A receiver includes a continuous-time equalizer, a decision-feedback equalizer (DFE), data and error sampling logic, and an adaptation engine. The receiver corrects for inter-symbol interference (ISI) associated with the most recent data symbol (first post cursor ISI) by establishing appropriate equalization settings for the continuous-time equalizer based upon a measure of the first-post-cursor ISI.

Circuits, methods, and apparatus that provide improved data recovery for data transmitted through a channel of limited bandwidth. An example can provide circuits, methods, and apparatus that can equalize losses in a physical channel. This equalization can provide an overall channel response that is more consistent and uniform.

Embodiments of the present disclosure provide example frequency domain equalization methods, example equalizers, example optical receivers, and example systems. One example method includes obtaining, by an optical receiver, a first complex signal. The first complex signal is a first time domain signal. The first complex signal is obtained based on two channels of mutually independent digital electrical signals. The optical receiver converts the first complex signal into a frequency domain signal, and multiplies the first complex signal in frequency domain by a tap coefficient to obtain a second complex signal. The tap coefficient is used to implement signal compensation for the first complex signal in frequency domain. The optical receiver converts the second complex signal into a second time domain signal, divides the second time domain signal into two channels of real signals, and outputs the two channels of the real signals.

A system and method of operating an Open Radio Access Network (O-RAN, in which O-RAN the system includes: a baseband unit (BBU) having an O-RAN centralized unit (O-CU) and an O-RAN distributed unit (O-DU); an O-RAN radio unit (O-RU) remote from the BBU; and a fronthaul interface between the O-RU and the BBU. A functional split of O-RAN functions respectively assigned to O-RU and O-DU for the fronthaul interface between the BBU and the O-RU is different for downlink (DL) and uplink (UL) so that at least one of i) demodulation reference signal (DM-RS)-based channel estimation is performed by the O-DU in the DL and by the O-RU in the UL, ii) equalization is performed by the O-DU in the DL and by the O-RU in the UL, and iii) demodulation is performed by the O-DU in the DL and by the O-RU in the UL.

In one example aspect, a method is provided of preparing a symbol for transmission, the method comprising applying a window function to a symbol to generate a modified symbol, wherein a property of the window function is based on a channel length of a transmission channel over which the modified symbol is to be transmitted, and causing the modified symbol to be transmitted over the transmission channel.

Apparatuses, systems, and methods for transmitting and multiplexing chirp signals for communications are provided. An example apparatus includes an antenna, a radio, and processing circuitry. The radio may be configured to transmit and receive wireless communications via the antenna, and the processing circuitry configured to establish a wireless communications link with a receiving communications device. The signaling transmitted by the antenna via the radio as controlled by the processing circuitry may include a plurality of sequenced chirp signals within an orthogonal frequency division multiplexing (OFDM) framework.

A device configured to perform a stage of circular convolutions in an Overlap-Save Filtered-Bank Multicarrier Communication (OS-FBMC) or Overlap-Save-Block FBMC (OSB-FBMC) receiver and the corresponding method, the stage of circular convolutions comprising P circular convolutions operated between subsets of input samples and frequency domain responses of a frequency shifted version of a prototype filter associated to an FBMC modulation having C.sub.g coefficients, with P an integer greater than one, the device comprising at least one Finite Impulse Response filter implemented in the form of a transposed direct filter having at least C.sub.g−1 taps numbered p=−Δ+1 to p=Δ with

[00001]$\Delta =\frac{c_g-1}{2},$

wherein the multiplier coefficient of each tap p within the set of taps −Δ+1; 0 has an equal absolute value to the multiplier coefficient of tap (1−p) . An FBMC equalization and demodulation unit or an FBMC receiver comprising the device.

A receiver unit comprising a signal input configured to receive a receive signal including a plurality of data symbols, a symbol detection circuit configured to detect a subset of data symbols, a reliability measuring circuit configured to determine a reliability value for the data symbols, a feedback loop configured to detect the subset of data symbols and the reliability value iteratively, and a signal output circuitry configured to determine output values of the subset of data symbols on the basis of the detected subset of data symbols and the determined reliability value.

System and method embodiments are provided for a receiver for circularly convolved signals. In an embodiment, a universal decoder for a circularly convolved signal includes a first decoder configured to decode the circularly convolved signal; a second decoder configured to decode a plurality of symbol lengths signal from a first portion of the circularly convolved signal, wherein the plurality of symbol lengths signal is time aligned with the circularly convolved signal before passing through the second decoder; and an adder component configured to sum a first decoder output coming from the first decoder and a second decoder output coming from the second decoder to produce a symbol value from which a log likelihood ratio (LLR) output is obtained.

Examples relate to a transmit apparatus, a receive apparatus, a method for transmitting, a method for receiving and computer readable storage media for transmitting and/or receiving in a communication network. A transmit apparatus for transmitting discontinuous time-frequency operation, DTFO, signals in a communication network comprises a transmitter configured to transmit a DTFO signal comprising monitoring symbols and regular DTFO symbols in the communication network. The apparatus further comprises processing circuitry, which is coupled to the transmitter and configured to generate at least one monitoring symbol for transmission by the transmitter if a time gap of the DTFO signal between two sub-sequent regular DTFO symbols exceeds a first time threshold, wherein the at least one monitoring symbol is configured to enable frequency-domain equalizer, FEQ, adjustment at a receiver of the DTFO signal; and generate a training sequence for transmission by the transmitter if a time period between a last transmission of a monitoring or regular DTFO symbol and a sub-sequent transmission of a DTFO symbol exceeds a second time threshold, the training sequence comprising at least one monitoring symbol preceding a regular DTFO symbol.