H04L7/007

FREQUENCY OFFSET ESTIMATION METHOD, DEVICE, COMMUNICATION DEVICE AND STORAGE MEDIUM

A frequency offset estimation method, device, communication device and storage medium are provided. The method comprises: acquiring a main peak and a secondary peak of a PRACH signal when detecting that an access signal is in the PRACH signal sent by the signal sending end, wherein the PRACH signal is composed of a preset number of identical leader sequences; determining a first frequency offset according to a peak value of the main peak and a peak value of the secondary peak; performing a frequency offset compensation on the PRACH signal according to the first frequency offset, to obtain a compensation sequence after the frequency offset compensation; and calculating a frequency offset between the compensation sequence and the leader sequences, to obtain a second frequency offset, so as to estimate a time delay of the access signal according to the second frequency offset.

Information transmission method, user equipment, and base station

Embodiments of the present application provide a method for acquiring information of access resources, a terminal device, and a base station. A terminal device detects a synchronization signal of a cell to be accessed by the terminal device. The terminal device further receives a broadcast channel of the cell on a broadcast channel resource. The terminal device then determines a resource on which the cell is located according to resource indication information carried in the broadcast channel. The broadcast channel resource corresponds to an actual access resource, and the synchronization signal is detected on the actual access resource. The actual access resource is one of a plurality of candidate access resources of the cell. The resource indication information indicates a location relationship between the actual access resource and the resource on which the cell is located.

Frequency tracking for beamformed systems

Systems, methods, and baseband processors are provided to generate or process symbols in a synchronization subframe. In one example, a method includes selecting non-consecutive orthogonal frequency division multiplexing (OFDM) symbols in a synchronization subframe. A transmitter is instructed to transmit demodulation reference symbols (DM-RS) on identical first sets of subcarriers in respective OFDM symbols of the selected non-consecutive OFDM symbols for a Physical Broadcast Channel (PBCH) using a same transmit beam, wherein a gap between two subcarriers in a respective set of the identical first sets of subcarriers is three subcarriers. The transmitter is instructed to transmit the PBCH on identical second sets of subcarriers in respective OFDM symbols in the selected non-consecutive OFDM symbols.

SYSTEMS AND METHODS FOR PROCESSING VARIABLE CODING AND MODULATION (VCM) BASED COMMUNICATION SIGNALS USING FEEDFORWARD CARRIER AND TIMING RECOVERY

Processing a digital bit stream and systems for implementing the methods are provided. The method includes dividing the digital bit stream into a plurality of data packets. In a first processing block performing a carrier recovery error calculation on a first portion of the plurality of data packets, comprising preforming a first phase locked loop (PLL) function on decimated data of the data packets and performing a carrier recovery operation on the first portion of the plurality of data packets. In a second processing block, in parallel with the processing of the first portion of the plurality of packets, performing the carrier recovery error calculation on a second portion of the plurality of data packets, comprising preforming the first PLL function on decimated data of the data packets and performing the carrier recovery operation on second portion of the plurality of data packets.

METHOD AND APPARATUS FOR SIGNAL PROCESSING IN A WIRELESS COMMUNICATION SYSTEM
20230180165 · 2023-06-08 ·

The present disclosure relates to a 5G communication system or a 6G communication system for supporting higher data rates beyond a 4G communication system such as long term evolution (LTE). The present disclosure provides a device in a wireless communication system and a method performed by the device. The method comprises: for a first transmitted signal transmitted by the device and a first received signal corresponding to the first transmitted signal and received by the device, compensating one of the first transmitted signal and the first received signal, according to a first synchronization delay part of a synchronization delay between a receiver and a transmitter of the device, wherein the first synchronization delay part is an integral multiple of a predefined baseband sampling interval of the device in the synchronization delay; determining a second synchronization delay part of the synchronization delay based on one of a collection of the first received signal and the compensated first transmitted signal and a collection of the first transmitted signal and the compensated first received signal, depending on which one of the first transmitted signal and the first received signal is compensated, wherein the second synchronization delay part is a fractional multiple of the predefined baseband sampling interval of the device in the synchronization delay.

