Apparatus for enhancing physical random access channel transmission

Abstract

The present disclosure relates to an apparatus for enhancing physical random access channel transmission. In brief, according to one or more embodiments, an apparatus of a user equipment (UE) comprises: one or more baseband processors for: processing a set of reciprocity offset thresholds received from a NR NodeB (gNB), and 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 or a configuration via higher layers; and a memory for: storing the repetition level.

Description

[0001] This application is a divisional application of Chinese patent application No. 201780042715.5, filed August 1, 2017, entitled “Apparatus for Enhancing Transmission of Physical Random Access Channel”, which claims priority to U.S. Provisional Application No. 62 / 372,660, filed August 9, 2016. Technical Field

[0002] This invention relates generally to the field of communications, and more specifically to an apparatus for enhancing transmission over a physical random access channel. Background Technology

[0003] Mobile communications have evolved significantly from early voice systems to today's highly complex integrated communication platforms. The next generation of wireless communication systems (fifth generation (5G)) will provide access to information and data sharing for a wide range of users and applications anytime, anywhere. 5G is envisioned as a unified network and / or system aimed at meeting vastly different and sometimes conflicting performance dimensions and services. This diverse, multidimensional demand is driven by various services and applications. Typically, 5G will evolve based on the 3rd Generation Partnership Project (3GPP) Long Term Evolution Advanced (LTE-Advanced) and additional potential New Radio Access Technologies (RATs) to enrich lives with better, simpler, and more seamless wireless connectivity solutions. 5G will enable everything to be wirelessly connected, providing fast and rich content and services.

[0004] For 5G systems, high-frequency communication has attracted significant attention from the industry because 5G systems can provide wider bandwidth to support future integrated communication systems. Beamforming is a crucial technology for realizing high-frequency systems because beamforming gain can compensate for severe path loss caused by atmospheric attenuation, improve the signal-to-noise ratio (SNR), and expand the coverage area. By aligning the transmitted beam with the target user equipment (UE), the radiated energy is focused to achieve higher energy efficiency and suppress mutual UE interference.

[0005] For centimeter-wave (cmWave) and millimeter-wave (mmWave) systems, a beam reference signal (BRS) or synchronization signal (SS) block is transmitted from the evolved Node B (eNodeB) to allow the UE to measure the RS received power (RSRP) and obtain the optimal eNodeB transmit (Tx) beam and UE receive (Rx) beam. If a one-to-one association rule is defined between 5G Physical Random Access Channel (PRACH) transmission resources and SS block antenna ports (APs), the UE can transmit PRACH using the optimal UE Rx beam acquired during the initial beam acquisition phase on the time or frequency resources associated with the optimal 5G Node B (gNB) Tx beam for uplink synchronization. This is primarily due to the assumption that downlink and uplink reciprocity is perfect in time-division duplex (TDD) systems. In cases where reciprocity between Tx and Rx beams is not ideal, certain mechanisms should be considered for PRACH transmissions used for initial access. Summary of the Invention

[0006] According to some implementations, an apparatus for a user equipment (UE) is provided, comprising: one or more baseband processors for: processing a set of reciprocity offset thresholds received from a base station and, via configuration at a higher layer, determining a repetition level for transmitting a 5G Physical Random Access Channel (PRACH) L times; and a memory for storing the repetition level.

[0007] According to some embodiments, an apparatus for a base station is provided, comprising: one or more baseband processors for: configuring a set of reciprocity offset thresholds for a user equipment (UE) and processing fifth-generation 5G physical random access channel (PRACH) received from the UE according to the set of reciprocity offset thresholds; and a memory for storing repetition levels, the repetition levels being determined by configuration via a higher layer.

[0008] According to some embodiments, an apparatus for a user equipment (UE) is provided, comprising: a module for processing a set of reciprocity offset thresholds received from a base station; a module for determining a repetition level for transmitting a 5G Physical Random Access Channel (PRACH) L times via configuration at a higher layer; and a module for storing the repetition level.

