WO2022098767A1 - Segmented pss and sss transmission for 5g and 6g networks - Google Patents

Abstract

A base station configured for operation in a sixth generation (6G) network generates a primary synchronization signal (PSS) that comprises a first and a second sequence for transmission in consecutive discrete Fourier transform (DFT) spread orthogonal frequency division multiplexed (s-OFDM) (DFT-s-OFDM) symbols. The first and second sequences may comprise a first Zadoff Chu (ZC) sequence having a length L with a first root index u and a second ZC sequence of the length L with a second root index L - u. The first root index u may have a value between one and one less than the length. The second root index may equal the first root index subtracted from the length (i.e., L - u). The base station may segment the first sequence into a first two blocks and may segment the second sequences into a second two blocks. The base station may modulate each block into one of the consecutive DFT-s-OFDM symbols to generate the four consecutive DFT-s-OFDM symbols comprising the PSS.

Description

SEGMENTED PSS AND SSS TRANSMISSION FOR 5G AND 6G

NETWORKS

PRIORITY CLAIMS

[0001] This application claims the benefit of priority to: United States Provisional Patent Application Serial No. 63/110,880, filed November 06, 2020 [reference number AD3579-Z], United States Provisional Patent Application Serial No. 63/115,371, filed November 18, 2020 [reference number AD3851-Z], United States Provisional Patent Application Serial No. 63/121,778 filed December 04, 2020 [reference number AD4093-Z] United States Provisional Patent Application Serial No. 63/127,016, filed December 17, 2020 [reference number AD4320-Z], and United States Provisional Patent Application Serial No. 63/144,403, filed February 02, 2021 [reference number AD4926-Z] which are incorporated herein by reference in their entireties.

TECHNICAL FIELD

[0002] Embodiments pertain to wireless communications. Some embodiments relate to wireless networks including 3GPP (Third Generation Partnership Project) and fifth-generation (5G) networks including 5G new radio (NR) (or 5G-NR) networks and sixth-generation (6G) networks. Some embodiments relate to generation and transmission of synchronization signals.

BACKGROUND

[0003] LTE and NR synchronization signals are optimized for receivers to potentially perform multiple accumulations during detection of the synchronization signal. Additionally, a separate demodulation reference signal for physical broadcast signal is used, requiring additional reference signal on top of the synchronization signal. The main drawback is that LTE and NR synchronization signal does not have enough number of samples and symbols to allow a single detection to meet the required performance requirements.

Additionally, the LTE and NR synchronization signal structure require a separate use of demodulation reference signal (DMRS) on top of the synchronization signal. This results in higher overhead and reduced overall efficiency of the system.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 A illustrates an architecture of a network, in accordance with some embodiments.

[0005] FIG. IB and FIG. 1C illustrate a non-roaming 5G system architecture in accordance with some embodiments.

[0006] FIG. 2 is a block diagram of a wireless communication device in accordance with some embodiments.

[0007] FIG. 3 illustrates synchronization signal block structure, in accordance with some embodiments.

[0008] FIG. 4 illustrates a proposed PSS structure options, in accordance with some embodiments.

[0009] FIG. 5 illustrates segmented and DFT precoded ZC sequence based PSS, in accordance with some embodiments.

[0010] FIG. 6 illustrates segmented and DFT precoded ZC sequence based PSS with symbol interleaving, in accordance with some embodiments.

[0011] FIG. 7 illustrates DFT precoded ZC sequence based PSS, in accordance with some embodiments.

[0012] FIG. 8 illustrates cyclic shift delay based transmit diversity transmission for PSS, in accordance with some embodiments,

[0013] FIG. 9 illustrates PSS based on DFT transform precoding of segmented Golay sequence modulated with pi/2-BPSK, in accordance with some embodiments.

[0014] FIG. 10 illustrates PSS based on segmented Golay sequence modulated with pi/2-BPSK or BPSK in accordance with some embodiments. [0015] FIG, 11 illustrates PSS based on DFT transform precoded Golay sequence modulated with pi/2-BPSK and ’4 subcarrier spacing of SSS and PBCH, in accordance with some embodiments.

[0016] FIG. 12 illustrates PSS based on Golay sequence modulated with pi/2-BPSK or BPSK and ’4 subcarrier spacing of SSS and PBCH, in accordance with some embodiments.

[0017] FIG. 13 illustrates complementary Golay mapping across symbols, in accordance with some embodiments.

[0018] FIG. 14 illustrates two antenna port transmission of PSS based on generation approach 2 with PSS structure #C, in accordance with some embodiments.

[0019] FIG. 15 illustrates two antenna port, transmission of PSS based on generation approach 2 with PSS structure #A, in accordance with some embodiments.

[0020] FIG. 16A and FIG. 16B illustrate aperiodic cross-correlation profile for pair of complementary Golay sequences, in accordance with some embodiments.

[0021] FIG. 17A and FIG. 17B illustrate the generation of two resequences with different primitive polynomials, in accordance with some embodiments.

[0022] FIG. 18 illustrates a same m-sequence DFT precoded into frequency domain values, where complex conjugate of the frequency domain samples are performed, then mapped back to time domain with iFFT operation, in accordance with some embodiments.

[0023] FIG. 19 illustrates a first SSS generation technique using complementary Golay sequence pairs, in accordance with some embodiments.

[0024] FIG. 20 illustrates a second SSS generation technique in accordance with some alternate embodiments.

[0025] FIG. 21 illustrates a third SSS generation technique in accordance with some alternate embodiments

[0026] FIG. 22 illustrates a fourth SSS generation technique in accordance with some alternate embodiments [0027] FIG, 23 illustrates a fifth SSS generation technique in accordance with some alternate embodiments

[0028] FIG. 24 illustrates a sixth SSS generation technique in accordance with some alternate embodiments

[0029] FIG. 25 illustrates a seventh SSS generation technique in accordance with some alternate embodiments

[0030] FIG. 26 illustrates space time block code transmission scheme for SSS, in accordance with some embodiments.

[0031] FIG. 27 illustrates detection with proposed space time block code, and of channel estimate for SSS, in accordance with some embodiments.

[0032] FIG. 28 illustrates cyclic delay diversity transmission scheme for SSS, in accordance with some embodiments.

[0033] FIG. 29 illustrates an eighth SSS generation technique in accordance with some alternate embodiments

[0034] FIG. 30A and FIG. 30B illustrate an SSS generation technique with a CDD transmit diversity scheme, in accordance with some embodiments,

DETAILED DESCRIPTION

[0035] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0036] Some of the embodiments described here allow single detection processing to meet the required performance for a synchronization channel and allow efficient transmission of system broadcast information as no separate demodulation reference signal may be needed. These embodiments are described in more detail below.

[0037] Some embodiments are directed to a base station configured for operation in a sixth generation (6G) network. In these embodiments, the base station may generate a primary' synchronization signal (PSS) for transmission. The PSS may comprise a first and a second sequence. In these embodiments, the base station may transmit the first and second sequences in consecutive discrete Fourier transform (DFT) spread orthogonal frequency division multiplexed (s- OFDM) (DFT-s-OFDM) symbols.

[0038] In some embodiments, the first and second sequences may comprise a first Zadoff Chu (ZC) sequence having a length L with a first root index u and a second ZC sequence of the length L with a second root index L - u. The first root index u may have a value between one and one less than the length. The second root index may equal the first root index subtracted from the length (i.e., L -• u). In these embodiments, the length L of the ZC sequences may be as great as 1000 or more. In some embodiments, the length L may be 63, 127, 255, 51 1 , 1023 (i.e., 2n-l where n is an integer), although the scope of the embodiments is not limited in this respect as other lengths may also be suitable. In these embodiments, the first ZC may have length L with root index u and the second ZC sequence may have length L with a root index of L - u. The root index ‘u’ may have value between 1 and L-l, although the scope of the embodiments in not limited in this respect.

[0039] In some embodiments, the first and second sequences may comprise a complementary pair of Golay binary sequences of length L modulated with BPSK or pi/2-BPSK modulation.

[0040] In some embodiments, the base station may generate the DFT-s- OFDM symbols by performing DFT precoding of an input sequence to generate a precoded input sequence, mapping the precoded input sequence onto frequency subcarriers, transforming the frequency subcarriers into time domain samples using an inverse DFT (IDFT), and adding a cyclic prefix to a beginning of each group of the domain samples. An example of these embodiments are illustrated in FIG. 5 and are described in more detail below.

[0041] In some embodiments, the PSS comprises four consecutive DFT- s-OFDM symbols. In these embodiments, a first of the symbols may be generated from a first segment of a first input sequence, a second of the symbols may be generated from a second segment of the first input sequence, a third of the of the symbols may be generated from a first segment of a second input sequence, and a fourth of the symbols may be generated from a second segment of the second input sequence. An example of these embodiments are illustrated in FIG. 6 and are described in more detail below.

