A wireless receiver receives location pilots embedded in received symbols and uses the location pilots to detect the first path for every base station the network has designated for the receiver to use in time of arrival estimation. The receiver preferably applies matching pursuit strategies to offer a robust and reliable identification of a channel impulse response's first path. The receiver may also receive and use estimation pilots as a supplement to the location pilot information in determining time of arrival. The receiver can use metrics characteristic of the channel to improve the robustness and reliability of the identification of a CIR's first path. With the first path identified, the receiver measures the time of arrival for signals from that path and the receiver determines the observed time difference of arrival (OTDOA) to respond to network requests for OTDOA and position determination measurements.

Certain aspects of the present disclosure relate to methods and apparatus for implementing a data transmission scheme for Narrow-Band Internet of Things (NB-IoT). A User Equipment (UE) combines pairs of antenna ports to generate at least first and second combined antennas ports. The UE receives reference signals transmitted in a narrow band region of a larger system bandwidth, and for each combined port, adds the references signals received on resource elements (REs) of each of the combined pair of antenna ports. The UE determines channel estimates for each combined antenna port based on the added reference signals for the combined port.

Embodiments of methods in a base station and a UE are disclosed. In some embodiments, a method implemented in a network node includes any one or more of: selectively puncturing transmission of LTE CRS symbols that overlap NR DMRS symbols in a downlink transmission time interval; selectively puncturing transmission of NR DMRS symbols that overlap LTE CRS symbols in the downlink transmission time interval; and selectively reducing a number of NR DMRS symbols transmitted to the UE in the downlink transmission time interval. In some embodiments, a method implemented in a UE includes identifying, in a downlink channel, subchannels containing NR DMRS symbols that are corrupted due to collision with LTE CRS symbols. For each identified subchannel: a respective time averaged channel estimate is determined based on NR DMRS symbols that are not corrupted due to collision with the LTE CRS symbols; and a respective MMSE weight is determined using the time averaged channel estimate.

A method of channel estimation for a precoded channel includes generating an initial frequency autocorrelation of the precoded channel for a current bundle of a received data transmission, generating an expanded frequency autocorrelation based on the initial frequency autocorrelation of the precoded channel, providing the expanded frequency autocorrelation to a neural network, generating, by the neural network, an estimated frequency autocorrelation of an unprecoded channel based on the expanded frequency autocorrelation, and generating an estimated power distribution profile of the unprecoded channel based on the estimated frequency autocorrelation.

A broadcast signal receiver is disclosed. A broadcast signal receiver according to an embodiment of the present invention comprises a synchronization & demodulation module performing signal detection and OFDM demodulation on a received broadcast signal; a frame parsing & deinterleaving module performing parsing and deinterleaving of a signal frame of the broadcast signal; a demapping & decoding module performing conversion of data of at least one Physical Layer Pipe (PLP) of the broadcast signal into the bit domain and FEC decoding of the converted PLP data; and an output processing module outputting a data stream by receiving the at least one PLP data.

A method for minimizing a time domain mean square error (MSE) of channel estimation (CE) includes estimating, by a processor, a power delay profile (PDP) from a time domain observation of reference signal (RS) channels; estimating, by the processor, a noise variance of the RS channels; and determining, by the processor, a first arrival path (FAP) value and a delay spread estimation (DSE) value based on the estimated PDP and the estimated noise variance for minimizing the MSE of CE.

A channel estimation method. For at least one temporal difference observed between two sub-sequences of channel measurements, or channel estimations, consisting of complex vectors or scalars, the method includes: a first extrapolation on the basis of channel measurements or channel estimations of the sub-sequence preceding the temporal difference, going forward in time; a second extrapolation on the basis of channel measurements or channel estimations of the sub-sequence following the temporal difference, going backward in time; and calculation of a weighted average of the extrapolated estimations or measurements forward in time and of the extrapolated estimations or measurements backward in time, in order to obtain channel measurements or channel estimations regularly spaced apart in the temporal difference. The method is suitable for radio communications between a base station and a moving connected vehicle.

Aspects of this disclosure relate to reference signal channel estimation. A wireless communication channel between two nodes can be estimated based on a received reference signal, such as a Sounding Reference Signal. Techniques are disclosed to improve performance of reference signal channel estimation and make channel estimates more robust in the presence of one or more of a variety of impairments. Frequency domain processing and/or time domain processing can be performed to reduce distortion in channel estimates.

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).

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a demodulation reference signal (DMRS) configuration that indicates a code-division multiplexing (CDM) group configured for the UE; receive a first indication of an antenna port, included in the CDM group, assigned to the UE for reception of a first set of DMRS transmissions; receive a second indication of whether a second set of DMRS transmissions for another antenna port, included in the CDM group, is present or absent for another UE; and perform channel estimation based at least in part on the first indication of the antenna port and the second indication of whether the second set of DMRS transmissions for the other antenna port is present or absent. Numerous other aspects are provided.