward-analogue-signal and the input-signal; an error-LNA configured to provide an amplified-error-signal based on the error-signal; an error-ADC configured to provide a digital-amplified-error-signal based on the amplified-error-signal; a mixer configured to down-convert a signal in a signal path between the input terminal and the error-ADC; and an error-cancellation-block configured to provide an error-cancelled-signal based on a difference between the digital-amplified-error-signal and the feedforward-digital-signal.

Certain features relate to optimizing the processing of downlink data in a telecommunications system by capturing a downlink data stream and transferring the downlink data to a memory device in parallel. A processing device can capture a first set of downlink data blocks from a base station and store the first set of downlink data blocks to a memory device. Once a sufficient number of downlink data blocks are written to the memory device, the first set of data blocks can be transferred to a digital signal processor. A second set of data blocks can be captured substantially simultaneous to the first set of data blocks being transferred to the digital signal processor. In additional aspects, the second set of data blocks can be processed by the digital signal processor substantially simultaneous to additional data blocks being captured and stored in the memory device.

An ultra-wideband radio frequency transmission system capable of receiving a first signal with discrete levels, and including: a voltage-controlled oscillator capable of supplying a first oscillating signal including an oscillating circuit powered by a power supply circuit comprising at least one first current source controlled by the first signal with discrete levels or a second signal with discrete levels obtained from the first signal with discrete levels; a mixer capable of receiving the first oscillating signal and of supplying a second oscillating signal equal to the first oscillating signal multiplied by a gain which depends on the first signal with discrete levels or on a third signal with discrete levels obtained from the first signal with discrete levels; and an antenna or an electromagnetic coupling device capable of transmitting a radio frequency signal based on the second oscillating signal.

Provided is an intermediate-frequency analog-to-digital conversion device, including: a gain attenuation module, a gain amplification module, a filter and an analog-to-digital conversion module. The gain attenuation module is configured to perform attenuation processing on a received intermediate-frequency signal. The gain amplification module is connected to the gain attenuation module, and configured to perform amplification processing on a signal that is output from the gain attenuation module. The filter is a variable filter, connected to the gain amplification module, and configured to perform filter processing on a signal that is amplified by a gain amplifier. The analog-to-digital conversion module is connected to the filter, and configured to convert a signal that is filtered by the filter into a digital signal. The technical solution solves the technical problem in the related art and achieves the technical effect of improving the universality of the intermediate-frequency analog-to-digital conversion device.

A digital-electrical to analog-optical converter for converting a N-bit digital data signal uses a non-linear optical element that is susceptible to the Kerr effect. N digitally modulated optical bit stream sources are co-polarized and modulated according to individual bit streams of the digital data. The co-polarized digitally modulated signals interact with a polarized probe signal in the optical element causing the polarization of the probe signal to be changed. Propagating the polarization-changed probe signal output from the optical element through a polarizer provides an amplitude modulated optical signal corresponding to the N-bit digital signal.

In some examples, a system includes at least two antennas configured to receive signals encoding first, second, and third messages in first, second, and third frequency bands. The system also includes a set of splitters configured to generate separate signals in the first, second, and third frequency bands. The system further includes a set of combiners, wherein each combiner of the set of combiners is configured to combine two or more of the separate signals. The system includes a set of mixers configured to down-convert the combined signals and at least one analog-to-digital converter configured to sample the down-converted signals. The system also includes processing circuitry configured to determine data in the first, second, and third messages based on an output of the at least one analog-to-digital converter.

The present invention relates to a transmitter, a receiver and to corresponding methods for transmitting and receiving data utilizing sequences of non-return-to-zero, inverted (NRZI) symbols and symbol rates higher than the Nyquist rate in data transmission systems, thus enabling an enlarged spectral efficiency while utilizing simple receivers only having sign information.

A receiving device includes: a receiver that receives a signal including PPM symbols; a clock generator that generates a clock for sampling; an A/D converter that digital-converts the received signal; a reference position detector that detects a leading position of the PPM symbols based on data from the A/D converter; and a clock error detector that detects a clock error. The clock error detector includes: a pulse position detector that detects a pulse position in the PPM symbols based on data from the reference position detector and A/D converter; a position error calculator that calculates a deviation of the pulse position based on data from the reference position detector, A/D converter, and pulse position detector; and a clock error calculator that calculates the clock error based on data from the position error calculator. The receiving device varies a frequency of the clock based on data from the clock error calculator.