A method for detecting an electromagnetic signal comprises: applying to the received electromagnetic signal a plurality of time-frequency transforms, for each time/frequency cell of a given set of cells, calculating the energy of the vector made up of the spectra over all of the antenna elements, applying the following nonlinear function T to the result of the energy calculation: if the norm of the energy is below a first predetermined threshold s, the result of the function T is zero, if the norm of the energy is above or equal to the first threshold s, the result of the function T is equal to the norm of the energy minus the value of the first threshold s, integrating, over the set of time/frequency cells, the result of the nonlinear function T, comparing the result of the integration to a second predetermined threshold, to detect the presence of the signal.

A communications system having two terminals, each including two antennas, the communications system using spatial multiplexing. One antenna of a first terminal transmits a tracking tone along with a data signal. Two antennas in a second terminal receive the tracking tone. The signals from the two antennas are processed by a feed circuit. The feed circuit includes a variable delay circuit and a combiner that forms, at a first difference output, a linear combination, of a signal from the first antenna and a signal from the second antenna, in which the tracking tone is canceled. The variable delay circuit is actively adjusted to maintain this cancellation.

Methods, devices, and apparatus to adapt operating parameters for satellite signal reception and transmission by a wireless device to mitigate effects of fading due to specular reflections are described herein. The wireless device measures received signal power levels and compares characteristics of the measurements over an observation duration to at least one fading criteria to determine whether to operate in a normal or adaptive mode. While operating in the adaptive mode, the wireless device alternates between high performance mode time periods and low performance mode time periods. The wireless device indicates to a ground station associated with the satellite in which operating mode the wireless device is operating via an uplink data message transmitted during a data cycle at the start of a high or low performance mode time period. The ground station schedules data transmissions accordingly during subsequent data cycles of the high or low performance mode time periods.

Embodiments are directed to operating an analog signal processing circuit to emulate a Rotman lens. The analog signal processing circuit applies a plurality of time delays to a plurality of signals associated with a plurality of beam ports. The analog signal processing circuit forms a plurality of output beams for transmission by a plurality of array ports included in an array based on the time delayed signals by summing the time delayed signals. The time delays are based on a direction of transmission of the output beams.

User equipment includes a receiver, a first antenna and a second antenna coupled to the receiver, and processing circuitry communicatively coupled to the receiver and configured to cause the receiver to receive a first signal via the first antenna and a second signal via the second antenna, adjust the first signal based on a first time offset and a first frequency offset associated with the first signal to generate a first adjusted signal, adjust the second signal based on a second time offset and a second frequency offset associated with the second signal to generate a second adjusted signal, and decode downlink information based on the first adjusted signal and the second adjusted signal.

User equipment includes a receiver, a first antenna and a second antenna coupled to the receiver, and processing circuitry communicatively coupled to the receiver and configured to cause the receiver to receive a first signal via the first antenna and a second signal via the second antenna, adjust the first signal based on a first time offset and a first frequency offset associated with the first signal to generate a first adjusted signal, adjust the second signal based on a second time offset and a second frequency offset associated with the second signal to generate a second adjusted signal, and decode downlink information based on the first adjusted signal and the second adjusted signal.