Method and apparatus for shared spectrum access for broadcast and bidirectional packet-switched communications

Abstract

Disclosed herein are techniques related to spectrum sharing between different radio access technologies. In some embodiments, a broadcast base station is configured to wirelessly broadcast audio and video data to a plurality of broadcast receiver devices using a specific frequency band. In these embodiments, the broadcast base station is configured to interrupt the broadcast in the specific frequency band during a scheduled time interval to enable one or more cellular base stations to perform cellular packet switched wireless data communications using the specific frequency band.

Description

Technical Field

[0001] The present application relates to dynamic spectrum sharing for wireless communications. Background Art

[0002] The use of wireless communication systems is growing rapidly. In addition, wireless communication technology has evolved from voice communications only to also include the transmission of data such as the Internet and multimedia content. The surge in wireless communications can lead to a scarcity of spectrum. In addition, the utilization of different parts of the spectrum can vary. For example, during some intervals, cellular communications in a particular frequency band may be high. At the same time, a broadcast television (TV) provider may not utilize all of its allocated frequency resources.

[0003] Therefore, in some embodiments, techniques for dynamic spectrum sharing between different radio technologies may be needed. Summary of the invention

[0004] Techniques related to dynamic spectrum sharing are disclosed. In some embodiments, a broadcast base station is configured to wirelessly broadcast audio and video data to a plurality of broadcast receiver devices using a specific frequency band. In these embodiments, the broadcast base station is configured to interrupt the broadcast in the specific frequency band during scheduled time intervals to enable one or more cellular base stations to perform two-way packet-switched wireless data communications using the specific frequency band.

[0005] In some embodiments, a base station (e.g., a long term evolution (LTE) base station) is configured to perform two-way packet exchange communications with one or more mobile devices using a first frequency band. In these embodiments, the base station is further configured to perform two-way packet exchange communications with one or more mobile devices using a second frequency band during scheduled time intervals, wherein the second frequency band is used to wirelessly broadcast audio and video data to multiple devices during one or more time intervals other than the scheduled time intervals.

[0006] In some embodiments, the disclosed techniques may allow for dynamic spectrum sharing between cellular and broadcast communications.In some embodiments, a single base station is configured as both a broadcast base station and a cellular base station.

[0007] In some embodiments, the mobile device is configured to switch between frequency bands in order to utilize the shared spectrum. In various embodiments, the mobile device may be configured to power down during a blanking interval for a corresponding radio technology (during which another radio technology's communication in the same spectrum may occur). In various embodiments, control signaling sent by a cellular base station and / or a broadcast base station may enable the wireless receiver device to maintain connectivity during dynamic spectrum sharing. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1is a diagram illustrating a user equipment device (UE) according to some embodiments.

[0009] Figure 2 is a block diagram illustrating an exemplary wireless communication environment including a broadcast base station and a cellular base station in accordance with some embodiments.

[0010] Figure 3 is a block diagram illustrating an exemplary base station according to some embodiments.

[0011] Figure 4 is a block diagram illustrating an exemplary UE according to some embodiments.

[0012] Figure 5 is a diagram illustrating an exemplary broadcast frame according to some embodiments.

[0013] Figure 6 is a diagram illustrating an exemplary LTE radio frame according to some embodiments.

[0014] Figure 7 is a diagram illustrating exemplary control signaling for spectrum sharing between LTE and broadcast transmissions according to some embodiments.

[0015] Figure 8 is a diagram illustrating exemplary blanking periods for LTE and broadcast transmissions for spectrum sharing in accordance with some embodiments.

[0016] Fig. 9 is a flow chart illustrating a method for operating a broadcast base station according to some embodiments.

[0017] Fig.10 is a flow chart illustrating a method for operating a cellular base station according to some embodiments.

[0018] Fig.11 is a flow chart illustrating a method for operating a UE according to some embodiments.

[0019] Fig.12 is a diagram illustrating an example ATSC 3.0 physical layer frame in accordance with some embodiments.

[0020] Fig.13 is a diagram illustrating an example sequential transmission of a broadcast frame in accordance with some embodiments.

[0021] Fig.14 is a diagram illustrating an example discontinuous reception (DRX) cycle in accordance with some embodiments.

[0022] Figures 15A to 15B is a diagram illustrating example gaps between broadcast frames in accordance with some embodiments.

[0023] Fig.16is a diagram illustrating example spectrum sharing for cellular communications between broadcast frames.

[0024] Fig.17 is a diagram illustrating an example of longer gaps between certain broadcast frames in accordance with some embodiments.

[0025] Fig.18 is a graph illustrating example power shifted to non-interfering frequencies in accordance with some embodiments.

[0026] Fig.19 is a diagram illustrating example guard intervals and power ramps according to some embodiments.

[0027] Various units, circuits, or other components may be described or claimed as being "configured to" perform one or more tasks. In such contexts, "configured to" is used to represent a structure by indicating that the unit / circuit / component includes a structure (e.g., a circuit system) that performs one or more tasks during operation. Thus, even when a specified unit / circuit / component is not currently operational (e.g., not turned on), the unit / circuit / component may be said to be configured to perform a task. Units / circuits / components used with the "configured to" language include hardware - e.g., circuits, memory storing program instructions executable to implement operations, etc. Reciting that a unit / circuit / component is "configured to" perform one or more tasks explicitly does not invoke 35 U.S.C. §112(f) for the unit / circuit / component. DETAILED DESCRIPTION

[0028] Abbreviations

[0029] The following abbreviations are used in this disclosure.

[0030] 3GPP: Third Generation Partnership Project

[0031] 5G: 5th Generation

[0032] ABS: Almost Blank Subframe

[0033] ATSC: Advanced Television Systems Committee

[0034] BS: Base Station

[0035] CDMA: Code Division Multiple Access

[0036] CRS: Cell-specific reference signal

[0037] DRX: Discontinuous Reception

[0038] EUTRA: Evolved Universal Terrestrial Radio Access

[0039] FDD: Frequency Division Duplex

[0040] GSM: Global System for Mobile Communications

[0041] LTE: Long Term Evolution

[0042] MAC: Media Access Control

[0043] MBSFN: Multicast / Broadcast Single Frequency Network

[0044] MHz: Megahertz

[0045] MIB: Master Information Block

[0046] Msps: Megasamples per second

[0047] NR: New Radio

[0048] OFDM: Orthogonal Frequency Division Multiplexing

[0049] PCFICH: Physical Control Format Indicator Channel

[0050] PDCCH: Physical Downlink Control Channel

[0051] PHICH: Physical Hybrid ARQ Indicator Channel

[0052] PLP: Physical Layer Pipeline

[0053] PMCH: Physical Multicast Channel

[0054] PRS: Positioning Reference Signal

[0055] PSS: Primary Synchronization Signal

[0056] RF: Radio Frequency

[0057] RRC: Radio Resource Control

[0058] SFN: System Frame Number

[0059] SIB: System Information Block

[0060] SSS: Subsynchronous Signal

[0061] TDD: Time Division Duplex

[0062] TDM: Time Division Multiplexing

[0063] NGBP: Next Generation Broadcast Platform

[0064] RAT: Radio Access Technology

[0065] RX: Receive

[0066] SIM: Subscriber Identity Module

[0067] TX: Transmit

[0068] UE: User Equipment

[0069] UMTS: Universal Mobile Telecommunications System

[0070] the term

[0071] The following is a glossary of terms used in this application:

[0072] Storage medium - any of various types of memory devices or storage devices. The term "storage medium" is intended to include installation media, such as CD-ROM, floppy disk or tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media, such as hard disk drives, or optical storage; registers or other similar types of memory elements, etc. The storage medium may also include other types of memory or combinations thereof. In addition, the storage medium may be located in a first computer system that executes the program, or may be located in a second different computer system connected to the first computer system through a network such as the Internet. In the latter case, the second computer system may provide program instructions to the first computer for execution. The term "storage medium" may include two or more storage media that may reside in different locations (e.g., in different computer systems connected through a network). The storage medium may store program instructions (e.g., implemented as a computer program) that may be executed by one or more processors.

[0073] Carrier Medium—storage media as described above, as well as physical transmission media such as a bus, network, and / or other physical transmission media that transport signals such as electrical, electromagnetic or digital signals.

[0074] Computer system - any of various types of computing or processing systems, including a personal computer system (PC), a mainframe computer system, a workstation, a network appliance, an Internet appliance, a personal digital assistant (PDA), a personal communication device, a smart phone, a television system, a grid computing system, or other devices or combinations of devices. In general, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a storage medium.

[0075] User Equipment (UE) (or "UE device") - any of various types of computer system devices that are mobile or portable and that perform wireless communications. Examples of UE devices include mobile phones or smartphones (e.g., iPhone-based TM 、Android TM mobile phones), portable gaming devices (e.g., Nintendo DS TM, PlayStation Portable TM 、Gameboy Advance TM , iPhone TM ), laptop computers, PDAs, portable Internet devices, music players, data storage devices, other handheld devices, and wearable devices (e.g., watches, headphones, pendants, earphones, etc.). In general, the term "UE" or "UE device" may be broadly defined to encompass any electronic, computing, and / or telecommunication device (or combination of devices) that is easily transported by a user and that is capable of wireless communication.