[0042] In some embodiments, the base station may segment the first sequence into a first two blocks and segment the second sequences into a second two blocks. In these embodiments, the base station may modulate each block into one of the consecutive DFT-s-OFDM symbols to generate the four consecutive DFT-s-OFDM symbols comprising the PSS.

[0043] In some embodiments, the base station may transmit the first and second sequences in the consecutive DFT-s-OFDM symbols using a first antenna port. In these embodiments, when the base station is configured for transmission of the PSS using two antenna ports, the base station may generate a time domain cyclic shifted version of the DFT-s-OFDM symbols for transmission by a second of the antenna pons.

[0044] In some embodiments, when the base station is configured for transmission of the PSS using the two antenna ports and when the first and second sequences comprise the complementary pair of Golay binary sequences, the base station may transmit a first of the Golay binary sequences of the complementary' pair using the first antenna port and transmit a second of the Golay binary sequences of the complementary pair using the second antenna port.

[0045] In some embodiments, the base station may transmit a synchronization signal block (SSB) comprising the PSS, a secondary synchronization signal (SSS) and a physical broadcast channel (PBCH). In these embodiments, when the first and second sequences comprise the ZC sequences, a subcarrier spacing used for generation of the DFT-s-OFDM symbols of the PSS may be half of a subcarrier spacing used for generation of DFT-s-OFDM symbols of the SSS. In these embodiments, when the first and second sequences comprise the complementary' pair of Golay binary sequences, the subcarrier spacing used for generation of the DFT-s-OFDM symbols of the PSS may be a quarter of the subcarrier spacing used for generation of DFT-s-OFDM symbols of the SSS.

[0046] In some embodiments, when the first and second sequences comprise the complementary' pair of Golay binary sequences, the base station may cyclically shift the complementary pair of Golay binary sequences after inverse fast Fourier Transform (iFFT) processing and prior to cyclic prefix (CP) insertion.

[0047] In some embodiments, the base station may operate as a generation Node B (gNB) and may comprise a baseband processor.

[0048] Some embodiments are directed to non-transitory computer- readable storage medium that stores instructions for execution by processing circuitry of a base station configured for operation in a sixth generation (6G) network. In these embodiments, the processing circuitry may generate a primary' synchronization signal (PSS) for transmission. The PSS may comprise a first and a second sequence. In these embodiments, the base station may be configured to transmit the first and second sequences in consecutive discrete Fourier transform (DFT) spread orthogonal frequency division multiplexed (s-OFDM ) (DFT-s- OFDM) symbols.

[0049] Some embodiments are directed to a user equipment (UE) configured for operation in a sixth-generation (6G) network. The UE may perform a synchronization process that may include detecting a primary synchronization signal (PSS) transmitted by a base station. The PSS may comprise a first and a second sequence and the first and second sequences may be received in consecutive discrete Fourier transform (DFT) spread orthogonal frequency division multiplexed (s-OFDM) (DFT-s-OFDM) symbols. In these embodiments, after detection of the PSS, the UE may detect a secondary synchronization signal (SSS) transmitted by the base station. In these embodiments, once the PSS has been detected, the UE proceeds with additional processing including the detection of the SSS allowing completion of the synchronization process and the detection of the start of the frame as well as the other part of the cell ID including the physical-layer cell-identity group.

[0050] In some embodiments, when the first and second sequences comprise ZC sequences, a subcarrier spacing for DFT-s-OFDM symbols of the PSS may be half of a subcarrier spacing for DFT-s-OFDM symbols of the SSS. In some embodiments, when the first and second sequences comprise a complementary pair of Golay binary? sequences, the subcarrier spacing for DFT- s-OFDM symbols of the PSS may be a quarter of the subcarrier spacing for DFT-s-OFDM symbols of the SSS.

[0051] FIG. I A illustrates an architecture of a network in accordance with some embodiments. The network 140A is shown to include user equipment (UE) 101 and UE 102, The UEs 101 and 102 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks) but may also include any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, drones, or any other computing device including a wired and/or wireless communications interface. The UEs 101 and 102 can be collectively referred to herein as UE 101, and UE 101 can be used to perform one or more of the techniques disclosed herein.

[0052] Any of the radio links described herein (e.g., as used in the network 140A or any other illustrated network) may operate according to any exemplary radio communication technology and/or standard.

[0053] LTE and LTE-Advanced are standards for wireless communications of high-speed data for UE such as mobile telephones. In LTE- Advanced and various wireless systems, carrier aggregation is a technology according to which multiple carrier signals operating on different frequencies may be used to carry communications for a single UE, thus increasing the bandwidth available to a single device. In some embodiments, carrier aggregation may be used where one or more component carriers operate on unlicensed frequencies.

[0054] Embodiments described herein can be used in the context of any spectrum management scheme including, for example, dedicated licensed spectrum, unlicensed spectrum, (licensed) shared spectrum (such as Licensed Shared Access (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and further frequencies and Spectrum Access System (SAS) in 3.55-3.7 GHz and further frequencies).

[0055] Embodiments described herein can also be applied to different Single Carrier or OFDM flavors (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.) and in particular 3GPP NR (New Radio) by allocating the OFDM earner data bit vectors to the corresponding symbol resources.

[0056] In some embodiments, any of the UEs 101 and 102 can comprise an Intemet-of-Things (loT) UE or a Cellular loT (CIoT) UE, which can comprise a network access layer designed for low-power loT applications utilizing short-lived UE connections. In some embodiments, any of the UEs 101 and 102 can include a narrowband (NB) loT UE (e.g., such as an enhanced NB- loT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An loT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Sendee (ProSe) or device-to-device (D2D) communication, sensor networks, or loT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An loT network includes interconnecting loT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The loT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the loT network.

[0057] In some embodiments, any of the UEs 101 and 102 can include enhanced MTC (eMTC) UEs or further enhanced MTC (FeMTC) UEs.

[0058] The UEs 101 and 102 may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) 110. The RAN 110 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN. The UEs 101 and 102 utilize connections 103 and 104, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections 103 and 104 are illustrated as an air interface to enable communicative coupling and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to- Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth-generation (5(3) protocol, a New Radio (NR) protocol, and the like.

[0059] In an aspect, the UEs 101 and 102 may further directly exchange communication data via a ProSe interface 105. The ProSe interface 105 may alternatively be referred to as a sidelink interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH).

[0060] The UE 102 is shown to be configured to access an access point (AP) 106 via connection 107. The connection 107 can comprise a local wireless connection, such as, for example, a connection consistent with any IEEE 802.11 protocol, according to which the AP 106 can comprise a wireless fidelity (WiFi) router. In this example, the AP 106 is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below).

[0061] The RAN 110 can include one or more access nodes that enable the connections 103 and 104. These access nodes ( ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), Next Generation NodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area, (e.g., a cell ). In some embodiments, the communication nodes 111 and 112 can be transmi ssion/recepti on points (TRPs). In instances when the communication nodes 111 and 112 are NodeBs (e.g., eNBs or gNBs), one or more TRPs can function within the communication cell of the NodeBs. The

RAN 110 may include one or more RAN nodes for providing macrocells, e.g., macro-RAN node 1 1 1, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node 112.

[0062] Any of the RAN nodes 111 and 112 can terminate the air interface protocol and can be the first point of contact for the UEs 101 and 102. In some embodiments, any of the RAN nodes 111 and 112 can fulfill various logical functions for the RAN 110 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In an example, any of the nodes 111 and/or 112 can be a new generation Node-B (gNB), an evolved node-B (eNB), or another type of RAN node.

[0063] The RAN 110 is shown to be communicatively coupled to a core network (CN) 120 via an S I interface 113. In embodiments, the CN 120 may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN (e.g., as illustrated in reference to FIGS. 1B-1C). In this aspect, the SI interface 113 is split into two parts: the Sl-U interface 114, which carries traffic data between the RAN nodes 111 and 112 and the serving gateway (S-GW) 122, and the SI -mobility management entity (MME) interface 115, which is a signaling interface between the RAN nodes 111 and 112 and MMEs 121.

[0064] In this aspect, the CN 120 comprises the MMEs 121 , the S-GW 122, the Packet Data Network (PDN) Gateway (P-GW) 123, and a home subscriber server (HSS) 124. The MMEs 121 may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs 121 may manage mobility embodiments in access such as gateway selection and tracking area list management. The HSS 124 may comprise a database for network users, including subscription-related information to support, the network entities' handling of communication sessions. The CN 120 may comprise one or several HSSs 124, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS 124 can provide support for routing/roaming, authentication, authorization, naming/ addressing resolution, location dependencies, etc.

