Abstract: Methods, systems, and devices for spectral sharing wireless systems, wherein multiple user devices share time and frequency resources for uplink and/or downlink transmissions, are described. One example method includes transmitting transmission symbols from the network station to at least one user device by processing through a first precoder and a pre-compensation stage, wherein the pre-compensation stage is selected to have the transmission symbols receivable at the at least one user device to appear as if the transmission symbols are processed by a second precoder different from the first precoder.

Abstract: A wireless communication method includes receiving, by a first wireless device during a training phase, reference tones using a first number of resource elements from a transmitter of a second wireless device, wherein the first wireless device comprises multiple receiving antennas, estimating, by the first wireless device, from the receiving the reference tones, a second order statistics of wireless channels between the multiple receiving antennas and the transmitter of the second wireless device, and performing channel estimation, during an operational phase subsequent to the training phase, using the second order statistics and reference tones received on a second number of resource elements, wherein the second number is less than the first number.

Abstract: Orthogonal Time Frequency Space (OTFS) is a novel modulation scheme with significant benefits for 5G systems. The fundamental theory behind OTFS is presented in this paper as well as its benefits. We start with a mathematical description of the doubly fading delay-Doppler channel and develop a modulation that is tailored to this channel. We model the time varying delay-Doppler channel in the time-frequency domain and derive a new domain (the OTFS domain) where we show that the channel is transformed to a time invariant one and all symbols see the same SNR. We explore aspects of the modulation like delay and Doppler resolution, and address design and implementation issues like multiplexing multiple users and evaluating complexity. Finally we present some performance results where we demonstrate the superiority of OTFS.

Abstract: Device, methods, and systems for implementing aspects of orthogonal time frequency space (OTFS) modulation in wireless systems are described. In an aspect, the device may include a surface of an object for receiving an electromagnetic signal. The surface may be structured to perform a non-electrical function for the object. The surface may generate an electrical signal from an electromagnetic signal. The electromagnetic signal may be received from a transmitter. The transmitter may map digital data to a digital amplitude modulation constellation in a time-frequency space. The digital amplitude modulation constellation may be mapped to a delay-Doppler domain and the transmitter may transmit to the surface according to an orthogonal time frequency space modulation signal scheme. The apparatus may further include a demodulator to demodulate the electrical signal to determine digital data.

Abstract: 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.

Abstract: Methods, systems and devices for wireless communication are described. One example method includes performing a first mapping in which information bits are mapped to transmission resources in a first portion of a two-dimensional delay-Doppler grid. Herein, the two-dimensional delay-Doppler grid comprises N Doppler elements and M delay elements, where N and M are positive integers. The method further includes performing a second mapping in which a reference signal is mapped to transmission resources in a second portion of the two-dimensional delay-Doppler grid, and generating a transmission waveform from a signal combination of an output of the first mapping and an output of the second mapping. The transmission waveform corresponds to an output of an orthogonal time frequency space (OTFS) waveform of the signal combination, and at least the output of the second mapping undergoes a time domain spreading.

Abstract: A wireless communication method includes determining, by a network device, uplink power allocations assigned to each user device of multiple user devices; estimating a channel response for each user device of multiple user devices based on a corresponding uplink reference signal transmission received from the each user device; computing, for the each user device, a covariance matrix based on a corresponding channel response, determining a maximum eigenvector of an uplink signal to interference and noise ratio (SINR) matrix for the each user device; computing, from the uplink SINR matrix, a downlink cross-interference matrix for the each user device; selecting, from the downlink cross-interference matrix for the each user device, a selected vector that maximizes a selected criterion for the each user device; and determining, from the selected vectors of the multiple user devices, a downlink power allocation for the each user device of multiple user devices.

Abstract: Methods, systems and devices for fractional cooperative multipoint network operation are described. One example method for wireless communication includes determining, by a network device, a cooperative multipoint (COMP) management status of wireless devices served by the network device, and providing, by the network device, wireless connectivity to the one or more wireless devices, wherein the network device jointly manages transmission resources for a first wireless device due to the COMP management status being a joint COMP status and the network device locally manages transmission resources for a second wireless device due to the COMP management status being a local COMP status.

Abstract: Methods, systems and devices for wireless communication, which include localization and auto-calibration, are described. One example method includes receiving, at a wireless device, signal transmissions from one or more network devices, and generating, by processing the signal transmissions, a feedback signal for antenna calibration of the one or more network devices. In some embodiments, the antenna calibration is used for performing device localization and feature map generation that is subsequently used for scheduling transmissions in a wireless network.

