Origin Wireless, Inc.

Qualcomm Incorporated

University System of Maryland

Yu-Han Yang

K J Ray Liu

Beibei Wang

Yan Chen

Yongle Wu

Hung-Quoc Duc Lai

Yi Han

RaviKiran Gopalan

Chen Chen

Feng Han

Qinyi Xu

Zoltan Safar

Hang Ma

Markos Troulis

Seyed Mohammad Ehsan Hosseini

An apparatus for determining symbol timing in a communication system is provided. The apparatus includes a memory communicatively coupled to at least one processor. The at least one processor is configured to receive a first signal that includes a preamble sent at a first sampling rate with a first modulation through a channel and a data frame sent at a second sampling rate with a second modulation through the channel. The preamble includes a received code sequence, and the data frame includes a plurality of data symbols. The at least one processor is configured to compute a second signal that represents an estimate of an equivalent channel response using at least one of a known code sequence and the received first signal, down-sample the second signal and compute signal-to-interference-plus-noise ratios at a plurality of candidate timing offsets, and determine a symbol timing based on a particular timing offset associated with one of the computed signal-to-interference-plus-noise ratios.

Time-reversal communication systems

There is provided a communication system including a transmitting section and a receiving section which includes a plurality of receivers. The transmitting section includes a communication unit which receives a plurality of signals respectively from the plurality of receivers, and stores a plurality of time-reversed signals corresponding to the received plurality of signals with respect to the plurality of receivers, and a first conversion unit which converts, by a first factor, a plurality of information sequences to be respectively transmitted to the plurality of receivers and forward the plurality of converted information sequences to the communication unit. The communication unit generates, based on the plurality of converted information sequences, a plurality of output signals to be respectively transmitted to the plurality of receivers, each of the plurality of the output signals including a location-specific signature unique to the corresponding receiver.

Systems and methods for time-reversal division multiple access wireless broadband communications

A transmitter receives channel impulse response signals derived from impulse signals sent from two or more receivers, each impulse signal being sent from one of the receivers to the transmitter through multiple propagation paths. Downlink waveforms for the two or more receivers are calculated in a way so as to increase a weighted sum-rate under a total power constraint, the downlink waveforms being determined based on time-reversed channel impulse response signals and initial virtual uplink power allocation coefficients. Updated virtual uplink power allocation coefficients are determined based on the downlink waveforms, and downlink power allocation coefficients are determined based on the downlink waveforms and the virtual uplink power allocation coefficients.

Waveform design for time-reversal systems

Time-reversal wireless communication includes: at a base station, receiving a probe signal from a terminal device; generating a signature waveform that is based on a time-reversed signal of a channel response signal derived from the probe signal; performing quadrature amplitude modulation (QAM) on a transmit signal to generate a quadrature amplitude modulated signal; and generating a transmission signal based on the quadrature amplitude modulated signal and the signature waveform.

Quadrature amplitude modulation for time-reversal systems

A base station having an input module for receiving a probe signal sent from a terminal device, and a data processor for generating a signature waveform that is based on channel information derived from the probe signal, identifying data symbols intended to be transmitted to the terminal device, and modifying the data symbols based on the channel information. The modification of the data symbols is designed to reduce inter-symbol interference when the data symbols are received by the terminal device. The data processor generates a downlink signal based on the modified data symbols and the signature waveform. The base station generates a wide-band a radio frequency signal based on the downlink signal and transmits the radio frequency signal to the terminal device through a multipath channel such that a portion of the radio frequency signal intended for the terminal device focuses at the terminal device.

Joint waveform design and interference pre-cancellation for time-reversal systems

A method for wireless communication is described. The method includes receiving a signal that is pattern-mapped and Gaussian frequency-shift keying (GFSK) modulated. The method also includes performing a joint demapping and demodulation of the received signal based on a stored accumulated phase. The method may further include updating the stored accumulated phase based on the joint demapping and demodulation.

Systems and methods for joint demodulation and demapping

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Santa Clara, CA, United States of America

Yu-Han Yang