[0076] Base Station - The term "base station" has the full breadth of its ordinary meaning and includes at least a wireless communication station installed in a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0077] Processing element - refers to various elements or combinations of elements. For example, a processing element includes a circuit such as an ASIC (Application Specific Integrated Circuit), a portion or circuit of a separate processor core, an entire processor core, a separate processor, a programmable hardware device such as a Field Programmable Gate Array (FPGA), and / or a larger portion of a system including multiple processors.

[0078] Automatically - refers to an action or operation performed by a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit system, a programmable hardware element, an ASIC, etc.) without user input directly specifying or performing the action or operation. Thus, the term "automatically" is in contrast to an operation manually performed or specified by a user, where the user provides input to directly perform the operation. An automatic process may be initiated by input provided by a user, but the subsequent actions performed "automatically" are not specified by the user, i.e., are not performed "manually," where the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each column and providing input specifying information (e.g., by typing in information, selecting checkboxes, radio selections, etc.) is manually filling out the form, even though the computer system must update the form in response to the user action. A form may be automatically filled out by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the columns of the form and fills out the form without any user input specifying the answers to the columns. As indicated above, a user may invoke automatic filling of a form, but is not involved in the actual filling out of the form (e.g., the user does not manually specify the answers to the columns, but rather they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions that a user has taken.

[0079] Figure 1 -User equipment

[0080] Figure 1 An example user equipment (UE) 106 according to some embodiments is shown. The term UE 106 may be any of the various devices as defined above. The UE device 106 may include a housing 12, which may be made of any of a variety of materials. The UE 106 may have a display 14, which may be a touch screen incorporating capacitive touch electrodes. The display 14 may be based on any of a variety of display technologies. The housing 12 of the UE 106 may contain or include openings for any of a variety of elements, such as a button 16, a speaker port 18, and other elements (not shown), such as a microphone, a data port, and possibly various types of buttons, such as a volume button, a ring button, and the like.

[0081] The UE 106 may support multiple radio access technologies (RATs). For example, the UE 106 may be configured to communicate using any of a variety of RATs, such as two or more of the following: Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access (CDMA) (e.g., CDMA2000 1XRTT or other CDMA radio access technologies), Long Term Evolution (LTE), Advanced LTE (LTE-A), and / or other RATs. For example, the UE 106 may support at least two radio access technologies, such as LTE and GSM. Various different or other RATs may be supported as needed.

[0082] In some embodiments, UE 106 is also configured to receive broadcast radio transmissions that may convey audio and / or video content. In other embodiments, UE 106 may be configured to receive broadcast radio transmissions and may not be configured to perform two-way communications with a base station (e.g., UE 106 may be a television).

[0083] Figure 2 - Overview of communication systems and spectrum sharing

[0084] Figure 2 An exemplary (and simplified) wireless environment including multiple communication systems is shown. In the illustrated embodiment, different UEs and broadcast receivers are configured to communicate via a broadcast network and / or a packet-switched cellular network. It should be noted that Figure 2 The system is only one example of a possible system, and embodiments may be implemented in any of a variety of systems as desired.

[0085] As shown, the exemplary wireless communication system includes base stations 102A and 102B that communicate over a transmission medium with one or more user equipment (UE) devices, represented as UEs 106A through 106C.

[0086] The cellular base station 102B may be a base transceiver station (BTS) or a cell site and may include hardware that enables wireless communication with UE 106B and UE 106C. In the illustrated embodiment, the base station 102B is also configured to communicate with the core network 100B. The core network 100B may also be coupled to one or more external networks (e.g., external network 108), which may include the Internet, a public switched telephone network (PSTN), and / or any other network. Thus, the base station 102B may facilitate communication between UE devices 106B and 106C and / or between UE devices 106B and / or 106C and networks 100B and / or 108.

[0087] Base station 102B and other base stations operating according to the same or different RAT or cellular communication standards can be provided as a network of cells, which can provide continuous or nearly continuous overlapping service to UE 106B and / or UE 106C and similar devices over a wide geographic area via one or more radio access technologies (RATs).

[0088] The broadcast base station 102A may be configured to broadcast multimedia content (e.g., video and audio content for TV transmissions) to multiple receivers such as UEs 106A and 106B. In the illustrated embodiment, the broadcast base station 102A is configured to communicate with an external network 108. In various embodiments, the broadcast base station 102A is also configured to communicate with one or more internal networks.

[0089] The term "broadcast" refers to a one-to-many transmission for receiving devices in a broadcast area rather than being addressed to specific devices. In addition, broadcast transmissions are typically unidirectional (from transmitter to receiver). In some cases, control signaling (e.g., rating information) may be transmitted from the receiver back to the broadcast transmitter, but content data is transmitted in only one direction. In contrast, cellular communications are typically bidirectional. "Cellular" communications may also involve handovers between cells. For example, when UE 106C (and / or UE 106B) moves out of a cell served by cellular base station 102B, it may switch to another cellular base station (and the handover may be handled by the network, including operations performed by base station 102B and another cellular base station). In contrast, when a user moves from an area covered by a first broadcast base station to an area covered by a second broadcast base station, it may switch to receiving content from the second broadcast base station, but the base stations do not need to facilitate the handover (e.g., they simply continue broadcasting and do not care which base station a particular UE is using).

[0090] Conventionally, broadcast transmissions are performed using frequency resources different from cellular transmissions. However, in some embodiments, frequency resources are shared between these different types of transmissions. For example, in some embodiments, broadcast base station 102A is configured to relinquish one or more frequency bands for use by cellular base station 102B for packet-switched communications during scheduled time intervals.

[0091] Dynamic spectrum sharing raises the potential for explicit coordination between networks to ensure seamless end-user connectivity. Dynamic spectrum sharing can provide a means for broadcast operators to earn additional revenue by temporarily relinquishing use of their spectrum holdings, in part or in full, to wireless carriers, e.g., pursuant to a written agreement expressed between the respective network operators. Configurable base stations that are proficient in the supplementation of the underlying signaling protocols can facilitate uninterrupted connectivity from end-user devices seeking access to broadcast or broadband services (or both) at a given point in time.

[0092] In some embodiments, control signaling sent by broadcast or cellular base stations can allow end-user devices to maintain full signaling connectivity (which can eliminate network perturbations), extend battery life (e.g., by determining when to remain in a low power mode when a base station is not transmitting), and / or actively manage coverage detection (e.g., rather than perceiving spectrum sharing periods as spotty coverage or temporary network outages).

[0093] Different levels of coordination can be utilized in various embodiments. In some embodiments, the broadcast operator can give up its spectrum to the cellular operator during the scheduled time period without intermediate signaling to the broadcast receiver. In these embodiments, the broadcast network is inaccessible during the duration of the postponement period, so that its receiver does not know the network status before the broadcast service is restored. This can be called a unilateral postponement. In some embodiments, the cellular operator can periodically blank its transmission to enable the broadcast operator to transmit control signaling to notify the broadcast receiver of its dormancy period. This can notify the broadcast receiver of the blanking period, but does not allow them to continue to receive broadcast data. This can be called a joint postponement. In some embodiments, the broadcast and cellular providers can fully coordinate and allow UEs and broadcast receivers to maintain uninterrupted connections to their respective networks. For example, the control signaling for broadcast transmissions can include sufficient synchronization information to allow broadcast receivers to receive broadcast content in active intervals (e.g., the intervals between broadcast blanking intervals during which cellular data is sent). In some embodiments, this can involve superimposing cellular synchronization and cell configuration parameters with broadcast frame parameters.

[0094] The base stations 102A and 102B and the UEs 106A, 106B, and 106C may be configured to communicate over a transmission medium using any of a variety of RATs (also referred to as wireless communication technologies or telecommunication standards), such as LTE, Next Generation Broadcast Platform (NGBP), W-CDMA, TDS-CDMA, and GSM, among other possible ones, such as UMTS, LTE-A, CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Advanced Television Systems Committee (ATSC) standards, Digital Video Broadcasting (DVB), etc.

[0095] Broadcast and cellular networks are discussed herein for ease of illustration, but these techniques are not intended to limit the scope of the present disclosure, and in other embodiments, the disclosed spectrum sharing techniques may be used between any of the various types of wireless networks.

[0096] Figure 3 - Base Station

[0097] Figure 3 An exemplary block diagram of a base station 102 is shown. In some embodiments, the base station 102 may be a broadcast base station (such as Figure 2 Base station 102A) and / or a cellular base station (such as Figure 2 Note that Figure 3 The base station of is only one example of a possible base station. As shown, the base station 102 may include a processor 304 that may execute program instructions for the base station 102. The processor 304 may also be coupled to a memory management unit (MMU) 340, which may be configured to receive addresses from the processor 304 and translate those addresses into locations in memory (e.g., memory 360 and read-only memory (ROM) 350) or to other circuits or devices.

