Listen-before-talk method and apparatus for new radio spectrum sharing discovery signals

Abstract

A wireless communication system and method are provided that involves performing listen-before-talk (LBT) in the case of discovery signal transmission for spectrum sharing. A wireless communication device senses a channel in a spatial domain based on a plurality of expected beam transmission directions, wherein the wireless communication device is associated with a first network operation entity, and wherein the channel is shared by a plurality of network operation entities including the first network operation entity. The wireless communication device transmits a plurality of discovery signals in one or more of the plurality of expected beam transmission directions during a discovery period based on the sensing to facilitate synchronization in the channel.

Description

[0001] This application is a divisional application of an invention patent application with an application date of August 7, 2018, application number 201880052670.4, and name “Listen-before-talk method and device for new radio spectrum sharing discovery signals”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to and the benefit of U.S. Non-Provisional Patent Application No. 16 / 056,128, filed on August 6, 2018, and U.S. Provisional Patent Application No. 62 / 546,426, filed on August 16, 2017, both of which are incorporated herein by reference in their entirety as fully set forth below and for all applicable purposes. Technical Field

[0004] The present application relates to wireless communication systems and methods, and more particularly, to performing listen-before-talk (LBT) prior to discovery signal transmission in a spectrum shared by multiple network operation entities. Background Art

[0005] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, etc. These systems are capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). A wireless multiple-access communication system may include multiple base stations (BSs), each of which simultaneously supports communication for multiple communication devices, which may also be referred to as user equipment (UE).

[0006] In order to meet the growing demand for extended mobile broadband connections, wireless communication technology is evolving from LTE technology to next generation New Radio (NR) technology. NR can provide dynamic medium sharing between network operators in licensed spectrum, shared spectrum and / or unlicensed spectrum. For example, shared spectrum and / or unlicensed spectrum can include frequency bands at about 3.5 gigahertz (GHz), about 6 GHz and about 60 GHz.

[0007] In a radio access network such as an NR network, a base station may send a synchronization signal to allow a UE to search for a cell within the radio access network and acquire synchronization therewith. In some cases, the base station may repeatedly send the synchronization signal at a predetermined period. When the network operates at a high frequency, for example, at about 6 GHz or above 6 GHz, the path loss may be high. In order to overcome the high path loss, the base station may perform beamforming (which may include analog and / or digital beamforming) to create a narrow beam for the UE in the network. For example, the base station may use a narrow transmission beam to send a synchronization signal in different beam directions. When the network operates in a shared medium or shared channel, the synchronization signal transmission may conflict with the transmission from other nodes sharing the channel. One way to avoid conflicts is to perform listen before talk (LBT) to ensure that the shared channel is idle before sending the synchronization signal. Since the base station can sweep across multiple narrow beams for synchronization signal transmission, an LBT process that considers beam scanning is desirable. Summary of the invention

[0008] In order to have a basic understanding of the technology discussed, some aspects of the present disclosure are summarized below. This summary is not an exhaustive overview of all expected features of the present disclosure, nor is it intended to identify key or important elements of all aspects of the present disclosure, or to describe the scope of any or all aspects of the present disclosure. Its sole purpose is to present some concepts of one or more aspects of the present disclosure in a summarized form as a prelude to the detailed description that follows.

[0009] For example, in one aspect of the present disclosure, a method of wireless communication includes: sensing a channel in a spatial domain by a wireless communication device based on a plurality of expected beam transmission directions, wherein the wireless communication device is associated with a first network operating entity, and wherein the channel is shared by a plurality of network operating entities including the first network operating entity; and sending a plurality of discovery signals by the wireless communication device in one or more of the plurality of expected beam transmission directions during a discovery period based on the sensing to facilitate synchronization in the channel.

[0010] In an additional aspect of the present disclosure, an apparatus includes: a unit for sensing a channel in a spatial domain based on a plurality of expected beam transmission directions, wherein the apparatus is associated with a first network operating entity and wherein the channel is shared by a plurality of network operating entities including the first network operating entity; and a unit for sending a plurality of discovery signals in one or more of the plurality of expected beam transmission directions during a discovery period based on the sensing to facilitate synchronization in the channel.

[0011] In an additional aspect of the present disclosure, a computer-readable medium having program code recorded thereon, the program code comprising: code for causing a wireless communication device to sense a channel in a spatial domain based on multiple expected beam transmission directions, wherein the wireless communication device is associated with a first network operating entity and wherein the channel is shared by multiple network operating entities including the first network operating entity; and code for causing the wireless communication device to send multiple discovery signals in one or more of the multiple expected beam transmission directions during a discovery period based on the sensing to facilitate synchronization in the channel.

[0012] After understanding the description of the specific, exemplary embodiments of the present disclosure below in conjunction with the accompanying drawings, other aspects, features and embodiments of the present disclosure will become apparent to those of ordinary skill in the art. Although the features of the present disclosure are discussed with respect to certain embodiments and accompanying drawings below, all embodiments of the present disclosure may include one or more of the advantageous features discussed herein. In other words, although one or more embodiments are discussed as having certain advantageous features, one or more of these features may also be used according to the various embodiments of the present disclosure discussed herein. In a similar manner, although the exemplary embodiments are discussed below as device, system or method embodiments, it should be understood that these exemplary embodiments may be implemented with a variety of devices, systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A wireless communication network according to an embodiment of the present disclosure is shown.

[0014] Figure 2 A discovery signal transmission scheme according to an embodiment of the present disclosure is shown.

[0015] Figure 3 A discovery signal transmission scheme according to an embodiment of the present disclosure is shown.

[0016] Figure 4 is a block diagram of an exemplary user equipment (UE) according to an embodiment of the present disclosure.

[0017] Figure 5 is a block diagram of an exemplary base station (BS) according to an embodiment of the present disclosure.

[0018] Figure 6 A discovery signal transmission scheme using omnidirectional listen-before-talk (LBT) according to an embodiment of the present disclosure is shown.

[0019] Figure 7 A discovery signal transmission scheme utilizing space-specific LBT according to an embodiment of the present disclosure is shown.

[0020] Figure 8 A discovery signal transmission scheme utilizing space-specific LBT according to an embodiment of the present disclosure is shown.

[0021] Fig. 9 A discovery signal transmission scheme utilizing space-specific LBT according to an embodiment of the present disclosure is shown.

[0022] Fig.10 A concurrent discovery signal and channel reservation signal transmission scheme according to an embodiment of the present disclosure is shown.

[0023] Fig.11 is a flowchart of a discovery signal communication method according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0024] The specific embodiments described below in conjunction with the accompanying drawings are intended only to describe various configurations and are not intended to represent the only configurations in which the concepts described herein can be implemented. In order to have a thorough understanding of the various concepts, the specific embodiments include some specific details. However, it will be apparent to those of ordinary skill in the art that these concepts can be implemented without using these specific details. In some instances, in order to avoid obscuring these concepts, known structures and components are shown in block diagram form.

[0025] The technology described herein can be used in various wireless communication networks, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier FDMA (SC-FDMA) and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network can implement wireless technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network can implement wireless technologies such as Global System for Mobile Communications (GSM). An OFDMA network can implement wireless technologies such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) and Advanced (LTE-A) are new releases of UMTS using E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The technology described herein can be used for the wireless networks and wireless technologies mentioned above as well as other wireless networks and wireless technologies, such as next generation (e.g., fifth generation (5G) operating in millimeter wave bands) networks.

[0026] In order to facilitate synchronization in the network, a base station (BS) may sweep multiple narrow beams pointing to different beam directions within a specified time period for sending a discovery signal. The specified time period may be referred to as a discovery reference signal (DRS) measurement timing configuration (DMTC) period. The DMTC period may be repeated at a predetermined period. The discovery signal may be referred to as a synchronization signal block (SSB). An SSB may include a combination of a synchronization signal, a broadcast system information signal, and / or a discovery reference signal. In some cases, each SSB in a DMTC period may be sent in different beam directions.

[0027] The present application describes a mechanism for performing LBT prior to discovery signal transmission in a spectrum shared by multiple network operating entities. For example, a BS may perform omnidirectional LBT and / or space-specific LBT to determine whether a channel is idle in a beam direction in which a discovery signal is expected to be sent in a subsequent time period. When omnidirectional LBT and / or space-specific LBT indicates that the channel is idle, the BS may proceed with discovery signal transmission. When omnidirectional LBT and / or space-specific LBT indicates that the channel is busy, the BS may avoid proceeding with discovery signal transmission.

[0028] In one embodiment, the BS may perform omnidirectional LBT before the DMTC period. For example, the BS may use an omnidirectional receive beam to monitor the channel for transmissions from another node. When the channel is idle, the BS may use an omnidirectional transmit beam to additionally transmit a channel reservation signal or a preamble signal to indicate reservation of the channel in a subsequent DMTC period.

