CN113765647A - Reference signal and physical broadcast channel for 5G system - Google Patents

Abstract

The present application relates generally to reference signals and physical broadcast channels for 5G systems. Methods and apparatus for transmitting Beamforming Reference Signals (BRSs) and Physical Broadcast Channel (PBCH) in a 5G system are described. Schemes for mapping BRS and PBCH to resource elements are also described. In some embodiments, the BRS and PBCH resource elements are mapped to a single OFDM symbol. The PBCH may be demodulated using BRS, or a dedicated demodulation reference signal may be employed for this purpose.

Description

Reference signal and physical broadcast channel for 5G system

The present application is a divisional application of an invention patent application having an international application date of 2016, 1/6, and a national application number of 201680076546.2 (international application number of PCT/US2016/035276), entitled "reference signal and physical broadcast channel for 5G system".

Priority requirement

This application claims priority from U.S. provisional patent application serial No. 62/287,791, filed on 27/1/2016, which is incorporated herein by reference in its entirety.

Technical Field

Embodiments described herein relate generally to wireless networks and communication systems. Some embodiments relate to a cellular communication network including a 3GPP (third generation partnership project) network, a 3GPP LTE (long term evolution) network, and a 3GPP LTE-a (LTE-advanced) network, although the scope of the embodiments is not limited in this respect.

Background

Mobile communications have evolved significantly from early voice systems to today's highly sophisticated integrated communication platforms. Fourth generation (4G) LTE networks are now widely deployed to provide services in various frequency band allocations according to a spectrum regime. Recently, there has been a remarkable momentum around the concept of the next generation (i.e., fifth generation (5G)) wireless communication technology.

Next generation wireless communication systems (5G) will provide access to information and sharing of data by various users and applications anywhere and anytime. It is expected that 5G will become a unified network/system with the goal of meeting distinct and sometimes conflicting performance specifications and services. In general, 5G will evolve based on 3GPP LTE-advanced and other potential new Radio Access Technologies (RATs) to provide better, simpler, more seamless radio connection solutions.

High-band communication has attracted considerable attention in the industry because it can provide wider bandwidth to support future integrated communication systems. Beamforming is a key technology for implementing high-band systems. The beamforming gain can compensate for the severe path loss caused by atmospheric attenuation, improve the SNR, and enlarge the coverage area. By directing the transmission beam to the target UE, the radiated energy is focused for higher energy efficiency and mutual UE interference is suppressed. The main focus of the present disclosure is the transmission of broadcast signals and beamformed reference signals.

Drawings

Fig. 1 illustrates an example UE and eNB in accordance with some embodiments.

Fig. 2 illustrates an example of synchronization signal resource mapping in accordance with some embodiments.

Figure 3 illustrates resource mapping for transmission of synchronization signals, BRS and PBCH within one OFDM symbol, in accordance with some embodiments.

Figure 4 illustrates an example of PBCH and BRS resource mapping scheme, in accordance with some embodiments.

Figure 5 illustrates an example of a DM-RS pattern for PBCH demodulation, in accordance with some embodiments.

Figure 6 illustrates an example of a DM-RS pattern for PBCH demodulation, in accordance with some embodiments.

Figure 7 illustrates an example of a DM-RS pattern for PBCH demodulation, in accordance with some embodiments.

Figure 8 illustrates an example of a transmit diversity transmission scheme for PBCH transmission, in accordance with some embodiments.

Figure 9 illustrates an example of resource mapping for BRS and PBCH, in accordance with some embodiments.

Figure 10 illustrates an example of resource mapping for BRS and PBCH, in accordance with some embodiments.

Figure 11 illustrates an example of resource mapping for BRS and PBCH, in accordance with some embodiments.

Figure 12 illustrates an example of resource mapping for BRS and PBCH, in accordance with some embodiments.

Figure 13 illustrates an example of resource mapping for BRS and PBCH, in accordance with some embodiments.

Figure 14 illustrates an example of resource mapping for BRS and PBCH, in accordance with some embodiments.

Figure 15 illustrates an example of resource mapping for BRS and PBCH, in accordance with some embodiments.

Figure 16 illustrates an example of frequency hopping for PBCH transmissions, in accordance with some embodiments.

Figure 17 illustrates an example of a user equipment device according to some embodiments.

FIG. 18 illustrates an example of a computing machine according to some embodiments.

Detailed Description

In a Long Term Evolution (LTE) system, mobile terminals (referred to as user equipment or UEs) are connected via an air interface to cells served by base stations (referred to as evolved node bs or enbs). Fig. 1 shows an example of components of a UE 400 and a base station or eNB 300. The eNB 300 comprises processing circuitry 301 connected to a radio transceiver 302 for providing an air interface. The UE 400 comprises processing circuitry 401 connected to a radio transceiver 402 for providing an interface. Each transceiver in the device is connected to an antenna 55.

The physical layer of LTE is based on Orthogonal Frequency Division Multiplexing (OFDM) for the downlink and correlation techniques (single carrier frequency division multiplexing (SC-FDM)) for the uplink. In OFDM/SC-FDM, complex modulation symbols according to a modulation scheme such as QAM (quadrature amplitude modulation) are each mapped to a particular OFDM/SC-FDM subcarrier, referred to as Resource Elements (REs), transmitted during the OFDM/SC-FDM symbol. The RE is the smallest physical resource in LTE. LTE also provides MIMO (multiple input multiple output) operation, where multiple data layers are transmitted and received by multiple antennas, and where each complex modulation symbol is mapped to one of multiple transport layers and then to a specific antenna port. Each RE is then uniquely identified by an antenna port, a subcarrier position, and an OFDM symbol index within the radio frame, as described below.

