Joint estimation of the framer index and the frequency offset in an optical communication system are described among various other features. A transmitter can transmit data frames using pilot and framer symbols. A receiver can estimate the framer index and frequency offset using the pilot and framer symbols, and identify the beginning of a header portion of a data frame. By identifying the beginning of the header portion of a data frame, the receiver can synchronize, with less error, the data transmitted by the transmitter and the data it received. To further improve the framer index estimation, a lock indicator signal can be generated to signal to other receiver components that the estimated framer indices are reliable. The receiver can determine frequency offset and additional framer index estimations with increased reliability when performed after the lock indicator signal is generated.

Systems and techniques are described that are directed to filter frequency response shift compensation, including compensating for shifting in the rejection band of the filter. Compensation for the shifting in the rejection band can include applying a pre-distortion to attenuate edge resource units (RUs), and applying PHY Protocol Data Unit (PPDU) scheduling schemes. For example, a PPDU scheduling scheme reduce bandwidth in the channel, thereby dropping the out of band RUs. Front ends provide feedback to a respective radio, which allows that radio to apply the appropriate pre-distortion. The front ends can include one or more filters enabling frequency domain coexistence between collocated radios operating in the differing Wi-Fi bands, and a coupler that provides the feedback indicating the frequency response shift to a radio. The radio can then apply a digital pre-distortion to compensate for the shifting in the rejection band.

Provided are a configuration method and a transmission method of a new reference signal for frequency offset estimation in a novel wireless communication system. The method may include configuring a synchronization signal to be transmitted through a first bandwidth part of one or more bandwidth parts configured by dividing an entire bandwidth into one or more parts, allocating the one or more reference signals for estimating the frequency offset on one or more resources other than a resource for configuring the synchronization signal, and transmitting the one or more reference signals for estimating the frequency offset.

Embodiments of the present application provide a signal transmission method, a terminal, a network device, and a storage medium. The method comprises: receiving multiple first downlink signals; determining downlink receiving frequency corresponding to the first downlink signal, and respectively determining, on the basis of the downlink receiving frequency corresponding to the first downlink signal, transmitting frequency of uplink signals in association with the first downlink signal; and transmitting the uplink signals on the basis of the transmitting frequency of the uplink signals, wherein a frequency shift determined on the basis of the uplink signals in association with the first downlink signal is used for determining transmitting frequency of second downlink signals. In the embodiments of the present application, a pre-compensation of a downlink Doppler shift is performed by means of each transmission receiving point, and therefore, an error of channel estimation is reduced, and the performance of downlink transmission is improved.

Systems, methods, apparatuses, and computer program products for transmitter residual carrier frequency offset compensation. The method may include receiving, at a reference user equipment, configuration for a positioning reference measurement from a network element. The method may also include estimating a transmission carrier frequency offset of the network element based on the positioning reference measurements. The method may further include transmitting the estimated transmission carrier frequency offset in a report to the network element.

A signal specification identification apparatus includes processing circuitry that estimates the transmission rate of a received signal, performs sampling frequency conversion on the received signal, calculates a probability corresponding to each of a plurality of candidates for a specification of the received signal, selects a candidate using the respective probabilities, and calculates reliability corresponding to a selected candidate, determines whether to output the selected candidate as an identification result or perform the sampling frequency conversion again, based on the reliability, and changes a parameter indicating the ratio of the sampling frequency conversion when it is determined that the sampling frequency conversion is to be performed again. Processing is repeated until the processing circuitry determines that the selected candidate as the identification result is to be output.

Methods and apparatus for preamble detection in a communication network are disclosed. In an exemplary embodiment, a method includes retrieving parameters from a parameter database, filling a buffer of preamble data received in an uplink transmission from user equipment, and frequency shifting the buffer of preamble data based on one or more first parameters to generate frequency shifted data. The method also includes oversampling the frequency shifted data to generates oversampled data, downsampling the over sampled data based on one or more second parameters to generate preamble samples, and updating the parameter database with updated values for the one or more first and second parameters. The method also includes repeating all the operations until a selected amount of preamble samples is obtained.

Various embodiments provide for data transmission using modulated carrier signals to carry data, where the carrier signal comprises a predetermined sequence of symbols. An embodiment can be used in such applications as data network communications between sensors (e.g., cameras, motion, radar, etc.) and computing equipment within vehicles (e.g., smart and autonomous cars).

The present disclosure provides a method for estimating a frequency offset, including: extracting sampling points from an input signal according to preset intervals to obtain a plurality of groups of sampling points, with the preset intervals of the groups of sampling points being different; performing processes on a current sampling point and the groups of sampling points to obtain data of arguments of complex numbers corresponding to the preset intervals; and determining an estimation value of a frequency offset of a current input signal according to the data of arguments of complex numbers corresponding to the preset intervals. The present disclosure further provides an apparatus for estimating a frequency offset, an electronic device and a computer-readable medium.

A converged radio unit (RU) configured for semantic-less retransmissions comprises a radio-frequency machine learning (RFML) radio unit (RFML RU) and a radio-access network (RAN) radio unit (RU). The RFML RU may be configured to receive an RF signal comprising a packet, decode a PHY layer preamble of the packet, and apply a machine-learning (ML) model to information obtained from only the PHY layer preamble to classify the packet. When the packet is classified be a tactical data link (TDL) packet based on the information obtained only from the PHY layer preamble, the RFML RU may retransmit the packet. When the packet is classified a RAN protocol packet, the RFML RU may be configured to signal the RAN RU to process the RAN protocol packet in accordance with a RAN protocol.