[0098] The base station 102 may include at least one network port 370. The network port 370 may be configured to couple to a telephone network and provide multiple devices (such as the UE device 106) with access to the telephone network as described above. In some embodiments, the network port 370 (or an additional network port) may be coupled to a television network and configured to receive content for broadcast. The network port 370 (or an additional network port) may also or alternatively be configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to multiple devices (such as the UE device 106). In some cases, the network port 370 may be coupled to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., in other UE devices 106 served by a cellular service provider).

[0099] The base station 102 may include at least one antenna 334. The at least one antenna 334 may be configured to operate as a wireless transceiver and may be further configured to communicate with the UE device 106 via the radio 330. In the illustrated embodiment, the antenna 334 communicates with the radio 330 via a communication chain 332. The communication chain 332 may be a receive chain, a transmit chain, or both. The radio 330 may be configured to communicate via various RATs.

[0100] The processor 304 of the base station 102 may be configured to implement part or all of the methods described herein, for example, by executing program instructions stored on a storage medium (e.g., a non-transitory computer-readable storage medium). Alternatively, the processor 304 may be configured as a programmable hardware element, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit) or a combination thereof.

[0101] In some embodiments, the base station 102 is configured to perform both broadcast and bidirectional packet-switched communications. In these embodiments, the base station 102 may include, for example, multiple radios 330, communication links 332, and / or antennas 334. In other embodiments, the disclosed spectrum sharing techniques may be performed by different base stations configured to perform only broadcast transmissions or only packet-switched communications.

[0102] Figure 4 -User Equipment (UE)

[0103] Figure 4 An example simplified block diagram of a UE 106 is shown. As shown, the UE 106 may include a system on a chip (SOC) 400, which may include parts for various purposes. The SOC 400 may be coupled to various other circuits of the UE 106. For example, the UE 106 may include various types of memory (e.g., including NAND flash memory 410), a connector interface 420 (e.g., for coupling to a computer system, a docking station, a charging station, etc.), a display 460, a wireless communication circuit system 430 (such as for LTE, GSM, Bluetooth, WLAN and / or broadcast), etc. The UE 106 may also include one or more smart cards that implement SIM (Subscriber Identity Module) functions. The wireless communication circuit system 430 may be coupled to one or more antennas, such as an antenna 435.

[0104] As shown, SOC 400 may include a processor 402 that may execute program instructions for UE 106 and a display circuit system 404 that may perform graphics processing and provide display signals to a display 460. Processor 402 may also be coupled to a memory management unit (MMU) 440 that may be configured to receive addresses from processor 402 and translate those addresses into locations in memory (e.g., memory 406 or NAND flash memory 410) and / or to other circuits or devices, such as display circuit system 404, wireless communication circuit system 430, connector I / F 420, and / or display 460. MMU 440 may be configured to perform memory protection and page table translation or setup. In some embodiments, MMU 440 may be included as part of processor 402.

[0105] In some embodiments (not shown), UE 106 is configured to, for example, Figure 2 106 may include a broadcast radio receiver. In some embodiments, UE 106 is configured to simultaneously receive broadcast data and perform packet-switched cellular communications (e.g., LTE) using different frequency bands and / or using the same frequency resources during different time slices. This may allow a user to watch a television broadcast while performing other tasks such as browsing the Internet (e.g., in split-screen mode), using a web application, or listening to streaming audio. In other embodiments, the disclosed technology may be used in a system having a device configured as a broadcast receiver or for cellular communications but not both.

[0106] The processor 402 of the UE device 106 may be configured to implement some or all of the features described herein, for example, by executing program instructions stored on a storage medium (e.g., a non-transitory computer-readable storage medium). Alternatively (or additionally), the processor 402 may be configured as a programmable hardware element, such as an FPGA (field programmable gate array), or an ASIC (application-specific integrated circuit). Alternatively (or additionally), the processor 402 of the UE device 106 in combination with one or more of the other components 400, 404, 406, 410, 420, 430, 435, 440, 460 may be configured to implement some or all of the features described herein.

[0107] Figure 5 -Demonstration Broadcast Frame

[0108] Figure 5A general broadcast superframe structure 502 is shown in accordance with some embodiments. In the illustrated embodiment, the superframe occupies a duration of 1 second, which is independent of the underlying frame configuration. In some embodiments, this fixed duration can facilitate coordination with the cellular network transport layer. The illustrated superframe 502 includes a payload area 504 that carries actual payload data, and zero or more non-payload areas 506 and 508 that can carry control or other signaling information. In the illustrated example, the separate non-payload areas 506 and 508 are indicated by the shaded areas at the beginning and end of the frame 502. In this example diagram, the relative time length (horizontal axis) and number of symbols of each area may not be shown to scale.

[0109] In some embodiments, the initial non-payload area 506 is used as a preamble to provide initial synchronization and frame configuration to the receiver device. In some embodiments, the detection of a specific preamble can set the context through which the remaining preamble symbols are to be detected. For example, if the base station 102A abandons part of its spectrum to LTE, it can indicate the separate context signaled in the broadcast preamble as "private". In some embodiments, other fields can indicate various information to the receiving device, such as how long the transmission will be occupied and the bandwidth of the signal. For example, a broadcast receiver device can use this information to determine when to start monitoring broadcast data again. A cellular device can use this information to determine how long it can transmit data in a borrowed frequency band. In some embodiments, the broadcast receiver is configured to ignore superframes belonging to service contexts other than the service context that the broadcast device is equipped to receive.

[0110] Figure 6 -Exemplary Cellular Frame

[0111] Figure 6 An exemplary cellular radio frame (LTE frame in the illustrated example) is shown. In the illustrated embodiment, the cellular radio frame 602 includes a plurality of subframes 604. In the illustrated embodiment, each subframe is 1 ms in length and consists of two 0.5 ms time slots 606. In various embodiments, the illustrated frame may be used for bidirectional packet-switched cellular communications.

[0112] In the illustrated embodiment, the primary synchronization signal PSS and the secondary synchronization signal SSS are inserted into subframes 0 and 5 in time slots 0 and 10. The PSS can be transmitted identically in both subframes. The SSS content can be modified in the second instance of each frame, which can enable the UE to uniquely determine the start of a 10ms radio frame. In some embodiments, the PSS and SSS are followed by a physical broadcast channel (BCH) 610 only in the first subframe of the radio frame. The BCH can transmit frame configurations to broadband receivers. Note that the term "broadcast" in the context of the BCH refers to control signaling that is equally distributed to receivers within the LTE cell and is therefore different from the broadcast data content distributed by the broadcast base station.

[0113] Figure 7 - Exemplary signaling structure for coordination of spectrum sharing

[0114] Figure 7 The incorporation of common signaling into the LTE frame structure is shown. In various embodiments, control signaling may be used to indicate the time intervals during which the frequency band will be available. This may signal to broadcast and broadband receivers similar to the expected usage of the spectrum resources in any given frame period.

[0115] In the illustrated embodiment, the preamble 702 is sent in the first LTE subframe 704 corresponding to the start of the broadcast superframe duration 706. In some embodiments, this may require synchronizing the broadcast superframe with the LTE frame (e.g., in some embodiments, the superframe should start at the same time as the LTE frame). The preamble 702 may be a "hybrid" preamble in the sense that broadcast and cellular control signaling are transmitted by the respective network during the preamble interval. In some embodiments, this signaling may be transmitted using different time and / or frequency resources to avoid interference.

[0116] In some embodiments, the broadcast portion of the preamble 702 contains initial synchronization information plus any additional configuration parameters that the broadband provider wishes to announce in the broadcast cell. In some embodiments, the first broadcast symbol is sent in a normal broadcast mode, which can ensure robust signal detection. In the illustrated embodiment, the remaining symbols transmitted from the broadband base station are modified as necessary (e.g., by blanking at least a portion of the spectrum during these intervals) to accommodate signaling fields to the cellular receiver, such as PSS, SSS, and BCH, so that continuous network connectivity can be enabled despite the surrounding broadcast signaling.

[0117] Therefore, in some embodiments, the broadcast symbols overlapping the wideband signaling field 708 are notched to accommodate the PSS, SSS, and BCH. In some embodiments, these cellular fields nominally occupy 72 subcarriers around a center carrier at 15 kHz subcarrier spacing (1.080 MHz). In these embodiments, the broadcast base station 102A can zero the equivalent signal bandwidth to avoid compromising the integrity of the cellular signaling field.

[0118] Additionally, cellular base station 102B may suspend scheduling of user data when subframe zero overlaps broadcast preamble 702. The loss of data in a subframe available for user data scheduling (1 / 1000 in the illustrated embodiment) may be inexpensive relative to the ability to share spectrum with broadcast base station 102A. Normal cellular data scheduling may resume after subframe zero for the remainder of the superframe duration.

[0119] In some embodiments, a single base station (e.g., a base station configured for both broadcast and cellular transmissions) may be configured to transmit the entire preamble 702. Additionally, in some embodiments, a cellular base station may be configured to send a portion of the broadcast control signaling and / or vice versa to facilitate scheduling.