LTE transmissions in the time domain are organized into radio frames, each radio frame having a duration of 10 ms. Each radio frame consists of 10 subframes, each consisting of two consecutive 0.5ms slots. Each slot includes six indexed OFDM symbols for an extended cyclic prefix and seven indexed OFDM symbols for a normal cyclic prefix. A group of resource elements corresponding to twelve consecutive subcarriers within a single slot is called a Resource Block (RB), or for the physical layer, a Physical Resource Block (PRB).

In order to access a cell served by an eNB, a UE needs to synchronize with the cell and acquire specific system information. To do so, the eNB reserves REs for periodic downlink transmission of Primary Synchronization Signals (PSS) and Secondary Synchronization Signals (SSS) to allow the UE to acquire frequency and symbol synchronization and frame timing. The eNB also reserves REs for transmitting system information required for access through a Physical Broadcast Channel (PBCH). The PBCH carries a Master Information Block (MIB), which includes information about the bandwidth and control channel configuration of the cell.

Described below are methods and apparatus for transmitting a Beamforming Reference Signal (BRS) and a Physical Broadcast Channel (PBCH) in a 5G system. Schemes for mapping BRS and PBCH to resource elements are also described. In the following description, references to PBCH and MIB should generally be understood to refer to 5G PBCH and MIB, respectively, rather than to PBCH and MIB currently used in LTE. In the drawing, the 5G PBCH is denoted as xPBCH.

In one embodiment of a 5G system, the synchronization signal, the Beamforming Reference Signal (BRS), and the 5G Physical Broadcast Channel (PBCH) may be designed as follows. The Primary Synchronization Signal (PSS) is the same as currently defined in LTE. The Secondary Synchronization Signal (SSS) used to derive the Physical Cell Identity (PCI) occupies 6 consecutive physical resource blocks, the sequence of which is the same as currently defined in LTE. The Extended Synchronization Signal (ESS) is also provided with at least 12 or 14 sequences (symbols within a subframe, i.e., 0, 1, 11 or 0, 1, 13) for supporting subframe timing. The ESS uses the same sequence as defined for SSS and occupies 6 consecutive PRBs. The resource mapping for the synchronization signals (PSS/SSS/ESS) is shown in fig. 2.

In one embodiment, the distributed BRS sequence spans the entire frequency band except (i.e., excluding) the middle 18 PRBs (i.e., "synchronization region") occupied by the PSS, ESS and SSS. Frequency Division Multiplexing (FDM) interleaving BRS REs are used for different beamformed antenna ports. The PBCH is frequency division multiplexed with the PSS/ESS/SSS/distributed BRS within a single OFDM symbol. Fig. 3 shows a resource mapping for transmitting a synchronization signal, BRS and PBCH within one OFDM symbol. Note that for BRS transmissions, different beamformed antenna ports are multiplexed in a Frequency Division Multiplexing (FDM) manner. Is assumed to be eachBRS transmissions in a symbol define K APs, and N is allocated for BRS transmissions within one subframe_symOne OFDM symbol, the total number of APs used for BRS transmission in one sub-frame can be calculated as K.N_sym。

As described above, the PBCH may be transmitted within one symbol. Depending on whether BRS can be used for channel estimation of PBCH, different embodiments related to the transmission scheme for PBCH are described below.

Transmission scheme for PBCH

In one embodiment, no dedicated reference signal is embedded within PBCH transmissions and BRS is used instead for PBCH channel estimation. Figure 4 shows an example of PBCH and BRS resource mapping scheme. In this example, BRSs are transmitted between two PBCH transport blocks, and the middle BRS may be used for channel estimation of PBCH. For PBCH demodulation and decoding, the relationship between the transmit (Tx) beam or Antenna Port (AP) used for BRS transmissions and the AP used for PBCH transmissions may be predefined in the specification or configured by higher layers via RRC signaling from the primary cell or LTE cell in a non-standalone deployment scenario. In other words, the UE may derive a channel estimate for the PBCH based on the channel estimates from the BRSs. For PBCH transmission, a single AP or multiple APs, e.g., 2, may be used. In the former case, the AP used for PBCH transmission is denoted as AP # 100; and for the latter case, the APs for PBCH transmission are denoted as AP #100 and AP #101, respectively. In one example, assume K is 4 and N_symWhen xPBCH transmission is performed using a single AP, 12 ═ p, it is possible to transmit data from BRS AP # (0+4 · n)_sym) mod K and AP # (1+ 4. n)_sym) mod K derived nth_symA symbol (n)_sym0, …, 11), where mod is the modulo operation. In another example, assume K is 8 and N_symWith PBCH transmission using two APs, 12, PBCH may be transmitted from BRS AP # (0+8 · n)_sym) mod 8 and AP # (1+8 n)_sym) mod 8 derives channel estimates for PBCH AP # 100; but can be selected from BRS AP # (4+8 n)_sym) mod 8 and AP # (5+8 n)_sym) mod 8 derives the channel estimate for PBCH AP # 101. Alternatively, the PBCH may use aggregated Tx beams from the BRSAP. For example, falseLet K equal to 4 and N_symThe first block of PBCH may use the aggregated beams from BRS APs 0 and 1, and the second block of PBCH may use the beams from BRS APs 2 and 3, 12. The estimated channel may be obtained as follows:

wherein,

representing the channel estimated from two BRS APs.

In another embodiment, a dedicated demodulation reference signal (DM-RS) is defined for PBCH channel estimation. Also, depending on the number of APs used for PBCH, different transmission schemes may be considered. In case of PBCH transmission using one AP, the PBCH may employ a single port transmission scheme. In the case of PBCH transmission using two or more APs, space-frequency block coding (SFBC) or transmit diversity on a per RE cycle basis may be employed. The DM-RS may be generated based on a pseudo-random sequence, for example, as defined in the LTE specification. Further, the pseudo-random sequence generator may be initialized according to the number of OFDM symbols and/or physical cell ID or virtual physical cell ID.

