CN109479327B

CN109479327B - Apparatus for enhancing physical random access channel transmission

Info

Publication number: CN109479327B
Application number: CN201780042715.5A
Authority: CN
Inventors: 熊岗; 张羽书; 何宏; 韩承希; A·达维多夫; 朱源; G·V·莫罗佐夫
Original assignee: Apple Inc
Current assignee: Apple Inc; Intel Corp
Priority date: 2016-08-09
Filing date: 2017-08-01
Publication date: 2023-07-14
Anticipated expiration: 2037-08-01
Also published as: WO2018031291A1; CN116634596A; CN109479327A

Abstract

Briefly, in accordance with one or more embodiments, an apparatus of a User Equipment (UE) comprises: one or more baseband processors to: processing a set of reciprocity offset thresholds received from a NR node B (gNB) and determining a repetition level for transmitting a fifth generation (5G) Physical Random Access Channel (PRACH) L times based on the set of reciprocity offset thresholds or configuration via higher layers; and a memory for: the repetition level is stored.

Description

Apparatus for enhancing physical random access channel transmission

Cross Reference to Related Applications

This application claims the benefit of U.S. provisional application No.62/372,660 (P108042Z), filed 8/9 a 2016. Said application No.62/372,660 is incorporated herein by reference in its entirety.

Background

Mobile communications have evolved significantly from early voice systems to today's highly complex integrated communication platforms. The next generation wireless communication system (fifth generation (5G)) will provide access to information and sharing of data by various users and applications anywhere and anytime. 5G is intended to be a unified network and/or system that aims at satisfying very different and sometimes conflicting performance dimensions and services. This diverse multidimensional requirement is driven by different services and applications. In general, 5G will enrich life with better, simpler and more seamless radio connection solutions based on third generation partnership project (3 GPP) long term evolution Advanced (LTE-Advanced) and additional potential new Radio Access Technology (RAT) evolution. The 5G will enable everything to go through the wireless connection and provide fast and rich content and services.

For 5G systems, high-band communications have attracted considerable attention in the industry because 5G systems can provide wider bandwidths to support future integrated communication systems. Beamforming is an important technique for implementing high-band systems because the beamforming gain can compensate for severe path loss caused by atmospheric attenuation, improve signal-to-noise ratio (SNR) and expand the coverage area. By aligning the transmit beam with the target User Equipment (UE), the radiated energy is focused for higher energy efficiency and mutual UE interference is suppressed.

For centimeter wave (cmWave) and millimeter wave (mmWave) systems, a Beam Reference Signal (BRS) or Synchronization Signal (SS) block is transmitted from an evolved node B (eNodeB) to allow the UE to measure RS received power (RSRP) and obtain an optimal eNodeB transmit (Tx) beam and UE receive (Rx) beam. If a one-to-one association rule is defined between a 5G Physical Random Access Channel (PRACH) transmission resource and an SS block Antenna Port (AP), the UE may transmit the PRACH on a time or frequency resource associated with the best 5G node B (gNB) Tx beam using the best UE Rx beam acquired during the initial beam acquisition phase for uplink synchronization. This is mainly due to the assumption that the downlink and uplink reciprocity of Time Division Duplex (TDD) systems is perfect. In case of non-ideal reciprocity between Tx and Rx beams, certain mechanisms should be considered for PRACH transmission for initial access.

Drawings

The claimed subject matter is particularly pointed out and distinctly claimed in the concluding portion of the specification. However, such subject matter may be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, in which:

fig. 1 is a diagram of a process for contention-based random access in accordance with one or more embodiments;

fig. 2 is a diagram of a process for contention-free random access in accordance with one or more embodiments;

FIG. 3 is a diagram of a random access channel process in a perfect reciprocity scenario in accordance with one or more embodiments;

FIG. 4 is a diagram of a physical random access procedure in a non-ideal reciprocity scenario in accordance with one or more embodiments;

fig. 5 is a diagram of a first option for physical random access channel hopping in accordance with one or more embodiments;

fig. 6 is a diagram of a second option of physical random access channel hopping in accordance with one or more embodiments;

fig. 7 is a diagram of a third option of physical random access channel hopping in accordance with one or more embodiments;

fig. 8 is a diagram of physical random access channel transmission timing in accordance with one or more embodiments;

fig. 9 is a diagram of dynamic panel switching for physical random access channel transmission in accordance with one or more embodiments; and

FIG. 10 is a diagram of example components of a device, according to some embodiments.

It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.

Detailed Description

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. However, it will be understood by those skilled in the art that the claimed subject matter may be practiced without these specific details. In other instances, well-known methods, procedures, components, and/or circuits have not been described in detail.

Referring now to fig. 1, a diagram of a process for contention-based random access in accordance with one or more embodiments will be discussed. In the example of fig. 1, the four-operation procedure 100 may be used for initial contention-based random access in accordance with the third generation partnership project (3 GPP) Long Term Evolution (LTE) specifications. In a first operation 114, a User Equipment (UE) 110 transmits a Physical Random Access Channel (PRACH) in an Uplink (UL) by randomly selecting a preamble signature that may allow an evolved node B (eNB) 112 to estimate a delay between the eNB 112 and the UE 110 for subsequent UL timing adjustment. In the fifth generation (5G) new air interface (NR) standard, the eNB 112 may include the gNB 112, although the scope of the claimed subject matter is not limited in this respect. Subsequently, in a second operation 116, the eNB feeds back a Random Access Response (RAR) carrying Timing Advance (TA) command information for uplink timing adjustment 122 and uplink grant for uplink transmission in a third operation (L2/L3 message) 118. UE 110 expects to receive the RAR within a time window, the beginning and end of which may be configured by a System Information Block (SIB). Finally, a contention resolution message sent from the eNB 112 to the UE 110 may occur at operation 120.

Referring now to fig. 2, a diagram of a process for contention-free random access in accordance with one or more embodiments will be discussed. For certain scenarios, including switching and resuming downlink traffic for UE 110, to reduce random access latency, UE 110 may be requested to perform contention-free random access procedure 200, which may be triggered by a Physical Downlink Control Channel (PDCCH) command. Specifically, at operation 210, the eNB 112 allocates a dedicated PRACH preamble signature to the UE 110, which may be outside of the preamble set for contention-based random access. Then, UE 110 transmits the random access preamble to eNB 112. Note that the contention-free random access procedure terminates with the RAR message of operation 214.

Referring now to fig. 3, a diagram of a random access channel process in a perfect reciprocity scenario in accordance with one or more embodiments will be discussed. As mentioned above, in the case of perfect reciprocity, UE 110 may select fifth generation (5G) Physical Random Access Channel (PRACH) resources from among time or frequency PRACH resources that may be associated with a best 5G new air interface (NR) node B (gNB) transmit (Tx) beam or Beam Reference Signal (BRS) or SS block Antenna Port (AP). In one or more embodiments, the Beam Reference Signal (BRS) may include, but is not limited to, a Synchronization Signal (SS) block for Downlink (DL) transmit (Tx) beam measurement, such as a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSs), or a Physical Broadcast Channel (PBCH), or a combination thereof, and the scope of the claimed subject matter is not limited in this respect.

