CN108476458B

CN108476458B - Discovery of PBCH transmissions to UEs operating in unlicensed bands inside and outside of a reference signal transmission window

Info

Publication number: CN108476458B
Application number: CN201680079487.4A
Authority: CN
Inventors: F·哈米迪赛贝尔; 叶悄扬; 全晸鍸; 牛华宁; 权桓俊
Original assignee: Apple Inc
Current assignee: Apple Inc
Priority date: 2016-02-19
Filing date: 2016-08-19
Publication date: 2021-03-09
Anticipated expiration: 2036-08-19
Also published as: WO2017142589A1; CN108476458A

Abstract

A base station may occasionally transmit a Physical Broadcast Channel (PBCH) outside of and within a Discovery Reference Signal (DRS) transmission window (DTxW). In some embodiments, the UE may use a Redundancy Version (RV) scrambling code of a Master Information Block (MIB) contained in the PBCH to avoid ambiguity at the UE and to determine whether the PBCH is inside or outside DTxW.

Description

Discovery of PBCH transmissions to UEs operating in unlicensed bands inside and outside of a reference signal transmission window

RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patent application No. 62/297,411 filed on 2016, 2, 19, the contents of which are incorporated herein by reference as if fully set forth herein.

Background

Wireless telecommunications networks typically include a Radio Access Network (RAN) that enables User Equipment (UE), such as smartphones, tablets, laptops, etc., to connect to a core network. An example of a wireless telecommunications network may include an Evolved Packet System (EPS) operating based on third generation partnership project (3GPP) communication standards. In cellular networks, UEs typically communicate with base stations using channels corresponding to licensed wireless spectrum (e.g., wireless spectrum designated for cellular network communications).

Such as Licensed Assisted Access (LAA), Carrier Aggregation (CA),

Etc. may be used to extend the connectivity of a UE to the core network using unlicensed spectrum, and examples include 5 gigahertz (GHz) unlicensed spectrum for Wi-Fi and other unlicensed uses proposed by the Federal Communications Commission (FCC) in the united states. Some of these techniques, such as LAA and CA, may require the UE to keep a carrier (also referred to as an "anchor") from the licensed spectrum in order to use the carrier in the unlicensed spectrum. In contrast, other technologies (such as "stand-alone technologies") referred to herein as "stand-alone technologies

) The UE may be enabled to obtain a network connection without an anchor point from the licensed spectrum.

For standalone technologies, system information (including a Master Information Block (MIB)) needs to be transmitted in the unlicensed spectrum because there is no anchor point in the licensed spectrum.

Drawings

The embodiments in the present embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. For convenience of description, the same reference numerals may denote the same structural elements. Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

FIG. 1 is a diagram of an exemplary environment in which systems and/or methods described herein may be implemented;

fig. 2 is a diagram illustrating an example of a subframe including a Discovery Reference Signal (DRS) transmission window (DTxW);

FIGS. 3 and 4 are flowcharts illustrating exemplary processing related to MIB transmission inside and outside of DTxW;

FIG. 5 is a block diagram conceptually illustrating an exemplary embodiment of transmit-side components for transmitting MIBs inside and outside of a DTxW;

FIG. 6 is a block diagram conceptually illustrating an exemplary embodiment of receive-side components for transmitting MIBs inside and outside of a DTxW; and

FIG. 7 illustrates, for one embodiment, exemplary components of an electronic device.

Detailed Description

The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents.

Systems operating in unlicensed spectrum are described herein (e.g.,

system) for Physical Broadcast Channel (PBCH) transmission outside of DTxW. In particular, a transmitting node (e.g., a base station) may opportunistically transmit PBCH outside of DTxW. In some embodiments, the UE may use a Redundancy Version (RV) scrambling code of the MIB contained in the PBCH to avoid ambiguity at the UE and to determine whether the PBCH is inside or outside of DTxW. Advantageously, can improve

Reliability of PBCH transmission in the system. Moreover, the techniques described herein may help reduce UE acquisition time for PBCH under different Listen Before Talk (LBT) conditions.

FIG. 1 is an illustration of an exemplary environment 100 in which systems and/or methods described herein may be implemented. Environment 100 may include a plurality of UEs 110, a wireless telecommunications network, and external networks and devices.

The wireless telecommunications network may include an Evolved Packet System (EPS) including a Long Term Evolution (LTE) network and/or an Evolved Packet Core (EPC) network operating based on a third generation partnership project (3GPP) wireless communication standard. The LTE network may be or may include a RAN that includes one or more base stations, such as eNB 120 and/or Wireless Local Area Network (WLAN) Access Points (APs) 130, via which UE 110 may communicate with the EPC network. The ENB 120 may be designed to operate using licensed spectrum and the WLAN AP130 may be designed to operate using unlicensed spectrum.

The EPC network may include a Serving Gateway (SGW)140, a PDN Gateway (PGW)150, and a Mobility Management Entity (MME) 160. As shown, the EPC network may enable UE 110 to communicate with external networks (labeled external networks and devices), such as Public Land Mobile Networks (PLMNs), Public Switched Telephone Networks (PSTNs), and/or Internet Protocol (IP) networks (e.g., the internet).

The UE 110 may include portable computing and communication devices, such as Personal Digital Assistants (PDAs), smart phones, cellular phones, laptop computers capable of connecting to wireless telecommunication networks. UE 110 may also include non-portable computing devices such as desktop computers, consumer or business devices, or other devices having the capability to connect to a RAN of a wireless telecommunications network. The UE 110 may also include computing and communication devices (also referred to as wearable devices) that the user may wear, such as watches, fitness bands, necklaces, glasses, lenses, rings, belts, headsets, or other types of wearable devices.