[0120] Demonstration spectrum sharing between LTE and NGBP

[0121] In some embodiments, the configurable eNB is configured to transmit NGBP (broadcast) and EUTRA (Evolved Universal Terrestrial Radio Access) (LTE, Long Term Evolution) (cellular) signals using similar bandwidth in the same spectrum by time interleaving the two signals. If the same base station (eNB, evolved Node B) is transmitting both signals, it may be relatively simple to maintain correct time alignment between the NGBP and EUTRA signals. In these embodiments, the eNB may transmit a single signal, portions of which correspond to the NGBP waveform, while other portions of the signal correspond to the EUTRA waveform. In other embodiments (e.g., embodiments in which different base stations are configured as broadcast-only or cellular-only), coordination between different networks may be required for time alignment.

[0122] For purposes of illustration, the embodiments discussed below utilize NGBP and LTE, but in other embodiments, similar techniques may be used for other broadcast and / or cellular protocols (e.g., NGBP, GSM, etc.), or may be used for protocols that are not broadcast or cellular in nature.

[0123] In some embodiments, MBSFN (multicast / broadcast single frequency network) subframes may be used by cellular networks for blanking to leave spectrum for broadcast transmission. In these embodiments, the EUTRA downlink signal may be configured with MBSFN subframes. In FDD (frequency division duplex) EUTRA systems, subframes 1, 2, 3 and 6, 7, 8 of each 10ms EUTRA radio frame may be configured as MBSFN subframes. MBSFN subframes may have the characteristic that EUTRA signals only need to be sent in the first 1 or 2 OFDM (orthogonal frequency division multiplexing) symbols of a 1ms subframe, while the remaining 13 or 12 OFDM symbols may be left blank respectively without a signal being transmitted. In particular, there is no need to transmit EUTRA reference symbols in OFDM symbols of the MBSFN area belonging to the MBSFN subframe. This means that a blank area with a time length of 0.857ms (12 OFDM symbols) or 0.929ms (13 OFDM symbols) may exist in each MBSFN subframe.

[0124] Assuming an example sampling rate of 12.288Msps (megasamples per second) for the NGBP signal, an MBSFN subframe with this blank region corresponds to approximately 10,500 or 11,400 samples available for use by the NGBP in the blank region of the MBSFN subframe for blank regions of 12 or 13 OFDM symbols in length, respectively. (Note that this is an example sampling rate, and higher sampling rates for the NGBP have also been proposed and can be selected in a dynamic manner.) For example, this set of samples is sufficient for two NGBP OFDM symbols using 4096 FFTs (Fast Fourier Transforms) or one NGBP OFDM symbol using 8192 FFTs plus an appropriately sized cyclic prefix.

[0125] The NGBP frame may be configured with multiple partitions, which may be referred to as physical partition data channels (PPDCHs). Exemplary techniques for forming a broadcast frame payload with multiple PPDCHs are discussed in U.S. Patent Application No. 14 / 805,004, "Multi-Partition Radio Frames," filed on July 21, 2015, issued as U.S. Patent No. 9,438,459 and incorporated herein by reference in its entirety. For time-interleaved NGBP and EUTRA signals, one or more PPDCHs may be configured to carry NGBP data during the blank region of the EUTRA MBSFN subframe, and one or more blanked PPDCHs may be configured to correspond to the active portion of the EUTRA signal. These latter NGBP PPDCHs may be configured so that NGBP signals (including suppressing any NGBP reference symbols) are transmitted during those PPDCHs so as not to interfere with the EUTRA signal. In some embodiments, the broadcast base station 102A is configured to notify the NGBP receiver that NGBP reference symbols will not be transmitted during the blank partitions, and the NGBP receiver may take this information into account when performing channel estimation.

[0126] In various embodiments or situations, the disclosed technology can be implemented using LTE time division duplex (TDD) radio frames, LTE frequency division duplex (FDD) radio frames, and / or other types of radio frames. Depending on the configuration of the cellular radio frame used, signaling information can be transmitted during different time and / or frequency portions of the cellular frame.

[0127] Figure 8 is a signal diagram showing exemplary time interleaving between broadcast and cellular transmissions according to some embodiments. This example uses a sampling rate of 12.288Msps for NGBP, but various sampling rates may be used as appropriate. Note that while Figure 8 Specific frequency bands are shown, but broadcast transmissions may or may not continue on other frequency bands during the period in which the shown frequency bands are abandoned.

[0128] In the example shown, PPDCH 0, 1, and 2 carry NGBP broadcast data. In this example, each of these PPDCHs is configured to use an FFT size of 4096 with a cyclic prefix length of 512 samples. In the embodiment shown, this results in a total of 9216 samples for two consecutive OFDM symbols, which fits into the blank area of ​​the EUTRA MBSFN subframe. (Alternatively, one OFDM symbol with an FFT size of 8192 and a cyclic prefix length of 1024 samples can be used for the same total length of 9216 samples.) In this example, PPDCH 0 has a periodicity of 5ms to cover MBSFN subframes 1 and 6, PPDCH 1 has a periodicity of 5ms to cover MBSFN subframes 2 and 7, and PPDCH 2 has a periodicity of 5ms to cover MBSFN subframes 3 and 8.

[0129] In the example shown, PPDCH 3 is a blank partition corresponding to the initial part of each MBSFN subframe (which carries an active EUTRA signal). A 1 ms EUTRA subframe corresponds to 12288 NGBP samples during the same time period. Of these samples, 9216 are allocated to PPDCH 0, 1 or 2, depending on the actual subframe index in question. This leaves 3072 samples for PPDCH 3, so it can be configured to use, for example, an OFDM symbol with an FFT size of 2048 and a cyclic prefix length of 1024 samples. PPDCH 3 can have a periodicity of 1 ms to cover the initial part of each subframe (and a small portion of the final part of the previous subframe in this example).

[0130] In the example shown, PPDCH 4 and 5 are blank partitions corresponding to the active EUTRA portion of non-MBSFN subframes 0, 4, 5 and 9. These two partitions may use the same configuration as the data carrying partitions 0, 1, 2 (i.e., two OFDM symbols with an FFT size of 4096 and a cyclic prefix length of 512 samples or one OFDM symbol with an FFT size of 8192 and a cyclic prefix length of 1024 samples and a periodicity of 5 ms).

[0131] In the illustrated embodiment, the shaded area represents the active transmission of the corresponding waveform, while the non-shaded area represents the inactive transmission of the corresponding waveform. It can be seen from the figure that the active part of the NGBP signal (PPDCH 0, 1 and 2) falls within the inactive part of the EUTRA signal (MBSFN part of EUTRA subframes 1, 2, 3 and 6, 7, 8) (and vice versa), so that there is no conflict between the two waveforms.

[0132] The following table summarizes the Figure 8 An exemplary NGBP PPDCH configuration is shown.

[0133]

[0134] In some embodiments, the control signaling transmitted in the NGBP frame (e.g., in the preamble at the beginning) may correspond to multiple LTE subframes. For example, the lengths of the PFCCH (physical format control channel) and PCCCH (physical content control channel) discussed in the '004 patent application and the corresponding '459 patent together may interfere with several EUTRA subframes. However, this may only occur once per NGBP frame, such as once per second. In addition, in some embodiments, the PFCCH and PCCCH positions are time-aligned with the MBSFN subframes to minimize the impact on EUTRA user devices. In some embodiments, the cellular base station 102B is configured to avoid scheduling transmissions to EUTRA devices during any overlapping periods with the NGBP PFCCH and PCCCH in order to reduce potential signal conflicts. Finally, in some embodiments, a specific preamble value for the PFCCH may be used to signal to the NGBP receiver that the PCCCH format is a special format (e.g., with some time gaps to avoid interfering with non-MBSFN subframes) rather than a normal NGBP signal.

[0135] In embodiments where a single base station is configured to transmit both EUTRA and NGBP signals, these signals may occupy the same (or similar) bandwidth with the same carrier frequency, which may avoid RF issues such as the need to re-tune the radio to a different frequency when switching between the two signals. In other embodiments, the signals may occupy different overlapping bandwidths and / or use different carrier frequencies.

[0136] Exemplary spectrum sharing embodiments for local / regional broadcasting

[0137] In some embodiments, spectrum sharing techniques may be used to share spectrum between broadcasts of local content and broadcasts of regional content (where regional content refers to content intended for a larger area than local content). In some embodiments, a single base station is configured to transmit both types of content, and is configured to transmit local content in some partitions of the broadcast frame and regional content in other partitions of the broadcast frame. In these embodiments, local / regional content may also be targeted to specific types of devices, such as mobile devices, fixed devices, etc.

[0138] In other embodiments, the regional broadcast base station and one or more local broadcast base stations can be configured to share spectrum. For example, the regional broadcast base station can be configured to blank a partition corresponding to transmissions by one or more local base stations. In these embodiments, the base stations can communicate to coordinate synchronization of broadcast frames and / or configure which base stations transmit or blank during which intervals.

[0139] In some embodiments, time slices of spectrum usage within the same frequency band may be allocated to: local broadcast content, regional broadcast content, and bidirectional packet-switched communications.