[0065] The S-GW 122 may terminate the SI interface 113 towards the RAN 1 10, and routes data packets between the RAN 110 and the CN 120. In addition, the S-GW 122 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities of the S-GW 122 may include a lawdul intercept, charging, and some policy enforcement. [0066] The P-GW 123 may terminate an SGi interface toward a PDN. The P-GW 123 may route data packets between the EPC network 120 and external networks such as a network including the application server 184 (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface 125. The P-GW 123 can also communicate data to other external networks 131 A, which can include the Internet, IP multimedia subsystem (IPS) network, and other networks. Generally, the application server 184 may be an element offering applications that use IP bearer resources with the core network (e.g., I MTS Packet Services (PS) domain, LTE PS data services, etc.). In this aspect, the P-GW 123 is shown to be communicatively coupled to an application server 184 via an IP interface 125. The application server 184 can also be configured to support one or more communication services (e.g., Voice-over- Internet Protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking sendees, etc.) for the UEs 101 and 102 via the CN 120.

[0067] The P-GW 123 may further be a. node for policy enforcement and charging data collection. Policy and Charging Rules Function (PCRF) 126 is the policy and charging control element of the CN 120. In a non-roaming scenario, in some embodiments, there may be a single PCRF in the Home Public Land Mobile Network (ITPLMN) associated with a UE's Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with a local breakout of traffic, there may be two PCRFs associated with a UE's IP- CAN session: a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 126 may be communicatively coupled to the application server 184 via the P- GW 123.

[0068] In some embodiments, the communication network 140A can be an loT network or a 5G network, including 5G new radio network using communications in the licensed (5G NR) and the unlicensed (5G NR-U) spectrum. One of the current enablers of loT is the narrowband-IoT (NB-IoT). [0069] An NG system architecture can include the RAN 110 and a 5G network core (5GC) 120. The NG-RAN 110 can include a plurality of nodes, such as gNBs and NG-eNBs. The core network 120 (e.g., a 5G core network or 5GC) can include an access and mobility function (AMF) and/or a user plane function (UPF). The AMF and the UPF can be communicatively coupled to the gNBs and the NG-eNBs via NG interfaces. More specifically, in some embodiments, the gNBs and the NG-eNBs can be connected to the AMF by NG- C interfaces, and to the UPF by NG-U interfaces. The gNBs and the NG-eNBs can be coupled to each other via Xn interfaces.

[0070] In some embodiments, the NG system architecture can use reference points between various nodes as provided by 3GPP Technical Specification (TS) 23.501 (e.g., V15.4.0, 2018-12). In some embodiments, each of the gNBs and the NG-eNBs can be implemented as a base station, a mobile edge server, a small cell, a home eNB, and so forth. In some embodiments, a gNB can be a master node (MN) and NG-eNB can be a secondary node (SN) in a 5G architecture.

[0071] FIG. I B illustrates a non-roaming 5G system architecture in accordance with some embodiments. Referring to FIG. IB, there is illustrated a 5G system architecture 140B in a reference point representation. More specifically, UE 102 can be in communi cation with RAN 110 as well as one or more other 5G core (5GC) network entities. The 5G system architecture 140B includes a plurality of network functions (NFs), such as access and mobility management function (AMF) 132, session management function (SMF) 136, policy control function (PCI j 148, application function (AF) 150, user plane function (UPF) 134, network slice selection function (NSSF) 142, authentication server function (AUSF) 144, and unified data management (UDM)/home subscriber server (HSS) 146. The UPF 134 can provide a connection to a data network (DN) 152, which can include, for example, operator services, Internet access, or third-party services. The AMF 132 can be used to manage access control and mobility and can also include network slice selection functionality. The SMF 136 can be configured to set up and manage various sessions according to network policy. The UPF 134 can be deployed in one or more configurations according to the desired sendee type. The PCF 148 can be configured to provide a policy framework using network slicing, mobility management, and roaming (similar to PCRF in a 4G communication system). The UDM can be configured to store subscriber profiles and data (similar to an HSS in a 4G communication system) [0072] In some embodiments, the 5G system architecture MOB includes an IP multimedia subsystem (IMS) 168B as well as a plurality of IP multimedia core network subsystem entities, such as call session control functions (CSCFs). More specifically, the IMS 168B includes a CSCF, which can act as a proxy CSCF (P-CSCF) 162BE, a serving CSCF (S-CSCF) 164B, an emergency CSCF (E-CSCF) (not illustrated in FIG. IB), or interrogating CSCF (I-CSCF) 166B. The P-CSCF 162B can be configured to be the first contact point for the LIE 102 within the M subsystem ( IMS) 168B. The S-CSCF 164B can be configured to handle the session states in the network, and the E-CSCF can be configured to handle certain embodiments of emergency sessions such as routing an emergency request to the correct emergency center or PSAP. The I-CSCF 166B can be configured to function as the contact point within an operator's network for all IMS connections destined to a subscriber of that network operator, or a roaming subscriber currently located within that network operator's sendee area. In some embodiments, the I-CSCF 166B can be connected to another IP multimedia network 170E, e.g. an IMS operated by a different network operator, [0073] In some embodiments, the UDM/HSS 146 can be coupled to an application server 160E, which can include a telephony application server (TAS) or another application server (AS), The AS 160B can be coupled to the IMS 168B via the S-CSCF 164B or the I-CSCF 166B.

[0074] A reference point representation shows that interaction can exist between corresponding NF services. For example, FIG. IB illustrates the following reference points: N1 (between the UE 102 and the AMF 132), N2 (between the RAN 110 and the AMF 132), N3 (between the RAN 1 10 and the UPF 134), N4 (between the SMF 136 and the UPF 134), N5 (between the PCF 148 and the AF 150, not shown), N6 (between the UPF 134 and the DN 152), N7 (between the SMF 136 and the PCF 148, not shown), N8 (between the UDM 146 and the AMF 132, not shown), N9 (between two UPFs 134, not shown). Ml 0 (between the UDM 146 and the SMF 136, not shown), N11 (between the AMF 132 and the SMF 136, not shown), N12 (between the AUSF 144 and the AMF 132, not shown), N13 (between the AUSF 144 and the UDM: 146, not shown), N14 (between two AMFs 132, not shown), N15 (between the PCF 148 and the AMF 132 in case of a non-roaming scenario, or between the PCF 148 and a visited network and AMF 132 in case of a roaming scenario, not shown), N16 (between two SMFs, not shown), and N22 (between AMF 132 and NSSF 142, not shown). Other reference point representations not shown in FIG. IB can also be used.

[0075] FIG. 1C illustrates a. 5G system architecture 140C and a servicebased representation. In addition to the network entities illustrated in FIG. IB, system architecture 140C can also include a network exposure function (NEF) 154 and a network repository; function (NRF) 156. In some embodiments, 5G system architectures can be service-based and interaction between network functions can be represented by corresponding point-to-point reference points Ni or as sendee-based interfaces.

[0076] In some embodiments, as illustrated in FIG. 1 C, service-based representations can be used to represent network functions within the control plane that enable other authorized network functions to access their services. In this regard, 5G system architecture 140C can include the following service-based interfaces: Namf 158H (a sendee-based interface exhibited by the AMF 132), Nsmf 1581 (a. service-based interface exhibited by the SMF 136), Nnef 158B (a sendee-based interface exhibited by the NEF 154), Npcf 158D (a sendee-based interface exhibited by the PCF 148), aNudm 158E (a. senice-based interface exhibited by the UDM 146), Naf 158F (a senice-based interface exhibited by the AF 150), Nnrf 158C (a service-based interface exhibited, by the NRF 156), Nnssf 158 A (a. service-based interface exhibited by the NSSF 142), Nausf 158G (a service-based interface exhibited by the AUSF 144). Other senice-based interfaces (e.g., Nudr, N5g-eir, and Nudsf) not shown in FIG. 1C can also be used.

[0077] In some embodiments, any of the UEs or base stations described in connection with FIGS. 1 A-1C can be configured to perform the functionalities described herein.

[0078] Mobile communication has evolved significantly from early voice systems to today’s highly sophisticated integrated communication platform. The next generation wireless communication system, 5G, or new radio (NR) will provide access to information and sharing of data anywhere, anytime by various users and applications. NR is expected to be a unified network/ system that targets to meet vastly different and sometimes conflicting performance dimensions and services. Such diverse multi-dimensional requirements are driven by different sendees and applications. In general, NR will evolve based on 3 GPP LTE- Advanced with additional potential new Radio Access Technologies (RATs) to enrich people's lives with better, simple, and seamless wireless connectivity solutions. NR will enable everything connected by wireless and deliver fast, rich content and sendees.

[0079] Rel-15 NR systems are designed to operate on the licensed spectrum. The NR-unlicensed (NR-U), a short-hand notation of the NR-based access to unlicensed spectrum, is a technology that enables the operation of NR systems on the unlicensed spectrum.

[0080] FIG. 2 illustrates a functional block diagram of a wireless communication device, in accordance with some embodiments. Wireless communication device 200 may be suitable for use as a UE or gNB configured for operation in a 5G NR network.

[0081] The communication device 200 may include communications circuitry 202 and a transceiver 210 for transmitting and receiving signals to and from other communication devices using one or more antennas 201. The communications circuitry 202 may include circuitry that, can operate the physical layer (PHY) communications and/or medium access control (MAC) communications for controlling access to the wireless medium, and/or any other communications layers for transmitting and receiving signals. The communication device 200 may also include processing circuitry' 206 and memory 208 arranged to perform the operations described herein. In some embodiments, the communications circuitry 202 and the processing circuitry' 206 may be configured to perform operations detailed in the above figures, diagrams, and flow's.

