WO2025129570A1

WO2025129570A1 - Initial network access with multiple communication units in a cell

Info

Publication number: WO2025129570A1
Application number: PCT/CN2023/140661
Authority: WO
Inventors: Xiaolong Guo; Bo Gao; Jiangyun Zhou; Jun Huang; Ke YAO; Yang Zhang
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2023-12-21
Filing date: 2023-12-21
Publication date: 2025-06-26
Anticipated expiration: 2026-06-21

Abstract

Methods, apparatus, and systems that relate to enabling a user equipment (UE) to gain access to multiple communication units and/or transmit and receives points (TRPs) associated with a cell during initial access procedure are disclosed. In one example aspect, a method for wireless communication includes determining, by a base station, information associated with a synchronization signal block (SSB). The SSB comprises synchronization signals and a physical broadcast channel, and the information indicates one or more communication units corresponding to the SSB. The method also includes performing, by the base station to a user equipment, a transmission of the information associated with the SSB.

Description

INITIAL NETWORK ACCESS WITH MULTIPLE COMMUNICATION UNITS IN A CELL

TECHNICAL FIELD

This patent document is directed to digital communications.

BACKGROUND

Mobile communication technologies are moving the world toward an increasingly connected and networked society. The rapid growth of mobile communications and advances in technology have led to greater demand for capacity and connectivity. Other aspects, such as energy consumption, device cost, spectral efficiency, and latency are also important to meeting the needs of various communication scenarios. Various techniques, including new ways to provide higher quality of service, longer battery life, and improved performance are being discussed.

SUMMARY

This patent document describes, among other things, techniques related to enabling a user equipment (UE) to gain access to multiple communication units and/or transmit and receives points (TRPs) associated with a cell during initial access procedure.

In one example aspect, a method for wireless communication includes determining, by a base station, information associated with a synchronization signal block (SSB) . The SSB comprises synchronization signals and a physical broadcast channel, and the information indicates one or more communication units corresponding to the SSB. The method also includes performing, by the base station to a user equipment, a transmission of the information associated with the SSB.

In another example aspect, a method for wireless communication includes receiving, by a user equipment from a base station, information associated with a synchronization signal block (SSB) . The SSB comprises synchronization signals and a physical broadcast channel, and the information indicates one or more communication units corresponding to the SSB. The method also includes performing, by the user equipment, a random access procedure with at least one of the one or more communication units based on the information associated with the SSB.

In another example aspect, a method for wireless communication includes performing, by a user equipment, a random access transmission based on information associated with a synchronization signal block and detecting, by the user equipment, control information in one or more search spaces. The control information schedules a transmission from a base station to the user equipment, and the control information correspond to one or more communication units associated with the base station. The method also includes receiving, by the user equipment, the transmission from at least one of the one or more communication units based on the control information.

In another example aspect, a method for wireless communication includes receiving, by a base station, a random access transmission from a user equipment and transmitting, by the base station, control information in one or more search spaces to the user equipment. The control information schedules a transmission to the user equipment, and the control information correspond to one or more communication units associated with the base station. The method also includes performing the transmission from the base station to the user equipment according to the control information.

In another example aspect, a communication apparatus is disclosed. The apparatus includes a processor that is configured to implement an above-described method.

In yet another example aspect, a computer-program storage medium is disclosed. The computer-program storage medium includes code stored thereon. The code, when executed by a processor, causes the processor to implement a described method.

These, and other, aspects are described in the present document.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an example scenario in which multiple TRPs associated with a cell can be used to perform transmissions after a UE gains access to the network in accordance with one or more embodiments of the present technology.

FIG. 2A is a flowchart representation of a method for wireless communication in accordance with one or more embodiments of the present technology.

FIG. 2B is a flowchart representation of another method for wireless communication in accordance with one or more embodiments of the present technology.

FIG. 3A is a flowchart representation of another method for wireless communication in accordance with one or more embodiments of the present technology.

