Wireless communications systems and methods related to determining and transmitting delay measurements, such as propagation delay, between a base station (BS) and a user equipment (UE) are provided. In some aspects, a UE may receive, from a BS, a positioning reference signal (PRS). The UE may further transmit, in response to and at a predetermined time after the receiving the PRS, a sounding reference signal (SRS) to the BS. Further, the UE may receive, from the BS, a delay measurement corresponding to the PRS.

An outdoor device of a timing system includes a receiver for receiving clock information from a satellite system, a processing system for running master functionality of a clock synchronization protocol to transfer the clock information to an indoor device of the timing system, and a transceiver for transferring data between the outdoor device and the indoor device. A memory device stores a fixed delay value estimating a time delay from a reception moment of a request message related to the clock synchronization protocol to a transmission moment of a reply message. There is no need to compute a difference between clock times corresponding to the reception moment and the transmission moment because the fixed delay value is used in lieu of the difference in the clock synchronization protocol. Thus, quality requirements related to an oscillator of the outdoor device can be mitigated.

A system can comprise a memory that is configured to store and retrieve a first signal. The system can further comprise a generator that is configured to generate first in-phase, quadrature sub-carrier values. The system can further comprise a look up table that stores predetermined second in-phase, quadrature sub-carrier values. The system can further comprise a pseudo-random look up table generator that is configured to operate on the predetermined second in-phase, quadrature sub-carrier values to produce a pseudo-random symbol of data values. The system can further comprise a component that is configured to time align, buffer, and inject a second signal into a radio used by the system, wherein the second signal is selected from the memory, the generator, the look up table, and the pseudo-random look up table generator.

Methods, systems, and devices for wireless communications are described. A base station that may include at least two transmission reception points (TRPs) next to a high speed train (HST) may transmit, to a user equipment (UE) on the HST, an indication of a quasi co-location (QCL) relationship indicating a relationship between a plurality of tracking reference signals (TRSs) and a demodulation reference signal (DMRS) of a data channel. The plurality of TRSs may include a first TRS and a second TRS. The UE may receive, from a first TRP, the first TRS associated with an occasion of the data channel, and receive, from a second TRP, the second TRS associated with the occasion of the data channel. The UE may perform, based on the indication of the QCL relationship, a channel estimation procedure for the data channel based on the DMRS, the received first TRS, and the received second TRS.

A method of synchronization of wireless communication system is provided. The method includes the following steps: receiving a symbol from a wireless communication system by a user equipment; detecting ISI-free region of the received symbol; setting an endpoint of a FFT window within the ISI-free region; detecting shifted primary control frequency and shifted secondary control frequency of the symbol; calculating ICFO based on the shifted primary control frequency and a primary control frequency; calculating secondary control frequency based on ICFO and shifted secondary control frequency; finding the preamble of a frame based on the secondary control frequency; and determining, based on the preamble, a start point of the frame.

The present disclosure describes devices, systems, and methods for synchronizing multiple-input/multiple-output (“MIMO”) signals or other signals in telecommunication systems. Some aspects may involve transmitting signals between a head-end unit and remote units of a telecommunication system. A first delay of a signal path between the head-end unit and a first remote unit of the remote units may be determined to be greater than each delay of signal paths between the head-end unit and other remote units. Based on the first delay, the telecommunication system may be configured to delay transmission of additional signals such that the additional signals are simultaneously transmitted to another unit by either the head-end unit or the remote units.

A method and multimedia device for calibrating audio delays of an audio system with wireless loudspeakers are disclosed. The method allows to emulate surround or 3D sound systems with spatially distributed wireless loudspeakers. A first probe signal for audio playback, having a first audio pattern, is transmitted by a loudspeaker. A signal quality is determined by listening to an acoustic response of the loudspeaker to the first probe signal. A second audio pattern is determined by modifying the first audio pattern based on the signal quality. A second probe signal for audio playback having the second audio pattern is transmitted by the loudspeaker. An audio delay compensation is then determined for the loudspeaker based on a measure of an audio delay between the transmitted second probe signal and an acoustic response of the loudspeaker in response to the second probe signal.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, a compensation indicator that is based at least in part on Doppler information associated with a group of UEs in a single frequency network (SFN). The UE may communicate based at least in part on the compensation indicator. Numerous other aspects are described.

Various solutions for system information design for synchronization in non-terrestrial network (NTN) communications are described. An apparatus (e.g., a UE) determines synchronization information with respect to an implicit time reference associated with a wireless network. Using the synchronization information, the apparatus maintains synchronization in performing NTN communications with the wireless network.

In order to perform small data transmission during an RRC_INACTIVE mode, a UE may need to determine whether the stored timing advance (TA) is valid. A TA may be valid if its usage would result in an uplink transmission arriving at a TRP of a base station during a time period during which the base station expects to receive uplink transmission. A UE may determine that a TA is valid based on a received fraction of the length of a cyclic prefix and observed SSB time shift.