Various embodiments of the present technology relate generally to wireless power systems. More specifically, some embodiments relate to the use of time reversal techniques utilizing time diversity (e.g., different multipath arrivals at the same antenna) to achieve coherency from the same transmission node. For example, instead of initiating outgoing transmissions (e.g., power signals) at the same time, various embodiments can initiate the outgoing signals from the various antennas in a staggered timing that is a reversal of the arrival times of an incoming signal. As a result of staggering the start of the outgoing signals, the signals will arrive at the destination at approximately the same time even though they have traveled different paths having different propagation delays.

A communication apparatus includes circuitry and a transmitter. The circuitry maps a precoded downlink control signal to one of a plurality of mapping candidates. The precoded downlink control signal is prepared using a first precoding for single-antenna port transmission with a single antenna port in localized allocation mode. The precoded downlink control signal is prepared using a second precoding for multi-antenna ports transmission with two antenna ports in distributed allocation mode. The plurality of mapping candidates is comprised of a plurality of aggregation levels, and one or more of the aggregation levels that is higher than a boundary among the plurality of aggregation levels is associated with only the multi-antenna ports transmission, the boundary being determined based on signaling indicated from the base station apparatus. The transmitter transmits the precoded downlink control signal.

Provided are M signal processors that respectively generate modulated signals for M reception apparatuses (where M is an integer equal to 2 or greater), a multiplexing signal processor, and N antenna sections (where N is an integer equal to 1 or greater). When transmitting multiple streams, each of the M signal processors generates two mapped signals, generates first and second precoded signals by precoding the two mapped signals, periodically changes the phase of signal points in the IQ plane with respect to the second precoded signal, outputs the phase-changed signal, and outputs the first precoded signal and the phase-changed second precoded signal as two modulated signals. When transmitting a single stream, each of the M signal processor outputs a single modulated signal. The multiplexing signal processor multiplexes the modulated signals output from the M signal processors, and generates N multiplexed signals. The N antenna sections respectively transmit the N multiplexed signals.

A transmission device includes a modulation unit that performs chirp-spread modulation on an input information series to generate a modulation signal; a delay unit that provides, to a plurality of modulation signals obtained by duplicating the modulation signal generated by the modulation unit, delays having lengths different from each other, a difference between the delays being an integral multiple of a reciprocal of a bandwidth of the modulation signal; and a plurality of transmission antennas that transmit the plurality of modulation signals, respectively, to which the delays are provided by the delay unit.

This document discloses a reflector antenna system with movable MIMO multiple feeds and adaptive field focusing method for wireless communication in multipath fading environment; the system comprises antenna reflector, multiple feeds, the equal number of the signal receiving channels and signal transmitting channels to the feeds, all the channels are capable to measure and adjust the amplitude and time delay of signals, and the method for amplitude and time delay adjustment of the powered signals. In signal receiving mode the antenna system makes the signal components arrived through unknown multipath superimpose synchronously; in signal transmitting mode, the system let the wave components radiated from different transmitting channels superimpose synchronously, realizing adaptive field focusing at the antenna of the communication target. This antenna system is suitable for point to point wireless communication in wireless propagation environment with multipath fading effect, showing remarkable improvement of SNR of the signals transmitted and received.

A phase shifter that includes an RF splitter is disclosed. The RF splitter is arranged so that an RF input signal is provided to, and split over portions of, a feed line that connects an antenna element with a radio transmitter/receiver/transceiver, thus realizing a feed line splitter. Feed line splitters described herein are provided with switches that allow changing a point at which the RF input signal is fed to the feed line, where the switches may be semiconductor-based or MEMS-based switches. The point at which the RF input signal is provided to the feed line to be split defines the electrical path length that the RF energy will travel down each respective path of the feed line splitter, which, in turn, changes the phase shift realized at each output of the feed line splitter. Different antenna elements may be coupled to different outputs of the feed line splitter.

An electronic device that uses an arbitrary transmit polarization is described. This electronic device includes: a first antenna having a first predefined polarization; and a second antenna having a second predefined polarization, where the second predefined polarization is different from the first predefined polarization. During operation, an interface circuit in the electronic device selectively transmits, from the first antenna, first wireless signals corresponding to the packet or the frame. Moreover, the interface circuit selectively transmits, from the second antenna, second wireless signals corresponding to the packet or the frame, where the second wireless signals have a same magnitude as the first wireless signals, and the second wireless signals are transmitted from the second antenna concurrently (or at the same time) as the first wireless signals are transmitted from the first antenna. Note that the interface circuit may dynamically modify the transmit polarization during the communication.

Aspects relate to mechanisms for a wireless communication device to select between a cyclic delay diversity mode and an antenna switch diversity mode for transmission of a signal based on at least one parameter associated with communication over a wireless channel. The parameter(s) may include a channel estimation parameter associated with the wireless channel, a communication parameter associated with at least one communication on the wireless channel, or a combination thereof.

A transmission method includes generating a first precoded signal and a second precoded signal by performing a precoding process on a first baseband signal and a second baseband signal, outputting a third signal by inserting a pilot signal into the first precoded signal, outputting a fourth signal by applying a first phase change to the second precoded signal, outputting a fifth signal by inserting a pilot signal into the fourth signal, and outputting a sixth signal by applying a second phase change to the fifth signal.

A precoding process is performed on a first baseband signal and a second baseband signal to generate a first precoding signal and a second precoding signal. A pilot signal is inserted into the first precoding signal and phase change is performed on the second precoding signal. A pilot signal is inserted into the phase changed second precoding signal, and phase change is further performed on the phase-changed second precoding signal with the pilot signal inserted.