Depending on the number of resource elements allocated for each PBCH block and the number of APs used for PBCH transmission, different options for DM-RS patterns may be provided. Fig. 5 and 6 illustrate examples of DM-RS patterns for single port transmission when PBCH occupies 8 REs and 12 REs, respectively. Note that similar patterns may be defined for two-port PBCH transmissions. Figure 7 shows one example of a DM-RS pattern for PBCH transmitted with two APs when PBCH occupies 12 REs. The DM-RSs for the two APs may be multiplexed using Frequency Division Multiplexing (FDM) or Code Division Multiplexing (CDM). In the case of CDM multiplexing between two APs, an Orthogonal Cover Code (OCC) applied on each AP may be defined as in table 1 below.

TABLE 1 OCC for two APs

Antenna port p	[wp(0)wp(1)]
		100	[1 1]
101	[1 -1]

In case SFBC is applied for PBCH transmission, two consecutive REs may be used for PBCH transmission. In case transmit diversity based on cycles per RE is applied for PBCH transmission, half of the REs in one AP may be used for PBCH transmission while the other half of the REs remain unused. Fig. 8 illustrates one example of a Tx diversity transmission scheme for PBCH transmission. In the present example, 0 denotes an RE associated with AP # 100, and 1 denotes an RE associated with AP # 101. The physical cell ID may be included in a 5G Master Information Block (MIB) carried by the PBCH or masked (mask) by a Cyclic Redundancy Check (CRC) to allow the UE to verify whether the PBCH was successfully decoded and/or used to generate a dedicated DM-RS associated with the PBCH. Furthermore, to reduce UE power consumption, the same Tx beam may be applied to both synchronization signals and PBCH transmissions.

Resource mapping for BRS and PBCH

As described above, the distributed BRS and PBCH may be multiplexed with other synchronization signals (i.e., PSS, SSS, and ESS) in an FDM manner within one OFDM symbol. Further, the BRS and PBCH are transmitted in frequency resources that do not include the middle 18 PRBs reserved for synchronization signals. In order to allow for proper decoding of PBCH, the number of REs allocated per PBCH transport block may be predefined in the specification. Furthermore, PBCH blocks may span the entire system bandwidth for better link budget. Embodiments related to resource mapping schemes for BRS and PBCH transmissions are described below.

In one embodiment, the PBCH is transmitted adjacent to a synchronization signal including PSS/SSS/ESS. In addition, BRS occupies the remaining REs in one OFDM symbol. Considering that PBCH and BRS are transmitted using different frequency resources, it may be necessary to insert a dedicated DM-RS for PBCH. Fig. 9 shows one example of resource mapping of BRS and PBCH, which will be referred to as option 1.

In another embodiment, the BRS and PBCHRE are interleaved in the frequency domain. In addition, the number of REs allocated per BRS block may be fixed in the specification, e.g., K_maxWherein, K is_maxMay be considered as the maximum number of Tx beams that can be supported at the eNB within one symbol. Depending on the eNB architecture capabilities, the eNB may use only K within one symbol (K < K)_max) A number of beamforming APs transmit the BRS. In this case, (K) within one BRS block_max-K) REs may not be used. Figure 10 shows the resource mapping for the BRS and PBCH transmission of the example referred to as option 2. Note that in this option, the number of APs used for BRS transmissions (i.e., K) may be indicated in a 5G Master Information Block (MIB) carried by the PBCH, or with CRC scrambling for PBCH transmissions, or configured by higher layers via an LTE link. In one example, K_maxK is 8 and the number of REs allocated for each PBCH is fixed to 12. Fig. 11 shows another example of resource mapping of BRS and PBCH of option 2. In this example, within one BRS block, 4 REs are not used.

In another embodiment, the BRS and PBCH are interleaved in the frequency domain. Further, the number of APs used for BRS transmission (i.e., K) within a symbol may be indicated via a higher layer from the primary LTE cell. Figure 12 shows an example of resource mapping for BRS and PBCH transmissions, referred to as option 3. Note that, compared to option 2, unused REs are not inserted between the BRS block and the PBCH block. In one example, K is 8 and the number of REs allocated for each xPBCH is fixed to 8. Fig. 13 shows another example of resource mapping of BRS and PBCH of option 3.

In another embodiment, the BRS and xPBCH are interleaved in the frequency domain. In addition, additional unused REs are inserted between the xPBCH block and the BRS block. Similar to options 2 and 3, mayFix K in Specification_maxAnd K may be included in xPBCH or configured by a higher layer via an LTE link. Figure 14 shows an example of such a scheme of resource mapping for BRS and PBCH transmissions, referred to as option 4. In one example, K_maxK is 8 and the number of REs allocated for each PBCH is fixed to 8. Fig. 15 shows another example of resource mapping of BRS and PBCH of option 4. In this example, 8 unused REs are inserted between the BRS block and the PBCH block.

Note that for option 4, the frequency location of the PBCH block may be the same or different for different OFDM symbols. In the latter case, a frequency hopping pattern may be defined according to a physical cell ID and a symbol index in order to achieve inter-cell interference randomization. In particular, the starting frequency position of each PBCH block transmission may be defined as

Wherein,

is a physical cell ID, and n_symIs a symbol index. Figure 16 shows one example of frequency hopping for PBCH transmission. Alternatively, the starting frequency position of each PBCH block transmission may be determined by the physical cell ID, symbol index and subframe index, which may be used as verification of the cell search results.

Example UE Recommendations

As used herein, the term "circuitry" may refer to, be a part of, or include: an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) or memory (shared, dedicated, or group) that executes 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 operable, at least in part, in hardware.

The embodiments described herein may be implemented into a system using any suitable configuration of hardware and/or software. Fig. 17 illustrates example components of a User Equipment (UE) device 100 for one embodiment. In some embodiments, the UE device 100 may include application circuitry 102, baseband circuitry 104, Radio Frequency (RF) circuitry 106, Front End Module (FEM) circuitry 108, and one or more antennas 110 coupled together at least as shown.