[0029] In one embodiment, the BS may perform multiple spatially specific or directional LBTs prior to a DMTC period to sweep a set of narrow directional receive beams. For example, the BS may monitor the channel in beam directions covering a group of one or more expected beam transmission directions in each directional LBT in a subsequent DMTC period. When the directional LBT indicates that the channel is idle, the BS may additionally send a channel reservation signal in the monitored direction.

[0030] In one embodiment, the BS may perform multiple spatially specific LBTs within a DMTC period to sweep across a set of directional beams. For example, the BS may monitor the channel in beam directions covering a group of one or more expected beam transmission directions in subsequent sub-periods within the DMTC period. When the directional LBT indicates that the channel is idle, the BS may additionally send a channel reservation signal in the monitored direction.

[0031] In one embodiment, the BS may send a discovery signal in a portion of the system frequency band. The BS may use frequency division multiplexing (FDM) in the system frequency band to send a channel reservation signal concurrently with the discovery signal. The BS may send a data signal on the remaining resources in the DMTC period. The BS may send a data signal in a beam direction based on the monitored beam direction.

[0032] Various aspects of the present application can provide several benefits. For example, omnidirectional LBT and omnidirectional channel reservation can avoid interference from nearby transmitters with minimal system overhead. Directional LBT and directional channel reservation can avoid interference from transmitters using directional transmit beams and / or directional receive beams. Therefore, directional LBT and directional channel reservation can further improve system performance and reduce conflicts. Performing directional LBT and directional channel reservation during the DMTC period can reduce the time interval between directional LBT and the transmission in the corresponding monitored beam direction. The reduction of this time interval can further improve system performance. Using FDM to send a channel reservation signal concurrently with a discovery signal can reduce system overhead. Using unused resources for data transmission during the DMTC period can improve system resource utilization efficiency. The disclosed embodiments can be suitable for use in spectrum sharing with any wireless communication protocol in any wireless network.

[0033] Figure 1 A wireless communication network 100 according to an embodiment of the present disclosure is shown. The network 100 includes a BS 105, a UE 115, and a core network 130. In some embodiments, the network 100 operates on a shared spectrum. The shared spectrum may be unlicensed or partially licensed to one or more network operators. Access to the spectrum may be restricted and may be controlled by a separate coordination entity. In some embodiments, the network 100 may be an LTE or LTE-A network. In other embodiments, the network 100 may be a millimeter wave (mmW) network, a new radio (NR) network, a 5G network, or any other successor network to LTE. The network 100 may be operated by more than one network operator. Wireless resources may be divided and arbitrated between different network operators for coordinated communications between network operators on the network 100.

[0034] BS105 can communicate wirelessly with UE 115 via one or more BS antennas. Each BS105 can provide communication coverage for the corresponding geographic coverage area 110. In 3GPP, the term "cell" can refer to the specific coverage area of ​​the BS and / or the BS subsystem serving the coverage area, depending on the context in which the term is used. In this regard, BS105 can provide communication coverage for macro cells, micro cells, femto cells and / or other types of cells. Macro cells usually cover relatively large geographic areas (e.g., several kilometers in radius) and can allow unrestricted access by UEs with service subscriptions to network providers. Pico cells can usually cover relatively small geographic areas and can allow unrestricted access by UEs with service subscriptions to network providers. Femto cells can usually cover relatively small geographic areas (e.g., residential) and, in addition to restricted access, can also provide restricted access by UEs with associations with the femto cells (e.g., UEs in closed subscriber groups (CSGs), UEs for users in residential areas, etc.). BSs for macro cells can be referred to as macro BSs. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. Figure 1 In the example shown in FIG. 1 , BSs 105a, 105b, and 105c are examples of macro BSs for coverage areas 110a, 110b, and 110c, respectively. BS 105d is an example of a pico BS or a femto BS for coverage area 110d. As will be appreciated, BS 105 may support one or more (e.g., two, three, four, etc.) cells.

[0035] The communication link 125 shown in the network 100 may include an uplink (UL) transmission from the UE 115 to the BS 105, or a downlink (DL) transmission from the BS 105 to the UE 115. The UE 115 may be dispersed throughout the network 100, and each UE 115 may be fixed or mobile. The UE 115 may also be referred to as a mobile station, a user station, a mobile unit, a user unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile user station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a mobile phone, a user agent, a mobile client, a client, or some other appropriate term. The UE 115 may also be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a personal electronic device, a handheld device, a personal computer, a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, a machine type communication (MTC) device, an appliance, a car, etc.

[0036] The BSs 105 may communicate with the core network 130 and with each other. The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (e.g., which may be examples of evolved Node Bs (eNBs), next generation Node Bs (gNBs), or access node controllers (ANCs)) may interface with the core network 130 via a backhaul link 132 (e.g., S1, S2, etc.) and may perform wireless configuration and scheduling for communications with the UE 115. In various examples, the BSs 105 may communicate with each other directly or indirectly (e.g., via the core network 130) via a backhaul link 134 (e.g., X1, X2, etc.), which may be a wired or wireless communication link.

[0037] Each BS 105 may also communicate with multiple UEs 115 through multiple other BSs 105, where the BSs 105 may be examples of smart radio heads. In alternative configurations, the various functions of each BS 105 may be distributed across the various BSs 105 (e.g., radio heads and access network controllers) or merged into a single BS 105.

[0038] In some implementations, the network 100 utilizes orthogonal frequency division multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the UL. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, frequency bins, etc. Each subcarrier can be modulated with data. Typically, modulation symbols are sent in the frequency domain using OFDM and in the time domain using SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. The system bandwidth can also be divided into subbands.

[0039] In one embodiment, BS105 may assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks) for DL ​​and UL transmissions in network 100. DL refers to the transmission direction from BS105 to UE 115, and UL refers to the transmission direction from UE 115 to BS105. Communication may be in the form of a radio frame. A radio frame may be divided into a plurality of subframes, e.g., about 10. Each subframe may be divided into time slots, e.g., about 2. Each time slot may be further divided into micro-slots. In frequency division duplex (FDD) mode, simultaneous UL and DL transmissions may occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In time division duplex (TDD) mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subframe subset (e.g., a DL subframe) in a radio frame may be used for DL ​​transmission, while another subframe subset (e.g., a UL subframe) in a radio frame may be used for UL transmission.

[0040] DL subframes and UL subframes may also be divided into several regions. For example, each DL or UL subframe may have a predefined region for the transmission of reference signals, control information, and data. A reference signal is a predetermined signal that facilitates communication between BS105 and UE 115. For example, a reference signal may have a specific pilot pattern or structure, wherein a pilot tone may span an operable bandwidth or frequency band, and each pilot tone may be located at a predefined time and a predefined frequency. For example, BS105 may send a cell-specific reference signal (CRS) and / or a channel state information-reference signal (CSI-RS) to enable UE 115 to estimate a DL channel. Similarly, UE 115 may send a sounding reference signal (SRS) to enable BS105 to estimate an UL channel. Control information may include resource assignments and protocol control. Data may include protocol data and / or operable data. In some embodiments, BS105 and UE 115 may communicate using a self-contained subframe. A self-contained subframe may include a portion for DL ​​communication and a portion for UL communication. A self-contained subframe may be DL-centric or UL-centric. A DL-centric subframe may include a longer duration for DL ​​communications than UL communications. A UL-centric subframe may include a longer duration for UL communications than UL communications.

[0041] In one embodiment, a UE 115 attempting to access the network 100 may perform an initial cell search by detecting a primary synchronization signal (PSS) from the BS 105. The PSS may enable synchronization of time period timing and may indicate a physical layer identity value. Subsequently, the UE 115 may receive a secondary synchronization signal (SSS). The SSS may enable wireless frame synchronization and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The SSS may also enable detection of duplex mode and cyclic prefix length. Some systems (such as TDD systems) may send an SSS without sending a PSS. Both the PSS and the SSS may be located in the central portion of the carrier, respectively.

[0042] After receiving the PSS and SSS, the UE 115 may receive a master information block (MIB), which may be sent in a physical broadcast channel (PBCH). The MIB may include system bandwidth information, a system frame number (SFN), and a physical hybrid ARQ indicator channel (PHICH) configuration. After decoding the MIB, the UE 115 may receive one or more system information blocks (SIBs). For example, SIB1 may include cell access parameters and scheduling information for other SIBs. Decoding SIB1 may enable the UE 115 to receive SIB2. SIB2 may include radio resource configuration (RRC) configuration information related to a random access channel (RACH) process, paging, a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), power control, SRS, and cell exclusion. After obtaining the MIB and / or SIB, the UE 115 may perform a random access process to establish a connection with the BS 105. After the connection is established, the UE 115 and BS 105 may enter a normal operation phase, wherein operational data may be exchanged.