[0140] Exemplary coordination scheme for spectrum sharing

[0141] In some embodiments, spectrum may be allocated using an exchange by which broadcast providers can list the spectrum they are willing to give up and cellular providers can purchase use of the listed spectrum. Broadcast providers can list specific percentages of time they are willing to give up spectrum (e.g., based on partition sizes in broadcast frames that they are willing to blank), specific intervals they are willing to give up spectrum, etc. In some embodiments, the exchange may also allow providers to coordinate frame synchronization and configuration of which base stations are configured to blank during what time intervals.

[0142] In some embodiments, the centralized system is configured to determine and indicate the spectrum sharing configuration, but is not configured to do so via exchange. In some embodiments, decisions about how to share the spectrum can be made in a distributed manner. For example, a broadcast base station can determine its spectrum usage based on current programs and communicate its ability to relinquish spectrum to nearby cellular base stations. Nearby base stations (e.g., stations with overlapping coverage areas) can then coordinate spectrum sharing parameters between them in a decentralized manner. These communications between broadcast and / or cellular base stations may or may not be performed wirelessly. In some embodiments, fields for such communications may be added to the cellular and / or broadcast frame structures.

[0143] Figures 9 to 11 - Demonstration Method

[0144] Now go to Fig. 9 , a flow chart illustrating an exemplary embodiment of a method for operating a broadcast base station is shown. Fig. 9 The method shown in can be used in conjunction with any one of the computer circuit systems, systems, devices, elements or components disclosed herein and other devices. In various embodiments, some of the method elements shown can be performed simultaneously in a different order than shown, or can be omitted. Additional method elements can also be performed as needed.

[0145] At 910, broadcast base station 102A wirelessly broadcasts audio and video data to multiple broadcast receivers using a specific frequency band. In some embodiments, this can be a portion of the UHF band, which ranges from 470 MHz to 884 MHz. In other embodiments, any of a variety of frequency bands can be used.

[0146] At 920, broadcast base station 102A interrupts broadcasting on a specific frequency band during a scheduled time interval to enable one or more cellular base stations (e.g., cellular base station 102B) to use the specific frequency band for two-way packet-switched wireless data communications. In some cases, the specific frequency band may be only a portion of the spectrum that the broadcast base station is configured to transmit, while in other cases, the broadcast base station may abandon its entire spectrum. Figure 8 As shown, in some embodiments, the scheduled time interval may correspond to a portion of a 1 ms LTE subframe.

[0147] In some embodiments, the base station is configured to transmit on a specific frequency band during other scheduled time intervals (e.g., during other subframes of a specific LTE frame). In some embodiments, the base station is configured to transmit control signaling to a receiving user device, and the control signaling indicates the time intervals during which the broadcasting base station will blank transmissions.

[0148] Now go to Fig.10 , a flow chart illustrating an exemplary embodiment of a method for operating a cellular base station is shown. Fig.10 The method shown in can be used in conjunction with any one of the computer circuit systems, systems, devices, elements or components disclosed herein and other devices. In various embodiments, some of the method elements shown can be performed simultaneously in a different order than shown, or can be omitted. Additional method elements can also be performed as needed.

[0149] At 1010, the cellular base station 102B performs two-way packet-switched communications with one or more mobile devices using a first frequency band. The first frequency band may be a frequency band allocated to a cellular provider associated with the base station 102B for cellular communications.

[0150] At 1020, cellular base station 102B performs communications with one or more mobile devices using the second frequency band during the scheduled time interval. In the illustrated embodiment, the second frequency band is used to wirelessly broadcast audio and video data to multiple devices during one or more time intervals other than the scheduled time interval. For example, the second frequency band may be allocated to a broadcast provider associated with broadcast base station 102A. However, the broadband provider may agree not to use at least a portion of its spectrum during the scheduled time interval. In some embodiments, cellular base station 102B may include multiple radio devices configured to communicate using different first and second frequency bands. Cellular base station 102B may notify the UE to communicate via the second frequency band during the scheduled time interval.

[0151] Now go to Fig.11 , a flowchart illustrating an exemplary embodiment of a method for operating a UE is shown. Fig.11The method shown in can be used in conjunction with any one of the computer circuit systems, systems, devices, elements or components disclosed herein and other devices. In various embodiments, some of the method elements shown can be performed simultaneously in a different order than shown, or can be omitted. Additional method elements can also be performed as needed.

[0152] At 1110, the UE performs bidirectional packet-switched wireless data communications with the base station using the first frequency band. In some embodiments, this may be performed within a cellular frequency band, which may vary from country to country, but is typically specified in a 10 MHz to 100 MHz frequency band between 700 MHz and 3600 MHz.

[0153] At 1120, the UE performs bidirectional packet-switched wireless data communications using the second frequency band during the scheduled time intervals in response to receiving the control signaling from the base station. In the illustrated embodiment, the second frequency band is used to wirelessly broadcast audio and video data to multiple devices during one or more time intervals other than the scheduled time intervals. This can allow the UE to communicate using a frequency band that is typically reserved for broadcast transmissions, which can increase data rates, reduce power consumption, increase battery life, etc. relative to communicating in a congested frequency band.

[0154] Overview of example ATSC 3.0 physical layer frames and example cellular standards

[0155] Fig.12 An overview of an ATSC 3.0 physical layer frame is shown. ATSC 3.0 frames are discussed here for purposes of illustration and are not intended to limit the scope of the present disclosure. Similar techniques may be applied to physical layer frames of any of the various broadcast standards.

[0156] The details of the ATSC 3.0 frame are described in Section 7.2.2.1 of the Advanced Television Systems Committee's "ATSC Standard: Physical Layer Protocol" document A / 322:2017 (hereinafter referred to as "A / 322") dated June 6, 2017. As can be seen, each physical layer frame includes a bootstrap portion at the beginning of the frame, followed by a preamble portion containing control signaling information, and then one or more subframes containing actual payload data in the form of a physical layer pipe (PLP).

[0157] A typical ATSC 3.0 broadcast waveform includes multiple physical layer frames time-division multiplexed together in the same RF channel. Fig.13 An example of one such time division multiplexing of physical layer frames is shown.

[0158] ATSC 3.0 physical layer frames are either time aligned or symbol aligned. A time aligned frame has a total length corresponding to an integer multiple of 5 ms, ranging from 50 ms to 5 s (inclusive). A symbol aligned frame typically has a frame length that is not an integer number of milliseconds, where the total frame length of the symbol aligned frame is equal to the sum of the lengths of the pilot symbol and the OFDM symbols containing the preamble and the subframe portion of the frame. The length of the symbol aligned frame may be measured in samples, where the sampling rate depends on the configured system bandwidth of the ATSC 3.0 waveform, as shown in the following table of ATSC 3.0 sampling rates as a function of system bandwidth

[0159]

[0160] An ATSC 3.0 physical layer frame always starts with a preamble, which serves as an entry point into the physical layer frame. That is, an ATSC 3.0 receiver will search for the preamble to identify the start of an ATSC 3.0 physical layer frame and synchronize with it.

[0161] The pilot has a very unique structure that allows it to be easily recognized by the receiver. The pilot also carries a small number of very robust signaling fields to indicate initial information that the receiver can use to start decoding the rest of the physical layer frame.

[0162] One of the pilot signaling fields is min_time_to_next, which indicates the time window during which the next pilot of the same version will appear, as discussed in section 6.1.1.1 of "ATSC Standard: A / 321, System Discovery and Signaling" document A / 321:2016 (hereinafter "A / 321") of the Advanced Television Systems Committee, dated March 23, 2016. An ATSC 3.0 receiver may optionally use this information along with the length of the corresponding physical layer frame to determine when to search for a pilot that identifies the start of the next physical layer frame of interest.

[0163] EUTRA (LTE) is used herein as an example wireless communication system or radio access technology (RAT). This RAT is discussed, for example, in 3GPP TS 36.300, “EUTRA: Overview”, V15.3.0 (2018-09) (“36.300”). The discussion of EUTRA herein is not intended to limit the scope of the present disclosure. The techniques disclosed herein may also be applied to various other wireless systems, such as 3GPP 5G NR. Example 5G NR parameters are discussed in 3GPP TS 38.300, “NR and NG-RAN Overview” V15.3.1 (2018-10).

[0164] The EUTRA frame has a duration of 10 ms and consists of ten subframes, each of which has a duration of 1 ms, as described in Section 4 of 3GPP TS 36.211, "EUTRA: Physical channels and modulation", V15.3.0 (2018-09) ("36.211"). Each frame is indexed by a system frame number (SFN) ranging from 0 to 1023 (inclusive). Thus, a complete SFN cycle corresponds to a time period of 10.24 seconds.

[0165] An EUTRA handset (or UE (User Equipment)) can be instructed to transmit data, receive data, or both within a given subframe. Similarly, an EUTRA base station (BS) can transmit data, receive data, or both for a particular subframe. In addition, it is also possible for the UE and BS to remain idle (i.e., without transmission or reception) for one or more subframes, it being understood that the scheduling of data transmission in the uplink (UE to BS) or downlink (BS to UE) direction is under the control of the BS. In other cellular standards, in addition to or instead of subframes, the UE can be instructed to transmit, receive, or remain idle at other granularities.

