Techniques for minimum-mean-square-error (MMSE) channel estimator using channel-dependent composite subcarriers and combined pilots reduce computational complexity and memory usage while still achieving near optimum performance. A set of interpolation filters, that are pre-calculated for different radio propagation environments, e.g., channel state information, are stored in look up tables at the receiver and used to interpolate channel estimates for combined pilots to obtain channel estimates for individual subcarriers.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may perform online spur detection and mitigation scheme. The UE may identify spurs during operation, in real time, and apply cancelation and noise equalization to address identified spurs. The UE may apply a high pass filter to reference signals. During a symbol, the UE may apply the high pass filter by estimating the channel on one or more neighbor tones (e.g., tones of higher frequency and tones of lower frequency that also carry reference symbols). Because the UE may assume that a channel will generally be smooth, and that noise may vary slowly or steadily across frequency resources, the UE may compare the channel noise of a particular tone to an average or normalized channel noise of the one or more neighbor tones.

A method, an apparatus and a device for simultaneously sampling multiples signals and a medium are provided. The method includes: modulating multiple target input signals with CDM, to obtain a single target analog signal; performing ΔΣ modulation on the single target analog signal to obtain a target digital bit stream; demodulating the target digital bit stream to obtain a target demodulated bit stream; and filtering the target demodulated bit stream to obtain multiple target output signals. With the method, the hardware overhead for simultaneous sampling of multiple-channel signals is reduced while ensuring accuracy. Accordingly, the apparatus and the device, and the medium have the above beneficial effects.

Provided are a channel flatness compensation method, a channel flatness compensation apparatus, a storage medium, a baseband chip, and a device, wherein the method is applied to a transmitting link modulated by orthogonal frequency division multiplexing and includes: receiving an input vector of a current sub-carrier subjected to sub-carrier mapping processing, and determining current values of preset configuration parameters corresponding to the current sub-carrier; querying a preset frequency domain compensation table according to the current values of the preset configuration parameters, and determining a target compensation vector according to a query result; and determining an output vector of the current sub-carrier according to the input vector and the target compensation vector, wherein the output vector is used in an inverse fast Fourier transform operation.

The apparatus may be a base station. The apparatus processes a first group of synchronization signals. The apparatus processes a second group of synchronization signals. The apparatus performs a first transmission by transmitting the processed first group of the synchronization signals in a first synchronization subframe. The apparatus performs a second transmission by transmitting the processed second group of the synchronization signals in a second synchronization subframe.

An efficiently-transformed digital self-interference canceller, preferably including an FD transformer, a TD transformer, a channel estimator, a composer, and a controller. The canceller can optionally include a channel memory, a predictor, and/or an extender. A method for digital self-interference cancelation, preferably including receiving inputs, transforming the inputs, generating outputs based on the transformed inputs, transforming the outputs, and/or generating a cancellation signal based on the outputs.

Infrastructure equipment forming part of a wireless communications network configured to receive data from a communications device via a communications channel between the infrastructure equipment and the communications device. The infrastructure equipment comprises circuitry configured to receive, from the communications device, a request for a resource allocation, to receive one or more reference symbols from the communications device, to estimate based on the received reference symbols, for each of a plurality of resource units, RUs, of the communications channel, a signal to interference and noise ratio, SINR, sequence of the communications channel, and to perform a first transform followed by a second transform on the SINR sequence to produce a cepstrum of the SINR sequence, the second transform being an inverse of the first transform, and to encode and to transmit the cepstrum to the communications device.

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.

Aspects of the present disclosure may involve use of a radio frequency receiver and in such a receiver, tracking multipath gains and delays of multipath reflections corresponding to an OFDM multipath transmission channel. The gains and delays are based on time-domain evolution of the channel impulse response. Multipath reflections are searched for and then used to calculate channel correlation information to provide channel estimations to aid in mitigating or cancelling distortion of the received signal.

Disclosed are a wireless transmitter and a reference signal transmission method that improve channel estimation accuracy. In a terminal, which transmits a reference signal using n (n is a non-negative integer 2 or greater) band blocks (which correspond to clusters here), which are disposed with spaces therebetween in a frequency direction, a reference signal controller switches the reference signal formation method of a reference signal generator between a first formation method and a second formation method based on the number (n) of band blocks. In addition, a threshold value setting unit adjusts a switching threshold value based on the frequency spacing between band blocks. Thus, the reference signal formation method can be selected with good accuracy and, as a result, channel estimation accuracy is further improved.