An example of a RACH procedure in case of perfect reciprocity is shown in fig. 3. The association in time or frequency between a Downlink (DL) beam or AP and the corresponding PRACH resource is cell-specific and may be signaled as part of the system information such that each DL Tx beam has a dedicated associated PRACH resource in the Uplink (UL). Alternatively, a one-to-one or many-to-one association between the beam index (i.e., BRS resource index) and PRACH resources, e.g., in the time, frequency, and/or sequence domain, may be predefined, e.g., based on a group index or symbol index. In any case, before initiating the RACH procedure, UE 110 should be aware of this association in idle mode. In the example shown in fig. 3, in slot #0 denoted by 310, the UE 110 measures the received power based on the BRS and determines the optimal gNB Tx beam. As shown in fig. 3, for UE #1, the best Tx beam of the gnb 112 is located in BRS beam group #0 and a third Orthogonal Frequency Division Multiplexing (OFDM) symbol 312. According to the association rule, UE 110 may accordingly transmit the PRACH in the associated PRACH resource (i.e., in the third PRACH slot 314 in slot #5, indicated at 316).

To increase random access capacity, UE 110 may randomly select one frequency resource for PRACH transmission. As shown in fig. 3, UE 110 may select PRACH frequency resource #1 for PRACH transmission. Alternatively, UE 110 may appropriately select PRACH resources from the set of available PRACH resources associated with the best Tx beam based at least in part on the potential message size (which is the data available for transmission plus a MAC header, optionally plus a MAC control element) and the path loss measured by the BRS based on the best beam. More specifically, if the message payload size is greater than the signaled threshold a and if the path loss is less than the threshold B, then the UE 110 should select from the first PRACH group. Otherwise, UE 110 may select one from the second PRACH group.

In one or more embodiments, the reciprocity offset may be defined as I _reciprocity Which may be used to indicate an offset between non-ideal reciprocity and perfect reciprocity. Based on the offset, eNB 112 may configure a set of thresholds to allow UE 110 to use the selected beam based on I _reciprocity The offset value of (2) is derived autonomously from the repetition level L for PRACH transmission. In one embodiment, the repetition level L may refer to the number of times the PRACH is transmitted, although the scope of the claimed subject matter is not limited in this respect. In one embodiment, the thresholds for the three levels, e.g., threshold_0, threshold_1, and threshold_2, may be configured by higher layers via a 5G Master Information Block (MIB), a 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling. In one or more embodiments, higher layers may include layers higher than the physical layer, such as in a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Resource Control (RRC) layer, or a non-access (NAS) layer, etc., although the scope of the claimed subject matter is not limited in this respect. In the case where the threshold is configured by a higher layer, UE 110 may derive the repetition level based on the following formula:

As a further extension, I _reciprocity May be beam specific and a set of thresholds may be configured by higher layers. In this case, UE 110 may send I for each particular beam _reciprocity Compare to a threshold list and determine the best Rx beam and corresponding repetition number for PRACH transmission.

It should be noted that the repeated PRACH may be transmitted in a continuous or discontinuous manner in the time domain. In the case of the time domain, UE 110 may transmit PRACH L times in resources corresponding to the L best Beam Reference Signals (BRS) Antenna Ports (APs), where L may be configured by higher layers via MIB or SIB or RRC signaling, or determined as mentioned above. Considering that a one-to-one resource association in the time domain between BRS antenna ports and PRACH resources may be defined, the UE 110 may derive corresponding time resources for PRACH transmission.

Furthermore, UE 110 may use the same PRACH preamble signature, which may allow the gNB 112 to perform combining to improve detection performance. Specifically, UE 110 may randomly select one PRACH preamble signature and use the selected PRACH preamble signature for subsequent PRACH transmissions. Alternatively, UE 110 may randomly select one PRACH preamble for each transmission, which may reduce collision probability.

To allow the gNB 112 to identify whether the UE 110 is in a non-ideal reciprocity condition or a perfect reciprocity condition, dedicated resources may be allocated for the UE 110 under the non-ideal reciprocity condition. In particular, such dedicated PRACH resources and resources for UE 110 under perfect reciprocity may be multiplexed in time division combinations. Furthermore, the partitioning of the set of dedicated resources for UE 110 under non-ideal reciprocity and perfect reciprocity may be predefined or configured by higher layers via MIB, SIB, or RRC signaling.

In one example, one or more of a signature, time, or frequency resources may be reserved for the PRACH of UE 110 under non-ideal reciprocity to transmit the PRACH. Furthermore, a combination of multiplexing schemes based on Time Division Multiplexing (TDM), frequency Division Multiplexing (FDM), and/or Code Division Multiplexing (CDM) may be used to separate resources for UE 110 under non-ideal reciprocity and perfect reciprocity.

In another example, the preamble signature for each PRACH transmission may be different. The preamble signatures can be divided into two groups: group a and group B. Group a indicates that the current PRACH resource is determined by the best DL beam index. Group B indicates that the PRACH resource is determined by other DL beam indexes. The preamble signatures in group a and group B should be one-to-one mapped. UE 110 may randomly select a preamble signature within group a and then select a preamble signature in group B that maps one-to-one to the selected one of group a. Thus, the gNB 112 may know which beam is the best DL beam for the UE 110 and use that DL beam to transmit the RAR.

In one or more embodiments, the association between one or more opportunities (occalations) of the downlink DL broadcast channel and/or signal and the subset of RACH or PRACH resources is notified to UE 110 by the gNB 112 through broadcast system information, or may be known to UE 110. Based at least in part on the DL measurements and the corresponding associations, UE 110 may select a subset of PRACH preamble indices. UE 110 may select one or more UE transmit (Tx) beams for one or more preamble transmissions. The UE 110 may use the same UE Tx beam during a single or multiple and/or repeated preamble PRACH transmission opportunity notified by broadcast system information, although the scope of the claimed subject matter is not limited in this respect. In one or more embodiments, PRACH transmission may occur in accordance with the third generation partnership project (3 GPP) new air interface (NR) standard (e.g., in accordance with 3GPP Technical Specification (TS) 38.211 or 3GPP TS 38.212, or as described in 3GPP Technical Report (TR) 38.802 release 14.1.0 (2017-06)), although the scope of the claimed subject matter is not limited in this respect.

In one or more embodiments, from the physical layer perspective, for the new air interface (NR) standard, it is assumed that the RACH procedure includes RACH preamble, message 1 (msg.1), random access response, message 2 (msg.2), message 3, and message 4. Both IDLE mode and CONNECTED mode UEs 110 support random access procedures. For a four-step RACH procedure, the RACH transmission opportunity may be defined as the time-frequency resource on which PRACH message 1 is transmitted using the configured PRACH preamble format over a single specific Tx beam.