The application circuitry 102 may include one or more application processors. For example, the application circuitry 102 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.

The baseband circuitry 104 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. Baseband circuitry 104 may include one or more baseband processors and/or control logic to process baseband signals received from the receive signal path of RF circuitry 106 and to generate baseband signals for the transmit signal path of RF circuitry 106. Baseband circuitry 104 may interface with application circuitry 102 for generating and processing baseband signals and controlling operation of RF circuitry 106. For example, in some embodiments, the baseband circuitry 104 may include a second generation (2G) baseband processor 104a, a third generation (3G) baseband processor 104b, a fourth generation (4G) baseband processor 104c, and/or other baseband processors 104d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 104 (e.g., one or more of the baseband processors 104 a-d) may process various radio control functions that enable communication with one or more radio networks via the RF circuitry 106. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, and the like. In some embodiments, the modulation/demodulation circuitry of baseband circuitry 104 may include Fast Fourier Transform (FFT), precoding, and/or constellation mapping/demapping functionality. In some embodiments, the encoding/decoding circuitry of baseband circuitry 104 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 104 may include elements of a protocol stack, such as elements of an Evolved Universal Terrestrial Radio Access Network (EUTRAN) protocol, including, for example, Physical (PHY) elements, Medium Access Control (MAC) elements, Radio Link Control (RLC) elements, Packet Data Convergence Protocol (PDCP) elements, and/or Radio Resource Control (RRC) elements. The Central Processing Unit (CPU)104e of the baseband circuitry 104 may be configured to: elements of the protocol stack are run for signaling of the PHY layer, MAC layer, RLC layer, PDCP layer, and/or RRC layer. In some embodiments, the baseband circuitry may include one or more audio Digital Signal Processors (DSPs) 104 f. The audio DSP 104f may include elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments. In some embodiments, the components of the baseband circuitry may be suitably combined 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 104 and application circuitry 102 may be implemented together, for example, on a system on a chip (SOC).

In some embodiments, the baseband circuitry 104 may provide communications compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 104 may support communication with an Evolved Universal Terrestrial Radio Access Network (EUTRAN) and/or other Wireless Metropolitan Area Networks (WMANs), Wireless Local Area Networks (WLANs), Wireless Personal Area Networks (WPANs). Embodiments in which the baseband circuitry 104 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

The RF circuitry 106 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 106 may include switches, filters, amplifiers, and the like to facilitate communication with the wireless network. RF circuitry 106 may include a receive signal path that may include circuitry to down-convert RF signals received from FEM circuitry 108 and provide baseband signals to baseband circuitry 104. RF circuitry 106 may also include a transmit signal path, which may include circuitry to up-convert baseband signals provided by baseband circuitry 104 and provide an RF output signal to FEM circuitry 108 for transmission.

In some embodiments, RF circuitry 106 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 106 may include mixer circuitry 106a, amplifier circuitry 106b, and filter circuitry 106 c. The transmit signal path of the RF circuitry 106 may include a filter circuit 106c and a mixer circuit 106 a. RF circuitry 106 may further include synthesizer circuitry 106d for synthesizing the frequencies used by mixer circuitry 106a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuit 106a of the receive signal path may be configured to: the RF signal received from the FEM circuitry 108 is downconverted based on the synthesized frequency provided by the synthesizer circuitry 106 d. The amplifier circuit 106b may be configured to: the downconverted signal is amplified, and the filter circuit 106c 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 104 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 106a 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 106a of the transmit signal path may be configured to: the input baseband signal is upconverted based on the synthesized frequency provided by synthesizer circuit 106d to generate an RF output signal for FEM circuitry 108. The baseband signal may be provided by the baseband circuitry 104 and may be filtered by the filter circuitry 106 c. Filter circuit 106c may include a Low Pass Filter (LPF), although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may comprise two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion, respectively. In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a 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, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a 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 106 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and baseband circuitry 104 may include a digital baseband interface to communicate with RF circuitry 106.

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 106d may be a fractional-N synthesizer or a fractional-N/N +1 synthesizer, although the scope of the embodiments is not so limited as other types of frequency synthesizers may be suitable. For example, the synthesizer circuit 106d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase locked loop with a frequency divider.

The synthesizer circuit 106d may be configured to: the output frequency used by the mixer circuit 106a of the RF circuit 106 is synthesized based on the frequency input and the divider control input. In some embodiments, the synthesizer circuit 106d may be a fractional N/N +1 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 104 or the application processor 102, 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 102.

The synthesizer circuit 106d of the RF circuit 106 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 +1 (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 106d 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 (f)_LO). In some embodiments, the RF circuitry 106 may include an IQ/polar converter.

FEM circuitry 108 may include a receive signal path, which may include circuitry configured to operate on RF signals received from one or more antennas 110, amplify the received signals, and provide amplified versions of the received signals to RF circuitry 106 for further processing. FEM circuitry 108 may further include a transmit signal path, which may include circuitry configured to amplify signals provided by RF circuitry 106 for transmission by one or more of one or more antennas 110.

In some embodiments, FEM circuitry 108 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 the RF circuitry 106). The transmit signal path of the FEM circuitry 108 may include: a Power Amplifier (PA) to amplify an input RF signal (e.g., provided by RF circuitry 106); and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 110).

In some embodiments, the UE device 100 may include additional elements, such as memory/storage, a display, a camera, sensors, and/or an input/output (I/O) interface.

