Disclosed is a blind authentication method for a frequency selective fading channel based on belief propagation. The method includes: transmitting carrier signals to a frequency selective fading channel with a plurality of paths, where each of the carrier signals includes an authentication signal, a pilot signal and an information signal, and the authentication signal is superimposed on the pilot signal; receiving the carrier signals, performing blind known interference cancellation (BKIC) processing on a carrier signal in each of the plurality of paths of the frequency selective fading channel to obtain a target signal, and performing differential signal processing on the target signal to obtain a target authentication signal, where in the BKIC processing, a pilot signal in the each of the plurality of paths is cancelled through a belief propagation technique by using a prior probability density function and a Tanner graph of the target signal; obtaining a reference signal based on a key and the pilot signal in the each of the plurality of paths, performing the differential signal processing on the reference signal to obtain a reference authentication signal, and calculating a correlation between the target authentication signal and the reference authentication signal to obtain a test statistic; and comparing the test statistic with a prescribed threshold to determine whether the carrier signal in the each of the plurality of paths can pass authentication.

A digital transmission system includes a transmitter configured to transmit an orthogonal frequency division multiplexing (OFDM) signal along a signal path, a receiver for receiving the OFDM signal from the transmitter and extracting OFDM symbols from the received OFDM signal, and a diagnostic unit configured to (i) demodulate the received OFDM signal to create an ideal signal, (ii) compare the received OFDM signal with the ideal signal to calculate an error signal, (iii) cross-correlate the error signal with the ideal signal, and (iv) determine a level nonlinear distortion from one of the transmitter and the signal path based on the correlation of the error signal with the ideal signal.

Methods and apparatuses disclosed herein enable the use of Demodulation Reference Signal, DMRS, sequences that are numbered relative to an overall system bandwidth, while simultaneously enabling wireless communication devices to determine the DRMS sequence elements mapped to their scheduled bandwidths within the system bandwidth. Advantageously, the wireless communication devices need not know the system bandwidth, or even be aware of where their scheduled bandwidths reside within the system bandwidth.

An interference cancelation receiver can cancel channel state information reference signal interference using a single fast fourier transform (FFT), thereby reducing the complexity of the receiver. The transmitter can multiplex CSI-RS with a physical downlink shared channel (PDSCH) of another numerology, thereby improving a resource utilization. Thus, significant gains in link and system throughputs can be achieved via the use of the interference cancelation receiver.

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). A method for operating a base station in a wireless communication system according to an embodiment includes determining interference between symbols of a signal received from at least one terminal, determining a time offset of the received signal based on the determined interference, and determining a detection interval of the signal received from the at least one terminal based on the time offset.

A plurality of multicarrier signals is generated. Each of the plurality of multicarrier signals includes a pilot symbol sequence at a same temporal point in each multicarrier signal. Each pilot symbol sequence includes a plurality of pilot symbols with non-zero amplitude. The pilot symbol sequences are orthogonal to each other at the same temporal point. A quantity of the plurality of pilot symbols in each pilot symbol sequence is greater than or equal to a quantity of the plurality of multicarrier signals to be transmitted. The plurality of multicarrier signals are transmitted in an identical frequency band from a plurality of antennas. The plurality of antennas includes two, three, or four antennas.

Techniques are described for wireless communication. A first method may include classifying feedback received for a first downlink transmission over a shared radio frequency spectrum band; identifying an interference parameter for a subsequent downlink transmission; and scheduling the subsequent downlink transmission based at least in part on feedback classified in a feedback category associated with the identified interference parameter for the subsequent downlink transmission. The feedback may be classified in one of a plurality of feedback categories, and the classifying may be based at least in part on an interference parameter for the first downlink transmission. A second method may include identifying an interference parameter for a first downlink transmission received over a shared radio frequency spectrum band; generating feedback for the first downlink transmission; and sending, to a base station, the feedback along with an indication of the interference parameter.

A radio transmission apparatus determines information indicative of an estimated communications channel condition and generates a single modulation signal or a plurality of modulation signals based on the estimated communications channel condition information. The single modulation signal is transmitted from a first antenna of a plurality of antenna or the plurality of modulation signals are transmitted from the first antenna and at least a second antenna of the plurality of antenna. The plurality of modulation signals include different information from each other and are transmitted over an identical frequency band and at an identical temporal point. The single modulation signal and the plurality of modulation signals contain parameter information indicating a number of modulation signals transmitted at the same time.

In a base station, an assignment circuit maps a phase tracking reference signal onto a subset of antenna ports of antenna ports each included in at least one group into which a plurality of antenna ports have been grouped. The group is determined on the basis of a measured value of phase noise measured for each of the plurality of antenna ports. A transmitting unit transmits a data signal and the phase tracking reference signal.

Certain aspects of the present disclosure provide techniques for handling collisions between PUSCH and sounding reference signal (SRS) on additional SRS symbols in an uplink subframe using carrier aggregation. The techniques provide rules that a user equipment (UE) may apply to decide if and when to drop or apply power scaling to SRS or PUSCH transmissions scheduled on overlapping time resources.