[0082] In accordance with some embodiments, the communications circuitry 202 may be arranged to contend for a wireless medium and configure frames or packets for communicating over the wireless medium. The communications circuitry' 202 may be arranged to transmit and receive signals. The communications circuitry' 202 may also include circuitry' for modulation/demodulation, upconversion/downconversion, filtering, amplification, etc. In some embodiments, the processing circuitry 206 of the communication device 200 may include one or more processors. In other embodiments, two or more antennas 201 may be coupled to the communications circuitry 202 arranged for sending and receiving signals. The memory 208 may store information for configuring the processing circuitry 206 to perform operations for configuring and transmitting message frames and performing the various operations described herein. The memory' 208 may include any type of memory', including non-transitory memory, for storing information in a form readable by a machine (e.g., a computer). For example, the memory 208 may include a computer-readable storage device, read-only memory (ROM), randomaccess memory' (RAM), magnetic disk storage media, optical storage media, flash-memory' devices and other storage devices and media.

[0083] In some embodiments, the communication device 200 may' be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), a wearable computer device, or another device that may receive and/or transmit information wirelessly.

[0084] In some embodiments, the communication device 200 may include one or more antennas 201. The antennas 201 may' include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some embodiments, instead of two or more antennas, a single antenna with multiple apertures may be used. In these embodiments, each aperture may be considered a separate antenna. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be effectively separated for spatial diversity and the different channel characteristics that may result between each of the antennas and the antennas of a transmitting device.

[0085] In some embodiments, the communication device 200 may include one or more of a keyboard, a display , a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0086] Although the communi cation device 200 is illustrated as having several separate functional elements, two or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements of the communication device 200 may refer to one or more processes operating on one or more processing elements.

[0087]

[0088] The proposed synchronization signal block (SSB) consists of primary synchronization signal (PSS), secondary synchronization signal (SSS), and physical broadcast channel (PBCH). The SSB contains PSS that span 4 symbol length duration, followed by 2 PBCH symbols, 2 SSS symbols, 2 PBCH symbols, 2 SSS symbols, and 2 PBCH symbols. Illustration of the SSB structure is provided in FIG. 3 as an example.

[0089] PSS generation

[0090] The PSS may be one of three sub-structures, structure #A, #B, and #C. PSS structure #A consist of long cyclic prefix (CP) equal to 4 regular CP lengths, followed by 4 discrete Fourier transform (DFT) lengths that contain PSS sequences. PSS structure #B consist of long CP equal to 2 regular CP lengths, followed by 2 DFT lengths that contain PSS sequences, another long CP equal to 2 regular CP lengths, and 2 DFT lengths that contain PSS sequences. PSS structure #C consist of 4 PSS symbols, where each symbol consists of CP followed by DFT length that contain PSS sequences. Illustration of the PSS structure options are provided in FIG. 4. [0091] PSS generation approach 1

[0092] PSS generation approach 1 uses two Zadoff Chu (ZC) sequences with mirror root index. ZC sequence with root index u and length L, x_u(n), is defined as:

[0093]

[0094] The first sequence of PSS uses ZC sequence with root index ‘u’, and the second sequence of PSS uses ZC sequence with root index ‘L-u’. One example of the two root indices are ‘ 1’ and ‘L-l’.

[0095] One method to send the two ZC sequences is to use PSS structure #C, where the each ZC sequence is split into two segment blocks, each segment block transform precoded using DFT, mapped to frequency resources, transformed into time domain using iFFT, and CP added. CP added time domain signal of a segment block corresponds to 1 symbol of the PSS. Illustration of segmented and DFT precoded ZC sequence based PSS (described in this paragraph) are shown in FIG. 5 and FIG. 6. FIG. 5 show's PSS that consist of two ZC sequences with root ‘u’ and ‘L-u’ that are segmented into two segments per sequence, each segment DFT precoded in frequency domain, and mapped into each PSS symbol starting with first segment of the first sequence, followed by second segment of the first, sequence, first segment of the second sequence, and second segment of the second sequence. FIG. 6 show's PSS that consist of two ZC sequences with root ‘u’ and ‘L-u’ that are segmented into two segments per sequence, each segment DFT precoded in frequency domain, and mapped into each PSS symbol starting with first segment of the first sequence, followed by first segment of the second sequence, second segment of the first sequence, and second segment of the second sequence. With ZC sequence, DFT precoding can be skipped by directly being mapped in frequency domain due to duality property of ZC sequence, but the same benefits can be obtained. [0096] Second method to send the two ZC sequences is to use PSS structure #B, where the each ZC sequence is transform precoded using DFT, mapped to frequency resources, transformed into time domain using iFFT, and CP added with a long CP. The CP added time domain signal of a ZC sequence will span 2 symbols worth of duration. This can be achieved by using half of the subcarrier spacing compared to subcarrier spacing used for SSS and PBCH. Illustration of DFT precoded ZC sequence based PSS (described in this paragraph) are shown in FIG. 7. FIG. 7 shows PSS that consist of two ZC sequences with root ⁴u’ and ‘L-u’ that are DFT precoded in frequency domain, and mapped into each PSS symbol with half of the subcarrier spacing compared to rest of the SSB using a long CP equal to the 2 regular CP lengths. With ZC sequence, DFT precoding can be skipped by directly being mapped in frequency domain due to duality property of ZC sequence, but the same benefits can be obtained.

[0097] The same mapping can be done by using PSS structure #A in both time and frequency domain.

[0098] PSS generation approach 1 described above are for single antenna port transmission of PSS. In case of two antenna port transmission of PSS, the first antenna port can use the PSS generation approach 1, and the second antenna port can perform a PSS generation approach 1 with each PSS symbol cyclic shifted prior to CP addition. FIG. 8 shows an example of two antenna port transmission of the PSS. The time domain cyclic shift of the PSS symbol on the second antenna port can be equivalently implemented by multiplying a linear phase ramp sequence in the frequency domain prior to iFFT and CP addition. The linear phase ramp sequence multiplication can be expressed mathematically as

[0099]

[00100] Where s(f) is the sequence in frequency domain, # is the unit phase corresponding to the time domain cyclic shift value, f is the frequency subcarrier index.

[00101] PSS generation approach 2 [00102] PSS generation approach 2 uses Golay sequence (also known as complementary sequence) modulated with π /2-BPSK modulation. π /2-BPSK modulation maps odd indexed binary' values of the sequence to real values {+1, - 1 } and even indexed binary' values of the sequence to imaginary' value {+j, -j} (or, opposite case also holds - real values {+1,-1 } for even index and imaginary value {+j,-j} for odd index).

[00103] One method to map the Golay sequence to PSS symbol is to first modulate the binary Golay sequence using n/2-BPSK modulation and segmenting the modulated sequence into 4 segments. Each segment is DFT transform precoded and mapped into frequency subcarriers, transformed into time domain using iFFT, and CP added into PSS symbols based on PSS structure #C. Illustration of the first method for PSS generation approach 2 is shown in FIG. 9.

[00104] Second method to map the Golay sequence to PSS symbol is to first modulate the binary' Golay sequence using u/2-BPSK modulation or BPSK modulation and segmenting the modulated sequence into 4 segments. Each segment is mapped (directly) into frequency subcarriers, transformed into time domain using iFFT, and CP added into PSS symbols based on PSS structure #C. Illustration of the second method for PSS generation approach 2 is shown in FIG. 10.

[00105] Third method to map the Golay sequence to PSS symbol is to first modulate the binary Golay sequence using π/2-BPSK modulation and DFT transform precoded and mapped into frequency subcarriers, transformed into time domain using iFFT, and CP added into PSS symbols based on PSS structure #A. The subcarrier spacing used will be ¼ of the subcarrier spacing used by SSS and PBCH, which creates 4 times longer symbol duration compared to SSS and PBCH. Illustration of the third method for PSS generation approach 2 is shown in FIG. 11.

[00106] Fourth method to map the Golay sequence to PSS symbol is to first modulate the binary Golay sequence using π/2-BPSK or BPSK modulation and map (directly) into frequency subcarriers, transformed into time domain using iFFT, and CP added into PSS symbols based on PSS structure #A. The subcarrier spacing used will be ¼ of the subcarrier spacing used by SSS and PBCH, which creates 4 times longer symbol duration compared to SSS and PBCH. Illustration of the third method for PSS generation approach 2 is shown in FIG. 12. Another example by using complementary Golay pair in time domain is shown in FIG. 13

[00107] Transmit diversity transmission for PSS

[00108] PSS generation approach 2 described above are for single antenna port transmission of PSS. In case of two antenna port transmission of PSS, the first antenna port can use the PSS generation approach 2 with a Golay sequence (first sequence of the complementary pair sequences), and the second antenna port can perform a PSS generation approach 2 with a complementary Golay sequence (second sequence of the complementary pair sequences; other non- complementary orthogonal Golay sequence is also possible to be mapped). Illustration of the two antenna port transmission based on PSS generation approach 2 is shown in FIG. 14 and FIG. 15. The time domain mapping of complementary Golay as in FIG. 13 can also apply for FIG. 14 and FIG, 15 as second antenna by selecting another complementary Golay pair being orthogonal to the first antenna.