[0043] In one embodiment, the network 100 can operate on a shared channel (which may include licensed spectrum, shared spectrum, and / or unlicensed spectrum) and can support dynamic medium sharing. The BS 105 and the UE 115 can be operated by multiple network operation entities that share resources in the shared channel. The BS 105 or the UE 115 can reserve a transmit opportunity (TXOP) in the shared channel by sending a reservation signal before sending data in the TXOP. Other BSs 105 and / or other UEs 115 can monitor the channel and avoid accessing the channel during the TXOP when the reservation signal is detected.

[0044] In one embodiment, the shared channel may be located at a frequency of about 6 GHz or above 6 GHz. When BS105 operates in a high frequency range, BS105 may use a narrow directional beam to communicate with UE 115 to overcome the high path loss in the high frequency range. For example, BS105 may use a narrow directional beam to send a discovery signal, such as PSS, SSS, PBCH signal and / or other discovery reference signal. BS105 may scan a narrow directional beam in multiple directions for discovery signal transmission to allow UE 115 located in different directions relative to BS105 to search for BS105 and synchronize with it. In order to avoid conflicts with transmissions from other BS105 and / or other UEs, BS105 may perform LBT (e.g., spatially aware LBT) in the spatial domain before sending a discovery signal. The mechanism for performing LBT in the case of discovery signal transmission is described in more detail herein.

[0045] Figure 2 and Figure 3 Various mechanisms for sending discovery signals in units of synchronization signal blocks (SSBs) are shown. Each SSB may include PSS, SSS, PBCH signals, and / or any discovery-related reference signals. Figure 2 and Figure 3 , the x-axis represents time in some constant units, and the y-axis represents frequency in some constant units.

[0046] Figure 2 A discovery signal transmission scheme 200 according to an embodiment of the present disclosure is shown. The scheme 200 may be employed by a BS (such as BS 105) in a network (such as network 100). The scheme 200 shows a plurality of transmission slots 210 in a frequency band 208 over a duration 202. Each transmission slot 210 includes a plurality of symbols 212. The frequency band 208 may be located at a frequency approximately below 6 GHz or above 6 GHz. In some embodiments, the frequency band 208 may be in an unlicensed spectrum or a shared spectrum. The transmission slot 210 may correspond to a subframe or a slot within a subframe. The symbol 212 may correspond to an OFDM symbol. The BS may communicate with a UE such as UE 115 in the transmission slot 210. The BS may send an SSB 220 in one or more of the transmission slots 210 in the duration 202. The SSB 220 may be sent over the frequency band 206. Transmissions are represented by squares filled with a pattern. In an embodiment, frequency band 208 may correspond to a system bandwidth of the network, and frequency band 206 may have a bandwidth much smaller than the system bandwidth and may be located within frequency band 208. Transmissions in SSB 220 in the narrower frequency band 206 allow the UE to synchronize with the network by operating in a bandwidth smaller than the system bandwidth, thereby reducing UE implementation complexity.

[0047] The duration 202 may be referred to as a DMTC window, which may include any suitable amount of time. As an example, the duration 202 may be approximately five milliseconds (ms). The number of transmission slots 210 within the duration 202 may vary depending on the subcarrier spacing (SCS) and the number of symbols 212 within the transmission slot 210. In an embodiment, each transmission slot 210 may include approximately fourteen symbols 212. When the SCS is approximately 15 kilohertz (kHz), each transmission slot 210 may span approximately 1 ms, and the duration 202 may include approximately five transmission slots 210. When the SCS is approximately 30 kHz, each transmission slot 210 may span approximately 0.5 ms, and the duration 202 may include approximately ten transmission slots 210. When the SCS is approximately 120 kHz, each transmission slot 210 may span approximately 0.125 ms, and the duration 202 may include approximately forty transmission slots 210. When the SCS is approximately 240 kHz, each transmission slot 210 may span approximately 62.5 microseconds (μs), and the duration 202 may include approximately eighty transmission slots 210 .

[0048] In the scheme 200, the BS may transmit L SSBs 220 in a duration 202, where L is a positive integer. As an example, each SSB 220 may span approximately four symbols 212. Thus, each transmission slot 210 may include a maximum of approximately two SSBs 220. As shown, an SSB 220a may be transmitted in the third, fourth, fifth, and sixth symbols 212 of the transmission slot 210, and another SSB 220b may be transmitted in the ninth, tenth, eleventh, and twelfth symbols 212 of the transmission slot 210. In some other embodiments, two SSBs 220a and 220b may be transmitted during other symbols 212 within the transmission slot 210. Depending on the SCS and the duration 202, L may have a value of approximately 4, 8, or 64. In an embodiment, for an SCS of approximately 15 kHz or approximately 30 kHz, L may be approximately 4 or 8. When L is 4, the BS may transmit four SSBs 220 in two transmission slots 210 within the duration 202. In some cases, the BS may transmit the SSBs 220 in consecutive transmission slots 210. When L is 8, the BS may transmit eight SSBs 220 in four transmission slots 210 within the duration 202 (eg, consecutively).

[0049] In an embodiment, for an SCS of about 120 kHz or about 240 kHz, L may be about 64. Thus, the BS may transmit sixty-four SSBs 220 in about thirty-two transmission slots 210 in the duration 202. In some cases, the BS may transmit the SSBs 220 in groups of eight SSBs 220 over four transmission slots 210, and the groups may be separated by one transmission slot 210.

[0050] In an embodiment, the BS may transmit SSB 220 in different beam directions over the duration 202. For example, the BS may include an array of antenna elements and may configure the array of antenna elements to form a transmission beam 211 in a certain direction. As an example, the BS may transmit SSB 220a on a transmission beam 211a (e.g., shown as a pattern fill) pointing in the direction 216, and may transmit SSB 220b on another transmission beam 211b (e.g., shown as a pattern fill) pointing in the direction 214. In some cases, the duration 202 or DMTC window may repeat at a predetermined period (e.g., at about 40 ms, about 80 ms, or about 100 ms), wherein the BS may periodically transmit SSB 220.

[0051] Figure 3 A discovery signal transmission scheme 300 according to an embodiment of the present disclosure is shown. The scheme 300 may be adopted by a BS (such as BS 105) in a network (such as network 100). The scheme 300 may have a transmission slot configuration substantially similar to that in the scheme 200. However, the scheme 300 may use different SCSs for data transmission and discovery signal or SSB transmission. As an example, the network may use an SCS of approximately 120kHz for data transmission and an SCS of approximately 240kHz for SSB transmission. Similar to the scheme 200, the transmission slot 210 may include approximately fourteen symbols 212. However, similar to the SSB 220, the BS may send up to approximately four SSBs 320 in the transmission slot 210. Each SSB 320 may span approximately two symbols 212 instead of four symbols 212 due to the larger SCS used for SSB transmission. Similar to the scheme 200, each SSB 320 may be transmitted in different beam directions. As shown, the BS may sweep multiple narrow directional transmission beams 211a, 211b, 211c, and 211d during transmission time slot 210 for transmitting SSBs 320a, 320b, 320c, and 320d, respectively.

[0052] Figure 44 is a block diagram of an exemplary UE 400 according to an embodiment of the present disclosure. UE 400 may be UE 115 as discussed above. As shown, UE 400 may include a processor 402, a memory 404, a communication discovery module 408, a transceiver 410 including a modem 412 and a radio frequency (RF) unit 414, and one or more antennas 416. These elements may communicate with each other directly or indirectly, for example, via one or more buses.

[0053] The processor 402 may include a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 402 may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0054] The memory 404 may include a cache memory (e.g., a cache memory of the processor 402), a random access memory (RAM), a magnetoresistive RAM (MRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a solid-state memory device, a hard disk drive, other forms of volatile and non-volatile memory, or a combination of different types of memory. In one embodiment, the memory 404 includes a non-transitory computer-readable medium. The memory 404 may store instructions 406. The instructions 406 may include instructions that, when executed by the processor 402, cause the processor 402 to perform the operations described herein in conjunction with the embodiments of the present disclosure with reference to the UE 115. The instructions 406 may also be referred to as code. The terms "instructions" and "code" should be interpreted broadly to include any type of computer-readable statements. For example, the terms "instructions" and "code" may refer to one or more programs, routines, subroutines, functions, processes, and the like. "Instructions" and "code" may include a single computer-readable statement or multiple computer-readable statements.

[0055] The communication discovery module 408 may be implemented via hardware, software, or a combination thereof. For example, the communication discovery module 408 may be implemented as a processor, circuit, and / or instructions 406 stored in the memory 404 and executed by the processor 402. The communication discovery module 408 may be used in various aspects of the present disclosure. For example, the communication discovery module 408 is configured to: receive a discovery signal (e.g., PSS, SSS, PBCH signal, discovery reference signal, and SSB 220 and 320) from a BS such as BS 105a on a shared channel (e.g., frequency band 208), synchronize with the BS based on the discovery signal, and / or communicate with the BS after synchronization, as described in more detail herein.