[0166] Discontinuous Reception (DRX) operation for EUTRA is specified in Section 5.7 of 3GPP TS 36.321, "EUTRA: Medium Access Control (MAC) Protocol Specification", V15.3.0 (2018-09) ("36.321"). In some embodiments, DRX allows the UE to stop monitoring the Physical Downlink Control Channel (PDCCH) for a certain period of time, which essentially allows the UE to disable reception and transmission during this period of time. DRX is often used as a power saving measure for battery operated UEs.

[0167] In its simplest form, a DRX cycle corresponds to a specific length of time divided into active time (when the UE may be actively receiving and / or transmitting) and inactive time (when the UE is not actively receiving or transmitting).

[0168] A number of different UE-specific timers control when a UE is considered to be in active time (and conversely, when a UE is considered to be in inactive time). These timers can be configured on a per-UE basis and can be configured very precisely to control the duration of activity. In addition, a DRX command MAC control element (discussed in section 6.1.3.3 of 36.321) can be sent to the UE to instruct the UE to stop certain DRX-related timers, which typically results in the UE immediately entering inactive time.

[0169] Fig.14An example of DRX activity at a UE is shown, where the DRX cycle length is 40 subframes (40ms), and the active time of the DRX cycle is 10 subframes (10ms). Therefore, the inactive time length of this DRX cycle is 30ms.

[0170] Each active UE on a particular EUTRA carrier may be individually configured for DRX operation with DRX parameters that are independent of the configuration of any other UE (i.e., a particular UE may be configured with DRX parameters that are the same or different from the DRX parameters of another UE). DRX parameters include, but are not limited to, the length of the DRX cycle, the amount of active time, and the specific starting point of the DRX cycle for the UE (specific subframe).

[0171] The DRX cycle time length may include, but is not necessarily limited to, {10, 20, 32, 40, 64, 80, 128, 160, 256, 320, 512, 640, 1024, 1280, 2048, 2560} ms. The DRX on duration timer value (which may control the amount of active time) may include, but is not necessarily limited to, {1, 2, 3, 4, 5, 6, 8, 10, 20, 30, 40, 50, 60, 80, 100, 200} ms. The DRX cycle start offset (i.e., when active time is considered to begin) may be set between 0 and 1 less than the DRX cycle length, inclusive. (See the MAC-MainConfig information element in section 6.3.2 of 36.331.)

[0172] The following discussion relates to techniques for sharing spectrum between cellular communications, such as EUTRA communications, and broadcast physical frames, such as ATSC 3.0 frames.

[0173] Example spectrum sharing technology with time interval between consecutive broadcast frames

[0174] In some embodiments, the disclosed technology facilitates dynamic sharing of spectrum between multiple radio access technologies (RATs). In various embodiments of dynamic sharing, each of the shared RATs can transmit frequently enough (e.g., at least once every few seconds, and more preferably once or more per second) to support near real-time operation. Near real-time operation means that many applications, such as video or audio broadcasting, web browsing, email, streaming, document downloading, etc., can be supported in a manner transparent to the end user, but applications that require real-time two-way communication (e.g., voice conversations) may not operate in a sufficiently satisfactory manner for the end user.

[0175] The shared RF spectrum involved in the present disclosure can originate from any participating RAT. For example, the RF spectrum may have been initially allocated to ATSC 3.0 for use, but then may be dynamically shared between ATSC 3.0 and EUTRA transmissions for a certain time period (or possibly an infinite time period) before finally reverting to full-time ATSC 3.0 transmission. Similarly, the RF spectrum may have been initially allocated to EUTRA for use, but then may be dynamically shared between EUTRA and ATSC 3.0 transmissions for a specific time period (or possibly an indefinite time period) before finally reverting to full-time EUTRA transmission. The system bandwidths of ATSC 3.0 and EUTRA transmissions may be the same or different from each other. In the latter case, a narrower bandwidth ATSC 3.0 signal may be transmitted in a wider bandwidth EUTRA RF channel allocation, or a narrower bandwidth EUTRA signal may be transmitted in a wider bandwidth ATSC 3.0 RF channel allocation. In addition, shared spectrum may be used to expand other spectrum allocated to a specific RAT, for example, using carrier aggregation or channel bonding.

[0176] Each of the multi-RAT transmissions originates from a transmitter capable of transmitting a waveform according to the corresponding RAT. The multi-RAT transmissions may originate from different transmitters (e.g., separate ATSC 3.0 and EUTRA transmitters) and / or the same transmitter (e.g., a transmitter capable of transmitting ATSC 3.0 and EUTRA waveforms). In the case of separate transmitters, the transmitters may be co-located or may be located in different geographic locations.

[0177] Similarly, a receiver in the context of the present disclosure may receive signals from one or more of the RATs associated with a transmitted waveform. For example, a receiver may receive only the ATSC 3.0 portion of a transmitted signal, only the EUTRA portion of a transmitted signal, or both the ATSC 3.0 and EUTRA portions of a transmitted signal.

[0178] In some embodiments, consecutive ATSC 3.0 physical layer frames are transmitted with a time gap between frames. As described above, the min_time_to_next signaling field in the guide indicates the time window in which the next guide of the same version is located, but there is no explicit requirement that the next guide will appear at the exact position within the time window, nor is there a requirement that the time window be positioned so that it includes the end of the current physical layer frame.

[0179] Fig.15A shows an example of a series of ATSC 3.0 physical layer frames with relatively small time gaps between consecutive frames, while Fig. 15B An example of a series of ATSC 3.0 physical layer frames is shown with relatively large time gaps between consecutive frames.

[0180] Through a carefully constructed broadcast schedule of programs and corresponding physical layer configuration, the data being broadcast (e.g., video, audio, subtitles, etc.) can be encoded and packaged into time-separated physical layer frames, such as Fig.15A and Fig. 15B In some embodiments, the receiver is configured to buffer the decoded data and play the data according to the specified time points to provide the end user with the appearance of continuous playback regardless of the time discontinuity in the ATSC 3.0 transmission waveform. This can advantageously provide playback while allowing spectrum sharing with another RAT between frames.

[0181] For example, Fig.16 A technique is shown where cellular transmissions may occur between each broadcast frame in a set of frames (three frames in the example shown) (e.g., during a DRX active interval). In this example, ATSC 3.0 transmissions may occupy 6 MHz of system bandwidth (as in North America), while EUTRA transmissions occupy 5 MHz of bandwidth. EUTRA transmissions may represent a downlink or uplink of a time division duplex (TDD) system or a frequency division duplex (FDD) system.

[0182] Fig.16 A separate single continuous ATSC 3.0 physical layer frame separated by a time gap is shown with an EUTRA transmission inserted therein. Note that in some embodiments, this figure is exemplary only, and multiple continuous ATSC 3.0 frames may be transmitted before a time gap occurs. For example, in some cases, a gap may be scheduled between a set of two consecutive broadcast frames or between a set of three consecutive broadcast frames while still maintaining near real-time shared spectrum communications. In some embodiments, gaps may be scheduled between sets of consecutive broadcast frames of different sizes (e.g., having a gap followed by a single broadcast frame, a gap, two consecutive broadcast frames, a gap, a single broadcast frame, etc.). In addition, gap intervals of various lengths between broadcast frames may be scheduled at different points in the frame sequence.

[0183] This can be managed by configuring all active UEs in a EUTRA cell to have the same or similar DRX cycle. Fig.16 . As shown, the EUTRA UE is configured to wake up from DRX (and enter DRX active time) at the beginning of a time gap between consecutive ATSC 3.0 frames, and enter DRX at the end of the same time gap. In this way, the EUTRA UE should not expect to receive EUTRA transmissions during the time period when ATSC 3.0 frames are transmitted.

[0184] An exemplary DRX configuration sets the DRX cycle length to 256 ms and the DRX On Duration timer to 100 ms. By setting the DRX cycle start offset appropriately (e.g., to 153) and using time-aligned ATSC 3.0 physical layer frames with a length of 150 ms, an exemplary time division multiplexing of ATSC 3.0 and EUTRA transmissions as shown in the following table can be achieved. It is not mandatory to use time-aligned ATSC 3.0 frames; for example, symbols of appropriate length can be used instead to align ATSC 3.0 frames.

[0185] Relative time period Transfer activity 0-150ms ATSC 3.0 physical layer frame 150-153ms Protection period between ATSC 3.0 and EUTRA 153-253ms EUTRA transmission 253-256ms Protection period between EUTRA and ATSC 3.0 256+ms Transmission cycle repeats

[0186] Conventionally, a EUTRA base station regularly and / or periodically transmits at least the following signals and physical channels on the downlink: a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a cell-specific reference signal (CRS) and a positioning reference signal (PRS). Conventionally, during normal EUTRA operation, for one or more UEs, the above transmissions will continue during the DRX inactive time.