Example machine description

Fig. 18 illustrates a block diagram of an example machine 500 on which any one or more of the techniques (e.g., methods) discussed herein may be performed. In alternative embodiments, the machine 500 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 500 may operate in the role of a server machine, a client machine, or both, in server-client network environments. In an example, machine 500 may operate in a peer-to-peer (P2P) (or other distributed) network environment as a peer machine. The machine 500 may be a User Equipment (UE), an evolved node b (enb), a Wi-Fi Access Point (AP), a Wi-Fi Station (STA), a Personal Computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a mobile telephone, a smartphone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term "machine" shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

Examples as described herein may include, or may operate on, logic or multiple components, modules, or structures. A module is a tangible entity (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, a circuit may be arranged (e.g., internally or with respect to an external entity such as other circuits) as a module in a specified manner. In an example, all or a portion of one or more computer systems (e.g., a stand-alone, client, or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, application portions, or applications) as a module that operates to perform specified operations. In an example, the software may reside on a machine-readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform specified operations.

Thus, the term "module" is understood to encompass a tangible entity, whether that entity is physically constructed, specially configured (e.g., hardwired), or temporarily (e.g., temporarily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any of the operations described herein. Considering the example of temporarily configuring modules, each module need not be instantiated at any one time. For example, where the modules include a general purpose hardware processor configured using software, the general purpose hardware processor may be configured as respective different modules at different times. The software may configure the hardware processor accordingly, e.g., to constitute a particular module at one instance in time and to constitute a different module at a different instance in time.

The machine (e.g., computer system) 500 may include a hardware processor 502 (e.g., a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a hardware processor core, or any combination thereof), a main memory 504 and a static memory 506, some or all of which may communicate with each other via an interconnection link (e.g., bus) 508. The machine 500 may also include a display unit 510, an alphanumeric input device 512 (e.g., a keyboard), and a User Interface (UI) navigation device 514 (e.g., a mouse). In an example, the display unit 510, the input device 512, and the UI navigation device 514 may be a touch screen display. The machine 500 may additionally include a storage device (e.g., drive unit) 516, a signal generation device 518 (e.g., a speaker), a network interface device 520, and one or more sensors 521 (e.g., a Global Positioning System (GPS) sensor, compass, accelerometer, or other sensor). The machine 500 may include an output controller 528, such as a serial (e.g., Universal Serial Bus (USB), parallel, or other wired or wireless (e.g., Infrared (IR), Near Field Communication (NFC), etc.) connection to communicate with or control one or more peripheral devices (e.g., a printer, card reader, etc.).

The storage device 516 may include a machine-readable medium 522 on which is stored one or more sets of data structures or instructions 524 (e.g., software) embodying or used by any one or more of the techniques or functions described herein. The instructions 524 may also reside, completely or at least partially, within the main memory 504, within static memory 506, or within the hardware processor 502 during execution thereof by the machine 500. In an example, one or any combination of the hardware processor 502, the main memory 504, the static memory 506, and the storage device 516 may constitute machine-readable media.

While the machine-readable medium 522 is shown to be a single medium, the term "machine-readable medium" can include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 524.

The term "machine-readable medium" may include any medium that is capable of storing, encoding or carrying instructions for execution by the machine 500 and that cause the machine 500 to perform any one or more of the techniques of this disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting examples of machine-readable media may include solid-state memory, and optical and magnetic media. Specific examples of the machine-readable medium may include: non-volatile memories such as semiconductor memory devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; a magnetic optical disk; random Access Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples, the machine-readable medium may include a non-transitory machine-readable medium. In some examples, a machine-readable medium may include a machine-readable medium that is not a transitory propagating signal.

The instructions 524 may further be transmitted or received over a communication network 526 using a transmission medium via the network interface device 520 utilizing any one of a number of transmission protocols (e.g., frame relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks can include a Local Area Network (LAN), a Wide Area Network (WAN), a packet data network (e.g., the internet), a mobile telephone network (e.g., a cellular network), a Plain Old Telephone (POTS) network, and a wireless data network (e.g., referred to as

Of the Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards, referred to as

IEEE 802.16 family of standards), IEEE 802.15.4 family of standards, Long Term Evolution (LTE) family of standards, Universal Mobile Telecommunications System (UMTS) family of standards, or peer-to-peer (P2P) networks, etc. In an example, the network interface device 520 may include one or more physical jacks (e.g., ethernet jacks, coaxial jacks, or telephone jacks) or one or more antennas to connect to the communication network 526. In an example, the network interface device 520 may include multiple antennas to use Single Input Multiple Output (SIMO), multiple input multiple output (memo)At least one of an out (MIMO) and a multiple-input single-output (MISO) technique for wireless communication. In some examples, the network interface device 520 may wirelessly communicate using multi-user MIMO techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the machine 500, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

Additional notes and examples:

in example 1, an apparatus for an evolved node b (enb), comprising: processing circuitry and memory to configure an eNB to provide an air interface to User Equipment (UE); wherein the circuit is further configured to: generating Beamforming Reference Signals (BRS) corresponding to a plurality of beamforming Antenna Ports (APs); encoding a Master Information Block (MIB) for transmission on a Physical Broadcast Channel (PBCH); and mapping the BRS and the PBCH to time-frequency Resource Elements (REs) frequency-division multiplexed in the same Orthogonal Frequency Division Multiplexing (OFDM) symbol.

In example 2, the subject matter of any example herein can optionally include wherein the relationship between the AP for BRS transmissions and the AP for PBCH transmissions is predefined to allow the UE to derive a channel estimate for PBCH based on channel estimates for one or more BRS APs.

In example 3, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the UE is informed of a relationship between the AP for BRS transmissions and the AP for PBCH transmissions via Radio Resource Control (RRC) signaling to allow the UE to derive a channel estimate for PBCH based on channel estimates for one or more BRS APs.

In example 4, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to map a plurality of PBCHs to REs in an OFDM symbol, wherein each such PBCH is transmitted from an AP corresponding to one or more BRS APs.

In example 5, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to map PBCH to REs in aggregated transmissions from APs, wherein each such AP is defined by one or more BRSs.