[0056] As shown, the transceiver 410 may include a modem 412 and an RF unit 414. The transceiver 410 may be configured to communicate bidirectionally with other devices, such as the BS 105. The modem 412 may be configured to modulate and / or encode data from the memory 404 and / or the communication discovery module 408 according to a modulation and coding scheme (MCS) (e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.). The RF unit 414 may be configured to process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) the modulated / encoded data from the modem 412 (for outbound transmissions) or a transmission originating from another source, such as the UE 115 or the BS 105. The RF unit 414 may also be configured to perform analog beamforming in conjunction with digital beamforming. Although shown as being integrated with the transceiver 410, the modem 412 and the RF unit 414 may be separate devices that are coupled together at the UE 115 to enable the UE 115 to communicate with other devices.

[0057] The RF unit 414 may provide modulated and / or processed data (e.g., data packets (or more generally, data messages that may include one or more data packets and other information)) to the antenna 416 for transmission to one or more other devices. For example, this may include the transmission of a random access signal for initial network attachment and / or a data signal carrying information data according to an embodiment of the present disclosure. The antenna 416 may also receive data messages sent from other devices. For example, this may include the reception of discovery signals (such as PSS, SSS, PBCH signals, discovery reference signals, and / or SSB) according to an embodiment of the present disclosure. The antenna 416 may provide the received data message for processing and / or demodulation at the transceiver 410. The antenna 416 may include multiple antennas of similar design or different design to maintain multiple transmission links. The RF unit 414 may configure the antenna 416.

[0058] Figure 5 5 is a block diagram of an exemplary BS 500 according to an embodiment of the present disclosure. BS 500 may be BS 105 as discussed above. As shown, BS 500 may include a processor 502, a memory 504, a communication discovery module 508, a transceiver 510 including a modem 512 and an RF unit 514, and one or more antennas 516. These elements may communicate with each other directly or indirectly, for example, via one or more buses.

[0059] Processor 502 may have various features as a particular type of processor. For example, these may include a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. Processor 502 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0060] Memory 504 may include cache memory (e.g., cache memory of processor 502), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, solid-state memory devices, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some embodiments, memory 504 may include non-transitory computer-readable media. Memory 504 may store instructions 506. Instructions 506 may include instructions that, when executed by processor 502, cause processor 502 to perform the operations described herein. Instructions 506 may also be referred to as code, which may be broadly interpreted to include any type of computer-readable statements, such as those described above with respect to Figure 5 Discussed.

[0061] The communication discovery module 508 may be implemented via hardware, software, or a combination thereof. For example, the communication discovery module 508 may be implemented as a processor, a circuit, and / or instructions 506 stored in the memory 504 and executed by the processor 502. The communication discovery module 508 may be used in various aspects of the present disclosure. For example, the communication discovery module 508 is configured to: perform spatial awareness or directional LBT in a shared channel (e.g., frequency band 208), send a discovery signal (e.g., SSB 220 and 320) based on the results of the LBT, and / or send a channel reservation signal or a preamble signal to silence other nearby transmitters that may interfere with the discovery signal transmission, as described in more detail herein.

[0062] As shown, the transceiver 510 may include a modem 512 and an RF unit 514. The transceiver 510 may be configured to communicate bidirectionally with other devices (such as UE 115 and / or another core network element). The modem 512 may be configured to modulate and / or encode data according to an MCS (e.g., an LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.). The RF unit 514 may be configured to process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) the modulated / encoded data from the modem 512 (regarding outbound transmission) or a transmission originating from another source (such as UE 115 or 400). The RF unit 514 may also be configured to perform analog beamforming and / or digital beamforming for directional signal transmission and / or reception. In some embodiments, the transceiver 510 may include antenna array elements and / or transceiver components (e.g., power amplifiers) that may be turned on or off to form a beam in a particular direction. Alternatively, the transceiver 510 may include multiple transmit / receive chains and may switch between the multiple transmit / receive chains to form a beam in a particular direction. Although shown as being integrated with the transceiver 510, the modem 512 and the RF unit 514 may be separate devices that are coupled together at the BS 105 to enable the BS 105 to communicate with other devices.

[0063] The RF unit 514 may provide modulated and / or processed data (e.g., data packets (or more generally, data messages that may include one or more data packets and other information)) to the antenna 516 for transmission to one or more other devices. For example, this may include information transmission in accordance with an embodiment of the present disclosure to complete attachment to a network and communication with a resident UE 115 or 400. The antenna 516 may also receive data messages sent from other devices and provide the received data messages for processing and / or demodulation at the transceiver 510. The antenna 516 may include multiple antennas of similar design or different designs in order to maintain multiple transmission links.

[0064] Figure 6-Figure 10 Various mechanisms are shown for performing spatial awareness or directional LBT in a shared channel before transmitting a discovery signal (e.g., PSS, SSS, PBCH signal, discovery reference signal, and / or SSB 220 and 320). Figure 6-Figure 10 In a graph, the x-axis represents time in some constant units, and the y-axis represents frequency in some constant units.

[0065] Figure 6A discovery signal transmission scheme 600 using omnidirectional LBT according to an embodiment of the present disclosure is shown. The scheme 600 may be employed by a BS (such as BSs 105 and 500) in a network (such as network 100). The scheme 600 includes a DMTC period 602 including a plurality of transmission slots 610 in a frequency band 608 shared by a plurality of network operation entities. The transmission slots 610 are shown as 610S(1) to 610S(N). Each transmission slot 610 includes a plurality of symbols 612. The DMTC period 602, the transmission slots 610, the symbols 612, and the frequency band 608 may be substantially similar to the duration 202, the transmission slots 210, the symbols 212, and the frequency band 208, respectively. The DMTC period 602 may be repeated at a sparse frequency rate (e.g., approximately every 80 ms, every 100 ms, or any suitable rate).

[0066] Similar to schemes 200 and 300, the BS may transmit multiple SSBs 620 in frequency band 606 within frequency band 608 using multiple directional transmission beams 611 pointing to different beam directions during DMTC period 602. Frequency band 606 may be substantially similar to frequency band 206. Directional transmission beams 611 may be substantially similar to directional transmission beams 211. For example, the BS may transmit a subset of SSBs 620 in transmission slot 610S(1) and another subset of SSBs 620 in transmission slot 610S(N). In transmission slot 610S(1), SSBs 620a, 620b, 620c, and 620d may be transmitted on different transmission beams 611a, 611b, 611c, and 611d, respectively, each transmission beam pointing to a different direction. Similarly, in transmission slot 610S(N), SSBs 620e, 620f, 620g, and 620h may be transmitted on different transmission beams 611e, 611f, 611g, and 611h, respectively, each transmission beam pointing in a different direction. SSBs 620 may be substantially similar to SSBs 220 and 320. For example, each SSB 620 may include a PSS, an SSS, a PBCH signal, and / or a discovery reference signal, as described in more detail herein.

[0067] To avoid conflicts with transmissions from other nodes (e.g., BS 105 and UE 115) in frequency band 208, the BS may monitor the channel (e.g., frequency band 608) before sending the SSB 620. For example, the BS may perform omnidirectional LBT 630 in period 604 before the DMTC period 602. The BS may configure the antenna array elements (e.g., in the transceiver 510) so that the BS can receive signals in all available directions, as shown by the omnidirectional receive beam 614. When the BS detects a transmission from another node (e.g., BS 105 or UE 115) in the channel from any direction, the BS may avoid continuing the transmission of the SSB 620 during the DMTC period 602. The detection may be based on energy detection and / or sequence (e.g., a predetermined waveform for channel reservation) detection and / or preamble (e.g., a predetermined waveform sent with a packet) detection. However, when the BS determines that the channel is idle, the BS may continue to send the SSB 620 during the DMTC period 602.

[0068] The BS may optionally send a channel reservation signal 640 after performing the omnidirectional LBT 630 to avoid interference from nearby transmitters. The BS may send the channel reservation signal 640 on an omnidirectional transmission beam in period 605. Since the BS is not required to switch beams between the omnidirectional LBT 630 and the omnidirectional transmission of the channel reservation signal 640, period 605 may follow period 604 without a time gap. As shown by the omnidirectional transmission beam 613, the BS may configure the antenna array elements to transmit in all directions. The channel reservation signal 640 may include a predetermined preamble sequence. When another transmitter detects the channel reservation signal 640, the transmitter may avoid transmitting in frequency band 608.

[0069] Scheme 600 may avoid interference sources sufficiently close to the BS. However, the omni-directional LBT 630 may not effectively detect energy or preamble transmissions from a particular beam direction, and nodes listening or sensing the channel in a particular beam direction may not hear the omni-directional channel reservation.