UE 110 may be designed to connect to a wireless telecommunications network via a licensed frequency band (e.g., through eNB 120) and/or an unlicensed frequency band (e.g., through WLAN AP 130). In one embodiment, the UE 110 may use CA and/or LAA technology to connect to the wireless telecommunications network using licensed and unlicensed frequencies. Alternatively, and as described in detail herein, UE 110 may use a technique such as

To connect to the wireless telecommunications network using only the WLAN AP130 (i.e., not communicating through the eNB 120). For example, when UE 110 is within wireless communication range of WLAN AP130 but not within range of eNB 120, use is made of

May be particularly useful.

eNB 120 may include one or more network devices that receive, process, and/or transmit traffic (e.g., via an air interface) to UE 110 and/or received from UE 110. The eNB 2120 may coordinate with the WLAN AP130 to implement LAA, CA, etc. in order to increase network resources (e.g., uplink and/or downlink bandwidth) of the wireless telecommunications network.

WLAN AP130 may include one or more network devices that receive, process, and/or transmit traffic (e.g., via an air interface) to UE 110 and/or received from UE 110. In some embodiments, the WLAN AP130 may implement a standalone (e.g., non-anchored) version of the 3GPP LTE communication standard in the 5 gigahertz (GHz) unlicensed spectrum proposed by the Federal Communications Commission (FCC) for Wi-Fi and other unlicensed uses. In some embodiments, this may include implementing

Technology or other types of independent communication standards. The WLAN AP130 may also coordinate with the eNB 120 to implement LAA, CA, etc., in order to increase network resources (e.g., uplink and/or downlink bandwidth) of the wireless telecommunications network.

The SGW 140 may aggregate traffic received from one or more enbs 120 and/or WLAN APs 130 and may transmit the aggregated traffic to an external network or device via the PGW 150. Additionally, the SGW 140 may aggregate traffic received from one or more PGWs 150 and may transmit the aggregated traffic to one or more enbs 120 and/or WLAN APs 130. The SWW140 may operate as an anchor for the user plane during inter-eNB handover and as an anchor for mobility between different telecommunication networks.

MME 160 may include one or more computing and communication devices that serve as a control node for eNB 120 and/or other devices that provide an air interface for a wireless telecommunications network (e.g., WLAN AP 130). For example, the MME 160 may perform operations to register the wireless telecommunication network with the UE 110 to establish a bearer channel (e.g., traffic flow) associated with a session of the UE 110, to handover the UE 110 to a different eNB, MME, or another network, and/or to perform other operations. MME 160 may perform policing operations on traffic to UE 110 and/or received from UE 110.

PGW 150 may include one or more network devices that may aggregate traffic received from one or more SGWs 140 and may send the aggregated traffic to an external network. PGW 150 may also or alternatively receive traffic from an external network and may transmit traffic to UE 110 (via eNB 120 and/or WLAN 130).

The number of devices and/or networks shown in fig. 1 is provided for purposes of explanation only. In practice, there may be additional devices and/or networks, fewer devices and/or networks, different devices and/or networks, or devices and/or networks arranged differently than shown in FIG. 1. Alternatively or additionally, one or more devices of system 100 may implement one or more functions described as being implemented by another one or more devices of system 100. Further, while "direct" connections are shown in fig. 1, these connections should be construed as logical communication paths, and in fact one or more intermediate devices (e.g., routers, gateways, modems, switches, hubs, etc.) may be present.

For the

DTxW is defined as a window in which eNB 120 may transmit DRS. In LTE systems, DRS is transmitted to enable UEs to facilitate small cell on/off switching. For example, the UE may use the DRS to perform cell detection, Radio Resource Management (RRM) measurements, and/or to determine appropriate time and frequency compensation parameters for the channel. Signals included in the DRS may include, for example, Primary Synchronization Signals (PSS), Secondary Synchronization Signals (SSS), cell-specific reference signals (CRS), and optionally channel state information reference signals (CSI-RS). For the

The system, PBCH carrying MIB may be additionally inserted into DRS.

To increase transmission opportunities, the location of DRS transmissions within DTxW may be variable (i.e., floating). For example, the DRS may be transmitted within any subframe of DTxW. In that

The specific location of the DRS within DTxW may be specified using a 3-bit field offset transmitted in the MIB. 3 bitsA field may be used to convey an offset value from a particular subframe number, such as relative to

subframe

0 or 5. The MIB may additionally include system control information, such as system bandwidth information and other control information that may be needed for the UE to communicate with a network communication cell. For example, the MIB may include a 3-bit bandwidth information field, a 3-bit physical hybrid ARQ indicator channel (PHICH) configuration field, and an 8-bit System Frame Number (SFN) field, in addition to the 3-bit offset field.

In addition to being able to transmit MIB in DTxW (via PBCH), WLAN AP 120 may opportunistically transmit PBCH outside DTxW (e.g., subject to LBT and based on eNB implementation) at subframe 0 of the frame.

Fig. 2 is a diagram illustrating an example of a subframe including a Discovery Reference Signal (DRS) transmission window (DTxW). Fig. 2 may particularly illustrate a channel diagram related to the use of Resource Elements (REs) in an Orthogonal Frequency Division Multiplexing (OFDM) transmission scheme. In fig. 2, the frequency domain is shown on the vertical axis, and the time domain is shown on the horizontal axis.

A single subframe 210 is shown in fig. 2. The subframes may be based on a particular carrier bandwidth (e.g., 5MHz, 10MHz, or 20 MHz). The total carrier bandwidth may be divided into a number of OFDM subcarriers. For example, each subcarrier may have a bandwidth of 15kHz or 7.5 kHz. In subframe 210, each subcarrier may be used to transmit a particular number of symbols (illustrated as 14 symbols, labeled as symbols 0 through 13 in fig. 2). The symbol may represent the smallest discrete portion of a frame/subframe. In various embodiments, the symbols may represent 2, 4, or 6 bits of information per symbol.

