Methods and systems relating to topics in space-polarization modulated communications. The topics include: adaptive space-polarization modulated communications using channel state information at the transmitter; adaptive decision boundaries at the receiver; carrier frequency offset estimation for multi-carrier modulation schemes; transmission of analog images using polarization and coherence dispersion information; and reduction of peak-to-average power ratio in multi-carrier modulation schemes.

A transmission method is provided for a communication system in which communications using a plurality of communication methods having different transmission parameters are performed at the same frequency (in frequency bands that at least partially overlap with each other). The transmission method includes: generating a first symbol group that includes a control symbol for causing a communication partner apparatus to recognize that communication using a first communication method is to be performed and a second symbol group that includes a data symbol for the first communication method; transmitting the first symbol group at a first transmit power; and transmitting the second symbol group at a second transmit power that is smaller than the first transmit power.

Methods and apparatus for early determination of an operation mode in a Narrowband Internet of Things (NB-IoT) system are provided. A User Equipment (UE) determines a mode of operation of a NB-IoT network before decoding a broadcast channel which indicates the mode of operation, based on at least one synchronization signal received at the UE, wherein the mode of operation indicates what bandwidth resources are used in the network. The UE processes signals based on the determined mode of operation.

A Long Range (LoRa) communication system with an improved data rate and method thereof are provided. When a packet to be transmitted is received, a transmission device determines a transmission scheme. When the determined transmission scheme is an enhanced transmission scheme, the transmission device transmits a preamble signal indicating that a packet is to be transmitted using the enhanced transmission scheme, converts n-th data of the packet to an up-chirp signal, converts (n+1)-th data of the packet to a down-chirp signal, generates a transmission signal by adding the n-th data converted to the up-chirp signal and the (n+1)-th data converted to the down-chirp signal, and transmits the transmission signal to a reception device.

Provided are a base station apparatus, a terminal apparatus, and a communication method that achieve a radio access network capable of being flexibly compatible with various requirements. The base station apparatus according to an aspect of the present invention includes a transmission unit configured to generate a transmit signal based on a frame format in which a radio parameter is configurable, and configured to notify the terminal apparatus of information indicating the radio parameter configured in the frame format. The terminal apparatus according to an aspect of the present invention includes a reception unit configured to acquire information indicating a radio parameter configured in a frame format, and configured to demodulate a signal generated based on the frame format, based on the radio parameter.

A method for a terminal performing communication using a TDD frame in a wireless communication system may comprise the steps of: receiving a synchronization signal (SS) from one symbol of a first subframe of a TDD frame; and transmitting uplink control information via an uplink control zone comprising at least one last symbol in the first subframe.

The present invention provides a signal sending apparatus, a signal detection apparatus, a signal sending and detection system, a signal sending method, and a signal detection method. The apparatus determines a time unit that is in each time window and that is used to transmit a synchronization signal, and transmits the synchronization signal in the determined time unit in each time window. Therefore, a synchronization signal is always located in a time unit that has a fixed location in each time window, so that a device at a receive end needs to perform detection only in a fixed time unit in each time window, thereby reducing complexity of designing and detecting the synchronization signal.

A Long Range (LoRa) communication system with an improved data rate and method thereof are provided. When a packet to be transmitted is received, a transmission device determines a transmission scheme. When the determined transmission scheme is an enhanced transmission scheme, the transmission device transmits a preamble signal indicating that a packet is to be transmitted using the enhanced transmission scheme, converts n-th data of the packet to an up-chirp signal, converts (n+1)-th data of the packet to a down-chirp signal, generates a transmission signal by adding the n-th data converted to the up-chirp signal and the (n+1)-th data converted to the down-chirp signal, and transmits the transmission signal to a reception device.

The present invention discloses a method and device for receiving a downlink control channel according to various embodiments. A method and device are disclosed, the method for receiving a downlink control channel according to an aspect of the present invention includes: a step for receiving a subframe including a downlink control region; and a step for performing blind decoding on a search space in the downlink control region, wherein the search space includes a plurality of PDCCH candidates which correspond to respective aggregation levels and include control channel elements (CCEs), and each of the plurality of PDCCH candidates overlaps at least one PDCCH candidate.

Methods, systems, and devices for wireless communications are described that provide for multiple-input multiple-output (MIMO) transmissions of control information using downlink control channel resources, such as physical downlink control channel (PDCCH) resources. The MIMO transmissions may provide control channel transmissions to multiple UEs using the same time-frequency resources. A base station may use a subset of control channel monitoring entities for MIMO control channel transmissions, and another subset of control channel monitoring candidates for non-MIMO control channel transmissions. Control channel monitoring entities for MIMO transmissions may be defined separately from non-MIMO or legacy control channel candidates.