[0070] Figure 7A discovery signal transmission scheme 700 utilizing space-specific LBT according to an embodiment of the present disclosure is shown. Scheme 700 may be adopted by a BS (such as BS105 and 500) in a network (such as network 100). Scheme 700 may be substantially similar to scheme 600. However, in addition to omnidirectional LBT and omnidirectional channel reservation, scheme 700 may also perform space-specific LBT and space-specific channel reservation. As shown, the BS may perform space-specific LBT 710 by sweeping multiple directional receive beams 712 in a period 702 before the DMTC period 602. For example, the BS may perform K space-specific LBT 710, as shown in 710B(1) to 710BB(K). Each receive beam 712 may have coverage on one or more of the transmission beams 611 used to transmit SSB 620 during the DMTC period 602. In other words, the receive beam 712 may have a wider beam width than the transmit beam 611. For example, the BS may configure antenna array elements to form a receive beam 712B(1) for sensing a channel (e.g., frequency band) in the beam directions of the transmit beams 611a, 611b, 611c, and 611d.

[0071] When the space-specific LBT 710 indicates that the channel is idle, the BS may continue to transmit the SSB 620 in the beam direction corresponding to the space-specific LBT 710. Conversely, when the space-specific LBT 710 indicates that the channel is occupied, the BS may avoid transmitting the SSB 620 in the beam direction corresponding to the space-specific LBT 710.

[0072] Similar to the scheme 600, the BS may optionally send a channel reservation signal 720 after performing each space-specific LBT 710. The channel reservation signal 720 may be substantially similar to the channel reservation signal 640. However, the channel reservation signal 720 may be sent using a directional beam 713. As shown, the channel reservation signal 720 may be sent in the same beam direction as the previous space-specific LBT 710.

[0073] The space-specific LBT and the space-specific channel reservation can effectively avoid the interference source from transmitting in a specific spatial direction and / or listening in a specific spatial direction. Therefore, compared with the scheme 600, the scheme 700 can further reduce the conflict. However, the BS may need a time gap 704 to switch from one beam direction to another beam direction between the space-specific LBT 710. The existence of the time gap 704 may cause a conflict from an interference source that starts transmitting in the time gap 704.

[0074] Figure 8A discovery signal transmission scheme 800 utilizing a space-specific LBT according to an embodiment of the present disclosure is shown. Scheme 800 may be adopted by a BS (such as BSs 105 and 500) in a network (such as network 100). Scheme 800 may be substantially similar to scheme 700. However, the BS may scan the space-specific LBT 710 in all K directions before sending the space-specific channel reservation signal 720 in response to the space-specific LBT 710. The transmission of the space-specific LBT 710 and the space-specific channel reservation signal 720 may be performed in a period 802 prior to the DMTC period 602. A time gap similar to time gap 704 may be required between each space-specific LBT 710 and each space-specific channel reservation signal 720 transmission to allow the BS to switch antenna array configurations.

[0075] Fig. 9 A discovery signal transmission scheme 900 utilizing space-specific LBT according to an embodiment of the present disclosure is shown. The scheme 900 may be employed by a BS (such as BSs 105 and 500) in a network (such as network 100). The scheme 900 may be substantially similar to schemes 700 and 800. However, in the scheme 900, the BS may perform space-specific LBT 710 and send a space-specific channel reservation signal 720 within the DMTC period 602 instead of before the DMTC period 602.

[0076] The BS may perform space-specific LBT 710 before transmitting a subset of one or more SSBs 620. The space-specific LBT 710 may be performed based on an expected beam transmission direction for transmitting the subset of SSBs 620. As an example, the BS may perform space-specific 710B(1) using a directional receive beam 712B(1) before transmitting SSBs 620a, 620b, 620c, and 620d. The directional receive beam 712B(1) may include coverage over transmit beams 611a, 611b, 611c, and 611d. The BS may optionally send a channel reservation signal 720 in response to each space-specific LBT 710 by using the same beam direction as the space-specific LBT 710. The BS may perform spatially specific LBT 710 and send a spatially specific channel reservation signal 720 transmission immediately prior to the transmission of the first SSB 620a in the subset (eg, in a period of one or two symbols 612).

[0077] When the space-specific LBT 710 (e.g., space-specific LBT 710B(1)) indicates that the channel is idle, the BS may continue to send SSBs 620 (e.g., SSBs 620a, 620b, 620c, and 620d) in the beam direction corresponding to the space-specific LBT 710. Conversely, when the space-specific LBT 710 (e.g., space-specific LBT 710B(K)) indicates that the channel is occupied, the BS may avoid sending SSBs 620 in the beam direction corresponding to the space-specific LBT 710, as indicated by the dashed box with a cross.

[0078] Comparing the scheme 900 with the schemes 700 and 800, the scheme 900 may further reduce collisions. In addition, as described in more detail herein, the scheme 900 may allow the channel reservation signal 720 to be multiplexed with the SSB 620.

[0079] Although schemes 700-900 are illustrated using omnidirectional LBT and omnidirectional channel reservation transmissions in combination with space-specific LBT and space-specific channel reservation, omnidirectional LBT and omnidirectional channel reservation transmissions may be optional.

[0080] Fig.10 A discovery signal transmission scheme 1000 with concurrent channel reservation signal transmission according to an embodiment of the present disclosure is shown. The scheme 1000 may be employed by a BS (such as BSs 105 and 500) in a network (such as network 100). In particular, the scheme 1000 may be used in conjunction with the scheme 900 to transmit a channel reservation signal 1010 using FDM instead of transmitting the channel reservation signal 720 (e.g., using TDM). For example, the BS may transmit an SSB 620 including a PSS 1022, an SSS 1026, and a PBCH signal 1024 in a frequency band 606, and may use the remaining unused resources (e.g., resource elements (REs)) in the frequency portion 1006 to transmit the channel reservation signal 1010 in the same symbol as the PSS 1022. The channel reservation signal 1010 may include a predetermined preamble sequence configured based on the number of unused resource elements in the frequency portion 1006. In addition, the BS may transmit a demodulation reference signal (DMRS) 1030 distributed in the frequency portion 1006 to facilitate decoding, channel discovery, and / or channel synchronization of the PBCH signal 1024. Since the channel reservation signal 1010 is frequency multiplexed with the SSB 620, the scheme 1000 may reduce system overhead compared to the scheme 900.

[0081] As shown in schemes 900 and 1000, there are unused resources (e.g., time-frequency resources) in the DMTC period 602. For example, the first, second, third, fourth, thirteenth, and fourteenth symbols 612 in the transmission slot 610S(1) are unused. Therefore, the BS can send data signals in the unused symbols 612. In an embodiment, the BS can send the data signal in a beam direction corresponding to the spatially specific LBT 710 performed for a subset of SSBs 620 in the transmission slot 610S(1). For example, the BS can use a directional transmission beam similar to the transmission beam 711B(1) used for data signal transmission, and the transmission beam 711B(1) can be wider than the transmission beams 611a, 611b, 611c, and 611d. Alternatively, the BS can select the directional transmission beam from any one of the transmission beams 611a, 611b, 611c, and 611d. The BS may also use the remaining unused frequency resources (e.g., in frequency portion 1006) and transmit the data signal in the same symbol 612 as the SSB 620 in the same beam direction as the SSB 620. Thus, the BS may multiplex the data signal with the SSB 620 in the transmission slot 610 in the time and / or frequency domain.

[0082] Fig.11 1 is a flow chart of a communication discovery method 1100 according to an embodiment of the present disclosure. The steps of the method 1100 may be performed by a computing device (eg, a processor, a processing circuit, and / or other suitable components) of a wireless communication device such as BS 105 and BS 500. The method 1100 may be implemented in the manner described in connection with the respective Figure 2 , 3 , 6, 7, 8, 9 and 10 described in the schemes 200, 300, 600, 700, 800, 900 and 1000. As shown, the method 1100 includes a plurality of enumerated steps, but embodiments of the method 1100 may include additional steps before, after and between the enumerated steps. In some embodiments, one or more of the enumerated steps may be omitted or performed in a different order.

[0083] At step 1110, method 1100 includes: sensing, by a wireless communication device, a channel in a spatial domain (e.g., frequency bands 208 and 608) based on a plurality of expected beam transmission directions (e.g., based on transmission beams 211 and 611). The wireless communication device may be associated with a first network operation entity. The channel may be shared by a plurality of network operation entities including the first network operation entity.

[0084] At step 1120, method 1100 includes: the wireless communication device sends multiple discovery signals (e.g., SSB 220 and 620, PSS1022, SSS1026, PBCH signal 1024 and / or any discovery reference signal) in one or more of a plurality of expected beam transmission directions during a discovery period (e.g., DMTC period 602) based on sensing to facilitate synchronization in the channel.