As described above, the subframe 210 may be a subframe designated to include DTxW, and thus may include DRS information. As shown in fig. 2, DRSs may be transmitted with various resource elements (e.g., OFDM symbols) of subframe 210 designated as CRS, PSS, SSS, CSI-RS, and PBCH resource elements. The resource elements corresponding to the PBCH may be particularly used for transmitting the MIB. As shown in fig. 2, PBCH may be transmitted using

symbols

4, 7, 8, 9, 10, and 11. These symbols may be used for PBCH inside and outside DTxW.

Although the MIB may be transmitted every 10ms, the information content (i.e., payload) of the MIB may change less frequently (e.g., every 40 ms). In this case, UE 110 may receive four redundant MIBs. Each of the four redundant MIBs may be encoded using one of four predefined Redundancy Version (RV) scrambling codes. Different RVs may result in the MIB being scrambled with different sequences.

As previously described, the MIB may include a 3-bit information field to indicate to the UE 110 the location of the DRS as a subframe offset value. At the UE 110, this may potentially cause problems when the MIB is transmitted outside of DTxW, since outside of DTxW, if the MIB is transmitted, it is always transmitted in subframe 0.

Fig. 3 is a flow diagram illustrating exemplary processing 300 related to MIB transmissions inside and outside of DTxW. Process 300 may be performed by, for example, UE 110.

Process 300 may include decoding a MIB received in a subframe (block 310). Decoding by UE 110 may generally include modulation or demodulation, descrambling, and de-rate matching. In one embodiment, the decoding may be performed by a baseband processor of UE 110. When descrambling the MIB, UE 110 may test the MIB to determine whether to encode the MIB using RV0 (redundancy version 0), RV1 (redundancy version 1), RV2 (redundancy version 2), or RV3 (redundancy version 3). In one embodiment, UE 110 may concurrently descramble the MIB using each of RV0, RV1, RV2, and RV 3. Thus, UE 110 may determine which redundancy version scrambling code (i.e., RV0, RV1, RV2, or RV3) to use based on which descrambled MIB is valid. In this manner, UE 110 may perform hypothesis testing to identify the RV scrambling code used to encode the MIB.

Process 300 may also include determining whether the redundancy version matches a predetermined redundancy version (block 320). In one embodiment, the predetermined redundancy version may be RV 0.

When the redundancy version matches a predetermined version value (e.g., RV0), this may be a signal to UE 110, i.e., the DRS is transmitted within DTxW. In this case, UE 110 may use the MIB offset field (i.e., the 3-bit offset field) to locate the subframe corresponding to the DRS (and thus the PBCH) (block 320-yes; block 330).

When the redundancy version does not match the predetermined version value (e.g., the RV value is not RV0), this may be a signal to UE 110, i.e., the DRS is transmitted outside of DTxW. In this case, the UE may determine that the PBCH is located at subframe 0 (block 320-no; block 340). UE 110 may effectively ignore the offset field (block 340). Thus, outside of DTxW, the MIB may still contain subframe offset information, but the UE 110 may ignore the subframe offset information.

Based on the location of the PBCH/DRS, the UE may continue to process the PBCH/DRS (block 350) as determined by the UE based on whether the 3-bit offset field is used (block 330) or ignored (block 340). Specifically, UE 110 may process the PBCH/DRS in a normal manner to obtain control information.

Fig. 4 is a flow diagram illustrating exemplary processing 400 related to MIB transmission inside and outside of DTxW. The process 400 may be performed by, for example, the WLAN AP130 (or eNB 120).

Process 400 may include opportunistically determining to transmit PBCH outside of DTxW (block 410). For example, to increase the transmission opportunity for the MIB, WLAN AP130 may determine to transmit the MIB in the PBCH outside of DTxW. In this case, PBCH may be transmitted at subframe 0 of the frame. PBCH may be opportunistically transmitted, which may refer to transmission of PBCH subject to LBT constraints. In LBT, the WLAN AP130 may "listen" to a particular channel before using the channel, and may use the channel only when it is determined that the channel is not being used by another device (e.g., a WiFi access point) (e.g., the interference of the channel is less than a threshold).

Process 400 may also include encoding the MIB with a redundancy version other than the predetermined redundancy version (block 420). As discussed with respect to fig. 3, in one embodiment, the predetermined redundancy value may be 0(RV 0). Thus, WLAN AP130 may encode the MIB using RV1, RV2, or RV 3. Process 400 may also include transmitting the PBCH (including the MIB) (block 430). By encoding the MIB with a redundancy version that is not the predetermined RV version, WLAN AP130 may signal UE 110 that PBCH is being transmitted outside of DTxW. Within DTxW, a predetermined redundancy version (e.g., RV0) may always be used. In this manner, the MIB may be opportunistically transmitted every 10ms outside of DTxW, however, only the predetermined RV version (e.g., RV0) is transmitted within DTxW.

Fig. 5 is a block diagram conceptually illustrating an exemplary embodiment of transmit-side components for transmitting MIB inside and outside DTxW. For example, the components of fig. 5 may be implemented by baseband processing logic in the WLAN AP130 (or eNB 120). The components of fig. 5 may be used to implement the process of fig. 4.

As described above, the MIB may include system control information required by the UE to be able to properly access and operate within the wireless telecommunications network. The MIB may be a 40-bit block, which may include multiple fields.

Tail-biting convolutional code (TBCC)510 may initially encode the 40 bits MIB with 1/3 rate tail-biting convolutional code to obtain 120 bits of encoded information. The encoded 120 bits may be repeated 16 times by the rate matcher 520, which may result in 2880 output bits. The scrambler 530 may operate to scramble 2880 output bits. Scrambling may be performed according to one of four 3GPP standardized scrambling techniques (i.e., RV0, RV1, RV2, or RV 3). In one embodiment, and as discussed with respect to fig. 4, scrambling may be performed by WLAN AP130 such that RV0 is used when the MIB is within DTxW. In addition to DTxW, one of RV1, RV2, and RV3 may be used instead. The output of the scrambler 530 may include 2880 scrambled bits. In some embodiments, the bit sequence may be 0-padded before or after scrambling by the scrambler 530.

