Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may generate a pseudorandom noise (PN) sequence, modulate the PN sequence based at least in part on a modulation order parameter, and transmit the PN sequence in one or more symbols prior to transmitting sidelink data. The one or more symbols used to transmit the PN sequence may be used for automatic gain control (AGC) training at a receiving device. The user equipment may then transmit the sidelink data in a plurality of symbols that are subsequent in time relative to the one or more symbols used to transmit the PN sequence, and the receiving device may process the sidelink data based on the AGC training. Numerous other aspects are provided.

Embodiments of this application disclose a random access method and an apparatus. The method includes: A terminal device performs first-type random access in a first bandwidth part, where the first bandwidth part is an active uplink bandwidth part; the terminal device determines a first parameter, where the first parameter is duration for performing first-type random access in the first bandwidth part, or the first parameter is a quantity of times of sending a first-type random access message; and the terminal device performs random access in a second bandwidth part if the first parameter is greater than a first threshold, where the second bandwidth part is an uplink bandwidth part, and an identifier of the second bandwidth part is different from an identifier of the first bandwidth part.

This application discloses a random access preamble configuration method applicable to a satellite network and a communication apparatus. In the method, a random access preamble location offset and duration of a PRACH occasion can be flexibly configured based on features of a satellite system. The method includes: A receiving apparatus receives first indication information, where the first indication information includes indication information used to identify the random access preamble location offset at the physical random access channel PRACH occasion. The receiving apparatus transmits a random preamble based on the first indication information, where the random preamble includes a sequence part and a guard time. Because a communication distance is relatively long and a transmission delay difference between users is relatively large in a satellite communication system, time domain resources occupied by the PRACH occasion can be minimized by using this method.

Disclosed are a method, an apparatus, and a system for performing channel access. In detail, provided are a method including: receiving uplink scheduling information; and when the user equipment has stopped an uplink transmission during the uplink transmission being performed according to the uplink scheduling information, to resume the uplink transmission, performing a second type channel access when a channel sensed by the user equipment is continuously idle after the uplink transmission has been stopped, and performing a first type channel access when the channel sensed by the user equipment is not continuously idle after the uplink transmission has been stopped, wherein the first type channel access comprises performing a random backoff after a channel sensing, and the second type channel access only comprises performing a channel sensing and an apparatus and a system therefor.

A wireless device (WD), network node and methods are provided for rate matching using dynamically indicated reference signals in a co-carrier co-existence scenario. According to one aspect, a method in a network node includes determining a physical downlink shared channel (PDSCH) resource element (RE) mapping for a plurality of aperiodic zero power reference signal (ZP-RS) resources. The method also includes transmitting to a first wireless device (WD) configured to operate according to a first radio access technology (RAT), a first indication of first aperiodic ZP-RS resources of the plurality of aperiodic ZP-RS resources to be excluded during a PDSCH RE mapping by the first WD to avoid a conflict with second aperiodic ZP-RS resources indicated to a second WD configured to operate according to a second RAT.

Disclosed are a method, an apparatus, and a system for performing channel access. In detail, provided are a method including: receiving uplink scheduling information; and when the user equipment has stopped an uplink transmission during the uplink transmission being performed according to the uplink scheduling information, to resume the uplink transmission, performing a second type channel access when a channel sensed by the user equipment is continuously idle after the uplink transmission has been stopped, and performing a first type channel access when the channel sensed by the user equipment is not continuously idle after the uplink transmission has been stopped, wherein the first type channel access comprises performing a random backoff after a channel sensing, and the second type channel access only comprises performing a channel sensing and an apparatus and a system therefor.

An embodiment of the present application relates to a signal processing method and apparatus. The method includes: determining a plurality of signals that are quasi-co-located with a first port set of a first reference signal, wherein the first port set is used to send or receive the first reference signal, and the first port set comprises at least one port; determining a target signal among the plurality of signals; and sending or receiving the first reference signal via the first port set according to a quasi-co-location relationship between the first port set and the target signal.

The present disclosure relates to a communication method and system for converging a 5.sup.th-Generation (5G) communication system for supporting higher data rates beyond a 4.sup.th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present invention relates to a method and an apparatus for performing random access in a wireless communication system. More specifically, proposed is a method of, when a terminal intends to perform random access through multiple PRACH preamble transmission in an unlicensed band, determining whether to change or reset a CP length of a channel access procedure gap or a PRACH preamble according to the number of multiple PRACH preamble transmissions.

Embodiments of this application disclose a random access method and apparatus. In one example method, when a terminal device supports positioning, the terminal device may adjust, based on a positioning capability, time for sending a preamble on a RACH Occasion (RO) resource. When the terminal device does not support positioning, a corresponding RO resource periodicity may be configured to be large. Therefore, regardless of whether the terminal device supports positioning, a network device can receive, at the same time or in a short preamble receiving time window, preambles sent on a same RO resource, and receive, at different time, in different small time ranges, or in different short preamble receiving time windows, preambles sent on different RO resources.

Aspects of the disclosure relate to a user equipment (UE) that receives a timing advance command from a network access node, sends a value indicative of a timing advance capability to the network access node, adjusts a timing advance indicated by the timing advance command based on the timing advance capability to yield an adjusted timing advance, and transmits an uplink signal to the network access node using the adjusted timing advance. Further aspects relate to a network access node that transmits a timing advance command to a user equipment (UE), receives a value indicative of a timing advance capability of the UE, and receives an uplink signal adjusted by a timing advance according to the timing advance capability of the UE. The timing advance capability may indicate that the UE has, or does not have, a capability to adjust the timing advance indicated by the timing advance command.