[0085] In an embodiment, sensing includes: monitoring a channel for transmissions from another wireless communication device using an omnidirectional receive beam (e.g., omnidirectional receive beam 614) prior to the discovery period. In response to sensing, the wireless communication device may transmit a channel reservation signal (e.g., channel reservation signal 640) on an omnidirectional transmit beam (e.g., omnidirectional transmit beam 613) prior to the discovery period.

[0086] In one embodiment, sensing includes: scanning across a plurality of narrow directional receive beams (e.g., receive beam 712) and listening to a channel in each of the beam directions. For example, sensing includes: monitoring a channel in a first subset of a plurality of expected beam transmission directions (e.g., beam directions of beams 611a, 611b, 611c, and 611d) for transmissions from another wireless communication device. Monitoring includes: configuring an antenna element of the wireless communication device (e.g., in transceiver 510) to direct reception in covered beam directions included in the first subset of the plurality of expected beam transmission directions. In such an embodiment, sending a plurality of discovery signals may include: sending a subset of a plurality of discovery signals (e.g., SSB 620a, 620b, 620c, and 620d), each discovery signal in a beam transmission direction in the first subset of the plurality of expected beam transmission directions. Sensing may also include monitoring the channel in a second subset of a plurality of expected beam transmission directions (e.g., based on beams 611e, 611f, 611g, and 611h) for transmissions from another wireless communication device. Sensing may be repeated in a subset of expected beam transmission directions until all beam directions are monitored.

[0087] In some embodiments, for example, as shown in schemes 700 and 800, directional sensing (e.g., using a narrow beam) can be performed before the discovery period. In response to the sensing, the wireless communication device can send a channel reservation signal (e.g., channel reservation signal 720) after sensing each beam direction before switching to another beam direction. Each channel reservation signal can be sent in the same direction as the sensing. Alternatively, the wireless communication device can sweep through all subsets of beam directions used for sensing before sweeping through a subset of beam directions used to send channel reservation signals.

[0088] In some embodiments, for example, as shown in scheme 900, directional sensing may be performed within a discovery period. For example, before sending a subset of multiple discovery signals, a channel is monitored within a discovery period in a first subset of multiple expected beam transmission directions. In response to the sensing, the wireless communication device may send a channel reservation signal in the same direction as the sensing before sending the subset of discovery signals. In some embodiments, for example, as shown in scheme 1000, the wireless communication device may use FDM to send a channel reservation signal concurrently with at least one discovery signal in the subset of discovery signals. In some embodiments, monitoring in a second subset of multiple expected beam transmission directions may detect a transmission from another wireless communication device. Upon detection, the wireless communication device may avoid sending a discovery signal in the second subset of multiple expected beam transmission directions.

[0089] Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0090] A general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware components or any combination thereof for performing the functions described herein may be used to implement or execute the various exemplary blocks and modules described in conjunction with the contents disclosed herein. A general purpose processor may be a microprocessor, or the processor may be any conventional processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such structure).

[0091] Another embodiment of the present disclosure includes a method for wireless communication, comprising: sensing a channel in a spatial domain by a wireless communication device based on multiple expected beam transmission directions, wherein the wireless communication device is associated with a first network operating entity, and wherein the channel is shared by multiple network operating entities including the first network operating entity; and sending multiple discovery signals by the wireless communication device in one or more of the multiple expected beam transmission directions during a discovery period based on the sensing to facilitate synchronization in the channel.

[0092] In some embodiments, wherein the sensing comprises: monitoring the channel for transmissions from another wireless communication device using an omnidirectional receive beam prior to the discovery period. In some embodiments, the method further comprises: transmitting, by the wireless communication device, a channel reservation signal using an omnidirectional transmit beam prior to the discovery period based on the sensing. In some embodiments, wherein the sensing comprises: monitoring the channel in a first subset of the plurality of expected beam transmission directions for transmissions from another wireless communication device. In some embodiments, wherein the monitoring comprises: configuring an antenna element of the wireless communication device to direct reception in a covered beam direction included in the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein the transmitting comprises: transmitting a subset of the plurality of discovery signals, each discovery signal in one beam transmission direction in the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein the sensing further comprises: monitoring the channel in a second subset of the plurality of expected beam transmission directions for transmissions from another wireless communication device, wherein the first subset and the second subset of the plurality of expected beam transmission directions are different, and wherein the channel is monitored in the first subset of the plurality of expected beam transmission directions and in the second subset of the plurality of expected beam transmission directions prior to the discovery period. In some embodiments, the method further comprises: sending, by the wireless communication device, a first channel reservation signal in the first subset of the plurality of expected beam transmission directions based on the monitoring in the first subset of the plurality of expected beam transmission directions; and sending, by the wireless communication device, a second channel reservation signal in the second subset of the plurality of expected beam transmission directions based on the monitoring in the second subset of the plurality of expected beam transmission directions. In some embodiments, wherein the channel is monitored in the first subset of the plurality of expected beam transmission directions during the discovery period prior to sending the subset of the plurality of discovery signals. In some embodiments, the method further comprises: the wireless communication device sends a channel reservation signal in the first subset of the plurality of expected beam transmission directions before sending the subset of the plurality of discovery signals based on the monitoring in the first subset of the plurality of expected beam transmission directions. In some embodiments, the method further comprises: the wireless communication device sends a channel reservation signal concurrently with one discovery signal in the subset of the plurality of discovery signals based on frequency division multiplexing (FDM).In some embodiments, wherein the sensing comprises: monitoring the channel in a second subset of the plurality of expected beam transmission directions during the discovery period; and detecting a transmission from another wireless communication device on the channel in the second subset of the plurality of expected beam transmission directions, and wherein the method further comprises: avoiding, by the wireless communication device, sending a discovery signal in the second subset of the plurality of expected beam transmission directions based on the detection. In some embodiments, the method further comprises: sending the data signal by multiplexing the data signal with one or more discovery signals in the subset of the plurality of discovery signals in at least one of the frequency domain or the time domain. In some embodiments, wherein the data signal is sent in at least one beam transmission direction in the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein each of the plurality of discovery signals comprises at least one of the following: a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) signal, or a discovery reference signal.

[0093] Another embodiment of the present disclosure includes an apparatus comprising: a processor configured to sense a channel in a spatial domain based on a plurality of expected beam transmission directions, wherein the apparatus is associated with a first network operating entity and wherein the channel is shared by a plurality of network operating entities including the first network operating entity; and a transceiver configured to: send a plurality of discovery signals in one or more of the plurality of expected beam transmission directions during a discovery period based on the sensing to facilitate synchronization in the channel.

[0094] In some embodiments, wherein the processor is further configured to sense the channel by monitoring the channel for transmissions from another wireless communication device using an omni-directional receive beam prior to the discovery period. In some embodiments, wherein the transceiver is further configured to send a channel reservation signal using an omni-directional transmit beam prior to the discovery period based on the sensing. In some embodiments, wherein the processor is further configured to sense the channel by monitoring the channel in a first subset of the plurality of expected beam transmission directions for transmissions from another wireless communication device. In some embodiments, wherein the processor is further configured to monitor the channel by configuring an antenna element of the wireless communication device to direct reception in a beam direction including coverage on the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein the transceiver is further configured to send the plurality of discovery signals by sending a subset of a plurality of discovery signals, each discovery signal in one beam transmission direction in the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein the processor is further configured to sense the channel by monitoring the channel in a second subset of the plurality of expected beam transmission directions for transmissions from another wireless communication device, wherein the first subset and the second subset of the plurality of expected beam transmission directions are different, and wherein the channel is monitored in the first subset of the plurality of expected beam transmission directions and in the second subset of the plurality of expected beam transmission directions prior to the discovery period. In some embodiments, wherein the transceiver is further configured to send a first channel reservation signal in the first subset of the plurality of expected beam transmission directions based on the monitoring in the first subset of the plurality of expected beam transmission directions; and send a second channel reservation signal in the second subset of the plurality of expected beam transmission directions based on the monitoring in the second subset of the plurality of expected beam transmission directions. In some embodiments, wherein the channel is monitored in the first subset of the plurality of expected beam transmission directions during the discovery period prior to sending the subset of the plurality of discovery signals. In some embodiments, wherein the transceiver is further configured to: based on the monitoring in the first subset of the plurality of expected beam transmission directions, send a channel reservation signal in the first subset of the plurality of expected beam transmission directions before sending the subset of the plurality of discovery signals. In some embodiments, wherein the transceiver is further configured to: send the channel reservation signal concurrently with one discovery signal in the subset of the plurality of discovery signals based on frequency division multiplexing (FDM).In some embodiments, wherein the processor is further configured to: sense the channel by monitoring the channel in a second subset of the plurality of expected beam transmission directions during the discovery period; and detecting a transmission from another wireless communication device on the channel in the second subset of the plurality of expected beam transmission directions; and avoid sending a discovery signal in the second subset of the plurality of expected beam transmission directions based on the detection. In some embodiments, wherein the transceiver is further configured to: send the data signal by multiplexing the data signal with one or more discovery signals in the subset of the plurality of discovery signals in at least one of the frequency domain or the time domain. In some embodiments, wherein the data signal is sent in at least one beam transmission direction in the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein each of the plurality of discovery signals includes at least one of the following: a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) signal, or a discovery reference signal.