The scrambled bits may then be divided into 4 parts (blocks) by a partitioner 540. Each block may be 720 bits, and the 720-bit block may be transmitted continuously every 10 ms. The WLAN AP130 may generate a new MIB every 40 ms.

Fig. 6 is a block diagram conceptually illustrating an exemplary embodiment of receive side components for transmitting MIB inside and outside DTxW. The components of fig. 6 may be implemented, for example, by baseband processing logic in UE 110. The components of fig. 6 may be used to implement the process of fig. 3.

Data received by UE 110 via the wireless link with WLAN AP130 may be processed to perform, for example, demodulation, OFDM processing, and Resource Element (RE) demapping (block 610) (shown as being performed by demodulation, OFDM processing, and RE demapping component 610). For the MIB, a sequence of 720 bits (i.e., the output of the process shown in fig. 5) may be received (e.g., every 10 ms).

Descrambler 620 may descramble the 720-bit sequence based on the correct redundancy version scrambling code. In one embodiment, descrambler 620 may perform a hypothesis test on the redundancy versions by performing descrambling using all possible redundancy version scrambling codes until a valid descrambled bit sequence is obtained. In some embodiments, all four redundancy version scrambling codes may be applied in parallel to obtain a correctly descrambled bit sequence (e.g., 720 bits). Descrambler 620 may additionally output an indication (RV) of the detected redundancy version scrambling code.

The output of descrambler 620 may be input to a de-rate matcher 630, which may de-rate match the sequence at a rate of 1/6. The output of the down matcher 630 may include a 120-bit sequence, which may be input to a decoder 640. The decoder 640 may perform TBCC decoding using 1/3 rate tail-biting convolutional codes to obtain 40 bits of payload data of the MIB.

Although the above description generally discusses a MIB having a length of 40 bits, in different embodiments MIB lengths other than 40 bits may be used. For example, different rate matching values and coded redundancy values may be used to modify the MIB length. In some embodiments, instead of 40 bits, the MIB length may be specifically set to 30 or 32 bits. More specifically, in one embodiment, the MIB payload may have a length of X bits (e.g., X equals 30, 32, or 40 bits). The MIB payload may be TBCC encoded at a rate of 1/3 and the resulting sequence of 3X bits may be repeated 4n times by a rate matcher with the output being 12X n X bits, where n is an integer (e.g., 6 or 7). The rate matched bits may then be scrambled. The scrambled bits may be divided into 4 blocks, and each block may be QPSK modulated to obtain (3nX-Y)/2 OFDM symbols and mapped to (3nX-Y)/2 REs for transmission every 10ms (where Y depends on X, n and available REs).

As used herein, the term "circuitry" or "processing circuitry" may refer to, be part of, or include: an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with, one or more software or firmware modules. In some embodiments, the circuitry may comprise logic that operates, at least in part, in hardware.

The embodiments described herein may be implemented into a system using suitably configured hardware and/or software. Fig. 7 illustrates, for one embodiment, exemplary components of an electronic device 700. In an embodiment, the electronic device 700 may be a UE, an eNB, a WLAN AP, or some other suitable electronic device. In some embodiments, electronic device 700 may include application circuitry 702, baseband circuitry 704, Radio Frequency (RF) circuitry 706, front-end module (FEM) circuitry 708, and one or more antennas 760, coupled together at least as shown. In other embodiments, any of the circuits may be included in different devices.

The application circuitry 702 may include one or more application processors. For example, the application circuitry 702 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled to and/or may include memory/storage and may be configured to: the instructions stored in the memory/storage are executed to enable various applications and/or operating systems to run on the system. In some implementations, the storage medium 703 may include a non-transitory computer-readable medium. The memory/storage may include, for example, computer-readable media 703, which may be non-transitory computer-readable media. In some embodiments, the application circuitry 702 may be connected to or include one or more sensors, such as environmental sensors, cameras, and the like.

The baseband circuitry 704 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. Baseband circuitry 704 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of RF circuitry 706 and to generate baseband signals for a transmit signal path of RF circuitry 706. Baseband circuitry 704 may be connected with application circuitry 702 for generating and processing baseband signals and controlling operation of RF circuitry 706. For example, in some embodiments, the baseband circuitry 704 may include a second generation (2G) baseband processor 704a, a third generation (3G) baseband processor 704b, a fourth generation (4G) baseband processor 704c, and/or other baseband processors 704d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 704 (e.g., one or more of the baseband processors 704 a-d) may process various radio control functions that enable communication with one or more radio networks via the RF circuitry 706. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, and the like. In some implementations, the baseband circuitry 704 may be associated with the storage medium 703 or with another storage medium.

In some embodiments, the modulation/demodulation circuitry of baseband circuitry 704 may include Fast Fourier Transform (FFT), precoding, and/or constellation mapping/demapping functionality. In some embodiments, the encoding/decoding circuitry of baseband circuitry 704 may include convolution, tail-biting convolution, turbo, viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functions are not limited to these examples, and other suitable functions may be included in other embodiments. In some embodiments, baseband circuitry 704 may include elements of a protocol stack, such as, for example, elements of an Evolved Universal Terrestrial Radio Access Network (EUTRAN) protocol, including, for example, Physical (PHY) elements, MAC elements, Radio Link Control (RLC) elements, PDCP elements, and/or Radio Resource Control (RRC) elements. The Central Processing Unit (CPU)704e of the baseband circuitry 704 may be configured to: elements of the protocol stack are run for signaling at the PHY, MAC, RLC, PDCP, and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio Digital Signal Processors (DSPs) 704 f. The audio DSP 704f may include elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments.