[0187] The following discussion provides techniques for processing the above-mentioned signals and physical channels when different RATs are time-division multiplexed into the same RF channel. In some embodiments, the EUTRA base station continues to transmit its regularly transmitted signals and physical channels as needed during the time period in which the ATSC 3.0 transmission occurs. If the relative transmission power of the ATSC 3.0 transmitter is significantly greater than the transmission power of the EUTRA base station, the EUTRA transmission will appear as a small amount of interference to the ATSC 3.0 transmission, which can be eliminated by selecting a sufficiently robust ATSC 3.0 configuration. Despite the presence of interfering ATSC 3.0 transmissions, any EUTRA UE that happens to be active will be able to detect those EUTRA transmissions.

[0188] In other embodiments, the EUTRA base station suspends all transmissions, including any regularly transmitted signals and physical channels, during the time period in which ATSC 3.0 transmissions occur. In this way, no interference is generated with active ATSC 3.0 transmissions.

[0189] In order to enable a UE to utilize a EUTRA carrier that is time-division multiplexed with an ATSC 3.0 transmission, there should be some feasible method to allow the UE to connect to the carrier, keeping in mind that the EUTRA carrier will only be available for a portion of the time during multiplexed operation. The following discussion assumes that the EUTRA transmission that is time-division multiplexed with an ATSC 3.0 transmission represents the downlink of a TDD system or an FDD system.

[0190] Note that Table 11.2-1 in Section 11.2 of 36.331 specifies the expected time to complete a number of different RRC procedures in EUTRA, ignoring any delays caused by the Random Access procedure. Typically, an RRC connection reconfiguration (including handover within EUTRA) is expected to complete within 15ms to 20ms, and the Random Access procedure may take another 20ms to 40ms depending on the system configuration related to supporting random access.

[0191] EUTRA cells broadcast system information, which provides parameters and other data about the configuration of the cell, which in turn allows the UE to connect to the cell. For example, there are multiple system information blocks (SIBs), the contents of which the UE should know before connecting to the corresponding cell. The Master Information Block (MIB) provides the information required by the UE to obtain System Information Block 1 (SIB1). The MIB has a fixed broadcast schedule with a period of 40ms, and different redundant versions of the MIB are broadcast every 10ms within the 40ms period. SIB1 contains scheduling information about the broadcast schedule of the remaining system information blocks and other parameter values. SIB1 has a fixed broadcast schedule with a period of 80ms, and different redundant versions of SIB1 are broadcast every 20ms within the 80ms period. SIB2 contains the remaining information required by the UE that has moved to or is already in the RRC_CONNECTED state. SIB2 has a configurable broadcast schedule that is signaled in SIB1.

[0192] In some embodiments, the time division multiplexing cellular cell is configured to broadcast the relevant system information block only during the DRX active time. In some embodiments, the cell is configured to broadcast the data according to the required scheduling rules regardless of whether the DRX active time is valid. In the latter case, the transmission of system information during ATSC 3.0 transmission may appear as interference to the ATSC 3.0 transmission.

[0193] In some embodiments, the cellular network is configured to schedule system information such as SIB2 so that it appears earlier in the DRX active time period in order to allow the UE to quickly acquire SIB2. For example, this can allow the UE to connect in the interval between broadcast frames. However, note that in the EUTRA example, the UE may first need to acquire the MIB and then SIB1 before acquiring SIB2, so the system information scheduling should take this into account to ensure that the UE has enough time to sequentially acquire these three information blocks within the same DRX active time period.

[0194] In some embodiments, the network is configured to set the system information modification period to a larger value (e.g., by configuring larger values ​​for modificationPeriodCoeff and defaultPagingCycle (see the RadioResourceConfigCommon information element in section 6.3.2 of 36.331)) to increase the amount of time that the acquired system information can be considered valid.

[0195] In some embodiments, depending on the actual time length of the DRX active time period, the UE may acquire system information of a time-division multiplexed EUTRA carrier during one DRX active time period before initiating a connection to an EUTRA base station in the next DRX active time period.

[0196] When a EUTRA UE attempts to connect to a cell, a certain amount of time is required to perform tasks such as the random access procedure (which may require multiple attempts to transmit the random access preamble), requesting a connection from the controlling base station, receiving configuration information from the base station, etc. In some embodiments, a sufficient amount of time is provided between consecutive ATSC 3.0 frames so that all of these tasks can be performed within the same DRX active time period. In this sense, Fig. 15B The time division multiplexing arrangement shown in can be superior to Fig.15A The time division multiplexing arrangement shown in , as the former provides longer continuous time periods during which EUTRA is active.

[0197] Depending on when the UE begins transmitting the random access preamble to initiate a connection, the UE may be temporarily unable to receive a random access response if an ATSC 3.0 frame is being transmitted. Therefore, in some embodiments, a parameter for the maximum allowed number of random access preamble transmission attempts (before the UE determines that the random access procedure has failed) is set to a large value. This may allow the UE to begin a random access procedure at the end of a first DRX active time period, continue to transmit random access preambles during an inactive time period (during which ATSC 3.0 transmissions are active and the UE will therefore not receive a random access response), and then successfully complete the random access procedure during a subsequent DRX active time period.

[0198] Furthermore, the EUTRA base station may, upon detecting a random access preamble determined to be potentially affected by time division multiplexing, endeavor to provide a random access response as quickly as possible in order to minimize the turnaround time during the random access procedure.

[0199] In some embodiments, a larger time gap is periodically inserted between two consecutive ATSC 3.0 frames to provide more time for the UE to connect to the EUTRA cell during the longer time period. Fig.17 This concept is illustrated in the example of . It can be seen that one of the regularly spaced ATSC 3.0 frame intervals has been omitted, allowing the previous EUTRA transmission to be extended over a time period equal in length to two DRX active time periods and one ATSC 3.0 frame. This provides a longer time opportunity for the UE to connect to the EUTRA base station during the interval. Such intervals may be inserted periodically or according to some other schedule.

[0200] In some embodiments, if the UE first connects to another EUTRA cell (the source cell), or even a non-EUTRA cell, and then switches to a EUTRA carrier that is time division multiplexed with ATSC 3.0 transmissions (referred to herein as a TDM carrier), this can reduce the time required for the UE to connect to the TDM carrier. After connecting to the first EUTRA cell, the UE will already be in the RRC_CONNECTED state, which eliminates the need to request an RRC connection with the TDM carrier. In addition, system information for the TDM carrier can be provided to the UE as part of the handover message, which eliminates the need to obtain system information from the TDM carrier before connecting to the TDM carrier (although the system information for the TDM carrier still needs to be verified by the UE after the handover is completed).

[0201] If a handover from a different EUTRA cell is performed to bring the UE onto a TDM carrier, then in some embodiments the source cell is configured to appropriately time the transmission of the handover message to the UE so that the UE begins its connection to the TDM carrier at the start of the DRX active time of the carrier, thereby advantageously increasing the amount of time available to complete the handover before the end of the DRX active time.

[0202] The above-mentioned technology for facilitating UE to connect to the EUTRA carrier multiplexed with ATSC 3.0 transmission time division can work with minimal changes or no changes required by EUTRA specification. However, for such UE, it may be useful to realize that EUTRA operation is multiplexed with other wireless transmission time division, and therefore EUTRA signal will basically disappear during periodic intervals. It may be necessary to incorporate it into EUTRA specification. Alternatively, UE that can identify this mode of operation and react accordingly can be designed or modified. This is particularly possible for dual-mode UE that may receive ATSC 3.0 and EUTRA transmissions, which are time-division multiplexed together in the same RF channel. In some embodiments, such UE is configured to receive a constant RF sample stream for a common system bandwidth (representing the maximum value of the configured ATSC 3.0 and EUTRA system bandwidths), and then process those RF samples accordingly according to whether the current time period represents ATSC 3.0 or EUTRA transmission.

[0203] In some embodiments, the UE may operate with multiple component carriers in the downlink direction. That is, the UE is able to receive data simultaneously on two or more EUTRA carriers, each of which is in a separate frequency band. In such a multi-carrier configuration, the UE may receive control signaling on one carrier (e.g., on the PDCCH), wherein the control signaling indicates the relevant downlink transmission for the UE on any of the multiple carriers that have been configured for the UE. The carrier that carries the control signaling for the UE may be referred to as a PCell (primary cell), and any supplementary carrier that is also configured for the UE may be referred to as an SCell (secondary cell).

[0204] The UE may first connect to a non-time division multiplexed EUTRA carrier in a first frequency band, which is then configured as the PCell of the UE. The UE may then additionally configure a supplementary time division multiplexed EUTRA carrier as an SCell in a second frequency band. In some embodiments, the base station may schedule SCell transmissions to the UE on the TDM SCell carrier only during time periods when ATSC 3.0 transmissions do not occur. In some embodiments, the base station may schedule PCell transmissions to the UE instead of SCell transmissions during time periods when ATSC 3.0 transmissions occur. In some embodiments, the UE may be configured to enter DRX on the SCell carrier and / or PCell carrier during time periods when ATSC 3.0 transmissions occur.