FIG. 3B is a flowchart representation of yet another method for wireless communication in accordance with one or more embodiments of the present technology.

FIG. 4 illustrates an example of SSB transmissions in accordance with one or more embodiments of the present technology.

FIG. 5 illustrates a diagram of space-division multiplexing of SSBs in accordance with one or more embodiments of the present technology.

FIG. 6 illustrates an example diagram of TRP-specific Physical Broadcast Channel (PBCH) payloads in accordance with one or more embodiments of the present technology.

FIG. 7 illustrates an example diagram of TRP-specific Demodulation Reference Signal (DMRS) sequences in accordance with one or more embodiments of the present technology.

FIG. 8 illustrates an example of search spaces corresponding to different TRPs in accordance with one or more embodiments of the present technology.

FIG. 9 illustrates an example of Radio Network Temporary Identifier (RNTI) values corresponding to different TRPs in accordance with one or more embodiments of the present technology.

FIG. 10 shows an example of a wireless communication system where techniques in accordance with one or more embodiments of the present technology can be applied.

FIG. 11 is a block diagram representation of a portion of a radio station in accordance with one or more embodiments of the present technology can be applied.

DETAILED DESCRIPTION

Section headings are used in the present document only to improve readability and do not limit scope of the disclosed embodiments and techniques in each section to only that section. Furthermore, some embodiments are described with reference to Third Generation Partnership Project (3GPP) Fifth Generation (5G) New Radio (NR) or Sixth Generation (6G) standard for ease of understanding and the described technology may be implemented in different wireless system that implement protocols other than the NR or 6G protocol.

In wireless communication systems, downlink and uplink synchronization procedures are necessary steps to ensure reliable wireless communication in wireless communication systems. Synchronization is also required to be performed when inter-cell mobility is executed. Downlink synchronization is performed using a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) .

The PSS and SSS is carried in a Synchronization Signal (SS) /Physical Broadcast Channel (PBCH) (SS/PBCH) block, also referred to as an SSB. A user equipment (UE) (also referred to as a terminal device or a user device) performs cell search, random access procedure, beam management, cell switch, pathloss estimation, downlink synchronization, etc. based on reception of the SSB. A SSB is formed by a PBCH, a PSS, and an SSS. In the time domain, an SSB includes four Orthogonal Frequency Division Multiplexing (OFDM) symbols, numbered in increasing order from 0 to 3 within the SS/PBCH block. In the frequency domain, an SS/PBCH block includes 240 contiguous subcarriers with the subcarriers numbered in increasing order from 0 to 239 within the block. PSS, SSS, and PBCH with associated DM-RS are mapped to the symbols and resource elements based on a predefined table.

Based on the frequency range or sub-carrier spacing, the maximum number of SSBs and the time/frequency position of each SSB are specified by the Third-Generation Partnership Project (3GPP) technical specification. The set of SS/PBCH blocks of a cell is transmitted in a half frame and is called an SSB burst. An SSB burst is transmitted periodically based on the periodicity configured by the network or based on a predefined rule. In addition, a MasterInformationBlock (MIB) is transmitted on the PBCH as part of the PBCH payload. The MIB indicates at least the following information: a system frame number (SFN) , a sub-carrier spacing, a ssb-subcarrier offset. An example MIB is shown in Table 1 below. In addition to MIB, timing related PBCH payload bits can be generated, including the least significant bits (LSB) of the SFN, a half frame bit, and/or the SSB index.

Table 1: MIB Information Element

Uplink synchronization is performed using the random access procedure on the physical random access channel (PRACH) and uplink timing alignment based on the Timing Advance Command (TAC) adjustment. The random access procedure or the uplink synchronization procedure can be triggered by network via a Physical Downlink Control Channel (PDCCH) order, or by higher layer of UE via a series of events. Both triggering mechanisms can trigger either contention based random access procedure (CBRA) or contention free random access procedure (CFRA) .

