High-frequency communications in 5G and especially 6G will require precise synchronization of user devices with the base station, including periodically setting the user device clock time and clock rate to mitigate oscillator drift. The base station can assist user devices by periodically providing a timing signal containing a mid-symbol timestamp point, which is a signal that includes an abrupt change in phase or amplitude centered in the symbol-time. A receiver can analyze the timing signal and determine precisely the time of arrival of the timestamp point, and correct the receiver's clock to ensure that uplink messages will then arrive at the base station synchronized with the base station's resource grid. In addition, the base station can provide two timing signals in which the mid-symbol timestamp points are separated by a predetermined separation, thereby assisting the user devices in adjusting their clock rates.

According to an aspect of the present disclosure, a method includes receiving, by a user equipment (UE) from a first base station, on a first carrier, a synchronization sequence (SS) and performing a radio resource management (RRM) measurement in accordance with the SS. The method also includes performing cell selection and mobility support in accordance with the RRM measurement, when the UE is in idle mode and generating an RRM measurement report in accordance with the RRM measurement and transmitting, by the UE to the first base station on the first carrier, the RRM measurement report, when the UE is in connected mode.

Uplink messages in 5G and 6G are expected to arrive at the base station in alignment with the base station's resource grid, at the proper time and frequency. Disclosed are lean procedures and compact timing signals that can enable user devices to maintain synchronization with a base station's resource grid. Shaped timing signals are disclosed that, when measured by a receiver, can indicate whether the receiver's clock is synchronized with the transmitter's clock, or is in disagreement, and in which direction, and by how much. The receiver thereby determines the clock error by amplitude measurements only, since the timing signal is configured to convert the timing error into a readily determined amplitude value, which the receiver can quantify using normal amplitude-demodulation procedures. The receiver's amplitude resolution corresponds to the time resolution achievable. No special time-measurement signal processing is required. No synchronization messages or other legacy overhead are required.

Methods, apparatuses, and systems are described for wireless communications. A transmission timing difference between a first cell group and a second cell group may be determined. If the transmission timing difference exceeds a threshold, one or more devices may stop transmitting uplink signals via one or more secondary cells and/or may not apply the timing adjustment for a cell group.

Systems and methods for transmitting data using various Modulation on Zeros schemes are described. In many embodiments, a communication system is utilized that includes a transmitter having a modulator that modulates a plurality of information bits to encode the bits in the zeros of the z-transform of a discrete-time baseband signal. In addition, the communication system includes a receiver having a decoder configured to decode a plurality of bits of information from the samples of a received signal by: determining a plurality of zeros of a z-transform of a received discrete-time baseband signal based upon samples from a received continuous-time signal, identifying zeros that encode the plurality of information bits, and outputting a plurality of decoded information bits based upon the identified zeros.

The user devices in managed networks, such as 5G and 6G networks, are required to adapt their uplink transmissions to the base station's resource grid, including the timing and frequency structure of the resource grid. Message-heavy legacy synchronization procedures can consume substantial resources. Therefore, a simpler, faster procedure is disclosed in which synchronization parameters are standardized where possible, timing signals are configured in minimal size where possible, and the user device collaborates with the base station to adjust the user device's clock setting, clock rate, timing advance (to match the base station's symbol boundaries), and Doppler correction (to match the base station's subcarrier frequency), without exchanging data messages other than very brief timing signals. Such ultra-lean synchronization procedures may enable low-complexity synchronization in future high-frequency communications.

Uplink messages in 5G and 6G are expected to arrive at the base station in alignment with the base station's resource grid, at the proper time and frequency. Disclosed are lean procedures and compact timing signals that can enable user devices to maintain synchronization with a base station's resource grid. Shaped timing signals are disclosed that, when measured by a receiver, can indicate whether the receiver's clock is synchronized with the transmitter's clock, or is in disagreement, and in which direction, and by how much. The receiver thereby determines the clock error by amplitude measurements only, since the timing signal is configured to convert the timing error into a readily determined amplitude value, which the receiver can quantify using normal amplitude-demodulation procedures. The receiver's amplitude resolution corresponds to the time resolution achievable. No special time-measurement signal processing is required. No synchronization messages or other legacy overhead are required.

According to an embodiment of the present disclosure, provided is a method by which a first apparatus performs sidelink communication. The method comprises the steps of: receiving, from a base station, information about an S-SSB transmission resource; determining, on the basis of the information about the S-SSB transmission resource, a plurality of first slots within a first S-SSB period having an S-SSB period length, associated with a plurality of first S-SSBs; transmitting, to a second apparatus, the plurality of first S-SSBs on the plurality of first slots, wherein a slot interval between the plurality of first slots may be the same within the first S-SSB period.

Provided are a method and an apparatus for performing, by a first device, wireless communication. The method may comprise the steps of: receiving, from a base station, first information related to SL synchronization priority; receiving, from the base station, second information indicating whether a base station-related synchronization reference can be selected as a synchronization source; and performing synchronization according to one synchronization reference of a GNSS-related synchronization reference and other terminals on the basis of the second information indicating that the base station-related synchronization reference cannot be selected as a synchronization source.

A that includes receiving, by a user equipment (UE) from a first base station, on a first carrier, a synchronization sequence (SS) and performing a radio resource management (RRM) measurement in accordance with the SS. The method also includes performing cell selection and mobility support in accordance with the RRM measurement, when the UE is in idle mode and generating an RRM measurement report in accordance with the RRM measurement and transmitting, by the UE to the first base station on the first carrier, the RRM measurement report, when the UE is in connected mode.