[00109] The autocorrelation profiles of two complementary Golay pair sequences as illustrated in FIG. 15 are shown in FIG. 16 A and FIG. 16B.

[00110] Alternative to using two Golay sequences, m-sequences may be used in the PSS generation method 2. For applying transmit diversity transmission, the two m-sequences could be used to generate the sequences for each antenna port. The two m-sequences could be generated with different primitive polynomials. An illustration of this is shown in FIGs. 17A and 17B. One example of the two primitive polynomials used for sequence are mirror symmetric primitive polynomials. For example, primitive polynomial gi(x) (as described below) is used to generate the first m-sequence, then g?.(x) (as described below) can be used to generate the second m-sequence for the second antenna port. [00111] [00112]

[00113] M-sequences generated with primitive polynomial f(x) (as described below) can be generated by the following equation for x[m], where ‘m’ is the sequence index starting from 0.

[00114]

[00115]

[00116] where polynomial coefficients, a_m, are binary values, [0 or 1 ], and sequence values x are the initialization values for the m-

sequence, and initialization values cannot be all zeros.

[00117] For the two polynomials, initialization value of

[00118] Another alternative to using two Golay sequences, m-sequence and complex conjugate in frequency domain version of the same m-sequence may be used in the PSS generation method 2. For applying transmit diversity transmission, the m-sequence could be used to generate the sequences for the first antenna port, and the same m-sequence would be DFT precoded into frequency domain values, where complex conjugate of the frequency domain samples are performed, then mapped back to time domain with iFFT operation.. An illustration of this is shown in FIG 18 One example of the primitive polynomials used, for sequence is primitive polynomial gi(x) (as described below) is used to generate the first m-sequence, then same sequence modulated with pi/2-BPSK modulation would be mapped to frequency domain and complex conjugate of the frequency domain sequence is performed and finally converted back to time domain with iFFT operation.

[00119]

[00120] The main benefit of using frequency domain conjugate based transmit diversity scheme is that pi/2-BPSK modulation characteristics are not lost from the frequency domain conjugate operation. If complex conjugate of a time domain sequence is performed in frequency domain, this is equivalent of taking the time flipped complex conjugate operation of the sequence in time domain. Because time flipped (meaning instead of indices incrementing from 0, 1, .... 255, the indices increment from 0, 255, 254, 253 3,2,1) pi/2-BPSK modulated sequence are still pi/2-BPSK modulated (i.e. even indices mapped to real (+1, -1} values and odd indices mapped to imaginary {4j -j] values. Furthermore complex conjugate of pi/2-BPSK modulated sequence is still pi/2- BPSK modulated. Therefore, frequency domain complex conjugate operation of the sequence still preserved the low PAPR properties and pi/2-BPSK modulated signal structure. Additional benefit of using original m-sequence and frequency domain complex conjugate of the same m-sequence is that cross correlation detection of the sequence allows efficient multiplication to be implemented such that detection of both sequences can be done using a same number of multiplication as when detecting for just one of the sequences. Basically, the detection of the second sequence is achieved with very low additional complexity.

[00121] For example, sequence generation fin* using frequency domain conjugate version of the same pi/2-BPSK modulated m-sequence for transmit diversity can be expressed as:

[00122]

[00123]

[00124]

[00125]

[00126]

[00127]

[00128] Where are frequency domain modulated symbols for

PSS prior to IFFT and CP insertion for antenna port 0 and 1, respectively.

[00129] SSS generation [00130] SSS in the proposed SSB is used as the demodulation reference signal for PBCH. In order to provide the best channel estimation performance as demodulation reference signal, it is important to achieve frequency flat response while providing low dynamic range (e.g. peak to average power ratio (PAPR)). We proposed to use complementary Golay sequence, where each Golay sequence of the pair of sequence is mapped to consecutive symbols using DFT- s-OFDM waveform. Each SSS symbol will have a flat frequency response.

However, if the two adjacent SSS symbols are processed together in the channel estimation, the complementary Golay sequence pair will get optimal channel estimation condition from effectively frequency-flat from two SSS symbols.

[00131] For example, length 256 Golay sequences may be indexed based on Hadamard expansion Golay sequence construction method, where initialization kernel matrix, Hi, is defined as below " and 128 pairs of

Golay sequence {ak, bk} are constructed based on recursive Hadamard expansion described below

[00133] and Golay sequences pair {(ao, bo)

are enumerated from index 1 to 256 and additional Golay sequence pairs generated with OCC such as,

are enumerated from index 257 to 512.

[00134] It is also possible to work with a smaller set of complementary’ Golay sequences (CGS) by pruning set of sequence from above 512 sequence set. For example, when working with only 64 sequences in total, we may be able to use the sequences with following indices

can be derived using the following equation:

[00135]

[00136] Use of smaller set of CGS is that cross correlation and time delayed cross correlation profile among CGS can be significantly improved.

[00137] SSS generation method 1

[00138] In these embodiments, complementary Golay pair in time domain offers frequency flat property across two symbols.

[00139] First generation method for SSS, is to use pair of sequences of complementary Golay sequence, modulate and cyclic shift the 1^st sequence of the pair of sequences and map to 1^st and 3^rd SSS symbol using DFT-s-OFDM waveform, and 2^nd sequence of the pair of sequences and map to 2^nd and 4^th SSS symbol using DFT-s-OFDM waveform. DFT-s-OFDM waveform is generated by taking the modulated sequence, performing transform DFT precoding, mapping to frequency subcarriers, transforming into time domain signal, and adding CP. Illustration of first generation method of SSS is shown in FIG, 19 [00140] For the first generation method, cell identification information that need to be conveyed by SSS can be represented by combination of complementary Golay sequence pair and cyclic shift values used to shift the 1 ^st and 2^nd Golay sequence.

[00141] SSS generation method 2

[00142] Second generation method for SSS, is to use pair of sequences of complementary' Golay sequence, modulate and cyclic shift the 1^st sequence of the pair of sequences and map to 1^st and 3^rd SSS symbol using OFDM waveform, and 2^nd sequence of the pair of sequences and map to 2^nd and 4^th SSS symbol using DFT-s-OFDM waveform. OFDM waveform is generated by taking the modulated sequence, mapping to frequency subcarriers, transforming into time domain signal, and adding CP. Illustration of second generation method of SSS is shown in FIG. 20.

[00143] For the second generation method, cell identification information that, need to be conveyed by SSS can be represented by combination of complementary' Golay sequence pair and cyclic shift values used to shift the 1^st and 2^nd Golay sequence.

[00144] SSS generation method 3

[00145] Third generation method for SSS, is to use a sequence of complementary' Golay sequence, modulate and cyclic shift the sequence and map to 1^st and 3^d SSS symbol using OFDM waveform, and cyclic shift, the same modulated Golay sequence and map to 2^nd and 4^ta SSS symbol using OFDM waveform. OFDM: waveform is generated by taking the modulated sequence, mapping to frequency subcarriers, transforming into time domain signal, and adding CP. Illustration of second generation method of SSS is shown in FIG. 21.

[00146] For the third generation method, cell identification information that, need to be conveyed by SSS can be represented by combination of complementary' Golay sequence and two cyclic shift values used to shift the Golay sequence.

[00147] SSS generation method 4

[00148] Fourth generation method for SSS, is to use a sequence of complementary' Golay sequence, modulate and cyclic shift the sequence and map to 1^st and 2^nd SSS symbol using OFDM waveform, and cyclic shift the same modulated Golay sequence and map to 3^rd and 4^th SSS symbol using OFDM waveform. OFDM: waveform is generated by taking the modulated sequence, mapping to frequency subcarriers, transforming into time domain signal, and adding CP. Illustration of second generation method of SSS is shown in FIG. 22. [00149] For the fourth generation method, ceil identification information that need to be conveyed by SSS can be represented by combination of complementary Golay sequence and two cyclic shift values used to shift the Golay sequence.

[00150] SSS generation method 5

[00151] Fifth generation method for SSS, is to use a sequence of complementary' Golay sequence, modulate and cyclic shift the sequence and segment the sequence into 2 segments, map the first segment to 1^st and 3 ^rd SSS symbol using OFDM waveform, and map the second segment to 2^nd and 4^th SSS symbol using OFDM waveform. OFDM waveform is generated by taking the modulated sequence, mapping to frequency subcarriers, transforming into time domain signal, and adding CP. Illustration of second generation method of SSS is shown in FIG. 23.

[00152]

[00153] For the fifth generation method, cell identification information that need to be conveyed by SSS can be represented by combination of complementary' Golay sequence and cyclic shift values used to shift the Golay sequence.

