A transmission device includes: a modulator that selects an Orbital Angular Momentum (OAM) propagation mode among N (N is an integer equal to or greater than 2) OAM propagation modes in accordance with a value of bit data to be transmitted; and a transmitter that transmits a signal of the OAM propagation mode selected by the modulator.

A communications system includes a maximum ratio combining (MRC) circuit for receiving a plurality of data streams and processing the plurality of input data streams using maximum ration combining to improve signal to noise ratio. A MIMO transmitter transmits the MRC processed plurality of data streams over a plurality of separate communications links from the MIMO transmitter. Each of the plurality of separate communications links from one transmitting antenna of a plurality of transmitting antennas to each of a plurality of receiving antennas at a MIMO receiver. The MIMO transmitter transmits the MRC processed plurality of data streams using a channel matrix of an impulse response of a channel. The channel matrix is created using a pilot signal transmitted on a pilot channel.

This disclosure describes methods, devices, and systems related to generate a trigger frame including one or more resource block identifications (RBIDs), each RBID being associated with a respective resource unit of one or more resource units on a communication channel; cause to transmit the first trigger frame to each of one or more devices; process a received power save poll (PS-poll) bit from a first device of the one or more devices on a spatial stream and a first resource unit of the one or more resource units; cause to transmit an acknowledgment to each of the one or more user devices; cause to transmit data buffered in the at least one processor to the first device; and process a received acknowledgment from the first device confirming receipt of the data.

Embodiments of the present application provide a signal sending method, a device, and a system. A base station modulates, by using a first modulation scheme, signaling carried in a control channel, and modulates, by using a second modulation scheme, data carried in a traffic channel; and the base station sends, to UE, a signal obtained after modulation. In this way, the base station can independently select a modulation scheme for the control channel and the traffic channel, avoiding a case in which a modulation scheme used by the control channel and a modulation scheme used by the traffic channel must be the same, so that the base station can flexibly select a channel modulation scheme.

An Orthogonal Time Frequency Space Modulation (OTFS) modulation scheme that maps data symbols, along with optional pilot symbols, using a symplectic-like transformation such as a 2D Fourier transform and optional scrambling operation, into a complex wave aggregate and be backward compatible with legacy OFDM systems, is described. This wave aggregate may be processed for transmission by selecting portions of the aggregate according to various time and frequency intervals. The output from this process can be used to modulate transmitted waveforms according to various time intervals over a plurality of narrow-band subcarriers, often by using mutually orthogonal subcarrier tones or carrier frequencies. The entire wave aggregate may be transmitted over various time intervals. At the receiver, an inverse of this process can be used to both characterize the data channel and to correct the received signals for channel distortions, thus receiving a clear form of the original data symbols.

Aspects of the present disclosure provide for the transmission of various synchronization signals with variable periodicity. For synchronization signals with long periodicity, in some aspects of the disclosure, the synchronization signals may be transmitted as single-frequency-network (SFN) synchronization signals and/or the synchronization signals may be repeated a number (N) of times within a synchronization burst to reduce user equipment (UE) search latency and improve UE measurement accuracy. In some examples, the synchronization signals may be repeated within a synchronization burst using a repetition pattern that may be configurable based on the periodicity of transmission or fixed for one or more periodicities of transmission.

A method and apparatus for performing measurement in a wireless communication system is provided. A user equipment (UE) receives both an unlicensed discovery reference signal (U-DRS) and data burst simultaneously in subframes in which the UE is expected to receive a synchronization signal in an unlicensed carrier, and performs measurement by using the U-DRS. The subframes in which the UE is expected to receive the synchronization signal may be subframes having an index of 0 and 5.

This disclosure describes methods, devices, and systems related to generate a trigger frame including one or more resource block identifications (RBIDs), each RBID being associated with a respective resource unit of one or more resource units on a communication channel; cause to transmit the first trigger frame to each of one or more devices; process a received power save poll (PS-poll) bit from a first device of the one or more devices on a spatial stream and a first resource unit of the one or more resource units; cause to transmit an acknowledgment to each of the one or more user devices; cause to transmit data buffered in the at least one processor to the first device; and process a received acknowledgment from the first device confirming receipt of the data.

Methods and apparatuses are described for providing a shared eNodeB that is configured to provide shared network access to UEs associated with disparate cellular service providers, or operators, over one or more unlicensed frequency bands in a multi-operator, heterogeneous, and dual-connectivity-compatible system. In an example methodology, a shared eNodeB may establish a secondary communication link with a first user equipment associated with a first operators primary cell, then may establish another secondary communication link with a second UE associated with a second operators primary cell, wherein the shared eNodeB is configured to communicate with both a first core network associated with the first operator and a second core network associated with the second operator, and may communicate wirelessly over one or more unlicensed frequency bands with both the first UE via the first communication link and the second UE via the second communication link.

Certain aspects of the present disclosure generally relate to wireless communications, and more specifically increasing user capacity through a frame structure which supports eMTC UL multi-user multiplexing. According to aspects, a UE may identify at least one narrowband region within a wider system bandwidth, determine at least one parameter assigned to the UE for transmitting symbols of a physical uplink channel in the narrowband region that are multiplexed with symbols transmitted by one or more other UEs, and transmit the physical uplink channel using the at least one determined parameter.