Abstract: A switchable element, a device and a method for analogue and programmable computing operating on electromagnetic waves having a frequency, wherein the switchable element is configured to configured to, in response to an activation signal, switch from having a first dielectric permittivity for electromagnetic waves having a frequency to having a second dielectric permittivity for electromagnetic waves having the frequency, and the device comprises a plurality of the switchable elements that are adapted to be switched individually in accordance with the computing operation.

Abstract: Composite substrate for a waveguide for RF signals having a signal frequency, wherein said composite substrate comprises at least a first layer of dielectric material and a second layer of dielectric material, and at least one conductor layer of an electrically conductive material arranged between said first layer and said second layer, wherein a layer thickness of said at least one conductor layer is smaller than about 120 percent of a skin depth of said RF signals within said electrically conductive material of said conductor layer.

Abstract: Apparatus comprising a first layer of electrically conductive material and a second layer of electrically conductive material, and a plurality of impedance elements connecting said first layer with said second layer, wherein an impedance value of at least some of said plurality of impedance elements is controllable.

Abstract: A switchable element, a device and a method for analogue and programmable computing operating on electromagnetic waves having a frequency, wherein the switchable element is configured to configured to, in response to an activation signal, switch from having a first dielectric permittivity for electromagnetic waves having a frequency to having a second dielectric permittivity for electromagnetic waves having the frequency, and the device comprises a plurality of the switchable elements that are adapted to be switched individually in accordance with the computing operation.

Abstract: Composite substrate for a waveguide for RF signals having a signal frequency, wherein said composite substrate comprises at least a first layer of dielectric material and a second layer of dielectric material, and at least one conductor layer of an electrically conductive material arranged between said first layer and said second layer, wherein a layer thickness of said at least one conductor layer is smaller than about 120 percent of a skin depth of said RF signals within said electrically conductive material of said conductor layer.

Abstract: Apparatus comprising a first layer of electrically conductive material and a second layer of electrically conductive material, and a plurality of impedance elements connecting said first layer with said second layer, wherein an impedance value of at least some of said plurality of impedance elements is controllable.

Abstract: A method of reducing a number of signals that are output for processing by an antenna array and the antenna array are disclosed. The method comprises: receiving signals at a plurality of antenna elements from at least one user equipment; transforming the signals to at least one different domain to generate sparse signals; combining at least some of the signals to form a reduced number of signals; and outputting the reduced number of sparse signals to signal processing circuitry.

Abstract: In a method for transmitting data through a Massive MIMO backhaul system, a central node of the MIMO backhaul system transmits, to a small cell repeater terminal on the downlink, a downlink pilot signal carrying a set of pilot sequences that are mutually orthogonal in the frequency domain. Each pilot sequence in the set of pilot sequences corresponds to an antenna of an antenna array at the central node. The central node receives an uplink pilot signal carrying the set of pilot sequences transmitted by the small cell repeater terminal on the uplink, where the received uplink pilot signal is a frequency converted retransmission of the downlink pilot signal. The central node estimates at least one of an uplink channel and a downlink channel between the central node and the small cell repeater terminal based on the set of pilot sequences and the received uplink pilot signal.

Abstract: In a method for transmitting data through a Massive MIMO backhaul system, a central node of the MIMO backhaul system transmits, to a small cell repeater terminal on the downlink, a downlink pilot signal carrying a set of pilot sequences that are mutually orthogonal in the frequency domain. Each pilot sequence in the set of pilot sequences corresponds to an antenna of an antenna array at the central node. The central node receives an uplink pilot signal carrying the set of pilot sequences transmitted by the small cell repeater terminal on the uplink, where the received uplink pilot signal is a frequency converted retransmission of the downlink pilot signal. The central node estimates at least one of an uplink channel and a downlink channel between the central node and the small cell repeater terminal based on the set of pilot sequences and the received uplink pilot signal.