[00154] SSS generation method 6

[00155] Sixth generation method for SSS, is to use pair of sequences of complementary Golay sequence, modulate, multiply an element of orthogonal cover code (OCC) for each sequence, and cyclic shift the 1^st sequence of the pair of sequences and map to 1^st and 3^rd SSS symbol using DFT-s-OFDM waveform, and 2^nd sequence of the pair of sequences and map to 2^nd and 4* SSS symbol using DFT-s-OFDM waveform. DFT-s-OFDM waveform is generated by taking the modulated sequence, performing transform DFT precoding, mapping to frequency subcarriers, transforming into time domain signal, and adding CP. Illustration of sixth generation method of SSS is shown in FIG. 24.

[00156] For the sixth generation method, cell identification information that need to be conveyed by SSS can be represented by combination of complementary Golay sequence pair, OCC, and cyclic shift values used to shift the 1^st and 2^nd Golay sequence.

[00157] It should be noted that since the multiplication of the OCC is linear process, the multiplication of the element of OCC can happen in any process of the modulation and waveform generation process. For example, the multiplication of the element of OCC can happen after DFT transform precoding, or after iFFT and CP insertion process.

[00158] Some examples of OCC could be {+1, +1 }, [+1, -1 }, {+1, +j }, {+1, -j}. If the total number OCC required 2, we can use a subset (two OCC) of the OCC examples listed. If the total number of OCC required is 4, we can use (all four) of the OCC examples listed.

[00159] SSS generation method 7

[00160] Seventh generation method for SSS, is to use pair of sequences of complementary Golay sequence, modulate, and cyclic shift the 1 ^st sequence of the pair of sequences and map to 1^st and 3^rd SSS symbol using DFT-s-OFDM waveform, and 2^nd sequence of the pair of sequences and map to 2^nd and 4^th SSS symbol using DFT-s-OFDM waveform. DFT-s-OFDM waveform is generated by taking the modulated sequence, performing transform DFT precoding, mapping to frequency subcarriers, transforming into time domain signal, and adding CP. Each DFT-s-OFDM waveform modulated symbols are multiplied an element of orthogonal cover code (OCC). Illustration of seventh generation method of SSS is shown in FIG. 25.

[00161] For the seventh generation method, cell identification information that need to be conveyed by SSS can be represented by combination of complementary Golay sequence pair, OCC, and cyclic shift values used to shift the I^s1 and 2^nd Golay sequence.

[00162] Some examples of OCC could be

. For example, if the total number OCC required 2, we can

use a subset (two OCC) of the OCC examples listed.

[00163] Complementary Golay Sequence Construction

[00164] One example of complementary Golay sequence construction is to utilize Hadamard base Golay code construction. We can use modified version of Hadamard expansion to expand Golay sequence by 2 times and increasing the length by factor of 2.

[00165] Modified version of the Hadamard expansion is given as

[00166]

[00167] where is a permutation matrix, and is negate of the binary

elements of #«. (also referred to as element wise binary inverse). One example of the permutation matrix is

[00168]

[00169] where G-r is an identity matrix with dimension of ‘

[00170] Golay sequence can be generated with starting of small kernel base sequence of [0, 0] and [0, 1] for the first and second pair of the complementary Golay sequence. We can put the two kernel base sequence into a matrix form [a; b] and define it as From we can now create larger

matrices using modified version of Hadamard expansion.

[00171]

[00172]

[00173]

[00174] Row vectors of the expanded matrix ^4 will correspond to the complementary Golay sequences, where the first half of the row vectors corresponds to the first pairs of the complementary Golay sequence, at, and second half of the row vectors corresponds to the second pairs of the complementary' Golay sequence, bk, where k subscript corresponds to the Golay sequence pair index and sequence (ak, bk) are the k-th complementary Golay sequence pair. Table 1 and Table 2 list the 128 complementary Golay sequence pairs, ak and bk, generated using the method above, where ak corresponds to the 1^st sequence of the complementary' Golay sequence pair, and bk corresponds to the 2^nd sequence of the complementary/ Golay sequence pair.

[00175] It is also possible to extend the total number of Golay sequences, by swapping the 1^st and 2^EiCi Golay sequence pair as a new Golay sequence pair. For example, use (bk, ak) as the Golay sequence pair.

[00176] If above sequence construction method is used, N/2 number of Golay sequences can be generated for the length N first and second sequences of the pair of Golay sequence pair each. This results in N/2 number of Golay sequence pairs with {ak, bk} and N/2 number of Golay sequence pairs with {bk, a_k}. [00177] Table 1

[00178] Table 2

[00179] Alternatively, complementary Golay sequence pair can be paired up between two consecutive rows of the generated matrix. For example, the complementary Golay sequence pairs can be defined as the following: [00180]

[00181] where (ak, bk) are the complementary' Golay sequence pair.

[00182] This results in using the sequence pair (azk, azk-t-i) or (b?k, bzk+i) for k = 0,1,.. .,63, as complementary Golay sequence pair. Transmit diversity transmission for SSS

[00183] SSS generation described above are for single antenna port transmission of SSS. In case of two antenna port transmission of SSS, Alamouti coding in time domain can be applied, resulting in space time block code (STBC). STBC is constructed by taking two modulated symbols from adjacent SSS symbols, sO and si, and sending the two modulated symbols in the second antenna negative of conjugate of si and conjugate of st) in the two adjacent SSS symbols. Illustration of STBC construction of two adjacent SSS symbols is shown in FIG, 26. [00184] FIG, 27 illustrates how to detect SSS sequence with space time block code and how to estimate channel.

[00185] Alternatively, cyclic delay diversity (CDD) transmission can be applied to SSS. CDD transmission for two antenna port is performed by taking each SSS symbol and mapping the SSS symbol to the first antenna port, and mapping a time domain cyclic shifted SSS symbols (prior to CP addition) to the second antenna port. Illustration of CDD construction for each SSS symbol is shown in FIG. 28.

SSS generation method 8

[00186] Eighth generation method for SSS is to use pair of sequences of complementary' Golay sequence, where each each Golay sequence is modulated, optionally cyclic shifted, and the 1 ^st sequence of the pair of first sequences and map to 1^st SSS symbol using DFT-s-OFDM waveform and 2^nd sequence of the first pair of sequences and map to 2^nd SSS symbol using DFT-s-OFDM waveform. A second pair of sequence of complementary Golay sequence is modulated, , optionally cyclic shifted, and the 1^st sequence of the second pair of sequences and map to 3^rd SSS symbol using DFT-s-OFDM waveform and 2^nd sequence of the second pair of sequences and map to 4th SSS symbol using DFT-s-OFDM waveform,

[00187] DFT-s-OFDM waveform is generated by taking the modulated sequence, performing transform DFT precoding, mapping to frequency subcarriers, transforming into time domain signal, and adding CP. Each DFT-s- OFDM waveform modulated symbols are multiplied an element of orthogonal cover code (OCC). Illustration of seventh generation method of SSS is shown in FIG. 29.

[00188] The and first and second set of complementary Golay sequence (CGS) is determined by the cell identification information, where there may be deterministic relationship between the sequence index for the first set of CGS pair and the sequence index for the second set of CGS pair. [00189] For the eighth generation method, cell identification information that need to be conveyed by SSS can be represented by combination of complementary Golay sequence pair, OCC, and cyclic shift values used to shift the 1^st and 2^nd Golay sequence.

[00190] Some examples of OCC could

{+1, -j}. The OCC can be applied for each set of CGS pairs.

[00191] For example, length 256 Golay sequences may be indexed based on Hadamard expansion Golay sequence construction method, where initialization kernel matrix, Hi, is defined as below

and 128 pairs of

Golay sequence {ak, bk} are constructed based on recursive Hadamard expansion described below

[00192]

[00193] and Golay sequences pair .

are enumerated from index 1 to 256 and additional Golay sequence pairs generated with OCC such as,

are enumerated from index 257 to 512.

[00194] With this Golay sequence enumeration method, the if the sequence index of the first set of CGS pairs and sequence index of the second set of CGS pairs is identical, then the SSS generation method become identical to SSS generation method 7.

[00195] With this Golay sequence enumeration method, the first set of 1^st and 2^tia sequence of the complementary Golay pair and second set of 1^st and 2^nd sequence of the complementary Golay pair can derived by the one of the following equations'. [00196]

[00197]

[00198]

[00199] where N is the total number of sequences, k is the sequence index of the first set of sequences (mapped to 1^st and 2^nd DFT-s-OFDM symbols) and & is the sequence index of the second set of sequence (mapped to 3^ra and 4^th DFT- s-OFDM symbols).

[00200] The main benefit of using different sequence index for the first and second pair of CGS is that cross-correlation profile of a specific CGS pair can be diversified and potential cross correlation peaks can be minimized.

