A wireless power-transmission apparatus includes at least one antenna element disposed at a specific position in a three-dimensional space having a predetermined shape and size, to transmit a power transmission beam, an acquirer to acquire an inclination angle of the antenna element to a plane direction of a reference plane and a height of the antenna element to the reference plane, and a controller to control at least one of antenna power and a power transmission direction of the power transmission beam so that interference power of the power transmission beam toward an outside of the three-dimensional space becomes equal to or smaller than a predetermined allowable value when the antenna element is disposed at the acquired inclination angle and height.

A method and apparatus of transmitting a reference signal in a wireless communication system is provided. The method includes generating a precoded reference signal or a non-precoded reference signal in accordance with a rank, and transmitting the generated reference signal. Uplink transmission using multiple transmit antennas is supported through reference signal design and related control signaling.

An advanced system and method is provided. The advanced system and method comprises: a set of antennas including a set of transmit antennas and a set of receive antennas; a digital beamformer; and a processor operably connected to the set of antennas and the digital beamformer, the processor configured to; identify a set of orthogonal multiple-input-multiple-output (MIMO) signals, generate a first set of beams via the digital beamformer, and map the set of orthogonal MIMO signals into each of the generated set of beams. The advanced system and method further comprises a transceiver operably connected to the processor, the transceiver configured to: transmit, to a target scene via the set of transmit antenna of the set of antennas, a first signal based on the first set of beams; and receive, via the set of receive antennas of the set of antennas, a second signal based on a second set of beams that is reflected or backscattered from the target scene.

An electronic device according to an embodiment of the present invention may include a housing and an antenna module disposed on one surface of the housing, wherein the antenna module may include a printed circuit board including a first layer facing the one surface of the housing, a second layer facing the first layer, and at least one ground layer disposed between the first layer and the second layer, a first antenna array disposed on the first layer, a second antenna array disposed on the second layer and at least partially overlapping the first antenna array when viewed from the one surface of the housing, and a communication circuit (radio frequency integrated circuit (RFIC)) electrically connected to the first antenna array and the second antenna array and feeding the first antenna array and the second antenna array, wherein the communication circuit may be configured to receive a first signal from an external device via at least one of the first antenna array or the second antenna array, change a phase of at least a portion of the first antenna array and the second antenna array based on the first signal, and transmit/receive a second signal in a direction of a beam formed by the changed phase. Other various embodiments could be derived from the description.

Wi-Fi communication is further secured by perturbation of a spatial mapping matrix. In an embodiment channel state information is obtained from a receiving device in a wireless network through the wireless network. A first set of beam steering vectors is derived based on the channel state information to direct a radio signal to the receiving device. A second set of beam steering vectors is derived based on the channel state information to direct a radio signal other than to the receiving device. A perturbation matrix is generated. A spatial mapping matrix is formed by combining the first and the second set of beam steering vectors with a perturbation matrix. Data symbols to be transmitted are pre-coded to the receiving device using the spatial mapping matrix and transmitted through the wireless network to the receiving device.

Wi-Fi communication is further secured by perturbation of a spatial mapping matrix. In an embodiment channel state information is obtained from a receiving device in a wireless network through the wireless network. A first set of beam steering vectors is derived based on the channel state information to direct a radio signal to the receiving device. A second set of beam steering vectors is derived based on the channel state information to direct a radio signal other than to the receiving device. A perturbation matrix is generated. A spatial mapping matrix is formed by combining the first and the second set of beam steering vectors with a perturbation matrix. Data symbols to be transmitted are pre-coded to the receiving device using the spatial mapping matrix and transmitted through the wireless network to the receiving device.

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

A transmission method for transmitting a first modulated signal and a second modulated signal in the same frequency at the same time. Each signal has been modulated according to a different modulation scheme. The transmission method applies precoding on both signals using a fixed precoding matrix, applies different power change to each signal, and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

Embodiments of wireless antenna array systems to achieve three-dimensional beam coverage are described herein. Other embodiments may be described and claimed.

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.