The baseband circuitry 704 may also include memory/storage 704 g. The memory/storage 704g may be used to load and store data and/or instructions for operations performed by the processor of the baseband circuitry 704. Memory/storage for one embodiment may include any combination of suitable volatile memory and/or non-volatile memory. Memory/storage 704g may include any combination of various levels of memory/storage, including but not limited to Read Only Memory (ROM) with embedded software instructions (e.g., firmware), random access memory (e.g., Dynamic Random Access Memory (DRAM)), cache, buffers, and the like. The memory/storage 704g may be shared among the various processors or may be dedicated to a particular processor.

In some embodiments, components of the baseband circuitry may be combined as appropriate in a single chip, a single chipset, or disposed on the same circuit board. In some embodiments, some or all of the constituent components of baseband circuitry 704 and application circuitry 702 may be implemented together, such as, for example, on a system on a chip (SOC).

In some embodiments, baseband circuitry 704 may provide communications compatible with one or more wireless technologies. For example, in some embodiments, the baseband circuitry 704 may support communication with E-UTRAN and/or other Wireless Metropolitan Area Networks (WMANs), WLANs, or Wireless Personal Area Networks (WPANs). Embodiments in which the baseband circuitry 704 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

The RF circuitry 706 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 706 may include switches, filters, amplifiers, and the like to facilitate communication with the wireless network. RF circuitry 706 may include a receive signal path that may include circuitry to down-convert RF signals received from FEM circuitry 708 and provide baseband signals to baseband circuitry 704. RF circuitry 706 may also include a transmit signal path, which may include circuitry to up-convert baseband signals provided by baseband circuitry 704 and provide an RF output signal to FEM circuitry 708 for transmission.

In some embodiments, RF circuitry 706 may include a receive signal path and a transmit signal path. The receive signal path of RF circuit 706 may include a mixer circuit 706a, an amplifier circuit 706b, and a filter circuit 706 c. The transmit signal path of RF circuitry 706 may include filter circuitry 706c and mixer circuitry 706 a. RF circuitry 706 may further include synthesizer circuitry 706d for synthesizing the frequencies used by mixer circuitry 706a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuit 706a of the receive signal path may be configured to: the RF signal received from the FEM circuit 708 is downconverted based on the synthesized frequency provided by the synthesizer circuit 706 d. The amplifier circuit 706b may be configured to: the downconverted signal is amplified, and the filter circuit 706c may be a Low Pass Filter (LPF) or a Band Pass Filter (BPF) configured to: unwanted signals are removed from the down-converted signal to generate an output baseband signal.

The output baseband signal may be provided to baseband circuitry 704 for further processing. In some embodiments, the output baseband signal may be a zero frequency baseband signal, but this is not required. In some embodiments, mixer circuit 706a of the receive signal path may comprise a passive mixer, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 706a of the transmit signal path may be configured to: the input baseband signal is upconverted based on the synthesized frequency provided by synthesizer circuit 706d to generate an RF output signal for FEM circuit 708. The baseband signal may be provided by baseband circuitry 704 and may be filtered by filter circuitry 706 c. Filter circuit 706c may include a Low Pass Filter (LPF), although the scope of the embodiments is not limited in this respect.

In some embodiments, mixer circuit 706a of the receive signal path and mixer circuit 706a of the transmit signal path may include two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion, respectively. In some embodiments, mixer circuit 706a of the receive signal path and mixer circuit 706a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, mixer circuit 706a of the receive signal path and mixer circuit 706a of the transmit signal path may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, mixer circuit 706a of the receive signal path and mixer circuit 706a of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, RF circuitry 706 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and baseband circuitry 704 may include a digital baseband interface to communicate with RF circuitry 706.

In some dual-mode embodiments, separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

In some embodiments, synthesizer circuit 706d may be a fractional-N synthesizer or a fractional-N/N +6 synthesizer, although the scope of embodiments is not so limited as other types of frequency synthesizers may be suitable. For example, the synthesizer circuit 706d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase locked loop with a frequency divider.

The synthesizer circuit 706d may be configured to: the output frequency used by mixer circuit 706a of RF circuit 706 is synthesized based on the frequency input and the divider control input. In some embodiments, the synthesizer circuit 706d may be a fractional N/N +6 synthesizer.

In some embodiments, the frequency input may be provided by a Voltage Controlled Oscillator (VCO), but this is not required. The divider control input may be provided by the baseband circuitry 704 or the application processor 702, depending on the desired output frequency. In some embodiments, the divider control input (e.g., N) may be determined from a look-up table based on the channel indicated by the application processor 702.

Synthesizer circuit 706d of RF circuit 706 may include a divider, a Delay Locked Loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the divider may be a dual-mode divider (DMD) and the phase accumulator may be a Digital Phase Accumulator (DPA). In some embodiments, the DMD may be configured to: the input signal is divided by N or N +6 (e.g., based on a carry) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay elements may be configured to decompose the VCO period into Nd equal phase groups, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, the synthesizer circuit 706d may be configured to: a carrier frequency is generated as the output frequency, while in other embodiments the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with a quadrature generator and divider circuit to generate a plurality of signals at the carrier frequency having a plurality of different phases relative to each other. In some embodiments, the output frequency may be the LO frequency (fLO). In some embodiments, the RF circuitry 706 may include an IQ/polar converter.

FEM circuitry 708 may include a receive signal path, which may include circuitry configured to operate on RF signals received from one or more antennas 760, amplify the received signals, and provide amplified versions of the received signals to RF circuitry 706 for further processing. FEM circuitry 708 may further include a transmit signal path, which may include circuitry configured to amplify signals provided by RF circuitry 706 for transmission by one or more of the one or more antennas 760.

In some embodiments, FEM circuitry 708 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a Low Noise Amplifier (LNA) to amplify the received RF signal and provide the amplified received RF signal as an output (e.g., to RF circuitry 706). The transmit signal path of the FEM circuitry 708 may include: a Power Amplifier (PA) to amplify an input RF signal (e.g., provided by RF circuitry 706); and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 760).