For the current generations of wireless communication systems, e.g., Long Term Evolution (LTE) and New Radio (NR) communication systems, during the procedure of initial access, a UE can access to only one cell using the random access procedure. After gaining access to a cell, the UE then receives configuration information indicative of resources of other cells. In the random access procedure, UE can select by itself or be indicated an SSB to determine a PRACH occasion and a random access preamble for the PRACH transmission.

Future generations of wireless communication systems will support enhanced cell deployment architectures, such as distributed Multi-Input-Multi-Output (MIMO) or super cells, in which multiple communication units and/or transmission-and-reception points (TRPs) associated with the same cell can perform joint transmission and/or reception at the same time. A cell comprises at least one of: a physical cell, a candidate cell, a non-serving cell, an additional physical cell, a base station, and/or a node. A TRP or a transmission unit can be considered as a radio unit or a distributed unit deployed in the super cell. In some embodiments, a TRP comprises at least one of: a set of panels of a base station, a group of beams, a group of TCI states, and/or a cell portion. Furthermore, in some embodiments, the TRP comprises, or be represented by, at least one of: one or more reference signals, a reference signal resource set, a Physical Uplink Control Channel (PUCCH) resource set, a search space, panel related information, a sub-array, an antenna group, an antenna port group, a group of antenna ports, a beam group, a control resource set (CORESET) , a CORESET pool, transmission configuration indication (TCI) state, Timing Advance Group (TAG) , UE capability value, and/or a UE capability set. TRP related information can be an indication, an information element, and/or an identifier of a TRP. A random access preamble transmission is also referred to as a PRACH transmission, a Msg1 transmission, and/or a MsgA transmission.

FIG. 1 illustrates an example scenario in which multiple TRPs 101, 103, 105, 107 associated with a cell 100 can be used to perform transmissions after a UE 111 gains access to the network in accordance with one or more embodiments of the present technology. In such scenarios, allowing UEs to access multiple TRPs during the initial access can reduce the latency of joint transmission/reception after the initial access completes.

This patent document discloses techniques that can be implemented in various embodiments to enable a UE to gain access to multiple transmission units and/or TRPs associated with a cell during initial access procedure. The disclosed techniques can also be applied in the random access procedure to enable the UE to perform transmissions associated with different TRPs based on the control information that it detects.

FIG. 2A is a flowchart representation of a method for wireless communication in accordance with one or more embodiments of the present technology. The method 200 includes, at operation 210, determining, by a base station, information associated with a synchronization signal block (SSB) . The SSB comprises synchronization signals and a physical broadcast channel. The information indicates one or more communication units (e.g., TRPs) corresponding to the SSB. The method 200 also includes, at operation 220, performing, by the base station to a user equipment, a transmission of the information associated with the SSB.

FIG. 2B is a flowchart representation of a method for wireless communication in accordance with one or more embodiments of the present technology. The method 250 includes, at operation 260, receiving, by a user equipment from a base station, information associated with a synchronization signal block (SSB) . The SSB comprises synchronization signals and a physical broadcast channel. The information indicates one or more communication units (e.g., TRPs) corresponding to the SSB. The method 250 also includes, at operation 270, performing, by the terminal device, a random access procedure with at least one of the one or more communication units based on the information associated with the SSB.

In some embodiments, the information about the communication units is included in a payload of the physical broadcast channel. In some embodiments, the information comprises an identification of a communication unit or a bitmap that indicates one or more identifications of one or more communication units. In some embodiments, the payload of the physical broadcast channel comprises a Master Information Block (MIB) that includes the information. In some embodiments, the bitmap comprises bits corresponding to a maximum number of communication units associated with the SSB.

In some embodiments, the information about the communication units comprises a Demodulation Reference Signal (DMRS) for the physical broadcast channel. In some embodiments, an initiation of a scrambling sequence for the DMRS is based on one or more identifications of one or more communication units associated with the SSB.

In some embodiments, the information about the communication units comprises a synchronization signal. In some embodiments, a sequence for the synchronization signal is determined based on an information of physical cell index and an identification of the communication unit.

