Fiber, cable, and wireless data channels are typically impaired by reflectors and other imperfections, producing a channel state with echoes and frequency shifts in data waveforms. Here, methods of using pilot symbol waveform bursts to automatically produce a detailed 2D model of the channel state are presented. This 2D channel state can then be used to optimize data transmission. For wireless data channels, an even more detailed 2D model of channel state can be produced by using polarization and multiple antennas in the process. Once 2D channel states are known, the system turns imperfect data channels from a liability to an advantage by using channel imperfections to boost data transmission rates. The methods can be used to improve legacy data transmission modes in multiple types of media, and are particularly useful for producing new types of robust and high capacity wireless communications using non-legacy data transmission methods as well.

Computerized wireless transmitter/receiver system that automatically uses combinations of various methods, including transmitting data symbols by weighing or modulating a family of time shifted and frequency shifted waveforms bursts, pilot symbol methods, error detection methods, MIMO methods, and other methods, to automatically determine the structure of a data channel, and automatically compensate for signal distortions caused by various structural aspects of the data channel, as well as changes in channel structure. Often the data channel is a two or three dimensional space in which various wireless transmitters, receivers and signal reflectors are moving. The invention's modulation methods detect locations and speeds of various reflectors and other channel impairments. Error detection schemes, variation of modulation methods, and MIMO techniques further detect and compensate for impairments. The invention can automatically optimize its operational parameters, and produce a deterministic non-fading signal in environments in which other methods would likely degrade.

A wireless communication device and method therein for time synchronization in a wireless communication network are disclosed. The wireless communication device determines a first timing (tc) by performing a coarse time synchronization based on a synchronization signal received by the wireless communication device, wherein the received synchronization signal is sampled either in an original sampling rate or a reduced sampling rate. The wireless communication device determines a second timing (tf) by performing a fine time synchronization based on the determined first timing (tc) and the to received synchronization signal.

A station configured to perform a method for determining a wireless property such as a channel estimate, a channel estimation track, a time tracking loop, and a frequency tracking loop. The method includes determining a set of consecutive subframes in which no transmission is scheduled, placing a processor into a first power mode during at least a portion of the set of consecutive subframes, placing the processor into a second power mode during at least another portion of the set of consecutive subframes, receiving a first reference symbol when the processor is in the second power mode and calculating a wireless property based on the first reference symbol.

A phase-shifter circuit arranged to receive a reference timing signal and to output a phase-shifted form of the reference timing signal. The phase-shifter circuit comprises a delay circuit arranged to receive the reference timing signal and a delay control signal, and to delay transitions within the reference timing signal to generate the phase-shifted form of the reference timing signal, wherein the amount of delay applied by the delay circuit to the transitions within the reference timing signal is controllable by the delay control signal. The phase-shifter circuit further comprises a delay control circuit arranged to receive a re-timed signal comprising transitions re-timed to transitions of the phase-shifted form of the reference timing signal output by the phase-shifter circuit, and to generate the delay control signal for the delay circuit based on the received re-timed signal.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station having one or more antenna ports, a communication that includes one or more data streams and a tone reservation signal, wherein a number of the one or more antenna ports is different than a number of the one or more data streams. The UE may perform channel estimation based at least in part on the communication. Numerous other aspects are described.

The apparatus may be a base station. The apparatus processes a plurality of synchronization signals by performing time-division multiplexing (TDM) of at least one of a plurality of first synchronization signals of different types and at least one of the plurality of second synchronization signals of different types, the plurality of synchronization signals including the plurality of first synchronization signals and the plurality of second synchronization signals. The apparatus transmits the processed synchronization signals to a user equipment (UE).

The apparatus may be a base station. The apparatus processes a first group of synchronization signals. The apparatus processes a second group of synchronization signals. The apparatus performs a first transmission by transmitting the processed first group of the synchronization signals in a first synchronization subframe. The apparatus performs a second transmission by transmitting the processed second group of the synchronization signals in a second synchronization subframe.

The apparatus may be a user equipment (UE). The apparatus receives a transmission of at least one of a plurality of first synchronization signals. The apparatus receives at least one repeat transmission of the at least one of the plurality of first synchronization signals. In an aspect, the transmission and the at least one repeat transmission are received in a same synchronization signal block.

The apparatus may be a base station. The apparatus sets a first numerology for at least one synchronization signal of one or more synchronization signals to be different from a second numerology for at least one data signal of one or more data signals. The apparatus transmits the one or more synchronization signals to a user equipment (UE) based on the first numerology. The apparatus transmits the one or more data signals to the UE based on the second numerology.