A digital radio receiver is adapted to receive radio signals modulated using continuous phase modulation. The receiver includes components for receiving analogue radio signals having various carrier frequencies and a plurality of correlators corresponding to different bit sequences. Each of the plurality of correlators share a common estimator for estimating a frequency offset between the radio signals carrier frequencies and nominal carrier frequencies. The receiver further includes components allowing the estimator to determine which of the correlators produce the most optimal output signal.

Methods, systems, and devices for wireless communications are described. A user equipment (UE), that is configured for demodulation reference signal (DMRS) bundling, may receive a control message that schedules first and second sets of repetitions of an uplink transmission. The UE may determine a phase coherency configuration to be applied for DMRS transmissions corresponding to each set of repetitions. The phase coherency configuration may be determined based on a phase coherency capability of the UE, and the phase coherency configuration may specify that phase coherency is to be maintained for one or more of the first set of repetitions separate from one or more of the second set of repetitions. The UE may transmit the first set of repetitions with a first set of demodulation reference signals and the second set of repetitions with a second set of demodulation reference signals in accordance with the phase coherency configuration.

A wireless device transmits a frame by determining a plurality of Resource Units (RUs) of the frame, providing pilots in a first RU of the frame at a first set of positions, providing pilots in a second RU of the frame at a second set of positions, and transmitting the frame. The first set of positions is different from the second set of positions. A wireless device receives a frame including an RU including pilots and processes the pilots. When an RU for the data symbol includes an odd-numbered lowest subcarrier, the pilots are included at a first set of positions in the resource unit. When the RU includes an even-numbered lowest subcarrier, the pilots are included at a second set of positions in the resource unit. The second set of positions is different from the first set of positions.

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.

A tracking and rejection filter for use in a receiver of a radio includes a selectable filter configured to provide an output digital in-phase signal and an output digital quadrature signal based on a center frequency, a digital in-phase signal corresponding to an in-phase component of a received radio frequency signal, and a digital quadrature signal corresponding to a quadrature component of the received radio frequency signal. The tracking and rejection filter includes a select circuit configured to select the center frequency of the selectable filter according to whether an interfering signal is detected in a target frequency band of the received radio frequency signal. The center frequency is selected from a predetermined frequency and an estimated center frequency determined using an instantaneous frequency signal. The instantaneous frequency signal is based on the digital in-phase signal and the digital quadrature signal.

The present invention relates to the field of digital signal processing, and in particular to a Costas sequence time-frequency joint synchronization method based on all-phase spectrum correction. The method improves the defects existing in a discrete frequency spectrum correction algorithm using short-time Fourier transform and sliding correlation. The improvement mainly comprises: the present disclosure provides a solution based on iterative optimization: when an actual frequency offset is an integral multiple of the spectral resolution, a large error can occur, frequency offset correction and time delay correction are carried out on a signal by using an estimated value having a large estimated error, then estimation is carried out again, and the frequency offset of the signal is not a special value by means of an iteration mode.

The present disclosure relates to a signal processing device and an image display apparatus including the same. A signal processing device according to an embodiment of the present disclosure includes a sampler to downsample a baseband signal; a memory to store the downsampled data; a frequency shifter to read the data in the memory and shift the read data in a frequency domain; a symbol rate calculator to calculate a symbol rate based on the shifted data; a first offset calculator to calculate a first carrier frequency offset based on the calculated symbol rate; a second offset calculator to calculate a second carrier frequency offset based on the calculated first carrier frequency offset; and an offset compensator to compensate for the second carrier frequency offset. Accordingly, a time up to the demodulation completion may be shortened based on the baseband signal.

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.

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 then process data received from the transmitter in a manner synchronous to the manner in which the data was transmitted by the transmitter.

A mixer in a receiver converts a sounding sequence of alternating ones and zeros to an intermediate frequency signal. A digital mixer converts the intermediate frequency signal to a baseband signal that contains a positive tone and a negative tone. A frequency offset correction circuit generates frequency offset corrections based on frequency offset estimates of the frequency offset between a transmitter of the sounding sequence and the receiver. A frequency adjustment circuit adjusts a frequency of the mixer or the digital mixer to thereby center the positive tone and the negative tone around DC. DFT circuits perform single bin DFTs respectively centered on the positive and negative tones. Phases of the positive and negative tones are calculated based on outputs of the DFT circuits and the phases are used to determine fractional time value associated with a distance measurement between the transmitter and receiver.