In some embodiments, the one or more communication units are associated with one or more SSB transmissions having a same SSB index.

FIG. 3A is a flowchart representation of a method for wireless communication in accordance with one or more embodiments of the present technology. The method 300 includes, at operation 310, performing, by a user equipment, a random access procedure based on information associated with a synchronization signal block. The method 300 includes, at operation 320, detecting, by the user equipment, control information in one or more search spaces. The control information schedules a transmission from a base station to the user equipment, and wherein the control information in the one or more search spaces corresponds to one or more communication units associated with the base station. The method 300 includes, at operation 330, receiving, by the user equipment, the transmission from at least one of the one or more communication units based on the control information.

FIG. 3B is a flowchart representation of a method for wireless communication in accordance with one or more embodiments of the present technology. The method 350 includes, at operation 360, receiving, by a base station, a random access transmission from a user equipment. The method 350 includes, at operation 370, transmitting, by the base station, control information in one or more search spaces to the user equipment. The control information schedules a transmission to the user equipment, and the control information in the one or more search spaces corresponds to one or more communication units associated with the base station. The method 350 also includes, at operation 380, performing the transmission from the base station to the user equipment according to the control information.

In some embodiments, configuration information from the base station configures the one or more search spaces, where each search space is associated with a communication unit. In some embodiments, the control information is scrambled using a temporary identifier determined based on an identification of a communication unit.

Details regarding the above techniques are further discussed in the embodiments below.

Embodiment 1

This embodiment is related to indicating information about one or more communication units (e.g., TRPs) in the SSB transmissions.

FIG. 4 illustrates an example of SSB transmissions in accordance with one or more embodiments of the present technology. As shown in FIG. 4, for the SSBs within a SSB burst corresponding to a cell, each TRP can transmit multiple SSBs. The SSB received by the UE can be formed by multiplexing information from one or more TRPs. The information can be code-domain (or space-domain) multiplexed so that the SSBs can be transmitted/received at the same time and frequency location. FIG. 5 illustrates a diagram of space-division multiplexing of SSBs in accordance with one or more embodiments of the present technology. For an SSB formed by transmissions from multiple TRPs (e.g., SSBn) , the time and frequency location of the SSB by each TRP is the same, but the contents can be different. Different contents are multiplexed together to be transmitted at the same time-frequency location.

In some embodiments, SSB transmissions from different TRPs at the same time and frequency domain are associated with the same SSB index. In some embodiments, SSB transmissions with the same SSB index can form or be assumed as a same SSB.

In some embodiments, PSS and SSS of the SSBs transmitted by multiple TRPs are different. The SSBs are associated with the same SSB index or transmitted using the same time and frequency domain resource (s) .

In some embodiments, the Physical Cell Index (PCI) is determined based on a first cell index (N_ID, 1) and a second cell index (N_ID, 2) . The sequence for PSS can be determined based on the second cell index and TRP related information. The sequence for SSS can be determined based on the first cell index and TRP related information. For example, the sequence for PSS is defined as d _PSS (n) =1-2 x (m) , 0 ≤ n ≤ 127, where x (m) is determined based on a basic binary sequence and a predefined rule, C₁ is a fixed constant value, N_trp, max is the maximum number of candidate values of N_trp. As another example, the sequence for SSS is defined as d_SSS (n) = [1-2x₀ ( (n+m₀) mod127) ] [1-2x₁ ( (n+m₁) mod127) ] , m₁=N_ID, ₁ mod112, 0≤n≤127, where x₀ (m) and x₁ (m) are determined based on two basic binary sequences and a predefined rule, C₂ is a fixed constant value, C₂ can equal to 5× (number of candidate values of N_ID, ₂) + (number of candidate values of N_trp) .