RACH resources may also be defined as time-frequency resources used to transmit RACH preambles. Whether the UE 110 is to transmit one or more and/or repeated preambles within a subset of RACH resources may be notified by broadcasting system information, for example to cover the gNB Rx beam scan without Tx/Rx beam correspondence at the gNB 112.

For at least multi-beam operation, whether Tx/Rx beam correspondence is available at the gNB 112 or not, the following RACH procedure may be considered at least for the UE 110 in idle mode. The association between one or more opportunities for Downlink (DL) broadcast channels and/or signals and a subset of RACH resources may be signaled to UE 110 by broadcast system information or may be known to UE 110. Based at least in part on the DL measurements and the corresponding associations, UE 110 may select a subset of RACH preamble indices. UE 110 may select one or more UE Tx beams for one or more preamble transmissions. During RACH transmission opportunities of single or multiple and/or repeated preambles broadcasting system information notifications, UE 110 may use the same UE Tx beam. The NR standard supports at least the transmission of a single message 1 before the end of the listening Random Access Response (RAR) window.

At least for the case where there is no gNB Tx/Rx beam correspondence, gNB 112 may configure the association between the DL signals and/or channels and the subset of RACH resources and/or the subset of preamble indexes for determining the Msg2 DL Tx beam. Based at least in part on the DL measurements and the corresponding associations, UE 110 may select a subset of RACH resources and/or a subset of RACH preamble indices. The preamble index consists of a preamble sequence index and an Orthogonal Cover Code (OCC) index if OCC is supported. It should be noted that a subset of the preambles may be indicated by an OCC index finger.

At least for multi-beam operation, whether Tx/Rx beam correspondence is available at the gNB 112, DL Tx beams for message 2 may be obtained based on the detected RACH preambles/resources and the corresponding associations. The Uplink (UL) grant in message 2 may indicate the timing of the transmission of message 3. As a baseline UE 110 behavior, UE 110 assumes that a single RAR is received within a given RAR window.

At least for UE 110 in idle mode, UE 110 may determine the UL Tx beam for message 3 transmission. UE 110 may use the same UL Tx beam for message 1 transmission. Different PRACH configurations may be supported, e.g., considering different parameter set (numerology) scenarios and whether Tx/Rx beam correspondence is available at the gNB 112.

For NR RACH message 1 retransmission at least for multi-beam operation, NR supports power ramping. If UE 110 does not change the beam, the counter of the power ramp may continue to increase. It should be noted that UE 110 may use the most recent or more recent estimate of the path loss to derive the uplink transmit power. Whether UE 110 performs UL beam switching during retransmission may depend on the implementation of UE 110. It should also be noted that which beam UE 110 switches to may also depend on the implementation of UE 110.

Referring now to fig. 4, a diagram of a physical random access procedure in a non-ideal reciprocity scenario in accordance with one or more embodiments will be discussed. An example of PRACH transmission in two Orthogonal Frequency Division Multiplexing (OFDM) symbols is shown in fig. 4. In addition, UE 110 may measure BRS received power and determine the two best BRS APs in symbol #2 410 and symbol #3 412, as shown in fig. 4. Based at least in part on the one-to-one association, UE 110 may repeat the PRACH in three different PRACH slots in slots #2 and #3 of the configured slots. The transmission scheme can enhance PRACH detection performance in the case of non-ideal reciprocity.

Referring now to fig. 5, a diagram of a first option for physical random access channel hopping in accordance with one or more embodiments will be discussed. In one or more embodiments, if multiple frequency resources are configured for PRACH transmissions, UE 110 may perform frequency hopping on the multiple PRACH transmissions to take advantage of the benefits of frequency diversity. A first option (i.e., option 1) is shown in fig. 5, wherein if L consecutive PRACH transmissions are performed, a constant frequency resource offset may be applied between two consecutive PRACH transmissions. More specifically, UE 110 may randomly select one frequency resource in the first PRACH slot and apply frequency hopping on subsequent PRACH transmissions. In one example, the constant frequency resource offset may be [ M/2], where M is the total number of PRACH frequency resources configured by higher layers. Fig. 5 shows one example of PRACH hopping for option 1. In this example, UE 110 randomly selects PRACH frequency resource #3, makes a first PRACH transmission 510 in PRACH slot 0 at 510, and performs frequency hopping on subsequent transmissions. Specifically, UE 110 transmits three PRACH transmissions, wherein transmission 512 is transmitted at PRACH slot 1 of frequency resource #1, transmission 514 is transmitted at PRACH slot 2 of frequency resource #3, and transmission 516 is transmitted at PRACH slot 3 of frequency resource #1, although the scope of the claimed subject matter is not limited in this respect.

Referring now to fig. 6, a diagram of a second option for physical random access channel hopping in accordance with one or more embodiments will be discussed. In a second option (i.e., option 2), UE 110 performs frequency hopping on PRACH transmissions between two PRACH frequency resources. More specifically, the UE 110 transmits a first [ L/2] prach using a first frequency resource and a second [ L/2] prach using a second frequency resource. The first frequency resources may be randomly selected by the UE 110 and the distance between the first frequency resources and the second frequency resources may be predefined or configured by higher layers. In one example, the frequency distance may be [ M/2]. Fig. 6 shows one example of PRACH hopping for option 2. In this example, the UE 110 randomly selects PRACH frequency resource #3 for the first PRACH transmission 610 and performs frequency hopping for subsequent transmissions. Specifically, the UE transmits three PRACH transmissions, transmission 612 in frequency resource #3, transmission 614 in frequency resource #1, and transmission 616 in frequency resource #1, although the scope of the claimed subject matter is not limited in this respect.

Referring now to fig. 7, a diagram of a third option for physical random access channel hopping in accordance with one or more embodiments will be discussed. In a third option (i.e., option 3), the UE 110 performs frequency hopping on the plurality of PRACH transmissions according to a frequency hopping pattern. In particular, the frequency hopping pattern may be defined as a function of at least one or more of the following parameters: a cell ID, frequency resources for the first PRACH transmission, a symbol and/or slot index for the PRACH transmission, and a UE ID (e.g., a cell radio network temporary identifier (C-RNTI)). In one example, the frequency resource index for each PRACH transmission may be given by:

Wherein, the liquid crystal display device comprises a liquid crystal display device,

is the physical cell ID, n _sf Is the slot index, I _freq Is used for PRACFrequency resource index for H transmission. Fig. 7 shows one example of PRACH hopping for option 3. In this example, the UE 110 randomly selects PRACH frequency resource #3 for the first PRACH transmission 710 and performs frequency hopping for subsequent transmissions. Specifically, UE 110 transmits three PRACH transmissions, transmission 712 in frequency resource #0, transmission 714 in frequency resource #1, and transmission 716 in frequency resource #3, although the scope of the claimed subject matter is not limited in this respect.