In example 6, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to map demodulation reference signals (DM-RSs) to REs corresponding to a same AP and in a same OFDM symbol as the PBCH to allow the UE to derive a channel estimate of the PBCH based on the DM-RSs.

In example 6a, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to transmit DM-RSs generated based on a pseudo-random sequence initialized according to an OFDM symbol number and/or a physical cell ID or a virtual physical cell ID.

In example 7, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to map the plurality of DM-RSs to REs corresponding to the plurality of APs, and wherein the plurality of DM-RSs are frequency division multiplexed or code division multiplexed within the OFDM symbol.

In example 8, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to map PBCH to REs corresponding to two or more APs using space-frequency block coding (SFBC) or transmit diversity based on cycles per RE.

In example 8a, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured such that for SFBC, two consecutive REs are grouped for PBCH transmission.

In example 8b, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured such that for transmit diversity on a per RE cycle basis, half of the REs in one AP are used for PBCH transmission, while the other half of the REs remain unused.

In example 8c, the subject matter of any example herein may optionally include, wherein the processing circuitry is further to: the eNB is configured to transmit a physical cell ID included in a Master Information Block (MIB) carried by the PBCH or masked by a Cyclic Redundancy Check (CRC).

In example 9, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to map PBCH, BRS and synchronization signals, including Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS) and Extended Synchronization Signal (ESS), to REs of the same OFDM symbol.

In example 10, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to map the PBCH to REs adjacent to the synchronization signal, and wherein the BRS occupies remaining REs in the OFDM symbol.

In example 11, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the BRS and PBCH are interleaved in the frequency domain.

In example 11a, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: configuring the eNB such that the maximum number of REs allowed to be allocated for each BRS block is predefined as K_maxAnd wherein when the eNB utilizes K within one OFDM symbol (K < K)_max) When a beamforming AP sends a BRS, K_maxK REs are not used within one BRS block.

In example 11b, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to send a number K of APs for BRS transmissions, which is indicated in a Master Information Block (MIB) carried by the PBCH or scrambled by a cyclic redundancy check, CRC, for PBCH transmissions.

In example 11c, the subject matter of any example herein may optionally include, wherein the processing circuitry is further to: the eNB is configured to insert unused REs between PBCH and BRS blocks in OFDM symbols.

In example 12, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to map PBCH to REs at different frequency locations in different OFDM symbols according to a defined frequency hopping pattern.

In example 12a, the subject matter of any example herein can optionally include, wherein the frequency hopping pattern is defined in terms of a physical cell ID and a symbol index and/or a subframe index, and wherein a starting frequency position of each PBCH block transmission is defined as:

wherein,

is a physical cell ID, and n_symIs a symbol index.

In example 13, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: the eNB is configured to map PBCH and synchronization signals, including Primary Synchronization Signals (PSS), Secondary Synchronization Signals (SSS), and Extended Synchronization Signals (ESS), to REs corresponding to the same one or more APs.

In example 14, the subject matter of any example herein can optionally include, wherein the processing circuitry comprises a baseband processor.

In example 15, the subject matter of any example herein may optionally include: a radio transceiver connected to the processing circuitry; a directional antenna array connected to the radio transceiver and operated by the processing circuitry to provide an AP for beamforming.

In example 16, an apparatus for a UE (user equipment) comprises: memory and processing circuitry to configure a UE to: demodulating a Beamforming Reference Signal (BRS) and a Physical Broadcast Channel (PBCH) from time-frequency Resource Elements (REs) frequency-division multiplexed in the same Orthogonal Frequency Division Multiplexing (OFDM) symbol; decoding a Master Information Block (MIB) from the PBCH; and deriving a beamformed Antenna Port (AP) corresponding to the BRS.

In example 17, the subject matter of any example herein can optionally include, wherein the processing circuitry is to: radio Resource Control (RRC) signaling information related to a relationship between APs for BRS transmissions and APs for PBCH transmissions is decoded to allow a UE to derive a channel estimate for PBCH based on channel estimates for one or more BRS APs.

In example 18, the subject matter of any example herein can optionally include, wherein the processing circuitry is further to: demodulating PBCH in the OFDM symbol, wherein the PBCH is transmitted from an AP corresponding to one or more BRSs.

In example 19, the subject matter of any example herein can optionally include, wherein the processing circuitry is to: demodulation reference signals (DM-RS) transmitted from the same AP and in the same OFDM symbol as PBCH are demodulated to allow the UE to derive a channel estimate of PBCH from the DM-RS.

In example 20, the subject matter of any example herein may optionally include, wherein the processing circuitry is further to: demodulating a plurality of DM-RSs corresponding to the plurality of APs, and wherein the plurality of DM-RSs are frequency division multiplexed or code division multiplexed within the OFDM symbol.

In example 20a, the subject matter of any example herein may optionally include, wherein the processing circuitry is further to: the UE is configured to receive PBCH from two or more APs using space-frequency block coding or transmit diversity based on cycles per RE.

In example 20b, the subject matter of any example herein may optionally include, wherein the processing circuitry is further to: the UE is configured to receive PBCH, BRS and synchronization signals (including Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS) and Extended Synchronization Signal (ESS)) in the same OFDM symbol.

In example 20c, the subject matter of any example herein may optionally include, wherein the processing circuitry is further to: the UE is configured to receive the PBCH adjacent to the synchronization signal in the same OFDM symbol, and wherein the BRS occupies the remaining REs in the OFMD symbol.

In example 20d, the subject matter of any example herein may optionally include, wherein the processing circuitry is further to: the UE is configured to receive PBCH at different frequency locations in different OFDM symbols according to a defined frequency hopping pattern.

In example 20e, the subject matter of any example herein can optionally include, wherein the frequency hopping pattern is defined in terms of a physical cell ID and a symbol index and/or a subframe index, and wherein a starting frequency position of each PBCH block transmission is defined as:

wherein,

is a physical cell ID, and n_symIs a symbol index.