In some embodiments, electronic device 700 may include additional elements, such as memory/storage, a display, a camera, sensors, and/or input/output (I/O) interfaces. In some embodiments, the electronic device of fig. 7 may be configured to perform one or more methods, processes, and/or techniques, such as those described herein.

A number of examples will be given below relating to embodiments of the above-described techniques.

In a first example, a baseband apparatus for a User Equipment (UE) of a cellular network may include one or more processors to: processing, for a wireless subframe within a Discovery Reference Signal (DRS) transmission window (DTxW) and received via an unlicensed frequency band, a Physical Broadcast Channel (PBCH) containing control information for connecting with a cellular network, the PBCH located within the DTxW at a particular subframe of a plurality of subframes within the DTxW, wherein the PBCH within the DTxW is received using at least Orthogonal Frequency Division Multiplexing (OFDM)

symbols

4, 7, 8, 9, 10, and 11 of the particular subframe; and processing PBCH from radio subframes that are not within DTxW and that are received via the unlicensed frequency band at radio subframe 0, wherein processing radio subframes that are inside and outside of DTxW includes identifying a Master Information Block (MIB) structure from PBCH that are inside and outside of DTxW.

In example 2, the subject matter of example 1 or any example herein, wherein the specific subframe is indicated as an offset value relative to

subframe

0 or 5 included in the MIB or an earlier MIB.

In example 3, the subject matter of example 1 or any example herein, wherein the one or more processors are further to: descrambling the MIB using a plurality of Redundancy Version (RV) scrambling codes; determining which one of a plurality of RV scrambling codes obtains effective descrambling of the MIB; and ignoring the offset value when the determined RV scrambling code does not match the predetermined RV scrambling code.

In example 4, the subject matter of example 3 or any example herein, wherein the RV scrambling code is 720 bits in length.

In example 5, example 1 or 2, or the subject matter of any example herein, wherein the MIB within the DTxW is scrambled using Redundancy Version (RV) 0.

In example 6, the subject matter of example 1 or 2, or any example herein, wherein the one or more processors are further to: descrambling the MIB by using a plurality of redundancy version scrambling codes; performing speed reduction matching on the descrambled version of the MIB at a rate of one sixth; and tail-biting convolutional decoding (TBCC) is performed on the down-matched output.

In example 7, the subject matter of example 1 or any example herein, wherein the MIB structure is periodically identified at 10 millisecond intervals.

In an eighth example, a UE comprises logic to: processing a Physical Broadcast Channel (PBCH) containing control information for connecting with a cellular network for subframes received within a Discovery Reference Signal (DRS) transmission window (DTxW) and via an unlicensed frequency band, the PBCH located at a particular subframe of a plurality of subframes within DTxW, the processing comprising descrambling the PBCH with a Redundancy Version (RV)0 scrambling code; processing a PBCH from a subframe that is not within DTxW and that is received via an unlicensed frequency band at subframe 0, processing subframe 0 comprising descrambling the PBCH using an RV scrambling code other than RV 0; wherein processing the subframe of DTxW includes identifying a Master Information Block (MIB) structure from PBCH within DTxW and not within DTxW.

In example 9, the subject matter of example 8 or any example herein, wherein the PBCH within DTxW is received using at least Orthogonal Frequency Division Multiplexing (OFDM)

symbols

4, 7, 8, 9, 10, and 11 of a particular subframe.

In example 10, example 8 or 9, or the subject matter of any example herein, wherein the specific subframe is indicated as an offset value, relative to

subframe

0 or 5, included in the MIB or an earlier MIB.

In example 11, the subject matter of example 10 or any example herein, further comprising logic to: descrambling the MIB using a plurality of Redundancy Version (RV) scrambling codes; determining which one of a plurality of RV scrambling codes obtains a correct code for achieving effective descrambling of the MIB; and ignoring the offset value when the determined RV scrambling code does not match a predetermined RV scrambling code defined for MIB transmission within the DTxW.

In example 12, the subject matter of example 11 or any example herein, wherein the RV scrambling code is 720 bits in length.

In example 13, example 8 or 9, or the subject matter of any example herein, wherein the MIB within the DTxW is scrambled using Redundancy Version (RV) 0.

In example 14, the subject matter of example 8 or 9, or any example herein, further comprising logic to: descrambling the MIB by using a plurality of redundancy version scrambling codes; performing speed reduction matching on the descrambled version of the MIB at a rate of one sixth; and tail-biting convolutional decoding (TBCC) is performed on the down-matched output.

In example 15, the subject matter of example 8 or any example herein, wherein the MIB structure is periodically identified at 10 millisecond intervals.

In a sixteenth example, a base station can comprise circuitry to: transmitting, via an unlicensed frequency band and for subframes of a frame corresponding to Discovery Reference Signal (DRS) transmission window (DTxW) subframes, a Physical Broadcast Channel (PBCH) containing control information for enabling a User Equipment (UE) to connect with a cellular network, the PBCH included within the DTxW at particular subframes, wherein the PBCH within the DTxW is encoded using at least Orthogonal Frequency Division Multiplexing (OFDM)

symbols

4, 7, 8, 9, 10, and 11 of the particular subframes within the DTxW; and opportunistically transmits a Physical Broadcast Channel (PBCH) outside of DTxW using the unlicensed band and at subframe 0 of the frame subject to listen-before-talk (LBT) constraints.

In example 17, the subject matter of example 16 or any example herein, wherein the PBCH inside and outside of DTxW comprises a Master Information Block (MIB) structure.

In example 18, the subject matter of example 17 or any example herein, wherein the optional subframe is indicated as an offset value included in the MIB or an earlier MIB.