[0095] Another embodiment of the present disclosure includes a computer-readable medium having program code recorded thereon, the program code including: code for causing a wireless communication device to sense a channel in a spatial domain based on multiple expected beam transmission directions, wherein the wireless communication device is associated with a first network operating entity and wherein the channel is shared by multiple network operating entities including the first network operating entity; and code for causing the wireless communication device to send multiple discovery signals in one or more of the multiple expected beam transmission directions during a discovery period based on the sensing to facilitate synchronization in the channel.

[0096] In some embodiments, wherein the code for causing the wireless communication device to sense the channel is further configured to: monitor the channel for transmissions from another wireless communication device using an omnidirectional receive beam prior to the discovery period. In some embodiments, the computer-readable medium further comprises: code for causing the wireless communication device to transmit a channel reservation signal using an omnidirectional transmit beam prior to the discovery period based on the sensing. In some embodiments, wherein the code for causing the wireless communication device to sense the channel is further configured to: monitor the channel in a first subset of the plurality of expected beam transmission directions for transmissions from another wireless communication device. In some embodiments, wherein the code for causing the wireless communication device to monitor the channel is further configured to: configure the antenna element of the wireless communication device to direct reception in a beam direction including coverage on the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein the code for causing the wireless communication device to transmit the plurality of discovery signals is further configured to: transmit a subset of the plurality of discovery signals, each discovery signal in one beam transmission direction of the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein the code for causing the wireless communication device to sense the channel is further configured to: monitor the channel in a second subset of the plurality of expected beam transmission directions for transmissions from another wireless communication device, wherein the first subset and the second subset of the plurality of expected beam transmission directions are different, and wherein the channel is monitored in the first subset of the plurality of expected beam transmission directions and in the second subset of the plurality of expected beam transmission directions prior to the discovery period. In some embodiments, the computer-readable medium further comprises: code for causing the wireless communication device to send a first channel reservation signal in the first subset of the plurality of expected beam transmission directions based on the monitoring in the first subset of the plurality of expected beam transmission directions; and code for causing the wireless communication device to send a second channel reservation signal in the second subset of the plurality of expected beam transmission directions based on the monitoring in the second subset of the plurality of expected beam transmission directions. In some embodiments, wherein the channel is monitored in the first subset of the plurality of expected beam transmission directions during the discovery period prior to sending the subset of the plurality of discovery signals. In some embodiments, the computer-readable medium also includes: code for causing the wireless communication device to send a channel reservation signal in the first subset of the multiple expected beam transmission directions before sending the subset of the multiple discovery signals based on the monitoring in the first subset of the multiple expected beam transmission directions.In some embodiments, the computer-readable medium further comprises: code for causing the wireless communication device to transmit a channel reservation signal concurrently with one discovery signal in the subset of the plurality of discovery signals based on frequency division multiplexing (FDM). In some embodiments, wherein the code for causing the wireless communication device to sense the channel is further configured to: monitor the channel in a second subset of the plurality of expected beam transmission directions during the discovery period; and detect a transmission from another wireless communication device on the channel in the second subset of the plurality of expected beam transmission directions, and wherein the computer-readable medium further comprises: code for causing the wireless communication device to avoid transmitting a discovery signal in the second subset of the plurality of expected beam transmission directions based on the detection. In some embodiments, the computer-readable medium further comprises: code for causing the wireless communication device to transmit the data signal by multiplexing the data signal with one or more discovery signals in the subset of the plurality of discovery signals in at least one of the frequency domain or the time domain. In some embodiments, wherein the data signal is transmitted in at least one beam transmission direction in the first subset of the plurality of expected beam transmission directions. In some embodiments, each of the plurality of discovery signals comprises at least one of: a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) signal, or a discovery reference signal.

[0097] Another embodiment of the present disclosure includes an apparatus comprising: a unit for sensing a channel in a spatial domain based on a plurality of expected beam transmission directions, wherein the apparatus is associated with a first network operating entity and wherein the channel is shared by a plurality of network operating entities including the first network operating entity; and a unit for sending a plurality of discovery signals in one or more of the plurality of expected beam transmission directions during a discovery period based on the sensing to facilitate synchronization in the channel.

[0098] In some embodiments, wherein the means for sensing is further configured to: monitor the channel for transmissions from another wireless communication device using an omnidirectional receive beam prior to the discovery period. In some embodiments, the apparatus further comprises: a means for transmitting a channel reservation signal using an omnidirectional transmit beam prior to the discovery period based on the sensing. In some embodiments, wherein the means for sensing is further configured to: monitor the channel in a first subset of the plurality of expected beam transmission directions for transmissions from another wireless communication device. In some embodiments, wherein the means for sensing is further configured to: monitor the channel by configuring antenna elements of the wireless communication device to direct reception in a covered beam direction included in the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein the means for transmitting the plurality of discovery signals is further configured to: transmit a subset of the plurality of discovery signals, each discovery signal in one beam transmission direction in the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein the means for sensing is further configured to: monitor the channel in a second subset of the plurality of expected beam transmission directions for transmissions from another wireless communication device, wherein the first subset and the second subset of the plurality of expected beam transmission directions are different, and wherein the channel is monitored in the first subset of the plurality of expected beam transmission directions and in the second subset of the plurality of expected beam transmission directions prior to the discovery period. In some embodiments, the apparatus further comprises: means for sending a first channel reservation signal in the first subset of the plurality of expected beam transmission directions based on the monitoring in the first subset of the plurality of expected beam transmission directions; and means for sending a second channel reservation signal in the second subset of the plurality of expected beam transmission directions based on the monitoring in the second subset of the plurality of expected beam transmission directions. In some embodiments, wherein the channel is monitored in the first subset of the plurality of expected beam transmission directions during the discovery period prior to sending the subset of the plurality of discovery signals. In some embodiments, the apparatus further comprises: a unit for transmitting a channel reservation signal in the first subset of the plurality of expected beam transmission directions before transmitting the subset of the plurality of discovery signals based on the monitoring in the first subset of the plurality of expected beam transmission directions. In some embodiments, the apparatus further comprises: a unit for transmitting the channel reservation signal concurrently with a discovery signal in the subset of the plurality of discovery signals based on frequency division multiplexing (FDM).In some embodiments, wherein the unit for sensing is further configured to: monitor the channel in a second subset of the plurality of expected beam transmission directions during the discovery period; and detect a transmission from another wireless communication device on the channel in the second subset of the plurality of expected beam transmission directions, and wherein the apparatus further comprises: a unit for avoiding sending a discovery signal in the second subset of the plurality of expected beam transmission directions based on the detection. In some embodiments, the apparatus further comprises: a unit for sending the data signal by multiplexing the data signal with one or more discovery signals in the subset of the plurality of discovery signals in at least one of the frequency domain or the time domain. In some embodiments, wherein the data signal is sent in at least one beam transmission direction in the first subset of the plurality of expected beam transmission directions. In some embodiments, wherein each of the plurality of discovery signals comprises at least one of the following: a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) signal, or a discovery reference signal.

[0099] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. When implemented in software executed by a processor, the functions may be stored on a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Other examples and implementations also fall within the scope of protection of the present disclosure and the claims thereto. For example, due to the nature of software, the functions described above may be implemented using software, hardware, firmware, hardware wiring, or any combination thereof executed by a processor. Features used to implement the functions may be physically located in multiple locations, including distributed ones, so that a portion of the functions are implemented in different physical locations. In addition, as used herein (including the claims), "or" as used in a list item (e.g., "or" used in a list item ending with "at least one of" or "one or more of") indicates an inclusive list, so that, for example, the list [at least one of A, B, or C] means: A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

[0100] As will be appreciated by those skilled in the art, many improvements, substitutions and changes may be made to the materials, devices, configurations and methods of use of the apparatus of the present disclosure, depending on the specific application at the time, without departing from the spirit and scope of protection of the present disclosure. In view of this, the scope of protection of the present disclosure shall not be limited to the specific embodiments shown and described herein, which are merely exemplary, but shall be fully commensurate with the claims appended hereto and their functional equivalents.