[0009] According to some embodiments, an apparatus for a base station is provided, comprising: a module for configuring a set of reciprocity offset thresholds for a user equipment (UE); a module for processing a fifth-generation 5G physical random access channel (PRACH) received from the UE according to the set of reciprocity offset thresholds; and a module for storing repetition levels, the repetition levels being determined by configuration via a higher layer. Attached Figure Description

[0010] The claimed subject matter is specifically pointed out and explicitly claimed in the conclusion of the specification. However, this subject matter can be understood by referring to the following specific embodiments when read in conjunction with the accompanying drawings, wherein:

[0011] Figure 1 It is a diagram illustrating a process for contention-based random access according to one or more embodiments;

[0012] Figure 2 This is a diagram illustrating a process for contention-free random access according to one or more embodiments;

[0013] Figure 3 This is a diagram illustrating a random access channel procedure in a perfectly reciprocal scenario according to one or more embodiments;

[0014] Figure 4 This is a diagram illustrating a physical random access procedure in a non-ideal reciprocity scenario according to one or more embodiments;

[0015] Figure 5 This is a diagram illustrating a first option for frequency hopping on a physical random access channel according to one or more embodiments;

[0016] Figure 6 This is a diagram illustrating a second option for physical random access channel frequency hopping according to one or more embodiments;

[0017] Figure 7 This is a diagram illustrating a third option for physical random access channel frequency hopping according to one or more embodiments;

[0018] Figure 8 This is a diagram illustrating the transmission timing of the physical random access channel according to one or more embodiments;

[0019] Figure 9 This is a diagram illustrating dynamic panel switching for physical random access channel transmission according to one or more embodiments; and

[0020] Figure 10 These are illustrations of example components of a device according to some embodiments.

[0021] It should be understood that, for the sake of simplicity and / or clarity, the elements shown in the accompanying drawings are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to others for clarity. Furthermore, reference numerals may be repeated in the drawings where appropriate to indicate corresponding and / or similar elements. Detailed Implementation

[0022] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter can be practiced without these specific details. In other instances, well-known methods, processes, components, and / or circuits have not been described in detail.

[0023] Now refer to Figure 1 This section will discuss diagrams illustrating a process for contention-based random access according to one or more embodiments. Figure 1 In the example, according to the 3GPP Long Term Evolution (LTE) specification, four operation procedures 100 can be used for initial contention-based random access. In the first operation 114, the User Equipment (UE) 110 transmits a Physical Random Access Channel (PRACH) in the uplink (UL) by randomly selecting a preamble signature, which allows the Evolved Node B (eNB) 112 to estimate the delay between eNB 112 and UE 110 for subsequent UL timing adjustments. In the 5G New Radio (NR) standard, eNB 112 may include gNB 112, but the scope of the claimed subject matter is not limited thereto. Subsequently, in the second operation 116, the eNB feeds back a Random Access Response (RAR) carrying timing advance (TA) command information for uplink timing adjustments 122 and uplink approval for uplink transmissions in the third operation (L2 / L3 message) 118. UE 110 is expected to receive RAR within a time window, the start and end of which can be configured via a System Information Block (SIB). Finally, at operation 120, a contention resolution message can occur from eNB 112 to UE 110.

[0024] Now refer to Figure 2 This section will discuss diagrams illustrating a contention-free random access procedure according to one or more embodiments. For certain scenarios (including handover and resumption of downlink services for UE 110), to reduce random access latency, UE 110 may be requested to perform a contention-free random access procedure 200, which can be triggered by a Physical Downlink Control Channel (PDCCH) command. Specifically, at operation 210, eNB 112 assigns a dedicated PRACH preamble signature to UE 110, which can be outside the preamble set used for contention-based random access. UE 110 then sends the random access preamble to eNB 112. Note that the contention-free random access procedure terminates with the RAR message of operation 214.

[0025] Now refer to Figure 3This section will discuss diagrams illustrating the random access channel procedure in a perfect reciprocity scenario according to one or more embodiments. As mentioned above, in the case of perfect reciprocity, UE 110 can select a fifth-generation (5G) Physical Random Access Channel (PRACH) resource from time or frequency PRACH resources that can be associated with the best 5G New Radio (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), secondary synchronization signal (SSS), or physical broadcast channel (PBCH) or a combination thereof, and the scope of the claimed subject matter is not limited thereto.

[0026] Figure 3 An example of a RACH procedure under perfect reciprocity is shown. The time or frequency association between a downlink (DL) beam or AP and its corresponding PRACH resource is cell-specific and can be communicated via signaling as part of 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 a beam index (i.e., a BRS resource index) and a PRACH resource can be predefined, for example, based on a group index or symbol index, in the time, frequency, and / or sequence domains. In any case, the UE 110 should be aware of this association in idle mode before initiating a RACH procedure. Figure 3 In the example shown, in time slot #0, represented by 310, UE 110 measures the received power based on BRS and determines the optimal gNB Tx beam. Figure 3 As shown, for UE#1, the optimal Tx beam of gNB 112 is located in BRS beamgroup #0 and third orthogonal frequency division multiplexing (OFDM) symbol 312. According to the association rules, UE 110 can correspondingly transmit PRACH in the associated PRACH resource (i.e., in the third PRACH slot 314 in slot #5 represented by 316).