In example 21, a computer-readable medium comprising instructions that when executed by processing circuitry of a User Equipment (UE) cause the UE to: receiving Beamforming Reference Signals (BRS) corresponding to a plurality of beamforming Antenna Ports (APs); receiving a Master Information Block (MIB) on a Physical Broadcast Channel (PBCH); and receiving the BRS and the PBCH mapped to time-frequency Resource Elements (REs) frequency division multiplexed in the same Orthogonal Frequency Division Multiplexing (OFDM) symbol.

In example 22, the subject matter of example 21 or any example herein may optionally include: instructions for receiving, via Radio Resource Control (RRC) signaling, information regarding a relationship between an AP for BRS transmissions and an AP for PBCH transmissions to allow a UE to derive a channel estimate for PBCH based on channel estimates for one or more BRS APs.

In example 23, the subject matter of example 21 or any example herein may optionally include: instructions for receiving a PBCH in an OFDM symbol, wherein the PBCH is transmitted from an AP corresponding to one or more BRSs.

In example 24, the subject matter of example 21 or any example herein may optionally include: instructions for receiving demodulation reference signals (DM-RS) from the same AP and in the same OFDM symbol as PBCH to allow a UE to derive a channel estimate for PBCH based on a channel estimate for DM-RS.

In example 25, the subject matter of example 21 or any example herein may optionally include: instructions for receiving a plurality of DM-RSs corresponding to the plurality of APs, and wherein the plurality of DM-RSs are frequency division multiplexed or code division multiplexed within the OFDM symbol.

In example 25a, the subject matter of example 21 or any example herein may optionally include: instructions for configuring a UE to receive PBCH from two or more APs using space-frequency block coding or transmit diversity on a per RE cycle basis.

In example 25b, the subject matter of example 21 or any example herein may optionally include: instructions for configuring a UE to receive PBCH, BRS, and synchronization signals, including a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and an Extended Synchronization Signal (ESS), in the same OFDM symbol.

In example 25c, the subject matter of example 21 or any example herein may optionally include: instructions for configuring the UE to receive PBCH adjacent to the synchronization signal in the same OFDM symbol, and wherein the BRS occupies remaining REs in the OFMD symbol.

In example 25d, the subject matter of example 21 or any example herein may optionally include: instructions for configuring the UE to receive PBCH at different frequency locations in different OFDM symbols according to a defined frequency hopping pattern.

In example 25e, the subject matter of example 21 or any example herein may optionally include, wherein the frequency hopping pattern is defined in terms of a physical cell ID and a symbol index and/or a subframe index, and wherein a starting frequency position of each PBCH block transmission is defined as:

wherein,

is a physical cell ID, and n_symIs a symbol index.

In example 26, a method of operating an eNB, comprising performing the functions of the processing circuitry of any of examples 1 to 15.

In example 27, an apparatus for an eNB, comprising means for performing the functions of the processing circuitry of any of examples 1 to 15.

In example 28, a computer-readable medium comprising instructions that, when executed by processing circuitry of an evolved node b (eNB), cause the eNB to perform the functions of the processing circuitry of any of examples 1 to 15.

In example 29, a method of operating a UE, comprising performing the functions of the processing circuitry of any of examples 16 to 20 e.

In example 30, an apparatus for a UE, comprising means for performing functions of processing circuitry as in any of examples 16 to 20 e.

The foregoing detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments that can be practiced. These embodiments are also referred to herein as "examples. Such examples may include elements other than those shown or described. However, examples including the elements shown or described are also contemplated. Moreover, it is also contemplated to use examples of any combination or permutation of those elements (or one or more aspects thereof) shown or described with respect to a particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof) shown or described herein.

The publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. The usage in the incorporated references is supplementary to the usage in this document if the usage between this document and those incorporated by reference is inconsistent; for irreconcilable inconsistencies, the usage in this document controls.

In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, regardless of any other instances or usages of "at least one" or "one or more. Unless otherwise indicated, in this document, the term "or" is used to refer to a non-exclusive "or" such that "a or B" includes "a, but not B", "B, but not a" and "a and B". In the appended claims, the terms "including" and "in which" are used as the plain-english equivalents of the respective terms "comprising" and "wherein". Furthermore, in the claims that follow, the terms "comprise" and "comprise" are open-ended; that is, a system, device, article, or process that includes an element other than those listed after such a word in a claim is still considered to be within the scope of that claim. Furthermore, in the claims that follow, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to imply a numerical order of their objects.

The embodiments described above may be implemented in various hardware configurations, which may include a processor for executing instructions that implement the described techniques. Such instructions may be embodied in a machine-readable medium, such as a suitable storage medium or memory or other processor-executable medium.

The embodiments described herein may be implemented in a variety of environments as part of, for example, a Wireless Local Area Network (WLAN), a third generation partnership project (3GPP) Universal Terrestrial Radio Access Network (UTRAN), or a Long Term Evolution (LTE) or Long Term Evolution (LTE) communication system, although the scope of the invention is not limited in this respect. An example LTE system includes a plurality of mobile stations, defined by the LTE specification as User Equipment (UE), that communicate with a base station, defined by the LTE specification as an eNB.

The antennas referred to herein may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas or other types of antennas suitable for transmission of RF signals. In some embodiments, instead of two or more antennas, a single antenna with multiple apertures may be used. In these embodiments, each aperture may be considered a separate antenna. In some multiple-input multiple-output (MIMO) embodiments, antennas may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result between each antenna and the antennas of the transmitting station. In some MIMO embodiments, the antennas may be separated by as much as 1/10 wavelengths or more.

