In one aspect, a wireless device receives a first data transmission from a base station in a first subframe interval and transmits HARQ feedback and/or CSI to the base station in a subsequent subframe interval, within a duration that is less than a maximum transmission duration that is possible within the subsequent subframe interval. In another aspect, a base station transmits a first data transmission to a wireless device in a first subframe interval and receives HARQ feedback and/or CSI from the wireless device in a subsequent subframe interval, within a duration that is less than a maximum transmission duration that is possible within the subsequent subframe interval.

Embodiments of the present application provide a method for acquiring information of access resources, a terminal device, and a base station. A terminal device detects a synchronization signal of a cell to be accessed by the terminal device. The terminal device further receives a broadcast channel of the cell on a broadcast channel resource. The terminal device then determines a resource on which the cell is located according to resource indication information carried in the broadcast channel. The broadcast channel resource corresponds to an actual access resource, and the synchronization signal is detected on the actual access resource. The actual access resource is one of a plurality of candidate access resources of the cell. The resource indication information indicates a location relationship between the actual access resource and the resource on which the cell is located.

Systems and methods for synchronize word correlation. The methods comprise: obtaining first values that each indicate a likelihood or probability that a respective timeslot in a symbol timing window of a carrier wave is meant or expected to include energy; multiplying, by the correlator, the first values respectively by correlation coefficients to produce a plurality of products (wherein at least one of the correlation coefficients comprises a negative coefficient value); generating a correlation value by combining the products together; determining whether a synchronization word has been detected with a given amount of likelihood based on the correlation value; and causing symbol timing synchronization at a receiver when a determination is made that the synchronization word has been detected with the given amount of likelihood based on the correlation value.

Aspects of the present disclosure directed to frequency drift compensation for coded-DAS systems that use chirped pulses as a probe signal. Our inventive approach estimates timing jitter by correlating the amplitude of the estimated Rayleigh impulse response of every frame with a reference frame, and then re-aligns each frame by the estimated timing jitter. As the amount of timing jitter varies within a frame, every frame is divided into blocks where all samples have similar timing jitter, and perform timing jitter estimation and compensation on a block-by-block, frame-by-frame basis using an overlap-and-save method. Tracking of a slowly changing channel is enabled by allowing the reference frame to be periodically updated.

A radar system processes signals in a flexible, adaptive manner to determine range, Doppler (velocity) and angle of objects in an environment. The radar system processes the received signal to achieve different objectives depending on the environment, the current information stored in the radar system, and/or external information provided to the radar system. The system allows improved resolution of range, Doppler and/or angle depending on the desired objective.

Example communication systems and methods are described. In one implementation, a method receives a first chaotic sequence of a first temporal length, and a second chaotic sequence of a second temporal length. The method also receives a data symbol for communication to a destination. Based on the data symbol, the second chaotic sequence is temporally shifted and combined with the first chaotic sequence to generate a composite chaotic sequence. The first chaotic sequence functions as a reference chaotic sequence while the second chaotic sequence functions as a data-carrying auxiliary chaotic sequence.

Embodiments provide a data receiver, the data receiver being configured to receive a signal including a sequence of N bits so as to obtain a reception signal, wherein N is a natural number greater than or equal to eight, N≥8, wherein the data receiver is configured to sample the reception signal with a sampling rate that corresponds, with an intentional deviation of up to 2/N, to one sample value per bit of the sequence of N bits so as to obtain a sequence of received bits, wherein the data receiver is configured to correlate the sequence of received bits with K different sequences of N-1 reference bits so as to obtain K partial correlation results, wherein K is smaller than or equal to N-1 and greater than or equal to three, N-1≥K≥3.

Systems and methods for synchronize word correlation. The methods comprise: obtaining first values that each indicate a likelihood or probability that a respective timeslot in a symbol timing window of a carrier wave is meant or expected to include energy; multiplying, by the correlator, the first values respectively by correlation coefficients to produce a plurality of products (wherein at least one of the correlation coefficients comprises a negative coefficient value); generating a correlation value by combining the products together; determining whether a synchronization word has been detected with a given amount of likelihood based on the correlation value; and causing symbol timing synchronization at a receiver when a determination is made that the synchronization word has been detected with the given amount of likelihood based on the correlation value.

A radar system processes signals in a flexible, adaptive manner to determine range, Doppler (velocity) and angle of objects in an environment. The radar system includes transmitters configured to transmit radio signals, receivers configured to receive radar signals, and a control unit. The received radio signals include transmitted radio signals transmitted by the transmitters and reflected from objects in an environment. The control unit adaptively controls the transmitters and the receivers based on a selected operating mode for the radar system. The selected operating mode meets a desired operational objective defined by current environmental conditions. The control unit is configured to control the receivers to produce and process data according to the selected operating mode.

Described are systems and methods for identifying the phase and polarization of independent modulation streams in quadrature channels of a coherent transmission system by using digital code. As a result, phase rotation and polarization of streams that during transmission may have become rotated and swapped around in the channel are correctly labeled and depermuted according to a known and predictable order.