In some embodiments, PSS and SSS of the SSBs transmitted by multiple TRPs are the same, but the payloads of the PBCH transmitted by multiple TRPs are different. FIG. 6 illustrates an example diagram of TRP-specific PBCH payloads in accordance with one or more embodiments of the present technology.

In some embodiments, the MIB in the PBCH payload of an SSB transmission indicates TRP related information. In an embodiment, an index of the TRP associated with the SSB transmission is indicated in MIB. Table 2 illustrates an example MIB structure in accordance with one or more embodiments of the present technology.

Table 2

In the example shown in Table 2, transmitReceivePointIndex is indicated in MIB to indicate the index of the TRP associated with the SSB for the cell. N_trpmax represents the maximum number of TRPs associated with an SSB. In some embodiments, the maximum number of TRPs associated with an SSB can be a fixed value or a value determined based on a predefined rule. In some embodiments, the predefined rule specifies that the value is related to a frequency range, a frequency band, a carrier frequency and/or a subcarrier spacing (SCS) .

In some embodiments, the MIB indicates a list of TRPs associated with the same SSB index for the SSB transmissions. Table 3 illustrates an example MIB structure in accordance with one or more embodiments of the present technology.

Table 3

In the example shown in Table 3, transmitReceivePointList is indicated in MIB to indicate one or more TRPs associated with the SSB for the serving cell. In some embodiments, the list can be represented using a bitmap, with a first bit corresponding to a first TRP having a lowest index and a second bit corresponding to a second TRP and so on. Value 0 in the bitmap indicates that the SSB is not associated with the corresponding TRP, while value 1 indicates that the SSB is associated with the corresponding TRP. In this example, the MIB information of SSB transmissions can be the same for the one or more TRPs associated with the same cell.

In some embodiments, TRP related information is included in an additional part of the PBCH payload other than MIB and existing timing information. For example, for the PBCH payload bits, a₀, a₁, a₂, ..., a_A-1 are generated for MIB, a_A, a_A+1, ..., a_A+B-1 are generated for the additional timing related PBCH payload bits (e.g., LSB of the SFN, a half frame bit, and/or SSB index) , a_A+B, a_A+B+1, ..., a_A+B+C-1 are generated for the additional TRP related PBCH payload.

In some embodiments, the TRP related information in the additional part of the PBCH payload can be implemented as a bitmap. Each bit of the bitmap indicates whether the SSB is associated with a TRP, with the size of the bitmap being equal to the maximum number of TRPs associated with an SSB. A first bit of the bitmap corresponds to a first TRP having a lowest index, a second bit of the bitmap corresponds to a second TRP having a second lowest index, and so on. For example, if the maximum number of TRPs associated with an SSB is 4, and the second and forth TRP are associated with the SSB, the additional TRP related PBCH payload bits are generated to be 0101.

In some embodiments, the TRP related information comprises the index of the TRP associated with the SSB transmission, and the size of the TRP related information equal to ceil (log2 (N_trpmax) ) , wherein N_trpmax is the maximum number of TRPs associated with an SSB. For example, if the maximum number of TRPs associated with an SSB is 4 and the second and forth TRP are associated with the SSB, the additional TRP related PBCH payload bits are generated to be 01 for PBCH payload in the SSB transmitted by the second TRP and the additional TRP related PBCH payload bits are generated to be 11 for PBCH payload in the SSB transmitted by the forth TRP. The first and the third TRP may not have additional TRP related information present in their PBCH payloads.

In some embodiments, other contents in MIB and/or the PBCH payloads can be TRP specific.

In some embodiments, the PBCH payloads of different TRPs remain the same, but the Demodulation Reference Signal (DMRS) sequences for demodulation of the PBCH can be different to correspond to different TRPs. FIG. 7 illustrates an example diagram of TRP-specific DMRS sequences in accordance with one or more embodiments of the present technology.