[0205] exist Fig.15A and Fig. 15B In the ideal case of the example ATSC 3.0 transmission shown, it can be seen that the RF power in the transmitted signal will rise suddenly from zero to full power at the beginning of the physical layer frame, and will similarly fall suddenly from full power to zero at the end of the physical layer frame.

[0206] In fact, any such sudden changes in transmit power can cause unwanted spurious RF emissions, which can cause interference to other wireless signals. This is especially true for high-power ATSC 3.0 transmitters where there is a lot of power in the transmit waveform. In these high-power situations, if there are such sudden fluctuations in RF power, it can actually damage the RF components of the transmitter. The following discussion proposes at least two solutions to this problem.

[0207] In a high-power ATSC 3.0 transmitter, it may not be possible to cut off the RF transmission power during time intervals where the absence of ATSC 3.0 physical layer frames is expected. However, in some embodiments, the transmitter is configured to direct RF power only to certain portions of the spectrum, leaving the remainder of the available spectrum occupied by cellular transmissions. In this way, signals from an ATSC 3.0 transmitter may appear as specific frequency interference to an EUTRA transmitter, where the latter transmitter is configured to schedule its transmissions in portions of the spectrum that are not occupied (or temporarily idle) by the ATSC 3.0 transmitter. Typically, as Fig.18 As shown on the left side of FIG, the average power distribution across the spectrum of the ATSC 3.0 waveform will appear substantially constant. During the time periods when EUTRA transmissions are scheduled, the broadcast power from the ATSC 3.0 transmitter can be directed to the band edge of the available spectrum, where EUTRA transmitters utilize the center portion of the band, such as Fig.18 as shown on the right. Fig.18 This ATSC 3.0 transmission in may not be a valid ATSC 3.0 transmission, but may represent the transmission of pseudo data on an OFDM carrier belonging to the corresponding frequency interval. There may be a frequency gap or frequency guard interval between the pseudo ATSC 3.0 transmission and the EUTRA transmission in order to mitigate any adjacent channel interference to the EUTRA transmission. Note that Fig.18 This is just an example, and ATSC transmitters may direct their broadcast power to other parts of the available spectrum. This may be accomplished in OFDM-based systems such as ATSC 3.0 (and EUTRA) by modulating OFDM carriers in one part of the spectrum at a greater than normal power, while not modulating (i.e., applying nulls, zero, or significantly reduced power) OFDM carriers in other parts of the spectrum reserved for EUTRA operation.

[0208] In other embodiments, a transmitter (e.g., a low power local ATSC 3.0 transmitter) is able to cut off its RF transmission power without damaging the RF circuitry and other RF components. However, this may take a small but non-zero amount of time to go from full power to zero and vice versa. Thus, a small time gap or guard interval may be left between the end of the ATSC 3.0 frame and the start of the EUTRA transmission to allow for this transition. A similar guard period may be located between the end of the EUTRA transmission and the start of the ATSC 3.0 frame. This guard period may prevent possible mutual interference between ATSC 3.0 transmissions and EUTRA transmissions that have been time division multiplexed into the same RF spectrum. This is particularly useful in Fig.19 Furthermore, when the two transmissions originate from different transmitters and / or from different geographical locations, the guard period will also mitigate any mutual interference that may occur due to any possible offset in the time synchronization between the different transmitters.

[0209] exist Fig.19 In FIG. 1 , the ramps of the ATSC 3.0 and EUTRA transmission powers are shown as non-overlapping. This is exemplary only, and the ramp-down and ramp-up periods of the different transmissions may or may not overlap in time. It should also be noted that Fig.19 The durations shown in FIG. 1 (and various diagrams herein) are not necessarily drawn to scale and, in some cases, are exaggerated for illustrative purposes.

[0210] It is generally expected that EUTRA base stations have lower transmit power than high-power ATSC 3.0 transmitters, and therefore turning their RF power on and off should be less problematic. In particular, this dynamic transmit power on / off functionality already exists in EUTRA functions such as TDD operation (e.g., Section 4.2 of 36.211), MBSFN subframes (where PMCH and MBSFN reference signals are not transmitted in the MBSFN area of ​​the MBSFN subframe (36.211 and Sections 6.1 and 6.10.2)), and almost blank subframes (Section 16.1.5 of 36.300). Turning the RF power on and off at the EUTRA base station can be handled accordingly.

[0211] ***

[0212] The embodiments described in this disclosure may be implemented in any of a variety of forms. For example, some embodiments may be implemented as computer-implemented methods, computer-readable storage media, or computer systems. Other embodiments may be implemented using one or more custom-designed hardware devices such as ASICs. Other embodiments may be implemented using one or more programmable hardware elements such as FPGAs.

[0213] In some embodiments, a non-transitory computer-readable storage medium may be configured to store program instructions and / or data, wherein the program instructions, when executed by a computer system, cause the computer system to perform a method, such as any one of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any one of the method embodiments described herein, or any combination of such subsets.

[0214] In some embodiments, an apparatus (e.g., a UE, a broadcast receiver, or a base station) may be configured to include a processor (or a group of processors) and a storage medium, wherein the storage medium stores program instructions, wherein the processor is configured to read and execute program instructions from the storage medium, wherein the program instructions are executable to implement any of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any method embodiments described herein, or any combination of such subsets). The processor may be, for example, a central processing unit (CPU) or a digital signal processor (DSP). The apparatus may be implemented in any of various forms.

[0215] Although the above embodiments have been described in considerable detail, numerous changes and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the appended claims be interpreted to encompass all such changes and modifications.

Claims

1. A method for performing shared spectrum access in wireless communication, the method comprising: wirelessly broadcasting, by a broadcast base station, a common set of audio and video data to a plurality of broadcast receiver devices using a specific frequency band and a set of three or more consecutive broadcast frames, wherein each broadcast frame in the set of three or more consecutive broadcast frames includes a preamble, wherein the broadcast base station does not receive content data from any of the broadcast receiver devices; and An interrupt is broadcast between each of the broadcast frames in the set of broadcast frames based on one or more predetermined durations between broadcast frames to enable one or more cellular base stations to perform cellular packet switched wireless data communications using the particular frequency band. 2 . The method of claim 1 , further comprising directing transmit power to one or more portions of the specific frequency band to achieve the blackout. The method of claim 1 , wherein the interrupting the broadcast comprises reducing a broadcast transmission power during a guard interval.

4. The method of claim 1, wherein at least one of the durations is sufficient for a cellular device to obtain system information and connect to one of the one or more cellular base stations.

5. A method for performing shared spectrum access in wireless communication, the method comprising: performing cellular packet switched communications with one or more mobile devices using a specific frequency band by a cellular base station; and During a broadcast frame transmission scheduled from a broadcast base station, communication using the specific frequency band is interrupted by the cellular base station, wherein the execution of the cellular packet switched communication occurs between each broadcast frame of a group of three or more consecutive broadcast frames, wherein each broadcast frame in the group of three or more consecutive broadcast frames includes a preamble code.

6. The method according to claim 5, further comprising: During the intervals between scheduled broadcast frames, active discontinuous reception intervals are scheduled for one or more user equipment devices.

7. The method according to claim 6, further comprising: A specific set of system information is transmitted only during active DRX intervals.

8. The method according to claim 5, further comprising: The specific group system information is transmitted within a threshold time interval after the scheduling of one of the broadcast frames ends.

9. The method according to claim 5, further comprising: The handoff to the cellular base station is timed to occur within a threshold time interval after a scheduled end of one of the broadcast frames.

10. The method of claim 5, wherein the interruption comprises interrupting transmission of a regularly transmitted signal in the specific frequency band.

11. The method according to claim 5, further comprising: Cellular packet switched communication with at least one of the one or more mobile devices is performed using another frequency band as a primary carrier, wherein the specific frequency band is a secondary carrier.

12. The method according to claim 11, further comprising: Control signaling of the secondary carrier is transmitted via the primary carrier.

13. A device configured to perform shared spectrum access in wireless communication, the device comprising: One or more processing elements configured to: receiving and decoding a plurality of consecutive broadcast frames in a group of three or more consecutive broadcast frames from a broadcast base station using a specific frequency band to determine broadcast audio and video data, wherein each broadcast frame in the group of three or more consecutive broadcast frames includes a preamble; and During a predetermined time interval between each of the broadcast frames in the set of three or more consecutive broadcast frames, cellular packet switched communications are performed with one or more cellular base stations using the specific frequency band.

14. The device of claim 13, wherein the device is configured to automatically determine the predetermined time interval based on a leading portion of the broadcast frame.

15. The apparatus of claim 13, wherein at least one of the predetermined time intervals is sufficient for a cellular device to obtain system information and connect to one of the one or more cellular base stations.

16. The device of claim 13, wherein the device is configured to use active discontinuous reception intervals for cellular communications during the predetermined time intervals between the broadcast frames.

17. The device of claim 13, wherein the device is further configured to perform cellular packet switched communications with the one or more cellular base stations using another frequency band as a primary carrier, wherein the specific frequency band is used as a secondary carrier.

18. The apparatus of claim 17, wherein the apparatus is further configured to receive control signaling of the secondary carrier via the primary carrier.

Images