In example 19, the subject matter of example 17 or any example herein, wherein the circuitry is further to: when the MIB is transmitted in the DTxW, scrambling the MIB by using a Redundancy Version (RV)0 scrambling code; and when the MIB is transmitted outside the DTxW, the MIB is scrambled using an RV other than 0.

In example 20, the subject matter of example 17 or any example herein, wherein the RV scrambling code is 720 bits in length.

In example 21, the subject matter of example 17 or any example herein, wherein the MIB structure is 30, 32, or 40 bits in length.

In a twenty-second example, a base station may comprise logic to: generating, for a subframe of a frame corresponding to a Discovery Reference Signal (DRS) transmission window (DTxW) subframe, first Physical Broadcast Channel (PBCH) data containing control information for enabling a User Equipment (UE) to connect with a cellular network, the first PBCH data located at a particular subframe of a plurality of subframes within DTxW, wherein the generating of the first PBCH data comprises scrambling the first PBCH data with a Redundancy Version (RV)0 scrambling code; generating second PBCH data at subframes other than DTxW, the generating of the second PBCH data comprising scrambling the second PBCH with an RV scrambling code other than RV 0; and transmitting the first and second PBCHs using the unlicensed frequency band.

In example 23, the subject matter of example 22 or any example herein, wherein the second PBCH data is opportunistically included within subframe 0 of the frame subject to a Listen Before Talk (LBT) constraint.

In example 24, the subject matter of example 22 or any example herein, wherein the first and second PBCH data are transmitted using at least Orthogonal Frequency Division Multiplexing (OFDM)

symbols

4, 7, 8, 9, 10, and 11.

In example 25, the subject matter of example 22 or any example herein, wherein the optional subframe is indicated as an offset value included in a Master Information Block (MIB).

In a twenty-sixth example, a method implemented by a User Equipment (UE) comprises: processing a Physical Broadcast Channel (PBCH) containing control information for connection with a cellular network for a radio subframe of a frame corresponding to a Discovery Reference Signal (DRS) transmission window (DTxW) subframe received via an unlicensed frequency band, the PBCH located within the DTxW at a particular subframe of a plurality of subframes within the DTxW, wherein the PBCH within the DTxW is received using at least Orthogonal Frequency Division Multiplexing (OFDM)

symbols

In example 27, the subject matter of example 26 or any example herein, wherein the specific subframe is indicated as an offset value included in the MIB or an earlier MIB.

In example 28, the subject matter of example 27 or any example herein, further comprising: descrambling the MIB using a plurality of Redundancy Version (RV) scrambling codes; determining which one of a plurality of RV scrambling codes obtains effective descrambling of the MIB; and ignoring the offset value when the determined correct code does not match the predetermined RV scrambling code.

In example 29, example 28, or the subject matter of any example herein, wherein the RV scrambling code is 720 bits in length.

In a thirty-first example, a UE may comprise: means for processing a Physical Broadcast Channel (PBCH) containing control information for connection with a cellular network for a radio subframe of a frame corresponding to a Discovery Reference Signal (DRS) transmission window (DTxW) subframe received via an unlicensed frequency band, the PBCH located within the DTxW at a particular subframe of a plurality of subframes within the DTxW, wherein the PBCH within the DTxW is received using at least Orthogonal Frequency Division Multiplexing (OFDM)

symbols

4, 7, 8, 9, 10, and 11 of the particular subframe; and means for processing a PBCH from a radio subframe that is not within DTxW and that is received via the unlicensed frequency band at radio subframe 0, wherein processing radio subframes that are inside and outside of DTxW includes identifying a Master Information Block (MIB) structure from the PBCH that is inside and outside of DTxW.

In example 31, the subject matter of example 30 or any example herein, wherein the particular subframe is indicated as an offset value, relative to

subframe

0 or 5, included in the MIB or an earlier MIB.

In example 32, the subject matter of example 32, or any example herein, further comprising: means for descrambling a MIB using a plurality of Redundancy Version (RV) scrambling codes; means for determining which of a plurality of RV scrambling codes results in effective descrambling of the MIB; and means for ignoring the offset value when the determined correct code does not match the predetermined RV scrambling code.

In example 33, the subject matter of example 32 or any example herein, wherein the RV scrambling code is 720 bits in length.

In the foregoing specification, various embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.

For example, while a series of signals and/or operations have been described with respect to one or more figures, the order of the signals may be modified in other embodiments. Furthermore, the uncorrelated signals/operations may be performed in parallel.

It should be apparent that the exemplary aspects described above may be implemented in many different forms of software, firmware, and hardware in the embodiments illustrated in the figures. The actual software code or specialized control hardware used to implement these aspects should not be construed as limiting. Thus, the operation and behavior of the aspects were described without reference to the specific software code — it being understood that software and control hardware may be designed to implement the aspects based on the description herein.

Further, certain portions may be implemented as "logic" that implements one or more functions. This logic may include hardware, such as an application specific integrated circuit ("ASIC") or a field programmable gate array ("FPGA"), or a combination of hardware and software.

Although particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to be limiting. Indeed, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification.

No element, act, or instruction used in the present application should be construed as critical or essential unless explicitly described as such. As used herein, use examples of the words "and" do not necessarily exclude interpretations in which the phrase "and/or" is intended in such instances. Also, as used herein, use cases of the word "or" do not necessarily preclude interpretation of the phrase "and/or" in such instances. Also, as used herein, the article "a" is intended to include one or more items and may be used interchangeably with the phrase "one or more. Where only one item is intended, the words "a," "an," "only," or similar language are used.

