Methods, systems, and devices for wireless communications are described. A user equipment (UE) may select a candidate pattern from a set of patterns for reference signals used to track phase error. The UE may transmit an indication of the selected pattern to a base station and receive, from the base station at least in part in response to the transmitted indication of the selected pattern, an indication of a configuration for the reference signals used to track phase error, the configuration indicating a pattern of the set of patterns, a number of reference signal groups, and a number of samples per reference signal group. The UE may receive the reference signals used to track phase error according to the indicated configuration.

A receiver is configured to capture a plurality of linearly distorted OFDM symbols transmitted over a signal path. The receiver forms the captured OFDM symbols into an overlapped compound data block that includes payload data and at least one pseudo-extension, processes the overlapped compound block with circular convolution in the time domain using an inverse channel response, or frequency domain equalization, to produce an equalized compound block, and discards end portions of the equalized block to produce a narrow equalized block. The end portion corresponds with the pseudo-extension, and the narrow block corresponds with the payload data. The receiver cascades multiple narrow equalized blocks to form a de-ghosted signal stream of OFDM symbols. The OFDM symbols may be OFDM or OFDMA, and may or may not include a cyclic prefix, which will have a different length from the pseudo-extension.

A transmitter includes a processor configured to convert a primary sequence of modulation symbols into a primary signal using a universal pulse shape. The processor is further configured to convert an auxiliary sequence of modulation symbols, created from the primary sequence, to an auxiliary signal using an altered version of the universal pulse shape. In addition, the processor is configured to combine the primary signal and the auxiliary signal to create a joint output signal.

A new configuration suitable for a downlink single carrier is provided in a downlink control signal of a radio communication system of the future. A user terminal includes: a reception section that receives a downlink signal including a downlink control signal and a downlink data signal; and a demodulation and decoding section that uses the downlink control signal to demodulate and decode the downlink data signal, in which the downlink control signal is mapped to signal transmission points of a single carrier in units of control channel elements.

In user terminal 20, reception section 204 receives one or more downlink signals mapped to a plurality of signal transmission points in a single carrier, and extraction section 214 extracts at least one of the one or more downlink signals that is assigned to at least one of the signal transmission points that belongs to a resource block group associated with user terminal 20, in which the resource block group is in units of a predetermined number of signal transmission points and the at least one of the one or more downlink signals is extracted based on a definition of the resource block group. This processing makes it possible to multiplex downlink signals for a plurality of terminals in a single-carrier transmission.

Methods and apparatus for frequency offset estimation are disclosed. In an exemplary embodiment, a method includes determining a demodulation reference signal (DMRS) frequency offset estimate from DMRS symbols in a received signal, and determining a cyclic prefix (CP) frequency offset estimate from cyclic prefix values in the received signal. The method also includes combining the DMRS and CP frequency offset estimates to determine a final frequency offset estimate. In an exemplary embodiment, an apparatus includes a DMRS frequency offset estimator that determines a DMRS frequency offset estimate based on DMRS symbols received in an uplink transmission, and a cyclic prefix (CP) frequency offset estimator that determines a CP frequency offset estimate based on cyclic prefix values in the uplink transmission. The apparatus also includes an offset combiner that combines the DMRS frequency offset estimate with the CP frequency offset estimate to generate a final frequency offset estimate.

A method including receiving a data subframe having a plurality of symbols, determining a location of invalid pseudo time-domain samples in the data subframe, and discarding invalid pseudo time domain samples and recovering valid pseudo time domain samples to produce an updated data subframe, and processing the updated data subframe to produce demodulated data.

The present specification provides a method by which a terminal transmits an uplink signal in a wireless communication system. Particularly, the terminal scrambles a plurality of bits for transmission of an uplink signal, and generates a plurality of complex symbols by modulating the plurality of bits according to a specific modulation method. In addition, the terminal repetitively performs, a predetermined number of times, discrete Fourier transform (DFT) and inverse fast Fourier transform (IFFT) on at least one complex symbol of the plurality of complex symbols, and transmits the uplink signal, which is generated through the DFT and IFFT, to a base station, wherein the at least one complex symbol has a phase value which is increased or reduced as much as a specific value according to a symbol index.

A system and method are provided for processing symbols for transmission. The method involves producing a single carrier offset quadrature amplitude modulation (OQAM) waveform signal from a set of K complex symbols. The method further involves pulse shaping 2K frequency domain samples of the OQAM waveform signal with J non-zero coefficients, where the J non-zero coefficients represent a frequency response of a conjugate symmetrical pulse shape, and K≤J≤2K−1. The approach has the advantage of avoiding self-interference, with the result that better BLER performance may be possible. The approach is applicable to any modulation order and also avoids bandwidth expansion. Flexibility is provided through a trade-off between PAPR vs. spectrum efficiency.

A data sending apparatus includes a processor and a transceiver. The processor is configured to generate K first frequency-domain data streams, wherein a k.sup.th first frequency-domain data stream of the K first frequency-domain data streams is determined by performing preprocessing on a k.sup.th first modulated data stream, and the preprocessing includes at least a Fourier transform, a cyclic extension, or a phase rotation. The processor is further configured to map the K first frequency-domain data streams to frequency-domain resources to generate a time-domain symbol, and the transceiver is configured to send the time-domain symbol. A length of the k.sup.th first frequency-domain data stream of the K first frequency-domain data streams is N.sub.k, and a length of the k.sup.th first modulated data stream is M.sub.k. K is a positive integer greater than 1, N.sub.k and M.sub.k are positive integers, and k is an integer k=0, 1, . . . , K−1.