[00201] In order to observe the benefit of SSS generation method 8 compared to SSS generation method 7, we show⁷ cross-correlation sidelobes, where x-axis of the plot represent timing errors in number of samples when cross-correlation is performed for a given SSB transmission, y-axis of the plot represent the index of the cell ID pairs, and z-axis of the plot represent normalized cross-correlation metric. Here index of the cell ID pair (n, m) represent cross correlation between SSS sequence using sequence index n, and sequence index m for SSS generation method 7, and index of the cel l ID pair (n,m) represent cross correlation between SSS sequence using sequence index n, and sequence m for the first set of the CGS pair and sequence index « and sequence index ^m for the second set of the CGS pair. In these embodiments, the cross-correlation profile reduces significantly when sequence randomization as described in SSS generation method 8 is used. The lower cross-correlation directly improve miss-detection and false-positive detection of the cell ID at the receiver when processing SSB transmissions.

[00202] Alternative to using a formula to define a mapping between the first sequence index and second sequence index that will be use to determine the first and second set of CGS pair, respectively, we can simply define a mapping relation table, where the mapping relation table may be based on some pseudo random number permutation. [00203] SSS generation method 6 (or?) with CDD

[00204] In case only few set of SSS sequence set is needed to represent cell-ID (or part of the cell-ID that is represented by SSS), better cross correlation properties can be achieved.

[00205] Using SSS generation method 6 (or 7) and using cyclic delaydiversity (CDD) for transmit diversity transmission for SSS, we propose the following set of sequence pairs and cyclic delay values for CDD transmission. [00206] Select k^th sequence pairs from 512 sequence pairs pool, where first 256 pair of sequences pool is given by {ao,bo}, {bo, ao}, {ai, bi }, {bi, ai},

and latter 256 pair of sequences pool

bi27},{bi27,-ai27}. The 1^st sequence pair from the sequence pair pool correspond to {ao,bo}, and 2^ad sequence pair from the sequence pair pool correspond to {bo,ao}, and so forth.

[00207] For example, if k= { 1, 2, 3, 4, 33, 34, 35, 36, 65, 66, 67, 68, 97, 98, 99, 100, 129, 130, 131, 132, 161, 162, 163, 164, 193, 194, 195, 196, 225, 226, 227, 228}, then this results in the following selected sequence pairs for SSS:

[00208]

[00209]

[00210]

[00211]

[00212]

[00213]

[00214]

[00215]

[00216] generated using complementary Golay sequence construction described in this document.

[00217] With the selected set of complementary Golay sequence pairs, cyclic delay diversity (CDD) transmission using M cyclic shift for the 2^nd antenna port results in extremely low cross correlation results with small time lags. An illustration of utilizing SSS generation method 1 with CDD transmit diversity transmission is shown in FIGs. 30A and 30B.

[00218] Some examples of selected sequence pairs and CDD cyclic shift value that results in low cross correlation are:

[00219] Candidate 1) k^dl sequence pairs, where k { 1 10 17 26 33 42 49 58 65 74 81 90 97 106 113 122 129 138 145 154 161 170 177 186 193 202 209 218 225 234 241 250}, and M - 64 cyclic shift for CDD. The cross correlation between different antenna port, denoted as APO and API, with different time lags. 1 sample timing error corresponds to 1 pi/2-BPSK modulated symbol delay, of the length 256 Golay sequence.

[00220] Candidate 2) k^th sequence pairs, where k= { 1 10 33 42 65 74 97 106 129 138 161 170 193 202 225 234 257 266 289 298 321 330 353 362 385 394 417 426 449 458 481 490}, and VI 64 cyclic shift for CDD. The cross correlation between different antenna port, denoted as APO and API, with different time lags. 1 sample timing error corresponds to 1 pi/2-BPSK modulated symbol delay, of the length 256 Golay sequence.

[00221] Examples

[00222] Additional examples of the presently described embodiments include the following, non-limiting implementations. Each of the following nonlimiting examples may stand on its own or may be combined in any permutation or combination with any one or more of the other examples provided below or throughout the present disclosure.

[00223] Example 1 includes a method for a transmission of primary' synchronization signal that consist of two Zadoff Chu (ZC) sequences of length L with root index V and

wherein ZC sequence with root index ‘u’ and ZC sequence with root index ‘L - u’ are transmitted in consecutive DFT-s- OFDM symbols, wherein DFT-s-OFDM symbols are generated by discrete Fourier transform (DFT) precoding of the input sequence, mapping the precoded sequence into frequency subcarriers, transforming the frequency subcarrier into time domain samples using inverse DFT (IDFT), and adding cyclic prefix to the beginning of the generated time domain samples.

[00224] Example 2 includes the method of example 1 and/or some other example(s) herein, subcarrier spacing used for DFT-s-OFDM symbol generation of PSS is half of subcarrier spacing of DFT-s-OFDM symbol generation of secondary' synchronization signal.

[00225] Example 3 includes the method of example 1 and/or some other example(s) herein, two ZC sequences is segmented into two blocks each, wherein each segmented block is modulated into DFT-s-OFDM symbols, resulting in 4 DFT-s-OFDM symbols for PSS.

[00226] Example 4 includes the method of example 1 and/or some other example(s) herein, time domain cyclic shifted version of the DFT-s-OFDM symbols for PSS is transmitted in second antenna port when two antenna port are utilized for PSS.

[00227] Example 5 may include a method for a transmission of primary⁷ synchronization signal that consist of complementary Golay binary sequences of length L is modulated with BPSK or pi/2-BPSK modulation and transmitted in consecutive DFT-s-OFDM or OFDM symbols, wherein DFT-s-OFDM symbols are generated by discrete Fourier transform (DFT) precoding of the input sequence, mapping the precoded sequence into frequency subcarriers, transforming the frequency subcarrier into time domain samples using inverse DFT (IDFT), and adding cyclic prefix to the beginning of the generated time domain samples, wherein OFDM symbol s are generated by mapping the modulated sequence into frequency subcarriers, transforming the frequency subcarrier into time domain samples using inverse DFT (IDFT), and adding cyclic prefix to the beginning of the generated time domain samples.

[00228] Example 6 includes the method of example 5 and/or some other example(s) herein, wherein subcarrier spacing used for DFT-s-OFDM symbol generation of PSS is quarter of subcarrier spacing of DFT-s-OFDM symbol generation of secondary' synchronization signal.

[00229] Example 7 includes the method of example 5 and/or some other example(s) herein, wherein Golay is segmented into four blocks, wherein each segmented block is modulated into DFT-s-OFDM or OFDM symbols, resulting in 4 DFT-s-OFDM or OFDM symbols for PSS.

[00230] Example 8 includes the method of example 5 and/or some other example(s) herein, wherein time domain cyclic shifted version of the DFT-s- OFDM symbols for PSS is transmitted in second antenna port when two antenna port are utilized for PSS.

[00231] Example 9 includes the method of example 5 and/or some other example(s) herein, wherein complementary Golay pair sequence is used for PSS when two antenna ports is utilized, wherein one of the complementary' Golay pair sequence is transmitted in first antenna port, and other complementary/ Golay pair sequence is transmitted in the second antenna port

[00232] Example 10 may include a method for a transmission of secondary⁷ synchronization signal that consist of pair of complementary Golay pair binary sequences of length L is modulated with BPSK or pi/2-BPSK modulation, and transmitted in two consecutive DFT-s-OFDM or OFDM symbols, wherein DFT-s-OFDM symbols are generated by discrete Fourier transform (DFT) precoding of the input sequence, mapping the precoded sequence into frequency subcarriers, transforming the frequency subcarrier into time domain samples using inverse DFT (IDFT), and adding cyclic prefix to the beginning of the generated time domain samples, wherein OFDM symbols are generated by mapping the modulated sequence into frequency subcarriers, transforming the frequency subcarrier into time domain samples using inverse DFT (IDFT), and adding cyclic prefix to the beginning of the generated time domain samples, wherein first complementary/ Golay pair binary⁷ sequence of the two pair of sequences is used for the first DFT-s-OFDM or OFDM symbol, and second complementary/ Golay pair binary sequence of the two pair of sequences is used for the second DFT-s-OFDM or OFDM symbol.

[00233] Example 1 1 includes the method of example 10 and/or some other example(s) herein, time domain cyclic shifted (prior to CP addition) version of the each DFT-s-OFDM or OFDM symbol for SSS is transmitted in second antenna port when two antenna port are utilized for SSS. [00234] Example 12 includes the method of example 10 and/or some other example(s) herein, wherein space time block code (STBC) is applied to two consecutive DFT-s-OFDM or OFDM symbol for SSS when two antenna port are utilized for SSS, wherein STBC is constructed by taking two modulated symbols from adjacent SSS symbols, sO and si, and sending the two modulated symbols in the second antenna with negative of conjugate of s i and conjugate of sO in each SSS symbol.

[00235] Example 13 may include the method of example 10 or some other example herein, wherein a sequence of complementary’ Golay sequence pair is cyclically shifted prior to modulation.