Abstract: Methods, apparatus and systems for wireless communication are described. One example method includes estimating, based on channel quality information for a first communication channel during a first time interval, a predicted quality of a second communication channel during a second time interval that is a latency interval after the first time interval and using the predicted quality for processing transmissions on the second communication channel during the second time interval.

Abstract: An Orthogonal Time Frequency Space Modulation (OTFS) modulation scheme achieving multiple access by multiplexing multiple signals at the transmitter-side performs allocation of transmission resources to a first signal and a second signal, combining and converting to a transmission format via OTFS modulation and transmitting the signal over a communication channel. At the receiver, multiplexed signals are recovered using orthogonality property of the basis functions used for the multiplexing at the transmitter.

Abstract: Methods, systems and devices for massive cooperative multipoint network operation are described. One example method for wireless communication includes transmitting, by a network node serving a plurality of mobile devices in a surrounding area, channel condition information and scheduling information for one or more of the plurality of mobile devices to a network-side server, receiving, by the network node from the network-side server, control information for scheduling transmissions to or from each of the one or more of the plurality of mobile devices, and controlling, by the network node and based on the control information, a communication to or from the one or more of the plurality of mobile devices at a future time or a different frequency band or a different spatial direction.

Abstract: 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.

Abstract: Methods, devices, and systems for communication techniques that use the quasi-static properties of wireless channels are described. One example method to improve communication performance includes receiving a set of pilots over a transmission channel between the wireless communication apparatus and a far-end communication apparatus, the transmission channel comprising a first portion that is time-invariant and a second portion that is time-variant, processing the received set of pilots to generate an estimate of the first portion, processing the received set of pilots to generate an estimate of the second portion, and performing a communication based on a channel state information that is a weighted combination of a first term based on the estimate of the first portion and a second term based on the estimate of the second portion.

Abstract: Methods, systems and devices for distributed cooperative operation of wireless cells based on sparse channel representations are described. One example method includes providing, using a server, seamless wireless connectivity in an area in which a plurality of network nodes are organized as clusters, where each network node is configured to provide wireless connectivity via N angular sectors covering a surrounding area, where N is an integer and wherein angular sectors of the plurality of network nodes collectively cover the area; controlling, by the server, network nodes in a cluster to collect channel condition information for the N angular sectors and communicate the channel condition information to the network-side server, and operating the server to use the channel condition information collected from the network nodes in the cluster to control communication for the network nodes in the cluster at a different time or a different frequency or a different spatial direction.

Abstract: Techniques for performing channel estimation in an orthogonal time, frequency and space (OTFS) communication system include receiving a wireless signal comprising a data signal portion and a pilot signal portion in which the pilot signal portion includes multiple pilot signals multiplexed together in the OTFS domain, performing two-dimensional channel estimation in a time-frequency domain based on a minimum mean square error (MMSE) optimization criterion, and recovering information bits using a channel estimate obtained from the two-dimensional channel estimation.

Abstract: Techniques for wireless networking that include transmission and reception of signals using orthogonal time frequency space (OTFS) modulation techniques are disclosed. For example, a wireless access point may communicate with a station using OFDM modulated WiFi (OFDM-WiFi) at one time and using OTFS modulated WiFi (OTFS-WiFi) at another time. The OTFS-WiFi may provide improved throughput and coverage over OFDM-WiFi in static and mobile environments.

Abstract: A wireless communication method includes receiving, by a first wireless device during a training phase, reference tones using a first number of resource elements from a transmitter of a second wireless device, wherein the first wireless device comprises multiple receiving antennas, estimating, by the first wireless device, from the receiving the reference tones, a second order statistics of wireless channels between the multiple receiving antennas and the transmitter of the second wireless device, and performing channel estimation, during an operational phase subsequent to the training phase, using the second order statistics and reference tones received on a second number of resource elements, wherein the second number is less than the first number.

Abstract: A wireless communication device includes a feed port comprising multiple input feeds, a precoding subsystem that is electrically connected to the feed port; and an antenna subsystem electrically connected to the precoding subsystem. The antenna subsystem is configured to transmit an output signal of the precoding subsystem to multiple wireless stations using multiple beams. The precoding subsystem is configured to perform a precoding operation on an input signal from the feed port, wherein the precoding operation maximizes a desired signal level to interference ratio of transmissions to the multiple wireless stations.

Abstract: A method for modulating data for transmission within a communication system. The method includes establishing a time-frequency shifting matrix of dimension N×N, wherein N is greater than one. The method further includes combining the time-frequency shifting matrix with a data frame to provide an intermediate data frame. A transformed data matrix is provided by permuting elements of the intermediate data frame. A modulated signal is generated in accordance with elements of the transformed data matrix.