Patent classifications
H04L25/0256
Method for estimating a wireless communication channel, device for estimating a wireless communication channel and computer program therefor
A method for estimating a wireless communication channel between a transmitter and a receiver, including a plurality of paths for propagation of a wave, at least one of the transmitter and the receiver being formed of a plurality of antennas. The method includes: for at least one path, determining a characteristic matrix, which depends on a first element representative of at least one propagation direction associated with the path, and a second element representative of a propagation distance associated with the path; and estimating the communication channel from the at least one obtained characteristic matrix.
RECONSTRUCTION OF CLIPPED SIGNALS
Using information contained in clipped samples from aualog-to-digital (ADC) conversion to improve receiver performance, by, for example, reducing the clipping distortion caused by ADCs due to its data resolution constraints. This provides an advantage over existing solutions, which perform suboptimally because the existing solution discard information in tire clipped samples.
Reception apparatus and method for demodulating signal in wireless AV system
The present specification relates to a reception apparatus and method for demodulating a signal in a wireless AV system. The reception apparatus estimates a transmission signal on the basis of an MMSE weight matrix. The reception apparatus divides the estimated transmission signal for respective reception antennas and performs an IFFT. The reception apparatus estimates and compensates for phase noise for the respective reception antennas on the basis of the signal for which the IFFT has been performed. The reception apparatus demodulates the estimated and compensated signal for respective streams.
CARRIER FREQUENCY OFFSET CORRECTION AND DOPPLER MITIGATION
Various strategies and devices for same are disclosed to correct for/mitigate frequency offset (such as due to differing accuracies between an oscillator of a transmitting device and an oscillator of a receiving device) and Doppler shift (such as due to a changing relative position between a receiving device and a transmitting device). These strategies may be employed in a MIMO setting, such as, e.g. a stationary base station and a plurality of terminal devices (e.g. user devices, mobile stations, etc.), in which the transmissions for each terminal device may be associated with a different frequency offset and a different Doppler shift.
Communication techniques using quasi-static properties of wireless channels
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.
Signal processing device, signal processing method, recording medium, and mobile body
A signal processing device includes: a transmission path estimator that estimates a first transmission path characteristic of a transmission signal using a vertical signal out of vertical and horizontal signals resulting from being received by a vertical polarization antenna and a horizontal polarization antenna; a transmission path estimator that estimates a second transmission path characteristic of the transmission signal using the horizontal signal; a weight calculator that calculates a first weight for the vertical signal and a second weight for the horizontal signal, using the first transmission path characteristic and the second transmission path characteristic; and a weighting applier that applies weighted summation to the vertical signal and the horizontal signal using the first weight and the second weight.
COMMUNICATION TECHNIQUES USING QUASI-STATIC PROPERTIES OF WIRELESS CHANNELS
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.
CIRCULAR PILOT SEQUENCES FOR JOINT CHANNEL AND PHASE NOISE ESTIMATION
The invention relates to a method for transmitting at least K reference signals in a radio signal to be transmitted over a wireless communication system, said radio signal being intended to be emitted by an emitter comprising at least a transmit antenna configured for emitting on a number M of subcarriers S.sub.1, . . . , S.sub.M amongst which at least a number K of different subcarriers S.sub.q+1, S.sub.q+2, . . . , S.sub.q+K are contiguous, the respective frequencies of the contiguous subcarriers S.sub.q+1, S.sub.q+2, . . . , S.sub.q+K being ordered, said radio signal being provided by: inserting the at least K reference signals P.sub.1, . . . , P.sub.K so that the at least K reference signals P.sub.1, . . . , P.sub.K are respectively transmitted on the K contiguous subcarriers S.sub.q+1, S.sub.q+2, . . . , S.sub.q+K; emitting the radio signal including the at least K reference signals.
Data detection in MIMO systems with demodulation and tracking reference signals
What is disclosed is a method for wireless communication comprising receiving a wireless communication via a receiver of the mobile communication device, deriving a demodulation reference signal from a first plurality of symbols of the wireless communication; creating a channel estimation matrix using the demodulation reference signal; inverting the channel estimation matrix to obtain a channel pseudo-inverse matrix; deriving a tracking reference signal from a second plurality of symbols of the wireless communication; calculating a phase shift for one or more additional symbols based on the tracking reference signal; determining a corrected channel pseudo-inverse matrix for the one or more additional symbols by adjusting the channel pseudo-inverse matrix according to the calculated phase shift; and controlling the receiver to accomplish data detection using the corrected channel pseudo-inverse matrix on one or more orthogonal frequency division multiplexing subcarriers.
ELECTRONIC DEVICE SUPPORTING MULI-BAND WIRELESS COMMUNICATIONS AND METHOD OF CONTROLLING SAME
Disclosed is an electronic device, including a housing, a first communication circuit disposed in the housing and configured to support omnidirectional wireless communication, a second communication circuit disposed in the housing and configured to support directional wireless communication using beamforming, a processor disposed in the housing and operatively coupled to the first communication circuit and the second communication circuit, and a memory disposed in the housing and operatively coupled to the processor. The processor may be configured to receive at least one first radio signal through a communication channel from an external device capable of supporting the omnidirectional wireless communication and the directional wireless communication using the first communication circuit, determine a state of the communication channel based on at least part of the at least one first radio signal, and activate the second communication circuit based on at least part of the determined state of the communication channel wherein the second communication circuit is configured to receive a second radio signal from the external device.