Referring now to fig. 8, a diagram of physical random access channel transmission timing in accordance with one or more embodiments will be discussed. Similar to the method used in LTE, for contention free random access, the gNB 112 will assign a dedicated PRACH preamble signature for PRACH transmission. For 5G systems, an enhanced embodiment for contention-free random access may be provided as follows. In one embodiment, a plurality of PRACH formats may be defined in a specification. The 5G PRACH format indicator may be included in a Downlink Control Information (DCI) format via a PDCCH order to trigger a contention-free PRACH transmission. In another embodiment, PRACH transmission timing and/or frequency resources may be indicated in the DCI format via a PDCCH order to trigger contention-free PRACH transmission.

The slot structure for PRACH transmission may be based on a self-contained slot structure, in which a PDCCH may be transmitted at the beginning of a slot and a PUCCH may be transmitted at the last part of the slot. In one example, the PRACH may be transmitted in the last part of the slot and multiplexed with the PUCCH in a Frequency Division Multiplexing (FDM) manner.

Further, the PRACH transmission timing or the transmission gap between the PDCCH order and the PRACH transmission slot may be explicitly indicated in the DCI format. As a further extension, a set of PRACH transmission timings may be predefined or configured by higher layers. A field in the DCI format may be used to indicate which transmission timing of the set of PRACH transmission timings is applied to PRACH transmission. A PRACH transmission timing or gap of value 0 may be considered as a self-contained PRACH transmission, i.e., PRACH is transmitted in the same time slot in which PDCCH is transmitted.

Fig. 8 shows two examples of PRACH transmission timing. In a first example, a self-contained PRACH transmission is triggered, i.e., PRACH transmission delay k=0, where PRACH transmission 810 occurs at the end of one slot 814, after a Guard Time (GT). In a second example, the gap between PDCCH and PRACH is 1 slot, i.e., k=1, where PRACH transmission 812 occurs at the end of two slots (slot 814 and slot 816) and after a Guard Time (GT).

In another embodiment, in the case of non-ideal reciprocity, the number of PRACH transmissions may be indicated in the DCI format via a PDCCH order to trigger a contention-free PRACH transmission. Further, an indicator for indicating whether PRACH hopping may be applied to a plurality of PRACH transmissions may be included in the DCI format. In one example, bit 1 may indicate that frequency hopping for PRACH transmission is enabled, while bit 0 may indicate that frequency hopping for PRACH transmission is disabled.

Referring now to fig. 9, a diagram of dynamic panel switching for physical random access channel transmission in accordance with one or more embodiments will be discussed. In another embodiment of the present invention, in case the UE is equipped with two or more sub-arrays or panels (e.g., panel (panel 0) 910 and panel (panel 1) 912), the beam or sub-array or panel index may be indicated in a Downlink Control Information (DCI) format via a PDCCH order, triggering contention-free PRACH transmission in a cross-beam manner. This arrangement may allow dynamic beam triggering and switching for PRACH transmission to further increase PRACH detection performance and connection robustness.

Fig. 9 shows one example of dynamic panel switching for PRACH transmission. In this example, UE 110 may measure beam reference signal received power (B-RSRP) using two panels ((panel 0) 910 and panel (panel 1) 912) and report the corresponding B-RSRP of the two panels to gNB 112. After receiving the B-RSRP from UE 110, the gNB 112 may select a panel with a stronger B-RSRP and inform UE 110 to use the panel to transmit PRACH. As shown in fig. 9, panel (panel 1) 912 may have a stronger B-RSRP from beam 916 of gNB 112 than the B-RSRP from beam 914 of gNB 112 at panel (panel 0) 910, where gNB 112 operates as a transmit/receive point (TRP). In this case, the panel (panel 1) 912 may be indicated in DCI and used for PRACH transmission, but the scope of the claimed subject matter is not limited in this respect.

Referring now to fig. 10, a diagram of example components of a device according to some embodiments will be discussed. Fig. 10 illustrates example components of a device 1000 in accordance with some embodiments. In some embodiments, device 1000 may include application circuitry 1002, baseband circuitry 1004, radio Frequency (RF) circuitry 1006, front End Module (FEM) circuitry 1008, one or more antennas 1010, and Power Management Circuitry (PMC) 1012, coupled at least as shown. The components of the apparatus 1000 shown may be included in a UE or RAN node. In some embodiments, device 1000 may include fewer elements (e.g., the RAN node may not utilize application circuitry 1002, but instead include a processor/controller to process IP data received from the EPC). In some embodiments, device 1000 may include additional elements, such as memory/storage, displays, cameras, sensors, or input/output (I/O) interfaces. In other embodiments, the components described below may be included in more than one device (e.g., for a cloud RAN (C-RAN) implementation, the circuitry may be included separately in more than one device).

The application circuitry 1002 may include one or more application processors. For example, the application circuitry 1002 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. Processors 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 or operating systems to run on the device 1000. In some embodiments, the processor of application circuit 1002 may process IP data packets received from the EPC.

Baseband circuitry 1004 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 1004 may include one or more baseband processors or control logic to process baseband signals received from the receive signal path of the RF circuitry 1006 and to generate baseband signals for the transmit signal path of the RF circuitry 1006. The baseband circuitry 1004 may interface with the application circuitry 1002 for generating and processing baseband signals and controlling the operation of the RF circuitry 1006. For example, in some embodiments, the baseband circuitry 1004 may include a third generation (3G) baseband processor 1004A, a fourth generation (4G) baseband processor 1004B, a fifth generation (5G) baseband processor 1004C, or other baseband processor 1004D for other existing generations, generations under development, or generations to be developed in the future (e.g., second generation (2G), sixth generation (6G), etc.). The baseband circuitry 1004 (e.g., one or more of the baseband processors 1004A-D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 1006. In other embodiments, some or all of the functionality of the baseband processors 1004A-D may be included in modules stored in the memory 1004G and executed via the Central Processing Unit (CPU) 1004E. 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 the baseband circuitry 1004 may include Fast Fourier Transform (FFT), precoding, or constellation mapping/demapping functions. In some embodiments, the encoding/decoding circuitry of the baseband circuitry 1004 may include convolution, tail-biting convolution, turbo, viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of the modem and encoder/decoder functions are not limited to these examples and may include other suitable functions in other embodiments.

In some embodiments, the baseband circuitry 1004 may include one or more audio Digital Signal Processors (DSPs) 1004F. The audio DSP 1004F may include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. In some embodiments, 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 1004 and application circuitry 1002 may be implemented together, for example, on a system on a chip (SOC).

In some embodiments, baseband circuitry 1004 may provide communications compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 1004 may support communication with an Evolved Universal Terrestrial Radio Access Network (EUTRAN) or other Wireless Metropolitan Area Network (WMAN), wireless Local Area Network (WLAN), wireless Personal Area Network (WPAN). Embodiments in which the baseband circuitry 1004 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

The RF circuitry 1006 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, RF circuitry 1006 may include switches, filters, amplifiers, and the like to facilitate communications with a wireless network. The RF circuitry 1006 may include a receive signal path, which may include circuitry for down-converting RF signals received from the FEM circuitry 1008 and providing baseband signals to the baseband circuitry 1004. The RF circuitry 1006 may also include a transmit signal path, which may include circuitry for up-converting the baseband signals provided by the baseband circuitry 1004 and providing RF output signals to the FEM circuitry 1008 for transmission.

