Radio equipment (10) is configured for tap separated channel estimation in a wireless communication system. The radio equipment (10) obtains a channel estimate (16) of a radio channel over which a reference signal (12) is received, and separates the channel estimate (16) into channel estimate components (20) that correspond to respective channel taps (22). The radio equipment (10) then compensates the channel estimate components (20) for Doppler shifts respectively associated with the channel taps (22) to which the channel estimate components (20) correspond. The radio equipment (10) processes the compensated channel estimate components (32) separately. Such processing comprises filtering, interpolating, and/or extrapolating. The radio equipment (10) then de-compensates the processed channel estimate components (34) for the respective Doppler shifts, and forms a combined channel estimate (42) of the radio channel by combining the de-compensated channel estimate components (38).

Methods, apparatus, and computer program products for a user equipment receiving CSI-RS and computing channel support information. Based on the CSI, the UE derives tap locations of channel support, depending on the observed channel and used subcarrier spacing. The deriving can additionally be done in relation to power class and window size. The UE apprises a base station of those tap locations of the channel support and also informs the base station of the strongest tap locations, which can be done in various ways comprising a bit mask. Methods, apparatus, and computer program products for a base station to send CSI-RS to a UE for computing CSI feedback. The CSI-RS resources can be for one or multiple transmit receive points. The base station receives back an indication of tap locations and a bit mask and builds information on tap locations by combining that received indication and bit mask.

An illustrative receiver includes: a decision element that derives symbol decisions from a slicer input signal; an equalizer that converts a receive signal into the slicer input signal; a summer that combines the symbol decisions with the slicer input signal to produce an error signal; and a level finder that operates on said signals to determine thresholds at which each signal has a given probability of exceeding the threshold. One illustrative level finder circuit includes: a gated comparator and an asymmetric accumulator. The gated comparator asserts a first or a second gated output signal to indicate when an input signal exceeds or falls below a threshold with a programmable condition being met. The asymmetric accumulator adapts the threshold using up steps for assertions of the first gated output signal and down steps for assertions of the second gated output signal, with the up-step size being different than the down-step size.

There are provided apparatuses, methods and computer program products. In accordance with an embodiment, there is disclosed a method including receiving positioning reference signals from a positioning signal transmitter; forming a delay search space from the received positioning reference signals to obtain a plurality of channel taps; estimating a noise precision for the channel taps; estimating channel gains for the channel taps; and estimating a probability of line of sight signal for the channel taps.

To provide a phase noise optimization device and a phase noise optimization method which are capable of automatically measuring optimum phase noise according to an offset frequency. There is included a phase noise data generation unit 28 that generates at least two types of phase noise data corresponding to at least two LPFs 15a and 15b selected by a filter selection unit 16 in at least one measurement frequency range, set in advance, out of a plurality of measurement frequency ranges, a comparison unit 29 that compares at least two types of phase noise data, and a phase noise optimization unit 30 that generates optimized phase noise data based on a comparison result of the comparison unit 29.

A method for accommodating users in an uplink channel is provided. The method comprises a processor for selecting a region of sub carriers in a frequency domain, wherein a channel value of a plurality of users over the selected region varies gradually. The processor is further configured to select the sub carriers within the selected region of sub carriers by skipping the sub carriers by an integer value which is 0 or more than 0. A product of a known sequence and an exponential sequence is transmitting over the selected sub carriers, wherein the exponential sequence is characterized by a cyclic shift value. Further, a base station is configured to perform channel estimation of the users using the received selected sub carriers within the selected region and the processor is also configured to perform data detection for the users over the selected sub carriers using the estimated channel value.

A method of determining a distance between a radio frequency device and a target is disclosed in which the radio frequency device receives a radio frequency signal from the target. The method comprises determining a time domain channel response from the received radio frequency signal, determining an amplitude of a largest peak in the time domain channel response, determining an amplitude of a second, earlier, peak in the time domain channel response, comparing the second peak amplitude to a threshold based on the largest peak amplitude, identifying the largest peak as a shortest path peak if the second peak amplitude is less than the threshold, identifying the second peak as a shortest path peak if the second peak amplitude is greater than the threshold, and calculating the distance between the radio frequency device and the target based on a time corresponding to the shortest path peak.

A method for uplink channel estimation in time domain is disclosed. A base station transmits downlink signals to a user equipment before estimating uplink channel. The user equipment estimates downlink channel based on the received signals and feeds back channel tap positions of the estimated downlink channel. Finally, the base stations estimate the uplink channel based on the channel tap positions and pilots transmitted by the user equipment. A system and apparatus employing the method are also disclosed.

Embodiments of this application disclose example phase detection methods, phase detection circuits, and clock recovery apparatuses. One example method includes receiving a first signal and deciding a (2M−1) level of the first signal to obtain a decision result, where the first signal is a (2M−1)-level signal, and M is a positive integer. A response amplitude parameter of a transmission channel can then be obtained. Clock phase information in the first signal can then be extracted based on the first signal, the decision result, and the response amplitude parameter. Output clock phase information can then be determined based on at least three decision results and at least three pieces of clock phase information in at least three symbol periods.

A channel prediction method and a related device, where the method includes: obtaining a first channel coefficient sequence in a first time period, where the first channel coefficient sequence includes a plurality of complex values of a channel coefficient; and determining a prediction value of the channel coefficient in a second time period based on the first channel coefficient sequence and a preset vocabulary of channel changes, where the preset vocabulary of channel changes includes a mapping relationship between a channel change value index and each change value of the channel coefficient, and where the second time period is later than the first time period.