In some embodiments, the initiation of the scrambling sequence generator for the DM-RS sequence generation is based on the TRP information of TRPs associated with the SSB. In some embodiments, the TRP information comprises the index of the TRP associated with the corresponding SSB transmission. For example, the scrambling sequence generator can be initialized as:

Here, i_TRP is the index of the TRP associated with the SSB transmission, Ntrp equals to ceil (log2 (N_trp, max) ) , N_trpmax is the maximum number of TRPs associated with an SSB, is related to the SSB index, andis related to the physical cell index.

For example, if Ntrp is 4. The first TRP having index 0 and the third TRP having index 2 are associated with an SSB n, i_TRP is 0 for DMRS sequence for SSB transmission from the first TRP and i_TRP is 2 for DMRS sequence for SSB transmission from the first TRP.

In some embodiments, the TRP information comprises the information of the TRPs associated with the SSB transmissions correspond to the same SSB. In this example, i_TRP is the decimal value of a bitmap. Each bit of the bitmap indicates whether the corresponding TRP is associated with the SSB. Bit value 0 represents that the TRP is not associated with the SSB, while value 1 represents that the TRP is associated with the SSB. For example, if Ntrp is 4, the second TRP with index 1 and the fourth TRP with index 3 are associated with the SSB, i_TRP equal to 5 according to the bitmap of 0101.

Embodiment 2

This embodiment is related to search spaces and/or scrambling sequences in the random access procedure.

For a random access procedure, when the SSB associated with the PRACH transmission is associated with one or more TRPs, in response to the PRACH transmission, UE detects PDCCH for random access response (RAR) and receives PDSCH for RAR which are transmitted from the one or more TRPs.

In some embodiments, different search spaces corresponding to different TRPs can be used. FIG. 8 illustrates an example of search spaces corresponding to different TRPs in accordance with one or more embodiments of the present technology. In some embodiments, the UE receives a network message (e.g., PDCCH-ConfigCommon) , indicating a random access search space list. The random access search space list comprises one or more random access search spaces, each of which is associated with a TRP. The UE detects PDCCH or monitors PDCCH candidates scrambled by a Random-Access Radio Network Temporary Identifier (RA-RNTI) or a Message B RNTI (MSGB-RNTI) in the random access search spaces. The RA-RNTI and/or MSGB-RNTI are associated with the random access preamble transmission. In this example, the PDCCH detected in a random access search space associated with a corresponding TRP, and a transmission on the Physical Downlink Shared Channel (PDSCH) scheduled by the PDCCH are associated with the same TRP. As shown in FIG. 8, the UE detects PDCCH 0, PDCCH 1 and PDCCH 2 with Cyclic Redundancy Check (CRC) scrambled by the same RA-RNTI in the random access search space 0, random access search space 1, and random access search space 2 respectively. That is, different search spaces can correspond to different TRPs. The UE then proceeds to perform PDSCHs according to the detected PDCCHs so that joint transmission/reception using one or more TRPs can then be enabled.

In some embodiments, if an SSB associated with the PRACH transmission is not associated with one or more TRPs, UE does not detect PDCCH scrambled by the RA-RNTI associated with the PRACH transmission in the random access search space configured for the one or more TRPs. For example, in response to a random access preamble transmission by PRACH, UE detects PDCCH (DCI format 1_0) with CRC scrambled by RA-RNTI in the random access spaces indicated in the random access search space list. If UE detects a first PDCCH with CRC scrambled by the RA-RNTI in a first random access search space and a second PDCCH with CRC scrambled by the RA-RNTI in a second random access search space, the PDSCH (containing RAR) scheduled by the first PDCCH is associated with the first TRP and the PDSCH (containing RAR) scheduled by the first PDCCH is associated with the second TRP.