In some embodiments, the receive signal path of the RF circuit 1006 may include a mixer circuit 1006a, an amplifier circuit 1006b, and a filter circuit 1006c. In some embodiments, the transmit signal path of the RF circuit 1006 may include a filter circuit 1006c and a mixer circuit 1006a. The RF circuit 1006 may also include a synthesizer circuit 1006d for synthesizing frequencies used by the mixer circuit 1006a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuit 1006a of the receive signal path may be configured to: the RF signal received from FEM circuit 1008 is down-converted based on the synthesized frequency provided by synthesizer circuit 1006 d. The amplifier circuit 1006b may be configured to: the down-converted signal is amplified, and the filter circuit 1006c may be a Low Pass Filter (LPF) or a Band Pass Filter (BPF) configured to: unwanted signals are removed from the down-converted signals to generate output baseband signals. The output baseband signal may be provided to baseband circuitry 1004 for further processing. In some embodiments, the output baseband signal may be a zero frequency baseband signal, although this is not a requirement. In some embodiments, the mixer circuit 1006a 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 1006a of the transmit signal path may be configured to: the input baseband signal is upconverted based on the synthesized frequency provided by synthesizer circuit 1006d to generate an RF output signal for FEM circuit 1008. The baseband signal may be provided by baseband circuitry 1004 and may be filtered by filter circuitry 1006 c.

In some embodiments, the mixer circuit 1006a of the receive signal path and the mixer circuit 1006a of the transmit signal path may comprise two or more mixers and may be arranged for quadrature down-conversion and up-conversion, respectively. In some embodiments, the mixer circuit 1006a of the receive signal path and the mixer circuit 1006a 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 1006a of the receive signal path and the mixer circuit 1006a of the transmit signal path may be arranged for direct down-conversion and direct up-conversion, respectively. In some embodiments, the mixer circuit 1006a of the receive signal path and the mixer circuit 1006a 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, the RF circuitry 1006 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and the baseband circuitry 1004 may include a digital baseband interface to communicate with the RF circuitry 1006.

In some dual mode embodiments, separate radio IC circuits may be provided for processing signals with respect to each spectrum, although the scope of the embodiments is not limited in this respect. In some embodiments, synthesizer circuit 1006d may be a fractional-N synthesizer or a fractional-N/n+1 synthesizer, although the scope of embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, the synthesizer circuit 1006d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase locked loop with a frequency divider. The synthesizer circuit 1006d may be configured to: the output frequency used by the mixer circuit 1006a of the input combining RF circuit 1006 is controlled based on the frequency input and the divider. In some embodiments, the synthesizer circuit 1006d may be a fractional N/n+1 synthesizer.

In some embodiments, the frequency input may be provided by a Voltage Controlled Oscillator (VCO), although this is not a requirement. The divider control input may be provided by the baseband circuitry 1004 or the application processor 1002, 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 a channel indicated by the application processor 1002.

The synthesizer circuit 1006d of the RF circuit 1006 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 the 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 packets, 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 1006d may be configured to: the 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 the quadrature generator and divider circuit to generate a plurality of signals having a plurality of different phases relative to each other at the carrier frequency. In some embodiments, the output frequency may be an LO frequency (fLO). In some embodiments, the RF circuit 1006 may include an IQ/polar converter.

FEM circuitry 1008 may include a receive signal path, which may include circuitry configured to operate on RF signals received from one or more antennas 1010, amplify the received signals, and provide an amplified version of the received signals to RF circuitry 1006 for further processing. The FEM circuitry 1008 may further include a transmit signal path, which may include circuitry configured to amplify signals provided by the RF circuitry 1006 for transmission by one or more of the one or more antennas 1010. In various embodiments, amplification through the transmit or receive signal path may be accomplished in the RF circuit 1006 alone, in the FEM 1008 alone, or in both the RF circuit 1006 and FEM 1008.

In some embodiments, FEM circuitry 1008 may include a TX/RX switch to switch between transmit and receive mode operation. The FEM circuitry 1008 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include an LNA to amplify the received RF signal and provide the amplified received RF signal as an output (e.g., to the RF circuitry 1006). The transmit signal path of FEM circuitry 1008 may include: a Power Amplifier (PA) for amplifying an input RF signal (e.g., provided by RF circuitry 1006); and one or more filters for generating RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 1010).

In some embodiments, PMC 1012 may manage the power provided to baseband circuitry 1004. In particular, PMC 1012 may control power supply selection, voltage scaling, battery charging, or DC-DC conversion. When the device 1000 is capable of being powered by a battery (e.g., when the device is included in a UE), the PMC 1012 may often be included. PMC 1012 may increase power conversion efficiency while providing desired implementation size and heat dissipation characteristics.

Fig. 10 shows that PMC 1012 is coupled only with baseband circuitry 1004. However, in other embodiments, the PMC 1012 may additionally or alternatively be coupled with other components (e.g., without limitation, the application circuit 1002, the RF circuit 1006, or the FEM 1008) and perform similar power management operations thereon.

In some embodiments, the PMC 1012 may control or be part of various power saving mechanisms of the device 1000. For example, if the device 1000 is in an RRC Connected state (where it is still Connected to the RAN node because it is expected to receive traffic soon), it may enter a state called discontinuous reception mode (DRX) after an inactivity period. During this state, the device 1000 may power down for a brief time interval and thus save power.

If there is no data traffic activity for an extended period of time, the device 1000 may transition to an rrc_idle state in which it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The device 1000 enters a very low power state and it performs paging in which it wakes up again periodically to listen to the network and then powers down again. The device 1000 may not be able to receive data in this state and it must transition back to the RRC Connected state in order to receive data.

The additional power saving mode may allow the device to be unavailable to the network for a period longer than the paging interval (ranging from a few seconds to a few hours). During this time, the device is completely unreachable to the network and may be completely powered down. Any data transmitted during this time causes a large delay and this delay is assumed to be acceptable.

The processor of the application circuit 1002 and the processor of the baseband circuit 1004 may be used to execute elements of one or more instances of a protocol stack. For example, the processor of baseband circuitry 1004, alone or in combination, may be used to perform layer 3, layer 2, or layer 1 functions, while the processor of application circuitry 1002 may utilize data (e.g., packet data) received from these layers and also perform layer 4 functions (e.g., transmission Communication Protocol (TCP) and User Datagram Protocol (UDP) layers). As referred to herein, layer 3 may include a Radio Resource Control (RRC) layer, as described in further detail below. As referred to herein, layer 2 may include a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, and a Packet Data Convergence Protocol (PDCP) layer, as described in further detail below. As referred to herein, layer 1 may include a Physical (PHY) layer of a UE/RAN node, as described in further detail below.

As used herein, the term "circuitry" or "circuitry" may refer to or be part of or include the following: 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 the functionality associated with one or more software or firmware modules. In some embodiments, the circuitry may comprise logic that is at least partially operable in hardware. The embodiments described herein may be implemented into a system using any suitable configuration of hardware and/or software.