In some embodiments, a receiver as described herein may be configured to receive signals in accordance with a particular communication standard, such as an Institute of Electrical and Electronics Engineers (IEEE) standard including an IEEE 802.11 standard and/or a specification set forth for WLANs, although the scope of the invention is not limited in this respect as they may also be suitable for transmitting and/or receiving communications in accordance with other techniques and standards. In some embodiments, the receiver may be configured to receive signals in accordance with the IEEE 802.16-2004, IEEE 802.16(e), and/or IEEE 802.16(m) standards for Wireless Metropolitan Area Networks (WMANs), including variations and evolutions thereof, although the scope of the invention is not limited in this respect as they may also be suitable to transmit and/or receive communications in accordance with other techniques and standards. In some embodiments, the receiver may be configured to receive signals in accordance with a Universal Terrestrial Radio Access Network (UTRAN) LTE communications standard. For more Information on the IEEE 802.11 and IEEE 802.16 Standards, see "IEEE Standards for Information Technology- -Telecommunications and Information Exchange between Systems" - -Local Area Networks-Specific Requirements- -Part 11, "Wireless LAN Medium Access Control (MAC) and Physical Layer 880880 (PHY), ISO/IEC 2-11: 1999" and Metapolian Area Networks-Specific Requirements- -Part 16: "Air Interface for Fixed Broadband Wireless Access Systems" month 5 2005 and related modifications/versions. For more information on the UTRAN LTE standard, see the third generation partnership project (3GPP) standard of UTRAN-LTE, including variations and evolutions thereof.

The above description is intended to be illustrative and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with other examples. For example, other embodiments may be used by those skilled in the art upon reading the above description. The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the following understanding: it is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the above detailed description, various features may be combined together to streamline the disclosure. However, the claims may not set forth every feature disclosed herein because embodiments may feature a subset of the features. Moreover, embodiments may include fewer features than those disclosed in the specific examples. Thus the following claims are hereby incorporated into the detailed description, with claims standing on their own as separate embodiments. The scope of the embodiments disclosed herein should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims (20)

1. A method, comprising:

performing, by a Base Station (BS):

providing an air interface to a User Equipment (UE);

transmitting a demodulation reference signal, DM-RS, on a first beamforming Antenna Port (AP);

transmitting a Master Information Block (MIB) to a UE on a Physical Broadcast Channel (PBCH); and

transmitting the DM-RS and the PBCH in frequency-division multiplexed time-frequency Resource Elements (REs) in respective orthogonal frequency-division multiplexed (OFDM) symbols of a plurality of OFDM symbols.

2. The method of claim 1, wherein a relationship between an AP for DM-RS transmission and an AP for PBCH transmission is predefined to allow a UE to derive a channel estimate for PBCH based on a channel estimate from the DM-RS.

3. The method of claim 1, further comprising:

notifying the UE of the AP for DM-RS transmission and PBCH transmission via Radio Resource Control (RRC) signaling to allow the UE to derive a channel estimate for the PBCH based on the channel estimate.

4. The method of claim 1, further comprising:

transmitting PBCH in a plurality of OFDM symbols within each semi-frame from an AP corresponding to the DM-RS AP.

5. The method of claim 1, further comprising:

transmitting PBCH within each half-frame by using a plurality of beams from the AP.

6. The method of claim 1, further comprising:

transmitting demodulation reference signals (DM-RS) from a same AP and in a same OFDM symbol as the PBCH to allow a UE to derive a channel estimate of the PBCH based on a channel estimate from the DM-RS.

7. The method of claim 6, further comprising:

transmitting a plurality of DM-RSs in a plurality of beams within a plurality of OFDM symbols within the semi-frame.

8. The method of any of claims 1 to 7, further comprising:

transmitting the PBCH, the DM-RS and a synchronization signal comprising a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS) in adjacent OFDM symbols.

9. The method of claim 8, further comprising:

transmitting the PBCH adjacent to the synchronization signal in the same OFDM symbol, and wherein a DM-RS occupies a portion of remaining REs in the OFDM symbol.

10. The method of claim 8, further comprising:

multiplexing the DM-RS and the PBCH in a frequency domain.

11. The method of any of claims 1 to 7, further comprising:

transmitting the PBCH in different OFDM symbol positions within the subframe.

12. The method of any of claims 1 to 7, further comprising:

transmitting the PBCH and synchronization signals including a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS) using the same AP.

13. A Base Station (BS), comprising:

one or more processors; and

memory having instructions stored thereon, which when executed by the one or more processors, perform the steps of the method of any one of claims 1 to 12.

14. The base station of claim 13, wherein the base station further comprises:

a radio transceiver connected to the one or more processors; and

a directional antenna array connected to the radio transceiver and operated by the one or more processors to transmit different PBCHs in different spatial directions using different beams.

15. A method, comprising:

performing, by a User Equipment (UE), the following:

receiving a demodulation reference signal DM-RS corresponding to a beamforming Antenna Port (AP);

receiving a Master Information Block (MIB) on a Physical Broadcast Channel (PBCH); and

receiving the DM-RS and the PBCH in frequency-division multiplexed time-frequency Resource Elements (REs) in respective orthogonal frequency-division multiplexed (OFDM) symbols of a plurality of OFDM symbols.

16. The method of claim 15, further comprising:

receiving information about an AP for DM-RS transmission and PBCH transmission via Radio Resource Control (RRC) signaling to allow the UE to derive a channel estimate for the PBCH based on the channel estimate.

17. The method of claim 15, further comprising:

receiving a PBCH in a plurality of OFDM symbols, wherein the PBCH is transmitted from an AP corresponding to a DM-RS AP.

18. The method of claim 15, further comprising:

receiving a plurality of DM-RSs corresponding to a plurality of SS bursts, and wherein the plurality of DM-RSs are frequency division multiplexed within a plurality of OFDM symbols.

19. A wireless device, comprising:

one or more processors; and

memory having instructions stored thereon which, when executed by the one or more processors, perform the steps of the method of any one of claims 15 to 19.

20. A computer program product comprising instructions which, when executed by one or more processors, perform the steps of the method according to any one of claims 15 to 19.

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