Claims

1. A baseband apparatus of a user equipment, UE, for a cellular network, comprising one or more processors to:

processing a physical broadcast channel, PBCH, containing control information for connection with the cellular network for a radio subframe received via an unlicensed frequency band and within a discovery reference signal, DRS, transmission window, DTxW, the PBCH located within the DTxW at a particular subframe of a plurality of subframes within the DTxW, wherein the PBCH within the DTxW is received using at least orthogonal frequency division multiplexing, OFDM, symbols 4, 7, 8, 9, 10, and 11 of the particular subframe; and is

Processing PBCH from a radio subframe that is not within the DTxW and that is received via the unlicensed frequency band at radio subframe 0,

wherein processing the radio subframes within and outside of the DTxW comprises identifying master information block MIB structures from the PBCH within and not within the DTxW.

2. The baseband apparatus of claim 1, wherein the specific subframe is indicated as an offset value included in the MIB structure that is offset from subframe 0 or 5.

3. The baseband apparatus of claim 2, wherein the one or more processors are further configured to:

descrambling the MIB by using a plurality of redundancy version RV scrambling codes;

determining which of the plurality of RV scrambling codes obtains an effective descrambling of the MIB; and is

Ignoring the offset value when the determined RV scrambling code does not match a predetermined RV scrambling code.

4. The baseband apparatus of claim 3, wherein the RV scrambling codes are each 720 bits in length.

5. The baseband apparatus of claim 1 or 2, wherein the MIB within the DTxW is scrambled using a redundancy version RV 0.

6. The baseband apparatus of claim 1 or 2, wherein the one or more processors are further to:

descrambling the MIB by using a plurality of redundancy version scrambling codes;

performing down-matching on the descrambled version of the MIB at a rate of one sixth; and is

Tail-biting convolutional decoding TBCC is performed on the down-matched output.

7. The baseband apparatus of claim 1, wherein the MIB structure is periodically identified at 10 millisecond intervals.

8. A user equipment, UE, comprising logic to:

processing, for a subframe that is within a discovery reference signal, DRS, transmission window, DTxW, and that is received via an unlicensed frequency band, a physical broadcast channel, PBCH, containing control information for connecting with a cellular network, the PBCH being at a particular subframe of a plurality of subframes within the DTxW that are located within the DTxW, the processing comprising:

descrambling the PBCH by using a redundancy version RV0 scrambling code;

processing PBCH from a subframe that is not within the DTxW and that is received via an unlicensed frequency band at subframe 0, processing subframe 0 comprising:

descrambling the PBCH by using RV scrambling codes except the RV 0;

wherein processing the subframe of DTxW includes identifying master information block MIB structures from the PBCH that are within the DTxW and that are not within the DTxW.

9. The UE of claim 8, wherein a PBCH within the DTxW is received using at least Orthogonal Frequency Division Multiplexing (OFDM) symbols 4, 7, 8, 9, 10, and 11 of the particular subframe.

10. The UE of claim 8 or 9, wherein the specific subframe is indicated as an offset value included in MIB in the MIB that is offset relative to subframe 0 or 5.

11. The UE of claim 10, further comprising logic to:

determining which of the plurality of RV scrambling codes obtains the correct code to achieve effective descrambling of the MIB; and is

Ignoring the offset value when the determined RV scrambling code does not match a predetermined RV scrambling code defined for MIB transmission within the DTxW.

12. The UE of claim 11, wherein the RV scrambling codes are each 720 bits in length.

13. The UE of claim 8 or 9, wherein the MIB within the DTxW is scrambled using a redundancy version RV 0.

14. The UE of claim 8 or 9, further comprising logic to:

15. The UE of claim 8, wherein the MIB structure is periodically identified at 10 millisecond intervals.

16. A base station comprising circuitry to:

transmitting, via an unlicensed frequency band and for subframes of a frame corresponding to discovery reference signal, DRS, transmission window, DTxW, subframes containing control information for enabling user equipment, UE, to connect with a cellular network, the PBCH included within the DTxW at a particular subframe, wherein the PBCH within the DTxW is encoded using at least orthogonal frequency division multiplexing, OFDM, symbols 4, 7, 8, 9, 10, and 11 of the particular subframe within the DTxW; and is

Using the unlicensed frequency band and opportunistically transmitting the physical broadcast channel PBCH outside of the DTxW at subframe 0 of a frame subject to listen-before-talk (LBT) constraints.

17. The base station of claim 16, wherein the PBCH includes a master information block MIB structure within and within the DTxW.

18. The base station of claim 17, wherein the specific subframe is indicated as an offset value included in the MIB or an earlier MIB.

19. The base station of claim 17, wherein the circuitry is further to:

when the MIB is transmitted in the DTxW, scrambling the MIB by using a redundancy version RV0 scrambling code; and is

And when the MIB is transmitted outside the DTxW, scrambling the MIB by using an RV scrambling code other than RV 0.

20. The base station of claim 19, wherein the RV0 scrambling code and the non-RV 0 scrambling code are each 720 bits in length.

21. The base station of claim 17, wherein the MIB structure is 30, 32, or 40 bits in length.

22. A base station comprising logic to:

generating, for a subframe of a frame corresponding to a discovery reference signal, DRS, transmission window, DTxW, subframe, first physical broadcast channel, PBCH, data containing control information for enabling a user equipment, UE, to connect with a cellular network, the first PBCH data located at a particular subframe of a plurality of subframes within the DTxW, wherein the generating of the first PBCH data comprises scrambling the first PBCH data with a redundancy version, RV0, scrambling code;

generating second PBCH data at subframes other than the DTxW, the generating of the second PBCH data comprising scrambling the second PBCH data with an RV scrambling code other than RV 0; and is

Transmitting the first PBCH data and the second PBCH data using an unlicensed frequency band.

23. The base station of claim 22, wherein the second PBCH data is opportunistically included within subframe 0 of a frame subject to a listen-before-talk, LBT, constraint.

24. The base station of claim 22, wherein at least orthogonal frequency division multiplexing, OFDM, symbols 4, 7, 8, 9, 10, and 11 are used for transmission of the first PBCH data and the second PBCH data.

25. The base station of claim 22, wherein the specific subframe is indicated as an offset value included in a master information block, MIB.