An apparatus includes a radio frequency (RF) receiver. The RF receiver includes a timing correlator and frequency offset estimator. The timing correlator and frequency offset estimator: (a) extracts timing from a set of samples derived from an RF signal, and (b) determines a frequency offset estimate from the set of samples.

Various embodiments relate to a method for processing received distributed multiple-input and multiple-output (DMIMO) OFDM signals from a plurality of transmitters, including: performing an initial carrier frequency offset (CFO) correction; receiving a plurality of OFDM symbols; re-constructing the channel every N symbols based upon a channel estimate for each transmitter and an estimate of residual CFO for each of the transmitters based upon the long term fields (LTF), wherein N is an integer; and equalizing the received OFDM symbols using the re-constructed channel.

The present disclosure includes a method of performing synchronization and frequency offset estimation The method includes an input signal corresponding to a single received training sequence. Phase information and a phase index are generated by performing an auto-correlation function (ACF) on the input signal. A templet signal associated with a sample index of the input signal is generated based on at least one pre-stored look-up table (LUT), the phase index, a frequency bandwidth of the input signal, and the sample index. Power associated with the sample index is calculated by performing a matched filtering on the input signal based on the templet signal. A synchronization timing and a frequency offset for the input signal are simultaneously determined based on a result of the matched filtering.

Systems and methods are described, and one method includes acquiring a frequency offset for a demodulator receiving one symbol rate in combination with acquiring another frequency offset for another demodulator, based on sweeping the other frequency offset until detecting a qualifying symbol pattern or acquiring the frequency offset for the demodulator receiving one symbol rate, whichever occurs first. Associated with acquiring the other frequency offset based on acquiring the frequency offset for the demodulator receiving one symbol rate, setting the other frequency offset includes adjusting the frequency offset for the demodulator receiving one symbol rate.

Various solutions for random access channel (RACH) preamble design in non-terrestrial network (NTN) communications with respect to user equipment and network apparatus are described. An apparatus may initiate a RACH procedure. The apparatus may determine a fractional frequency offset pattern or a cover code across groups of preamble sequences. The apparatus may generate a RACH preamble signal according to at least one of the fractional frequency offset pattern and the cover code. The apparatus may transmit the RACH preamble signal to a network node.

In one embodiment, an apparatus includes: a radio frequency (RF) front end circuit to receive and downconvert a RF signal to a second frequency signal, the RF signal comprising an orthogonal frequency division multiplexing (OFDM) transmission; a digitizer coupled to the RF front end circuit to digitize the second frequency signal to a digital signal; and a baseband processor coupled to the digitizer to process the digital signal. The baseband circuit comprises a first circuit having a first plurality of correlators having an irregular comb structure, each of the first plurality of correlators associated with a carrier frequency offset and to calculate a first correlation on a first portion of a preamble of the OFDM transmission.

Configuring control information comprises determining a frequency offset including an RB and RE level frequency offset, where the frequency offset is determined based on a lowest RE of an SS/PBCH block and a lowest RE of CORESET for RMSI, jointly configuring, using a first field of 4 bits, the RB level frequency offset with a multiplexing pattern of the SS/PBCH block and the CORESET, a BW of the CORESET, and a number of symbols for the CORESET for a combination of a SCS of the SS/PBCH block and a SCS of the CORESET, configuring using a second field of the 4 bits generating an MIB including the RB level frequency offset and the RE level frequency offset; and transmitting, to a UE, the MIB over a PBCH.

Provided are a preamble symbol receiving method and device, characterizing in that the method comprises the following steps: processing a received signal; judging whether the processed signal obtained contains the preamble symbol desired to be received; and if a judgement result is yes, determining the position of the preamble symbol and resolving signalling information carried by the preamble symbol, wherein the received preamble symbol comprises at least one time-domain symbol generated by a transmitting end using a free combination of any number of first three-segment structures and/or second three-segment structures according to a predefined generation rule, the first three-segment structure containing: a time-domain main body signal, a prefix generated based on the entirety or a portion of the time-domain main body signal, and a postfix generated based on the entirety or a portion of a partial time-domain main body signal, and the second three segment structure containing: the time domain main body signal, a prefix generated based on the entirety or a portion of the time domain main body signal, and a hyper prefix generated based on the entirety or a portion of the partial time domain main body signal.

In one embodiment, an apparatus includes: a baseband processor having a preamble generation circuit to generate a preamble for an orthogonal frequency division multiplexing (OFDM) transmission, the preamble generation circuit to generate the preamble having a first portion comprising a first plurality of symbols, each of the first plurality of symbols having a plurality of carriers, where a subset of the plurality of carriers have non-zero values, the preamble generation circuit to generate the non-zero values using a sequence of complex values selected to optimize a peak-to-average power ratio (PAPR); a digital-to-analog converter (DAC) coupled to the baseband processor to convert the first plurality of symbols to analog signals; a mixer coupled to the DAC to upconvert the analog signals to radio frequency (RF) signals; and a power amplifier coupled to the mixer to amplify the RF signals.

A telecommunications receiver is adapted to communicate with mobile devices that operate according to a protocol where the telecommunications receiver operates outside of expected ranges for the protocol but modifies its communications with mobile devices to appear to those mobile devices as being within the expected ranges. To determine what modifications to make to transmissions, the telecommunication receiver processes signals from mobile devices to determine where a communications channel is relative to the expected ranges and uses that information to modify transmissions to mobile devices. The expected ranges might relate to maximum distance between telecommunications receiver and a mobile device, maximum relative velocity, power etc. Determining a relative velocity, and therefore a Doppler shift, can be done by determining a fractional frequency offset, determining an expected subchannel, and determining an integer frequency offset based on the expected subchannel carrier frequency and the measured carrier frequency.