Communication unit and method for clock distribution and synchronization

A communication unit (300) is described that includes a plurality of cascaded devices that includes at least one master device and at least one slave device configured in a master-slave arrangement. The at least one master device comprises a modulator circuit (362) configured to: receive a system clock signal and a frame start signal; modulate the system clock signal with the frame start signal to produce a modulated master-slave clock signal (384); and transmit the modulated master-slave clock signal (384) to the at least one slave device. The at least one slave device comprises a demodulator circuit (364) configured to: receive and demodulate the modulated master-slave clock signal (384); and re-create therefrom the system clock signal (388, 385) and the frame start signal (390, 386).

Method for precise timestamping of narrowband signals in the presence of multipath
11722979 · 2023-08-08 · ·

A method for detecting times-of-arrival of signals comprising, at a receiving node: during a time slot, receiving a signal comprising a carrier signal characterized by a carrier frequency and modulated by a template signal defining a code sequence characterized by a transmitter chip period; demodulating the signal according to a local oscillator frequency to generate a received baseband signal, the local oscillator frequency and the carrier frequency defining a desynchronization ratio characterized by a denominator greater than a threshold denominator; sampling the received baseband signal at the transmitter chip period to generate a set of digital samples; generating a reconstructed baseband signal based on the set of digital samples; calculating a cross-correlation function comprising a cross-correlation of the reconstructed baseband signal and the template signal; and calculating, on the fine time grid, a time-of-arrival of the signal based on the cross-correlation function.

Guard-space timestamp point for precision synchronization in 5G and 6G
11722980 · 2023-08-08 · ·

High-frequency communications in 5G and especially 6G will require precise synchronization of user devices with the base station, including setting the user device clock time and clock rate. The base station can assist user devices by periodically providing a guard-space timestamp point, at which a phase or amplitude of the timing signal abruptly changes in the middle of the guard-space of a particular resource element or a particular OFDM symbol. A receiver can determine precisely the time of arrival of the timestamp point, and correct its clock setting to agree with the time of the timestamp point. The receiver can then provide uplink messages aligned with the base station's clock, by adding a previously determined timing advance to each uplink transmission. In addition, the user device can measure two guard-space timing signals with a predetermined separation, thereby adjusting the clock rate.

Frequency tracking for beamformed systems

A method is provided to generate and control transmission of reference symbols in a synchronization subframe, wherein a reference symbol includes reference values mapped to a block of K subcarriers. The method includes generating data corresponding to a basic subsequence of K−R1−R2 reference values, where R1 and R2 are integers such that 1≤R1+R2<K, and mapping the data corresponding to the basic subsequence to an original range of K−R1−R2 contiguous subcarriers in the block such that there is a first set of R1 unmapped subcarriers above the original range of subcarriers and a second set of R2 unmapped subcarriers below the original range of subcarriers. Data corresponding to last R1 values in the basic subsequence is mapped to the first set of unmapped subcarriers. Data corresponding to first R2 values in the basic subsequence is mapped to the second set of unmapped subcarriers.

METHOD FOR PRECISE TIMESTAMPING OF NARROWBAND SIGNALS IN THE PRESENCE OF MULTIPATH
20230337164 · 2023-10-19 ·

A method for detecting times-of-arrival of signals comprising, at a receiving node: during a time slot, receiving a signal comprising a carrier signal characterized by a carrier frequency and modulated by a template signal defining a code sequence characterized by a transmitter chip period; demodulating the signal according to a local oscillator frequency to generate a received baseband signal, the local oscillator frequency and the carrier frequency defining a desynchronization ratio characterized by a denominator greater than a threshold denominator; sampling the received baseband signal at the transmitter chip period to generate a set of digital samples; generating a reconstructed baseband signal based on the set of digital samples; calculating a cross-correlation function comprising a cross-correlation of the reconstructed baseband signal and the template signal; and calculating, on the fine time grid, a time-of-arrival of the signal based on the cross-correlation function.