The following are example implementations of the subject matter described herein. It should be noted that any of the examples described herein and variations thereof may be used in any permutation or combination of any other example or examples or variations, although the scope of the claimed subject matter is not limited in this respect.

In example 1, an apparatus of a User Equipment (UE) includes: one or more baseband processors to: processing a set of reciprocity offset thresholds received from a new air interface (NR) node B (gNB) and determining a repetition level for transmitting a fifth generation (5G) Physical Random Access Channel (PRACH) L times based on the set of reciprocity offset thresholds or configuration via higher layers; and a memory for storing the repetition level. Example 2 may include the subject matter of example 1 or any of the examples described herein, further comprising: a radio frequency transceiver for: and sending the PRACH to the gNB for a plurality of times according to the repetition level. Example 3 may include the subject matter of example 1 or any of the examples described herein, wherein the set of reciprocity offset thresholds is configured by a higher layer via a 5G Master Information Block (MIB), via a 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling. Example 4 may include the subject matter of example 1 or any of the examples described herein, wherein the one or more baseband processors are to: PRACH resources are selected from a set of available PRACH resources associated with an optimal gNB transmit (Tx) beam based at least in part on a potential message size including data available for transmission, a Medium Access Control (MAC) header, or a MAC control element, or a combination thereof, and a measured pathloss based at least in part on a Beam Reference Signal (BRS) or Synchronization Signal (SS) block of the optimal gNB Tx beam. Example 5 may include the subject matter of example 1 or any of examples described herein, wherein the reciprocity offsets in the set of reciprocity offset thresholds are beam-specific, and wherein the one or more baseband processors are to: the reciprocity offset is compared to a threshold list and a best receive (Rx) beam and corresponding repetition level for PRACH transmission are determined. Example 6 may include the subject matter of example 1 or any of examples described herein, wherein the one or more baseband processors are to: it is determined whether to transmit the PRACH in a continuous or discontinuous manner in the time domain, and the PRACH is configured to be transmitted L times in resources corresponding to L best Beam Reference Signals (BRSs) or Synchronization Signal (SS) block Antenna Ports (APs), wherein L may be configured by a higher layer via MIB, SIB, or RRC signaling. Example 7 may include the subject matter of example 1 or any of the examples described herein, wherein the one or more baseband processors are to: randomly selecting one PRACH preamble signature and configuring the selected PRACH preamble signature for subsequent repeated PRACH transmissions, and wherein the one or more baseband processors are configured to: one PRACH preamble is randomly selected for repeated transmission. Example 8 may include the subject matter of example 1 or any of examples described herein, wherein the one or more baseband processors are to: if multiple frequency resources are configured for the PRACH transmission, frequency hopping is configured on the multiple PRACH transmissions. Example 9 may include the subject matter of example 1 or any of examples described herein, wherein the one or more baseband processors are to: a constant frequency resource offset is applied between two consecutive PRACH transmissions. Example 10 may include the subject matter of example 1 or any of the examples described herein, wherein the one or more baseband processors are to: frequency hopping is configured on PRACH transmissions between two PRACH frequency resources, and wherein the one or more baseband processors are to: the transmission of the first [ L/2] prach is configured using the first frequency resource and the transmission of the second [ L/2] prach is configured using the second frequency resource. Example 11 may include the subject matter of example 1 or any of examples described herein, wherein the one or more baseband processors are to: configuring frequency hopping over a plurality of PRACH transmissions according to a frequency hopping pattern, wherein the frequency hopping pattern is defined as a function of at least one or more of the following parameters: a cell Identifier (ID), a frequency resource for a first PRACH transmission, a symbol or slot index for a PRACH transmission, a cell radio network temporary identifier (C-RNTI), or a UE ID, or a combination thereof.

In example 12, an apparatus of a new air interface (NR) node B (gNB) includes: one or more baseband processors to: configuring a set of reciprocity offset thresholds for a User Equipment (UE) and processing a fifth generation (5G) Physical Random Access Channel (PRACH) received from the UE according to the set of reciprocity offset thresholds; and a memory for: and storing the repetition level. Example 13 may include the subject matter of example 12 or any of examples described herein, wherein the one or more baseband processors are to: the UE is allocated dedicated resources under non-ideal reciprocity conditions, wherein the dedicated resources under non-ideal reciprocity conditions and the resources under perfect reciprocity are to be multiplexed in Time Division Multiplexing (TDM), frequency Division Multiplexing (FDM), or Code Division Multiplexing (CDM), or a combination thereof, wherein the partitioning of the dedicated resources under non-ideal reciprocity and the resources under perfect reciprocity is predefined or configured by higher layers via a 5G Master Information Block (MIB), via a 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling. Example 14 may include the subject matter of example 12 or any of the examples described herein, wherein the one or more baseband processors are to: the PRACH format indicator, PRACH transmission timing, or PRACH time-frequency resources, or a combination thereof, are encoded in a Downlink Control Information (DCI) format via a PDCCH order to trigger a contention-free PRACH transmission. Example 15 may include the subject matter of example 12 or any of the examples described herein, wherein, for non-ideal reciprocity, the one or more baseband processors are to: the number of PRACH transmissions is encoded in a Downlink Control Information (DCI) format via a PDCCH order to trigger a contention-free PRACH transmission, and an indicator to indicate whether PRACH hopping is to be applied to multiple PRACH transmissions is encoded. Example 16 may include the subject matter of example 12 or any of examples described herein, wherein the one or more baseband processors are to: if the UE includes two or more sub-arrays or panels, a beam or sub-array or panel index is encoded in a Downlink Control Information (DCI) format via a PDCCH order, triggering contention-free PRACH transmission in a cross-beam manner.

In example 17, one or more machine-readable media may have instructions stored thereon that, if executed by a User Equipment (UE), cause: processing a set of reciprocity offset thresholds received from a new air interface (NR) node B (gNB); determining a repetition level for transmitting a fifth generation (5G) Physical Random Access Channel (PRACH) L times according to the set of reciprocity offset thresholds or according to a configuration by a higher layer; and storing the repetition level in a memory. Example 18 may include the subject matter of example 17 or any of the examples described herein, wherein the instructions, if executed, further cause: and enabling a radio frequency transceiver to send the PRACH to the gNB for a plurality of times according to the repetition level. Example 19 may include the subject matter of example 17 or any example described herein, wherein the set of reciprocity offset thresholds is configured by a higher layer via a 5G Master Information Block (MIB), via a 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling. Example 20 may include the subject matter of example 17 or any of the examples described herein, wherein the instructions, if executed, further cause: PRACH resources are selected from a set of available PRACH resources associated with an optimal gNB transmit (Tx) beam based at least in part on a potential message size including data available for transmission, a Medium Access Control (MAC) header, or a MAC control element, or a combination thereof, and a measured pathloss based at least in part on a Beam Reference Signal (BRS) or Synchronization Signal (SS) block of the optimal gNB Tx beam. Example 21 may include the subject matter of example 17 or any of examples described herein, wherein the reciprocity offsets in the set of reciprocity offset thresholds are beam-specific, and wherein the one or more baseband processors are to: the reciprocity offset is compared to a threshold list and a best receive (Rx) beam and corresponding repetition level for PRACH transmission are determined.