[00236] Example 14 may include the method of example 10 or some other example herein, wherein a sequence of complementary Golay sequence pair is multiplied with an element of orthogonal cover code after modulation.

[00237] Example 15 may include the method of claim 10, wherein a sequence of complementary Golay sequence pair is cyclically shifted after iFFT processing and prior to CP insertion.

[00238] The Abstract is provided to comply with 37 C.F.R. Section

1 .72(b) requiring an abstract that will allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the cl aims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.

Claims

CLAIMS What is claimed is:

1. An apparatus of a base station configured for operation in a sixth generation (6G) network, the apparatus comprising: processing circuitry; and memory/, wherein the processing circuitry is configured to: generate a primary synchronization signal (PSS) for transmission, the PSS comprising a first and a second sequence; and configure the base station to transmit the first and second sequences in consecutive discrete Fourier transform (DFT) spread orthogonal frequency division multiplexed (s-OFDM) (DFT-s-OFDM) symbols, wherein the memory is configured to store the first and second sequences.

2. The apparatus of claim 1, wherein the first and second sequences comprise at least one of: a first Zadoff Chu (ZC) sequence having a length with a first root index and a second ZC sequence of the length with a second root index, the first root index having a value between one and one less than the length, the second root index equaling the first root index subtracted from the length; and a complementary pair of Golay binary sequences with Binary Phase-shift keying (BPSK) or pi/2-BPSK modulation.

3. The apparatus of claim 2, wherein the processing circuitry is configured to generate the DFT-s-OFDM symbols by performing DFT precoding of an input sequence to generate a precoded input sequence, mapping the precoded input sequence onto frequency subcarriers, transforming the frequency subcarriers into time domain samples using an inverse DFT (IDFT), and adding a cyclic prefix to a beginning of each group of the domain samples.

4. The apparatus of claim 3, wherein the PSS comprises four consecutive DFT-s-OFDM symbols, wherein a first of the symbols is generated from a first segment of a first input sequence, a second of the symbols is generated from a second segment of the first input sequence, a third of the of the symbols is generated from a first, segment of a second input sequence, and a fourth of the symbols is generated from a second segment of the second input sequence.

5. The apparatus of claim 4, wherein the processing circuitry is configured to: segment the first sequence into a first two blocks and segment the second sequences into a second two blocks; and modulate each block into one of the consecutive DFT-s-OFDM symbols to generate the four consecutive DFT-s-OFDM symbols comprising the PSS.

6. The apparatus of claim 5, wherein when the base station is configured for transmission of the PSS using a single antenna port, the processing circuitry configure the base station to transmit the first and second sequences in the consecutive DFT-s-OFDM symbols using a first antenna port, and wherein when the base station is configured for transmission of the PSS using two antenna ports, the processing circuitry is configured to generate a time domain cyclic shifted version of the DFT-s-OFDM symbols for transmission by a second of the antenna ports.

7. The apparatus of claim 6, wherein when the base station is configured for transmission of the PSS using the two antenna ports and when the first and second sequences comprise the complementary pair of Golay binary sequences, the processing circuitry’ configures the base station to: transmit a first of the Golay binary' sequences of the complementary pair using the first antenna port; and transmit a second of the Golay binary sequences of the complementary pair using the second antenna port.

8. The apparatus of claim 5, wherein the processing circuitry is configured to cause the base station to transmit a synchronization signal block (SSB) comprising the PSS, a secondary synchronization signal (SSS) and a physical broadcast channel (PBCH), wherein when the first and second sequences comprise the ZC sequences, a subcarrier spacing used for generation of the DFT-s-OFDM symbols of the PSS is half of a subcarrier spacing used for generation of DFT-s-OFDM symbols of the SSS, and wherein when the first and second sequences comprise the complementary pair of Golay binary sequences, the subcarrier spacing used for generation of the DFT-s-OFDM symbols of the PSS is a quarter of the subcarrier spacing used for generation of DFT-s-OFDM symbols of the SSS.

9. The apparatus of claim 5, wherein when the first and second sequences comprise the complementary pair of Golay binary sequences, the processing circuitry is configured to cyclically shift, the complementary pair of Golay binary sequences after inverse fast Fourier Transform (iFFT) processing and prior to cyclic prefix (CP) insertion.

10. The apparatus of any of claims 1 - 9, wherein the base station is configured to operate as a generation Node B (gNB) and wherein the processing circuitry comprises a baseband processor.

11. A non-transi tory computer-readable storage medium that stores instructions for execution by processing circuitry of a base station configured for operation in a. sixth generation (6G) network, wherein the processing circuitry' is configured to: generate a primary synchronization signal (PSS) for transmission, the PSS comprising a first and a second sequence; and configure the base station to transmit the first and second sequences in consecutive discrete Fourier transform (DFT) spread orthogonal frequency division multiplexed (s-OFDM) (DFT-s-OFDM) symbols.

12. The non-transitory computer-readable storage medium of claim 11, wherein the first and second sequences comprise at least one of: a first Zadoff Chu (ZC) sequence having a length with a first root index and a second ZC sequence of the lengthwith a second root index, the first root indexhaving a value between one and one less than the length, the second root index equaling the first root index subtracted from the length; and a complementary pair of Golay binary sequences with Binary Phase-shift keying (BPSK) or pi/2-BPSK modulation.

13. The non-transitory computer-readable storage medium of claim 12, wherein the processing circuitry is configured to generate the DFT-s-OFDM symbols by performing DFT precoding of an input sequence to generate a precoded input sequence, mapping the precoded input sequence onto frequency subcarriers, transforming the frequency subcarriers into time domain samples using an inverse DFT (IDFT), and adding a cyclic prefix to a beginning of each group of the domain samples.

14. The non-transitory computer-readable storage medium of claim 13, wherein the PSS comprises four consecutive DFT-s-OFDM symbols, wherein a first of the symbols is generated from a first segment of a first input sequence, a second of the symbols is generated from a second segment of the first input sequence, a third of the of the symbols is generated from a first segment of a second input sequence, and a fourth of the symbols is generated from a second segment of the second input sequence.

15. The non-transitory computer-readable storage medium of claim 14, wherein the processing circuitry/ is configured to: segment the first sequence into a first two blocks and segment the second sequences into a second two blocks, and modulate each block into one of the consecutive DFT-s-OFDM symbols to generate the four consecutive DFT-s-OFDM symbols comprising the PSS.

16. The non-transitory computer-readable storage medium of claim 15, when the base station is configured for transmission of the PSS using a single antenna port, the processing circuitry' is to configure the base station to transmit the first and second sequences in the consecutive DFT-s-OFDM symbols using a first antenna port, and wherein when the base station is configured for transmission of the PSS using two antenna ports, the processing circuitry is configured to generate a time domain cyclic shifted version of the DFT-s-OFDM symbols for transmission by a second of the antenna ports.

17. The non-transitory/ computer-readable storage medium of claim 15, wherein the processing circuitry is configured to cause the base station to transmit a synchronization signal block (SSB) comprising the PSS, a secondary synchronization signal (SSS) and a physical broadcast channel (PBCH), wherein when the first and second sequences comprise the ZC sequences, a subcarrier spacing used for generation of the DFT-s-OFDM symbols of the PSS is half of a subcarrier spacing used for generation of DFT-s-OFDM symbols of the SSS, and wherein when the first and second sequences comprise the complementary/ pair of Golay binary sequences, the subcarrier spacing used for generation of the DFT-s-OFDM symbols of the PSS is a quarter of the subcarrier spacing used for generation of DFT-s-OFDM symbols of the SSS.

18. An apparatus for a user equipment (UE) configured for operation in a sixth -gen eration (6G) network, the apparatus comprising: processing circuitry/; and memory, wherein to configure the UE to perform a synchronization process, the processing circuitry configures the UE to: detect a primary' synchronization signal (PSS) transmitted by a base station, the PSS comprising a first and a second sequence, wherein the first, and second sequences are received in consecutive discrete Fourier transform (DFT) spread orthogonal frequency division multiplexed (s-OFDM) (DFT-s-OFDM) symbols, after detection of the PSS, detect a secondary' sy nchronization signal (SSS) transmitted by the base station.

19. The apparatus of claim 18, wherein the first and second sequences comprise at least one of: a first Zadoff Chu (ZC) sequence having a length with a first root index and a second ZC sequence of the length with a second root index, the first root index having a value between one and one less than the length, the second root index equaling the first root index subtracted from the length; and a complementary' pair of Golay binary sequences with Binary Phase-shift keying (BPSK) or pi/2-BPSK modulation.

20. The apparatus of claim 19, wherein when the first and second sequences comprise the ZC sequences, a subcarrier spacing for DFT-s-OFDM symbols of the PSS is half of a subcarrier spacing for DFT-s-OFDM symbols of the SSS, and wherein when the first and second sequences comprise the complementary pair of Golay binary' sequences, the subcarrier spacing for DFT- s-OFDM symbols of the PSS is a quarter of the subcarrier spacing for DFT-s- OFDM symbols of the SSS.