Patent classifications
H04L27/2665
Dynamic receiver timing for downlink transmissions
Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive signaling, such as a downlink control information (DCI), that identifies a transmission configuration state from a set of transmission configuration states, from which the UE may determine a receiver timing. The UE may then receive a downlink transmission, such as a physical downlink shared channel (PDSCH), from one or more transmission/reception points (TRPs). The UE may use the receiver timing to decode the downlink transmission by performing a fast fourier transform (FFT) with the receiver timing for the downlink transmission.
METHOD TO GENERATE A WIRELESS WAVEFORM FOR USE IN A WIRELESS COMMUNICATION SYSTEM, A WIRELESS COMMUNICATION SYSTEM AND COMPUTER PROGRAM PRODUCTS THEREOF
A method to generate a wireless waveform for use in a wireless communication system, a wireless communication system and computer program product thereof
The method comprises the generation of a waveform for application in the wireless communication system characterized by significant phase noise, Doppler spread, multipath, frequency instability, and/or low power efficiency by at the transmitter side: creating a discrete-time instantaneous frequency signal {tilde over (f)}[n]; appending a cyclic prefix with length L.sub.CP to the beginning of the discrete-time instantaneous frequency signal {tilde over (f)}[n]; constructing a discrete-time unwrapped instantaneous phase φ[n]; constructing a discrete-time complex baseband signal, and appending at the beginning a Constant Amplitude Zero Autocorrelation, CAZAC, signal of length L.sub.CP for multipath detection; and passing the constructed discrete-time complex baseband signal through a digital-to-analog, DAC, converter to yield the continuous-time radio frequency signal s(t) after conversion to the carrier frequency.
WIRELESS COMMUNICATION DEVICE AND METHOD THEREIN FOR TIME SYNCHRONIZATION IN A WIRELESS COMMUNICATION NETWORK
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.
Dynamic trigger compensation in OFDM systems
Systems and methods for enabling pre-compensation of timing offsets in OFDM receivers without invalidating channel estimates are described. Timing offset estimations may be sent along with the received OFDM symbols for FFT computation and generating a de-rotated signal output. The timing offset estimation may provide a reference point for dynamic tracking of timing for an OFDM signal and estimated based on an integral value associated with the OFDM signal.
Systems, methods, and apparatus for symbol timing recovery based on machine learning
A method may include generating an estimated time offset based on a reference signal in a communication system, and adjusting a transform window in the communication system based on the estimated time offset, wherein the estimated time offset is generated based on machine learning. Generating the estimated time offset may include applying the machine learning to one or more channel estimates. Generating the estimated time offset may include extracting one or more features from one or more channel estimates, and generating the estimated time offset based on the one or more features. Extracting the one or more features may include determining a correlation between a first channel and a second channel. The correlation may include a frequency domain correlation between the first channel and the second channel. Extracting the one or more features may include extracting a subset of a set of features of the one or more channel estimates.
TECHNIQUES FOR RANDOM ACCESS COMMUNICATION SUPPORT USING REMOTELY-LOCATED NODES IN A WIRELESS NETWORK
Aspects described herein relate to sending, from a distributed unit (DU), a control signal that is transparent to communications on an uplink data channel and a random access channel, receiving, at the DU, a signal from a radio unit (RU) over resources for the random access channel, and decoding a random access communication from the signal at least in part by applying a phase compensation to the signal.
METHOD AND APPARATUS FOR SIGNAL DETECTION IN A WIRELESS COMMUNICATION SYSTEM
The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A method for operating a receiving device in a wireless communication system comprises determining inter-symbol interference between symbols in a received signal, determining a location of a receive detection window according to the inter-symbol interference, and demodulating the received signal based on the location of the receive detection window. A receiving device includes at least one transceiver, and at least one processor configured to determine inter-symbol interference between symbols in a received signal, determine a location of a receive detection window according to the inter-symbol interference, and demodulate the received signal based on the location of the receive detection window. A transmitting device includes at least one processor configured to estimate an equivalent channel frequency response based on characteristic information of a time-domain filter, estimate an inter-symbol interference based on the equivalent channel frequency response, and generate indication information regarding an adjustment of a location of a receive detection window.
Mitigation of Negative Delay via Half CP Shift
A Long Term Evolution (LTE) receiver performing a half cyclic prefix (CP) shift on received subframes is disclosed, comprising: an analog to digital conversion (ADC) module; a cyclic prefix (CP) removal module coupled to the ADC module configured to retain a portion of cyclic prefix samples; a fast Fourier transform (FFT) module configured to receive samples from the cyclic prefix removal module, and to perform a FFT procedure on the received samples using a FFT window, the FFT window being shifted ahead based on the retained portion of cyclic prefix samples, to output an orthogonal frequency division multiplexed (OFDM) symbol; and a rotation compensation module coupled to the FFT module, the rotation compensation module configured to perform phase de-rotation of the OFDM symbol.
Receiver and associated signal processing method
A signal processing method including the steps of: using a FFT window to process a last symbol of a first sub-frame of a frame to generate a frequency-domain signal, wherein the FFT window has a first start point; performing an IFFT operation on the frequency-domain signal to generate a channel impulse response; performing a channel estimation on the channel impulse response to generate a channel profile; referring to the channel profile of the last symbol of the first sub-frame, an attribute of a start symbol of a second sub-frame and the first FFT window start point to determine a second FFT window start point; using the FFT window having the second start point to process the start symbol of the second sub-frame to generate another frequency-domain signal.
Adaptive channel prediction and mitigating interference in OFDM systems
One embodiment provides an apparatus. The apparatus includes an optimization module configured to determine a guard interval remainder based, at least in part on a comparison of an allowable microreflection interference level and an actual microreflection interference level; and a windowing module configured to window an OFDM (orthogonal frequency division multiplexed) symbol utilizing the guard interval remainder. The apparatus may further include a channel estimator module configured to determine a predicted channel frequency response based, at least in part, on a probing symbol; and a pre-equalizer module configured to pre-equalize the OFDM symbol based, at least in part, on the predicted channel frequency response.