In some embodiments, the UE determines RA-RNTI and/or MSGB-RNTI based on the TRP information associated with the random access preamble transmission, in addition to the time and frequency domain information of the PRACH occasion in which the random access preamble is transmitted. The time domain information comprises the index of the first OFDM symbol of the PRACH occasion and the index of the first slot of the PRACH occasion in a frame. The frequency domain information comprises the index of the PRACH occasion in the frequency domain and information of the uplink carrier used for the random access preamble transmission. FIG. 9 illustrates an example of RNTI values corresponding to different TRPs in accordance with one or more embodiments of the present technology. As shown in FIG. 9, the UE detects PDCCH 0, PDCCH 1 and PDCCH 2 with CRC scrambled by the RA-RNTI 0, RA-RNTI 1 and RA-RNTI 2 respectively in the same random access search space. Different RA-RNTI value corresponds to different TRPs. The UE then proceeds to perform PDSCHs according to the detected PDCCHs so that joint transmission/reception using one or more TRPs can then be enabled.

For example, the RA-RNTI associated with the PRACH transmission (or preamble transmission) can be computed as: RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 ×f_id + 14 × 80 × 8 × ul_carrier_id + 14 × 80 × 8 × 2 × trp_id. As another example, the MSGB-RNTI associated with the PRACH transmission can be computed as: MSGB-RNTI =1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id + 14 × 80 × 8 × 2 × trp_id + 14 × 80 × 8 × 2 × N_trp, max.

In the examples above, s_id is the index of the first OFDM symbol of the PRACH occasion (0 ≤ s_id < 14) , t_id is the index of the first slot of the PRACH occasion in a frame (0 ≤t_id< 80) , f_id is the index of the PRACH occasion in the frequency domain (0 ≤ f_id <8) , ul_carrier_id is the UL carrier used for random access preamble transmission (0 for NUL carrier, and 1 for SUL carrier) , and trp_id is the index of the transmit and receive point associated with the random access preamble transmission (0 ≤ trp_id < N_trpmax) , where N_trpmax is the maximum number of TRPs associated with an SS/PBCH block.

FIG. 10 shows an example of a wireless communication system 1000 where techniques in accordance with one or more embodiments of the present technology can be applied. A wireless communication system 1000 can include one or more base stations (BSs) 1005a, 1005b, one or more wireless devices (or UEs) 1010a, 1010b, 1010c, 1010d, and a core network 1025. A base station 1005a, 1005b can provide wireless service to user devices 1010a, 1010b, 1010c and 1010d in one or more wireless sectors. In some implementations, a base station 1005a, 1005b includes directional antennas to produce two or more directional beams to provide wireless coverage in different sectors. The core network 1025 can communicate with one or more base stations 1005a, 1005b. The core network 1025 provides connectivity with other wireless communication systems and wired communication systems. The core network may include one or more service subscription databases to store information related to the subscribed user devices 1010a, 1010b, 1010c, and 1010d. A first base station 1005a can provide wireless service based on a first radio access technology, whereas a second base station 1005b can provide wireless service based on a second radio access technology. The base stations 1005a and 1005b may be co-located or may be separately installed in the field according to the deployment scenario. The user devices 1010a, 1010b, 1010c, and 1010d can support multiple different radio access technologies. The techniques and embodiments described in the present document may be implemented by the base stations of wireless devices described in the present document.

FIG. 11 is a block diagram representation of a portion of a radio station in accordance with one or more embodiments of the present technology can be applied. A radio station 1105 such as a network node, a base station, or a wireless device (or a user device, UE) can include processor electronics 1110 such as a microprocessor that implements one or more of the wireless techniques presented in this document. The radio station 1105 can include transceiver electronics 1115 to send and/or receive wireless signals over one or more communication interfaces such as antenna 1120. The radio station 1105 can include other communication interfaces for transmitting and receiving data. Radio station 1105 can include one or more memories (not explicitly shown) configured to store information such as data and/or instructions. In some implementations, the processor electronics 1110 can include at least a portion of the transceiver electronics 1115. In some embodiments, at least some of the disclosed techniques, modules or functions are implemented using the radio station 1105. In some embodiments, the radio station 1105 may be configured to perform the methods described herein.

The disclosed and other embodiments, modules and the functional operations described in this document can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, or in combinations of one or more of them. The disclosed and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more them. The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus.