In example 22, the one or more machine-readable media may have instructions stored thereon that, if executed by a new air interface (NR) node B (gNB), cause: configuring a set of reciprocity offset thresholds for a User Equipment (UE); processing a fifth generation (5G) Physical Random Access Channel (PRACH) received from the UE according to the set of reciprocity offset thresholds; and storing the repetition level in a memory. Example 23 may include the subject matter of example 22 or any of the examples described herein, wherein the instructions, if executed, further cause: the UE is allocated dedicated resources under non-ideal reciprocity conditions, wherein the dedicated resources under non-ideal reciprocity conditions and the resources under perfect reciprocity are to be multiplexed in Time Division Multiplexing (TDM), frequency Division Multiplexing (FDM), or Code Division Multiplexing (CDM), or a combination thereof, wherein the partitioning of the dedicated resources under non-ideal reciprocity and the resources under perfect reciprocity is predefined or configured by higher layers via a 5G Master Information Block (MIB), via a 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling. Example 24 may include the subject matter of example 22 or any of the examples described herein, wherein the instructions, if executed, further cause: the PRACH format indicator, PRACH transmission timing, or PRACH time-frequency resources, or a combination thereof, are encoded in a Downlink Control Information (DCI) format via a PDCCH order to trigger a contention-free PRACH transmission. Example 25 may include the subject matter of example 22 or any of examples described herein, wherein, for non-ideal reciprocity, the one or more baseband processors are to: the number of PRACH transmissions is encoded in a Downlink Control Information (DCI) format via a PDCCH order to trigger a contention-free PRACH transmission, and an indicator to indicate whether PRACH hopping is to be applied to multiple PRACH transmissions is encoded.

In example 26, an apparatus of a User Equipment (UE) includes: means for processing a set of reciprocity offset thresholds received from a new air interface (NR) node B (gNB); means for determining a repetition level for transmitting a fifth generation (5G) Physical Random Access Channel (PRACH) L times based on the set of reciprocity offset thresholds or via a configuration by a higher layer; and means for storing the repetition level. Example 27 may include the subject matter of example 26 or any of the examples described herein, wherein the instructions further comprise: and sending the PRACH to the gNB for a plurality of times according to the repetition level. Example 28 may include the subject matter of example 26 or any example described herein, wherein the set of reciprocity offset thresholds is configured by a higher layer via a 5G Master Information Block (MIB), via a 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling. Example 29 may include the subject matter of example 26 or any of the examples described herein, further comprising: means for selecting PRACH resources from a set of available PRACH resources associated with an optimal gNB transmit (Tx) beam based at least in part on a potential message size including data available for transmission, a Medium Access Control (MAC) header, or a MAC control element, or a combination thereof, and a measured pathloss based at least in part on a Beam Reference Signal (BRS) or a Synchronization Signal (SS) block of the optimal gNB Tx beam. Example 30 may include the subject matter of example 26 or any example described herein, wherein the reciprocity offsets in the set of reciprocity offset thresholds are beam-specific, and wherein the one or more baseband processors are to: the reciprocity offset is compared to a threshold list and a best receive (Rx) beam and corresponding repetition level for PRACH transmission are determined.

In example 31, an apparatus of a new air interface (NR) node B (gNB) includes: means for configuring a set of reciprocity offset thresholds for a User Equipment (UE); means for processing a fifth generation (5G) Physical Random Access Channel (PRACH) received from the UE in accordance with the set of reciprocity offset thresholds; and means for storing the repetition level. Example 32 may include the subject matter of example 31 or any of the examples described herein, further comprising: the apparatus comprises means for allocating dedicated resources for the UE under non-ideal reciprocity conditions, wherein the dedicated resources under non-ideal reciprocity conditions and the resources under perfect reciprocity are to be multiplexed in Time Division Multiplexing (TDM), frequency Division Multiplexing (FDM) or Code Division Multiplexing (CDM) or a combination thereof, wherein the partitioning of the dedicated resources under non-ideal reciprocity and the resources under perfect reciprocity is predefined or configured by higher layers via a 5G Master Information Block (MIB), via a 5G System Information Block (SIB) or via Radio Resource Control (RRC) signaling. Example 33 may include the subject matter of example 31 or any of the examples described herein, further comprising: means for encoding a PRACH format indicator, PRACH transmission timing, or PRACH time-frequency resources, or a combination thereof, in a Downlink Control Information (DCI) format via a PDCCH order to trigger a contention-free PRACH transmission. Example 34 may include the subject matter of example 31 or any of the examples described herein, further comprising: the apparatus includes means for encoding a number of PRACH transmissions in a Downlink Control Information (DCI) format via a PDCCH order to trigger a contention-free PRACH transmission, and means for encoding an indicator indicating whether PRACH hopping is to be applied to a plurality of PRACH transmissions. In example 35, the machine-readable storage may comprise machine-readable instructions that, when executed, implement the apparatus recited in any preceding claim.

In the description and/or claims herein, "coupled" and/or "connected" along with their derivatives may be used. In particular embodiments, "connected" may be used to indicate that two or more elements are in direct physical and/or electrical contact with each other. "coupled" may mean that two or more elements are in direct physical and/or electrical contact. However, "coupled" may also mean that two or more elements may not be in direct contact with each other, but may still cooperate and/or interact with each other. For example, "coupled" may mean that two or more elements are not in contact with each other, but are indirectly joined together via another element or intermediate elements. Finally, the terms "above," "above," and "above" may be used in the following description and claims. "on," "above," and "above" may be used to indicate that two or more elements are in direct physical contact with each other. It should be noted, however, that "above" may also mean that two or more elements are not in direct contact with each other. For example, "above" may mean that one element is above another element, but not in contact with each other, and that there may be another element or elements between the two elements. Furthermore, the term "and/or" may mean "and", it may mean "or", it may mean "exclusive or", it may mean "one", it may mean "some, but not all", it may mean "none", and/or it may mean "both", although the scope of the claimed subject matter is not limited in this respect. In the description and/or claims herein, the terms "comprise" and "include," along with their derivatives, may be used and are intended as synonyms for each other.

Although the claimed subject matter has been described with a certain degree of particularity, it should be recognized that elements thereof may be altered by persons skilled in the art without departing from the spirit and/or scope of the claimed subject matter. It is believed that the foregoing description will be understood that the subject matter relates to new air interface standards and enhanced physical random access channel transmissions in many of its attendant thereto and that it will be apparent that various changes may be made in the form, construction and/or arrangement of the components thereof without departing from the scope and/or spirit of the claimed subject matter or without sacrificing all of its material advantages, the form herein before described being merely an explanatory embodiment thereof, and/or further without providing substantial change thereto. The claims are intended to encompass and/or include such variations.