Claims

1. A method of wireless communication, comprising: sensing, by a wireless communication device, a channel in a spatial domain based on a plurality of expected beam transmission directions, wherein the channel is shared by a plurality of network operating entities including a first network operating entity associated with the wireless communication device, wherein the sensing comprises scanning through a plurality of directional receive beams and listening to the channel in a direction of each of the plurality of directional receive beams prior to a discovery period; transmitting, by the wireless communication device and prior to the discovery period, a channel reservation signal based on the sensing using an omni-directional transmit beam, the channel reservation signal indicating a reservation for the channel in the discovery period; and After the sensing, a discovery signal is transmitted by the wireless communication device in one or more of the plurality of expected beam transmission directions during the discovery period to facilitate synchronization in the channel.

2. The method according to claim 1, wherein: The plurality of directional receive beams includes a first subset of the plurality of expected beam transmission directions.

3. The method according to claim 2, wherein: The sending of the discovery signal includes: sending a subset of multiple discovery signals, each of the discovery signals being sent in an expected beam transmission direction in the first subset of the multiple expected beam transmission directions.

4. The method according to claim 3, wherein: The plurality of directional receive beams further comprises a second subset of the plurality of expected beam transmission directions, and wherein the first subset and the second subset of the plurality of expected beam transmission directions are different.

5. The method according to claim 4, further comprising: further scanning through the plurality of directional receive beams and listening for the channel in the direction of each of the plurality of directional receive beams in the second subset of the plurality of expected beam transmission directions during the discovery period; as well as detecting, during the discovery period, for transmissions from another wireless communication device on the channel in the second subset of the plurality of expected beam transmission directions; as well as and refraining, by the wireless communication device based on detecting the transmission, from transmitting a discovery signal in the second subset of the plurality of expected beam transmission directions.

6. The method according to claim 3, further comprising: The data signal is sent by multiplexing the data signal with one or more discovery signals in the subset of the discovery signal in at least one of the frequency domain or the time domain, wherein the data signal is sent in at least one expected beam transmission direction in the first subset of the multiple expected beam transmission directions.

7. The method according to claim 1, wherein: Each of the discovery signals includes at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) signal, or a discovery reference signal.

8. A wireless communication device, comprising: Memory; Transceiver; as well as a processor in communication with the memory and the transceiver, the processor being configured to: sensing a channel in a spatial domain based on a plurality of expected beam transmission directions, wherein the channel is shared by a plurality of network operating entities including a first network operating entity associated with the wireless communication device, wherein the processor configured to sense the channel comprises the processor configured to: scan through a plurality of directional receive beams via the transceiver and listen for the channel in a direction of each of the plurality of directional receive beams prior to a discovery period; transmitting, via the transceiver and prior to the discovery period, a channel reservation signal based on the sensing using an omni-directional transmit beam, the channel reservation signal indicating a reservation for the channel in the discovery period; and After sensing the channel, a discovery signal is transmitted via the transceiver in one or more of the plurality of expected beam transmission directions during the discovery period to facilitate synchronization in the channel.

9. The wireless communication device according to claim 8, wherein: The multiple directional receive beams include: a first subset of the multiple expected beam transmission directions, and wherein the processor is configured to send the discovery signal in the following manner: sending a subset of multiple discovery signals, each discovery signal being sent in an expected beam transmission direction in the first subset of the multiple expected beam transmission directions.

10. The wireless communication device according to claim 9, wherein: The plurality of directional receive beams further comprises a second subset of the plurality of expected beam transmission directions, and wherein the first subset and the second subset of the plurality of expected beam transmission directions are different.

11. The wireless communication device of claim 10, wherein the processor is further configured to perform the following operations via the transceiver: further scanning through the plurality of directional receive beams and listening for the channel in the direction of each of the plurality of directional receive beams in the second subset of the plurality of expected beam transmission directions during the discovery period; as well as detecting, during the discovery period, for transmissions from another wireless communication device on the channel in the second subset of the plurality of expected beam transmission directions; as well as refraining from transmitting a discovery signal in the second subset of the plurality of expected beam transmission directions based on detecting the transmission.

12. The wireless communication device according to claim 9, wherein the processor is further configured to send the data signal by multiplexing the data signal with one or more discovery signals in the subset of the discovery signals in at least one of the frequency domain or the time domain, wherein The data signal is transmitted in at least one expected beam transmission direction in the first subset of the plurality of expected beam transmission directions.

13. The wireless communication device according to claim 8, wherein: Each of the discovery signals includes at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) signal, or a discovery reference signal.

14. A wireless communication device, comprising: means for sensing a channel in a spatial domain based on a plurality of expected beam transmission directions, wherein the channel is shared by a plurality of network operating entities including a first network operating entity associated with the wireless communication device, wherein the means for sensing comprises: means for scanning through a plurality of directional receive beams, and means for listening to the channel in a direction of each of the plurality of directional receive beams prior to a discovery period; means for transmitting a channel reservation signal using an omni-directional transmit beam based on the sensing prior to the discovery period, the channel reservation signal indicating a reservation for the channel in the discovery period; and Means for transmitting a discovery signal in one or more of the plurality of expected beam transmission directions during the discovery period after the sensing to facilitate synchronization in the channel.

15. The wireless communication device according to claim 14, wherein: The multiple directional receive beams include: a first subset of the multiple expected beam transmission directions, and wherein the unit for sending the discovery signal includes a unit for sending a subset of multiple discovery signals, each of the discovery signals is sent in an expected beam transmission direction in the first subset of the multiple expected beam transmission directions.

16. The wireless communication device according to claim 15, wherein: The plurality of directional receive beams further comprises a second subset of the plurality of expected beam transmission directions, and wherein the first subset and the second subset of the plurality of expected beam transmission directions are different.

17. The wireless communication device of claim 16, further comprising: means for further scanning through the plurality of directional receive beams and listening for the channel in the direction of each of the plurality of directional receive beams in the second subset of the plurality of expected beam transmission directions during the discovery period; as well as means for detecting a transmission from another wireless communication device on said channel in said second subset of said plurality of expected beam transmission directions during said discovery period; as well as means for refraining from transmitting a discovery signal in the second subset of the plurality of expected beam transmission directions based on detecting the transmission.

18. The wireless communication device of claim 15, further comprising: A unit for sending the data signal by multiplexing the data signal with one or more discovery signals in the subset of the discovery signal in at least one of the frequency domain or the time domain, wherein the data signal is sent in at least one expected beam transmission direction in the first subset of the multiple expected beam transmission directions.

19. The wireless communication device according to claim 14, wherein: Each of the discovery signals includes at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) signal, or a discovery reference signal.

20. A non-transitory computer readable medium storing code for wireless communication by a wireless communication device, the code comprising instructions stored thereon, the instructions, when executed by a processor of the wireless communication device, directing the processor to: The channel in the spatial domain is sensed based on multiple expected beam transmission directions, where: the channel being shared by a plurality of network operating entities including a first network operating entity associated with the wireless communication device, wherein the sensing comprises scanning through a plurality of directional receive beams and listening to the channel in a direction of each of the plurality of directional receive beams prior to a discovery period; Before the discovery period, transmitting a channel reservation signal using an omni-directional transmission beam based on the sensing, the channel reservation signal indicating a reservation for the channel in the discovery period; and After the sensing, a discovery signal is transmitted in one or more of the plurality of expected beam transmission directions during the discovery period to facilitate synchronization in the channel.

21. The non-transitory computer readable medium of claim 20, wherein: The multiple directional receive beams include: a first subset of the multiple expected beam transmission directions, and wherein the instruction instructing the processor to send the discovery signal includes an instruction instructing the processor to perform the following operations: sending a subset of multiple discovery signals, each discovery signal being sent in an expected beam transmission direction in the first subset of the multiple expected beam transmission directions to send the discovery signal.

22. The non-transitory computer readable medium of claim 21, wherein: The plurality of directional receive beams further comprises a second subset of the plurality of expected beam transmission directions, and wherein the first subset and the second subset of the plurality of expected beam transmission directions are different.

23. The non-transitory computer readable medium of claim 22, wherein the instructions further comprise instructions for instructing the processor to: further scanning through the plurality of directional receive beams and listening for the channel in the direction of each of the plurality of directional receive beams in the second subset of the plurality of expected beam transmission directions during the discovery period; as well as detecting, during the discovery period, for transmissions from another wireless communication device on the channel in the second subset of the plurality of expected beam transmission directions; as well as refraining from transmitting a discovery signal in the second subset of the plurality of expected beam transmission directions based on detecting the transmission.

24. The non-transitory computer-readable medium of claim 21, the instructions further comprising instructions for instructing the processor to: transmit the data signal by multiplexing the data signal with one or more discovery signals in the subset of the discovery signals in at least one of a frequency domain or a time domain, wherein The data signal is to be transmitted in at least one expected beam transmission direction in the first subset of the plurality of expected beam transmission directions.

25. The non-transitory computer readable medium of claim 20, wherein: Each of the discovery signals includes at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH) signal, or a discovery reference signal.

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