A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document) , in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code) . A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

The processes and logic flows described in this document can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit) . Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random-access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

While this patent document contains many specifics, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this patent document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

Only a few implementations and examples are described, and other implementations, enhancements and variations can be made based on what is described and illustrated in this patent document.

Claims

A method for wireless communication, comprising:

determining, by a base station, information associated with a synchronization signal block (SSB) , wherein the SSB comprises synchronization signals and a physical broadcast channel, and wherein the information indicates one or more communication units corresponding to the SSB; and

performing, by the base station to a user equipment, a transmission of the information associated with the SSB.
A method for wireless communication, comprising:

receiving, by a user equipment from a base station, information associated with a synchronization signal block (SSB) , wherein the SSB comprises synchronization signals and a physical broadcast channel, and wherein the information indicates one or more communication units corresponding to the SSB; and

performing, by the user equipment, a random access procedure with at least one of the one or more communication units based on the information associated with the SSB.
The method of claim 1 or 2, wherein the information is included in a payload of the physical broadcast channel.
The method of claim 3, wherein the information comprises an identification of a communication unit or a bitmap that indicates one or more identifications of the one or more communication units.
The method of claim 4, wherein the payload of the physical broadcast channel comprises a Master Information Block (MIB) that includes the information.
The method of claim 4, wherein the bitmap comprises bits corresponding to a maximum number of communication units associated with the SSB.
The method of claim 4, wherein N denotes a maximum number of communication units associated with the synchronization signal block, and wherein a size of the identification is ceil (log2 (N) ) .
The method of claim 1 or 2, wherein the information comprises a Demodulation Reference Signal (DMRS) for the physical broadcast channel.
The method of claim 8, wherein an initiation of a scrambling sequence for the DMRS is based on one or more identifications of the one or more communication units associated with the SSB.
The method of claim 9, wherein a parameter C_init for the initiation of the scrambling sequence for the DMRS is defined as:

wherein i_TRP is an index of a communication unit associated with the SSB, Ntrp equals to ceil (log2 (N_trp, max) ) , where N_trp, max is a maximum number of communication units associated with the SSB, is related to an SSB index, is related to a physical cell index.
The method of claim 1 or 2, wherein the information comprises a synchronization signal.
The method of claim 11, wherein a sequence for the synchronization signal is determined based on a physical cell index and an identification of a communication unit.
The method of any of claims 1 to 12, wherein the one or more communication units are associated with one or more SSB transmissions having a same SSB index.
A method for wireless communication, comprising:

performing, by a user equipment, a random access procedure based on information associated with a synchronization signal block;

detecting, by the user equipment, control information in one or more search spaces, wherein the control information schedules a transmission from a base station to the user equipment, and wherein the control information in the one or more search spaces corresponds to one or more communication units associated with the base station; and

receiving, by the user equipment, the transmission from at least one of the one or more communication units based on the control information.
The method of claim 14, comprising:

receiving, by the user equipment, configuration information from the base station configuring the one or more search spaces,

wherein each search space is associated with a communication unit.
A method for wireless communication, comprising:

receiving, by a base station, a random access transmission from a user equipment;

transmitting, by the base station, control information in one or more search spaces to the user equipment, wherein the control information schedules a transmission to the user equipment, and the control information in the one or more search spaces corresponds to one or more communication units associated with the base station; and

performing the transmission to the user equipment using at least one of the one or more communication units according to the control information.
The method of claim 16, comprising:

transmitting, by the base station, configuration information to the user equipment configuring the one or more search spaces,

wherein each search space is associated with a communication unit.
The method of any of claims 14 to 17, wherein the control information is scrambled using a temporary identifier determined based on an identification of a communication unit.
A communication apparatus, comprising at least one processor configured to implement a method recited in any one or more of claims 1 to 18.
A computer program product having code stored thereon, the code, when executed by at least one processor, causing the at least one processor to implement a method recited in any one or more of claims 1 to 18.