Claims

1. An apparatus of a user equipment, UE, comprising:

one or more baseband processors to:

processing a set of reciprocity offset thresholds received from the base station and determining a repetition level for transmitting the fifth generation 5G physical random access channel PRACH L times in accordance with the set of reciprocity offset thresholds; and

and the memory is used for storing the repetition level.

2. The apparatus of claim 1, further comprising:

And the radio frequency transceiver is used for transmitting the PRACH to the base station for a plurality of times according to the repetition level.

3. The apparatus of claim 1 or 2, wherein the set of reciprocity offset thresholds is configured by a higher layer via a 5G master information block, MIB, via a 5G system information block, SIB, or via radio resource control, RRC, signaling.

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

PRACH resources are selected from a set of available PRACH resources associated with an optimal base station transmit Tx beam based at least in part on a potential message size including data available for transmission, a medium access control MAC header or MAC control element, or a combination thereof, and a measured pathloss based at least in part on a beam reference signal BRS or a synchronization signal SS block of the optimal base station transmit Tx beam.

5. The apparatus of claim 1 or 2, wherein the reciprocity offsets in the set of reciprocity offset thresholds are beam-specific, and wherein the one or more baseband processors are to:

the reciprocity offset is compared to a threshold list and the best received Rx beam and corresponding repetition level for PRACH transmission is determined.

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

it is determined whether the PRACH is to be transmitted in a continuous or discontinuous manner in the time domain and is configured to be transmitted L times in resources corresponding to the L best beam reference signals BRS or the synchronization signal SS block antenna ports AP.

7. The apparatus of claim 6, wherein the one or more baseband processors are configured to randomly select one PRACH preamble signature and configure the selected PRACH preamble signature for a subsequent repeated PRACH transmission,

and wherein the one or more baseband processors are configured to randomly select one PRACH preamble for repeated transmission.

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

if multiple frequency resources are configured for the PRACH transmission, frequency hopping is configured on the multiple PRACH transmissions.

9. The apparatus of claim 8, wherein the one or more baseband processors are to:

a constant frequency resource offset is applied between two consecutive PRACH transmissions.

10. The apparatus of claim 8, wherein the one or more baseband processors are configured to configure frequency hopping on PRACH transmissions between two PRACH frequency resources,

And wherein the one or more baseband processors are configured to configure transmission of a first [ L/2] prach using a first frequency resource and configure transmission of a second [ L/2] prach using a second frequency resource.

11. The apparatus of claim 8, wherein the one or more baseband processors are configured to configure frequency hopping over a plurality of PRACH transmissions according to a frequency hopping pattern,

wherein the frequency hopping pattern is defined as a function of at least one or more of the following parameters: a cell identifier ID, a frequency resource for a first PRACH transmission, a symbol or slot index for a PRACH transmission, a cell radio network temporary identifier C-RNTI or a UE ID, or a combination thereof.

12. An apparatus of a base station, comprising:

one or more baseband processors to:

configuring a group of reciprocity offset thresholds for User Equipment (UE), and processing a fifth generation 5G Physical Random Access Channel (PRACH) received from the UE according to the group of reciprocity offset thresholds; and

a memory for storing a repetition level, the repetition level being determined in accordance with the set of reciprocity offset thresholds.

13. The apparatus of claim 12, wherein the one or more baseband processors are configured to allocate dedicated resources for the UE under non-ideal reciprocity conditions,

Wherein the dedicated resources under non-ideal reciprocity conditions and the resources under perfect reciprocity are to be multiplexed in time division multiplexing TDM, frequency division multiplexing FDM or code division multiplexing CDM, or a combination thereof,

wherein the partitioning of said dedicated resources under non-ideal reciprocity and under perfect reciprocity is predefined or configured by higher layers via a 5G master information block MIB, via a 5G system information block SIB or via radio resource control RRC signaling.

14. The apparatus of claim 12 or 13, wherein the one or more baseband processors are to:

the PRACH format indicator, PRACH transmission timing or PRACH time and frequency resources, or a combination thereof, are encoded in the downlink control information DCI format via a PDCCH order to trigger a contention-free PRACH transmission.

15. The apparatus of claim 12 or 13, wherein for non-ideal reciprocity, the one or more baseband processors are to:

the number of PRACH transmissions is encoded in a downlink control information, DCI, format via a PDCCH order to trigger a contention-free PRACH transmission and an indicator to indicate whether PRACH hopping is to be applied to multiple PRACH transmissions.

16. The apparatus of claim 12 or 13, wherein the one or more baseband processors are to:

if the UE comprises two or more sub-arrays or panels, the beam or sub-array or panel index is encoded in the downlink control information DCI format via a PDCCH order, triggering contention-free PRACH transmission in a cross-beam manner.

17. An apparatus of a user equipment, UE, comprising:

means for processing a set of reciprocity offset thresholds received from a base station;

means for determining a repetition level for transmitting a fifth generation 5G physical random access channel, PRACH, L times in accordance with the set of reciprocity offset thresholds; and

and a module for storing the repetition level.

18. The apparatus of claim 17, further comprising:

and means for transmitting the PRACH to the base station a plurality of times according to the repetition level.

19. The apparatus of claim 17 or 18, wherein the set of reciprocity offset thresholds are configured by higher layers via a 5G master information block MIB, via a 5G system information block SIB, or via radio resource control, RRC, signaling.

20. The apparatus of claim 17 or 18, further comprising:

means for selecting PRACH resources from a set of available PRACH resources associated with an optimal base station transmit Tx beam based at least in part on a potential message size including data available for transmission, a medium access control, MAC, header, or MAC control element, or a combination thereof, and a measured path loss based at least in part on a beam reference signal, BRS, or a synchronization signal, SS, block of the optimal base station transmit Tx beam.

21. The apparatus of claim 17 or 18, wherein the reciprocity offsets in the set of reciprocity offset thresholds are beam-specific,

and wherein the apparatus further comprises means for comparing the reciprocity offset to a list of thresholds and determining an optimal receive Rx beam and corresponding repetition level for PRACH transmission.

22. An apparatus of a base station, comprising:

means for configuring a set of reciprocity offset thresholds for a user equipment, UE;

means for processing a fifth generation 5G physical random access channel, PRACH, received from the UE in accordance with the set of reciprocity offset thresholds; and

the apparatus includes means for storing a repetition level, the repetition level determined from the set of reciprocity offset thresholds.

23. The apparatus of claim 22, further comprising: means for allocating dedicated resources for the UE under non-ideal reciprocity conditions,

24. The apparatus of claim 22 or 23, further comprising:

means for encoding a PRACH format indicator, PRACH transmission timing or PRACH time and frequency resources, or a combination thereof, in a downlink control information, DCI, format via a PDCCH order to trigger a contention free PRACH transmission.

25. The apparatus of claim 22 or 23, further comprising:

the apparatus includes means for encoding a number of PRACH transmissions in a downlink control information, DCI, format via a PDCCH order to trigger a contention-free PRACH transmission and means for encoding an indicator indicating whether PRACH hopping is to be applied to a plurality of PRACH transmissions.