A method for selection by an ambient backscatter system including a source as well as transmitting and receiving devices, the source being associated with a precoder for focusing signals towards the devices. Furthermore, the method includes, for a plurality of values ϕ_1, . . . , ϕ_N: a phase-shift, by the source, of one of the components of the precoder according to the value ϕ_i, so as to obtain a precoder Q_i; an emission, by the source, using the precoder Q_i; an acquisition, by the receiving device, of power measurements during non-backscattering and backscattering states, a determination, by the receiving device, of a value D1_i representative of a power deviation between the measurements. The method also includes a selection, by the receiving device, of a maximum value among the values D1_1, . . . , D1_N.

A method and system for transpositional modulation fortified communication includes an original carrier of an RF channel operating within a spectral mask. The original carrier has a carrier signal with a first quantity of data. At least one transpositional modulation (TM) channel has a TM signal second quantity of data. The at least one TM channel is added to the original carrier thereby generating a TM fortified carrier signal having the first and second quantities of data. The at least one TM channel and the original carrier do not exceed the spectral mask. At least one device with a receiver receives the TM fortified carrier signal.

A system for switching between different communication modes by network nodes according to a time-division schedule to transmit and receive data packets is provided. For example, a transmitting node is configured to determine a scheduled communication mode of an upcoming time division according to a time-division schedule, and transmit a data packet in that time division when the scheduled communication mode matches a selected communication mode supported by both the transmitting node and a receiving node. The receiving node operates in a scheduled communication mode specified for a current time division by the time-division schedule and determines whether a header of the data packet is detected in the current time division. If not, the receiving node switches to a second scheduled communication mode specified for the subsequent time division by the time-division schedule to detect the header of the data packet in a subsequent time division.

A modulation module includes a first modulation circuit that, upon receiving input of first setting information including first information designating a modulation mode, outputs a prescribed auxiliary signal as a first output signal, but upon receiving input of second setting information including second information designating a different modulation mode from the first information, outputs a first modulation signal generated by subjecting an input signal to modulation processing based on the second setting information as the first output signal. The modulation module further includes a second modulation circuit that is configured to output, as a second output signal, a signal generated by combining a second modulation signal generated by modulation processing and the first output signal.

A communication device includes a receiver, a transmitter and a control circuit. The receiver is configured to receive, from an infrastructure equipment of a mobile communications network, downlink signals on a downlink via a wireless access interface of the mobile communications network. The transmitter is configured to transmit, to the infrastructure equipment, uplink signals on an uplink via the wireless access interface. The control circuit is configured to control the receiver to receive the downlink signals and control the transmitter to transmit the uplink signals. The control circuit is further configured to delay a reception period for the receiver to receive the downlink signals after a transmission period in which the transmitter transmits the uplink signals when a duration of the transmission period exceeds a predetermined threshold.

A modulation format estimation device 100 includes: a frequency shift correction unit 112 configured to estimate the amount of a frequency shift using a baseband signal acquired from a received signal and correct the baseband signal based on an estimation result; a frequency error generation unit 122 configured to generate a plurality of frequency errors from a range set based on an error occurring in the estimation of the frequency shift amount; a frequency error introduction unit 123 configured to acquire learning baseband signals in which each of a plurality of source signals modulated by different modulation formats is frequency-shifted by each frequency error; and a modulation format estimation unit 113 configured to input a corrected baseband signal to a first machine learning model created by machine learning using learning data including the plurality of learning baseband signals and a label, and estimate a modulation format of the received signal.

An intelligent data and knowledge-driven method for modulation recognition includes the following steps: collecting spectrum data; constructing corresponding attribute vector labels for different modulation schemes; constructing and pre-training an attribute learning model based on the attribute vector labels for different modulation schemes; constructing and pre-training a visual model for modulation recognition; constructing a feature space transformation model, and constructing an intelligent data and knowledge-driven model for modulation recognition based on the attribute learning model and the visual model; transferring parameters of the pre-trained visual model and the pre-trained attribute learning model and retraining the transformation model; and determining whether training on a network is completed and outputting a classification result. The intelligent data and knowledge-driven method for modulation recognition significantly improves the recognition accuracy at low SNRs and reduces the confusion between higher-order modulation schemes.

A method of transmitting a discovery reference signal (DRS) by a base station in a wireless access system supporting an unlicensed band, includes transmitting the DRS in a DRS occasion via the unlicensed band, wherein the DRS includes a secondary synchronization signal (SSS), wherein the DRS is transmitted in a subframe (SF) among SF #1, SF #2, SF #3, SF #4, SF #6, SF #7, SF #8, and SF #9, and wherein the SSS is generated based on a SSS sequence related to a SF number where the DRS occasion occurs.

A method implemented by a Wireless Transmit/Receive Unit (WTRU) includes receiving a DeModulation Interference Measurement (DM-IM) resource, determining an interference measurement based on the DM-IM resource, and demodulating a received signal based on the interference measurement. An interference is suppressed based on the interference measurement. At least one DM-IM resource is located in a Physical Resource Block (PRB). The DM-IM resource is located in a PRB allocated for the WTRU. The DM-IM resource is a plurality of DM-IM resources which form a DM-IM pattern, and the DM-IM pattern is located on a Physical Downlink Shared Channel (PDSCH) and/or an enhanced Physical Downlink Shared Channel (E-PDSCH) of at least one Long Term Evolution (LTE) subframe. The DM-IM resources are different for different Physical Resource Blocks (PRB) in the LTE subframe. The DM-IM is located in a Long Term Evolution (LTE) Resource Block (RB), and the DM-IM pattern is adjusted.

The present invention provides a method of determining a transmission power for device to device, D2D, transmissions between a first user equipment device and a second user equipment device using transmission resources being used for transmissions to a cellular network entity by a third user equipment device, the method comprising determining a measure of a path loss between the cellular network entity and the first user equipment device, and using the measure of the path loss to determine a maximum transmission power such that the D2D transmissions are received at the cellular network entity with a signal level around or below a noise level.