FIELD OF TECHNOLOGY

The following relates generally to wireless communications and more specifically to periodic lean synchronization signal design.

BACKGROUND

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).

In some cases, a UE may perform a synchronization procedure during initial access to establish a connection via a channel. The UE may receive synchronization signals and system information from a base station. However, the UE may perform a number of steps before receiving the system information. For example, a UE may receive and decode a synchronization signal block (SSB), a master information block (MIB), a set of control resources, a downlink control channel, and a downlink shared channel to receive the system information. In some cases, some synchronization steps may be a computation burden on the UE, and conventional techniques for synchronization may have limitations for different types of devices including devices employing coverage enhancement or reduced computational complexity.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support periodic lean synchronization signal design. Generally, the described techniques provide for a lean synchronization signal block (SSB) design (e.g., for a subset of signals in an SSB). For example, an SSB (e.g., used when initially establishing a connection) may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). According to the techniques described herein, a lean SSB may include one of either a PSS or an SSS or another type of synchronization signal (e.g., such that the lean SSB may include, for example, 12 resource blocks compared to the 20 resource blocks associated with an SSB). As such, a lean SSB may be transmitted within a configured narrow bandwidth part (NBWP) and may support reduced capability devices (e.g., bandwidth reduced user equipment (UEs)) while maintaining compatibility with other devices (e.g., traditional or full capability devices). The techniques described herein may further provide for lean SSB repetition, beam management (e.g., narrower beams) enabled via lean SSBs, etc.

For example, a base station and UE may establish a connection during an initial connection procedure using the SSB from the base station, e.g., the full SSB, which may include at least a first synchronization signal. However, the configuration for a transmission pattern for the first synchronization signal (e.g., the lean synchronization signal, which may also be called the lean SSB) may be identified by the base station and UE, e.g., the configuration may be adopted in standards and therefore known by the base station and UE, using a configuration signal from the base station, and/or implicitly indicated to the UE. Accordingly the base station may transmit the first synchronization signal according to the transmission pattern (e.g., the base station may transmit the lean SSB according to the transmission pattern identified in the configuration). The UE may receive one or more instances of the first synchronization signal and modify its established connection with the base station using the received instances of the first synchronization signal. For example, the UE may utilize one or more instances of the received first synchronization signal for beam management as well as time, phase, and/or frequency tracking purposes.

A method of wireless communication at a UE is described. The method may include establishing a connection with a base station based on a SSB from the base station, the SSB includes at least a first synchronization signal, identifying a configuration for a transmission pattern for the first synchronization signal to be transmitted by the base station, receiving one or more instances of the first synchronization signal according to the transmission pattern for the first synchronization signal, and modifying the established connection with the base station based on the received one or more instances of the first synchronization signal.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to establish a connection with a base station based on a SSB from the base station, the SSB includes at least a first synchronization signal, identify a configuration for a transmission pattern for the first synchronization signal to be transmitted by the base station, receive one or more instances of the first synchronization signal according to the transmission pattern for the first synchronization signal, and modify the established connection with the base station based on the received one or more instances of the first synchronization signal.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for establishing a connection with a base station based on a SSB from the base station, the SSB includes at least a first synchronization signal, identifying a configuration for a transmission pattern for the first synchronization signal to be transmitted by the base station, receiving one or more instances of the first synchronization signal according to the transmission pattern for the first synchronization signal, and modifying the established connection with the base station based on the received one or more instances of the first synchronization signal.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to establish a connection with a base station based on a SSB from the base station, the SSB includes at least a first synchronization signal, identify a configuration for a transmission pattern for the first synchronization signal to be transmitted by the base station, receive one or more instances of the first synchronization signal according to the transmission pattern for the first synchronization signal, and modify the established connection with the base station based on the received one or more instances of the first synchronization signal.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying, based on the configuration for the transmission pattern, one or more parameters for the one or more instances of the first synchronization signal, and receiving the one or more instances of the first synchronization signal according to the one or more parameters.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the one or more parameters include at least one of a slot periodicity within a transmission window for the first synchronization signal, a slot offset for a first slot including the first synchronization signal transmission within the transmission window, a symbol offset for the first synchronization signal transmission within a slot occurring within the transmission window, a symbol periodicity within a slot occurring within the transmission window, or a combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, based on the transmission pattern, a first one or more instances of the first synchronization signal associated with a first beam, and receiving, based on the transmission pattern, a second one or more instances of the first synchronization signal associated with a second beam that may be different than the first beam.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first beam and the second beam may be associated with a same set of the one or more instances of the first synchronization signal.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first beam and the second beam may be associated with different sets of the one or more instances of the first synchronization signal.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first beam and the second beam include transmit beams of the base station transmitting the first synchronization signal.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on the configuration, that a beam repetition pattern may be enabled for synchronization signal transmissions, identifying, based on beam repetition being enabled, a beam repetition pattern for receiving the one or more instances of the first synchronization signal, and receiving the one or more instances of the first synchronization signal according to the beam repetition pattern.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the configuration may include operations, features, means, or instructions for identifying the configuration via at least one of a configuration adopted by the wireless communication system, or a configuration signal received from the base station, or an implicit indication associated with a different signal configured for the UE.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying, based on the configuration, a first bandwidth part for the first synchronization signal, where the first bandwidth part may be different from a second bandwidth part for the SSB used to establish the connection.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on the configuration, that the transmission pattern for the first synchronization signal may be UE-specific or cell-specific.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a signal activating or deactivating the one or more instances of the first synchronization signal according to the transmission pattern.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the signal includes at least one of a radio resource control (RRC) signal, or a medium access control (MAC) control element (CE), or a combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the signal activates or deactivates the one or more instances of the first synchronization signal for at least one of the UE, or a group of UEs that include the UE, or for a bandwidth part, or for the base station, or a combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a signal requesting activation or deactivation of the one or more instances of the first synchronization signal according to the transmission pattern.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the signal indicates one or more requested parameters for the one or more instances of the first synchronization signal.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the synchronization signal block includes a primary synchronization signal, a secondary synchronization signal, and a physical broadcast channel, and the first synchronization signal is the primary synchronization signal or the secondary synchronization signal.

