A reference signaling scheme is provided that is based on the use of a Zadoff Chu sequence with cyclic repetition, optionally code division multiplexing precoding, together with frequency domain spectral shaping (FDSS). A specific pulse shape design for the FDSS part of the reference signal scheme in some embodiments involves the use of a raised cosine pulse raised to the power of β. The new solution for generating reference signals has a Low peak average power ratio that matches the PAPR of SC-OQAM, good channel estimation performance, and the ability to implement CDM in the frequency domain to increase multiplexing gain.

This application provides a signal generation method and an apparatus. In the method, a first communication apparatus generates a first signal, and sends the first signal to a second communication apparatus, who receives the first signal, and then demodulates the first signal. A symbol included in the first signal is carried on K+2(M−1) subcarriers. Middle K subcarriers are valid subcarriers, start M−1 subcarriers and last M−1 subcarriers are redundant subcarriers, and a subcarrier spacing between adjacent subcarriers is related to a feature of a time domain pulse used to shape the subcarrier, wherein a width of each of some or all side lobes of a spectrum of the time domain pulse is equal to 1/M of a main lobe width of the time domain pulse, the subcarrier spacing is 1/M of the main lobe width. K is a positive integer, and M is a positive integer greater than 1.

A wideband transmission circuit is provided. The wideband transmission circuit includes a transceiver circuit and a power amplifier circuit(s). The transceiver circuit generates a radio frequency (RF) signal(s) from a time-variant input vector and provides the RF signal(s) to the power amplifier circuit(s). The power amplifier circuit(s) amplifies the RF signal(s) based on a modulated voltage and provides the amplified RF signal(s) to a coupled RF front-end circuit (e.g., filter/multiplexer circuit). In embodiments disclosed herein, the transceiver circuit is configured to apply an equalization filter to the time-variant input vector to thereby compensate for a voltage distortion filter caused by a coupling of the power amplifier circuit(s) and the RF front-end circuit. As a result, it is possible to reduce undesired instantaneous excessive compression and/or spectrum regrowth resulting from the voltage distortion filter to thereby improve efficiency and linearity of the power amplifier circuit(s).

Systems and methods for automatic level control (ALC) are provided. In one embodiment, an ALC system for communications signals comprises: a multi-threshold programmable ALC controller; and at least one signal path that includes: a digital step attenuator configured to receive an analog communications signal and attenuate the analog communications signal in response to an attenuation adjustment signal from the ALC controller; and an analog-to-digital converter configured to receive the analog communications signal as attenuated by the digital step attenuator and generate samples of the attenuated analog communications signal, wherein the ALC controller receives the samples. The ALC controller comprises a plurality of clip detectors that function in parallel. Each of the clip detectors are programmed with a respective amplitude and time threshold. Based on which of the plurality of clip detectors determine that the samples exceed their respective amplitude and time threshold, the ALC controller generates the attenuation adjustment signal.

A radio communication apparatus comprises a spreading unit and a transmitting unit. The spreading unit spreads an ACK/NACK signal or a CQI signal with a sequence defined by one of a plurality of cyclic shift values. The transmitting unit transmits the ACK/NACK signal or the CQI signal. In each symbol that forms the ACK/NACK signal or the CQI signal, the spreading unit uses one of first cyclic shift values, which form a portion of the plurality of the cyclic shift values and which are adjacent to each other, for the ACK/NACK signal, and uses one of second cyclic shift values, which are not within the portion of the plurality of the cyclic shift values, for the CQI signal. At least one cyclic shift value that is cyclically subsequent to the first cyclic shift values or the second cyclic shift values is not used for either the ACK/NACK signal or the CQI signal.

An Ethernet physical layer (PHY) transceiver includes a transmitter and a receiver. The transmitter is configured to precode a first data stream by summing two or more mutually-delayed replicas of the first data stream, and to transmit the precoded first data stream over a full-duplex wired channel to a peer Ethernet PHY transceiver. The receiver is configured to receive a second data stream from the peer Ethernet PHY transceiver over the full-duplex wired channel, and to decode the received second data stream while the transmitter concurrently is transmitting the precoded first data stream.

A method and apparatus for generating a signal. The method includes: by taking a reference signal as a standard, cyclically performing isoprobabilistic processing and isospectral processing, or cyclically perform isoprobabilistic processing, perturbation processing and isospectral processing, on an input signal, until an obtained signal satisfies both a requirement on a target probability distribution and a requirement on a target spectrum, where a probability distribution of the reference signal satisfying the requirement on a target probability distribution, the isoprobabilistic processing referring to processing that makes the probability distribution of an output signal identical to the probability distribution of the reference signal. Therefore, a signal that satisfies both the requirement on the specific probability distribution and the requirement on the spectrum can be generated, and the degree of compliance is higher.

A system for selecting an equalizer setting of an equalizer to equalize signals received via a communications link. Starting with a first (e.g., minimum) equalizer setting and a threshold voltage near the mid-eye voltage of the equalized output signal, the system estimates the amplitude of the inner eye of the equalized output signal by comparing the equalized output signal to a series of threshold voltages. If the amplitude of the equalized output signal is less than ideal, the system dynamically increases the equalizer setting. The system quickly converges on the equalizer setting for the communication link because, rather than comparing the output signal at every voltage offset using every equalizer setting, the system only evaluates the equalizer settings necessary to select the equalizer setting for the communications link and uses only the voltage offsets necessary to evaluate each equalizer setting.

Disclosed are techniques for wireless communication. In an aspect, a wireless device determines a symbol configuration for transmission of SC-FDE waveform with zero gaps arranged between a communication channel part, RS part, and CP part. The SC-FDE waveform is transmitted to another wireless device, which processes the SC-FDE waveform.

A transceiver includes a transmitter up-converting a frequency of input data to transmit data of a first frequency, an orthogonal basis generator receiving the input data from the transmitter to generate an orthogonal basis; and a receiver receiving the orthogonal basis from the orthogonal basis generator and receiving the transmitted data for down-converting a frequency of the received data to a second frequency different from the first frequency. The orthogonal basis generator includes, a multiplier multiplying the input data by a Gaussian characteristic value obtained by extracting a Gaussian characteristic of the data to generate an out of band emission (OOBE) value, and a polynomial block generating the orthogonal basis by using the OOBE value as an input to an Itô-Hermite polynomial.