A method of wireless communication at a base station is described. The method may include establishing a connection with a UE based on a SSB from the base station, the SSB includes at least a first synchronization signal, identifying a configuration for a transmission pattern for the first synchronization signal to be transmitted by the base station, and transmitting one or more instances of the first synchronization signal according to the transmission pattern for the first synchronization signal.

An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to establish a connection with a UE based on a SSB from the base station, the SSB includes at least a first synchronization signal, identify a configuration for a transmission pattern for the first synchronization signal to be transmitted by the base station, and transmit one or more instances of the first synchronization signal according to the transmission pattern for the first synchronization signal.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for establishing a connection with a UE based on a SSB from the base station, the SSB includes at least a first synchronization signal, identifying a configuration for a transmission pattern for the first synchronization signal to be transmitted by the base station, and transmitting one or more instances of the first synchronization signal according to the transmission pattern for the first synchronization signal.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to establish a connection with a UE based on a SSB from the base station, the SSB includes at least a first synchronization signal, identify a configuration for a transmission pattern for the first synchronization signal to be transmitted by the base station, and transmit one or more instances of the first synchronization signal according to the transmission pattern for the first synchronization signal.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying, based on the configuration for the transmission pattern, one or more parameters for the one or more instances of the first synchronization signal, and transmitting the one or more instances of the first synchronization signal according to the one or more parameters.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the one or more parameters include at least one of a slot periodicity within a transmission window for the first synchronization signal, a slot offset for a first slot including the first synchronization signal transmission within the transmission window, a symbol offset for the first synchronization signal transmission within a slot occurring within the transmission window, a symbol periodicity within a slot occurring within the transmission window, or a combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, based on the transmission pattern, a first one or more instances of the first synchronization signal associated with a first beam, and transmitting, based on the transmission pattern, a second one or more instances of the first synchronization signal associated with a second beam that may be different than the first beam.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first beam and the second beam may be associated with a same set of the one or more instances of the first synchronization signal.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first beam and the second beam may be associated with different sets of the one or more instances of the first synchronization signal.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first beam and the second beam include transmit beams of the base station transmitting the first synchronization signal.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on the configuration, that a beam repetition pattern may be enabled for the first synchronization signal transmissions, identifying, based on beam repetition being enabled, a beam repetition pattern for transmitting the one or more instances of the first synchronization signal, and transmitting the one or more instances of the first synchronization signal according to the beam repetition pattern.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the configuration may include operations, features, means, or instructions for identifying the configuration via at least one of a configuration adopted by the wireless communication system, or a configuration signal transmitted from the base station, or an implicit indication associated with a different signal configured for the UE.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying, based on the configuration, a first bandwidth part for the first synchronization signal, where the first bandwidth part may be different from a second bandwidth part for the SSB used to establish the connection.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining, based on the configuration, that the transmission pattern for the first synchronization signal may be UE-specific or cell-specific.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a signal activating or deactivating the one or more instances of the first synchronization signal according to the transmission pattern.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the signal includes at least one of an RRC signal, or a MAC CE, or a combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the signal activates or deactivates the one or more instances of the first synchronization signal for at least one of the UE, or a group of UEs that include the UE, or for a bandwidth part, or for the base station, or a combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a signal requesting activation or deactivation of the one or more instances of the first synchronization signal according to the transmission pattern.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the signal indicates one or more requested parameters for the one or more instances of the first synchronization signal.