[0027] To increase random access capacity, UE 110 can randomly select a frequency resource for PRACH transmission. For example... Figure 3As shown, UE 110 can select PRACH frequency resource #1 for PRACH transmission. Alternatively, UE 110 can appropriately select a PRACH resource from the set of available PRACH resources associated with the optimal Tx beam, based at least in part on the potential message size (which is the data available for transmission plus a MAC header, and optionally MAC control elements) and the path loss measured by the BRS based on the optimal beam. More specifically, if the message payload size is greater than a threshold A indicated by signaling, and if the path loss is less than a threshold B, then UE 110 should select from the first PRACH group. Otherwise, UE 110 can select from the second PRACH group.

[0028] In one or more embodiments, the reciprocity offset can be defined as I. reciprocity This can be used to indicate the offset between non-ideal reciprocity and perfect reciprocity. Based on this offset, the eNB 112 can configure a set of thresholds to allow the UE 110 to use the selected beam, based on I... reciprocity The offset value is derived from the repetition level L used for PRACH transmission. In one embodiment, the repetition level L may refer to the number of times PRACH is transmitted, but the scope of the claimed subject matter is not limited thereto. In one embodiment, thresholds for three levels, such as Threshold_0, Threshold_1, and Threshold_2, may be configured by a higher layer via the 5G Master Information Block (MIB), the 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling. In one or more embodiments, the higher layer may include layers above the physical layer, such as the Media Access Control (MAC) layer, the Radio Link Control (RLC) layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Resource Control (RRC) layer, or the Non-Access (NAS) layer, but the scope of the claimed subject matter is not limited thereto. When the thresholds are configured by a higher layer, UE 110 may derive the repetition level based on the following formula:

[0029]

[0030] As a further extension, I reciprocity It can be beam-specific, and a set of thresholds can be configured by a higher layer. In this case, for each specific beam, UE 110 can... reciprocity The optimal Rx beam and corresponding number of repetitions for PRACH transmission are determined by comparing it with a threshold list.

[0031] It should be noted that repeated PRACHs can be transmitted continuously or discontinuously in the time domain. In the time domain, UE 110 can transmit PRACHs L times in resources corresponding to L Optimal Beam Reference Signal (BRS) antenna ports (APs), where L can be configured by higher layers via MIB, SIB, or RRC signaling, or determined as mentioned above. Considering that a one-to-one resource association between BRS antenna ports and PRACH resources can be defined in the time domain, UE 110 can derive the corresponding time resources for PRACH transmission.

[0032] Furthermore, UE 110 can use the same PRACH preamble signature, which allows gNB 112 to perform combination to improve detection performance. Specifically, UE 110 can randomly select a PRACH preamble signature and use the selected PRACH preamble signature for subsequent PRACH transmissions. Alternatively, UE 110 can randomly select a PRACH preamble for each transmission, which can reduce the probability of collisions.

[0033] To allow gNB 112 to identify whether UE 110 is under non-ideal reciprocity or perfect reciprocity conditions, dedicated resources can be allocated to UE 110 under non-ideal reciprocity conditions. Specifically, these dedicated PRACH resources and the resources used for UE 110 under perfect reciprocity conditions can be multiplexed in a time-division configuration. Furthermore, the allocation of this set of dedicated resources for UE 110 under non-ideal and perfect reciprocity conditions can be predefined or configured by higher layers via MIB, SIB, or RRC signaling.

[0034] In one example, under non-ideal reciprocity, one or more of the signature, time, or frequency resources can be reserved for UE 110 to transmit PRACH. Furthermore, a combination of multiplexing schemes based on Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), and / or Code Division Multiplexing (CDM) can be used to separate resources for UE 110 under non-ideal and perfect reciprocity.

[0035] In another example, the preamble signature used for each PRACH transmission can 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 another DL beam index. The preamble signatures in Group A and Group B should be mapped one-to-one. UE 110 can randomly select a preamble signature from Group A and then select a preamble signature from Group B that is mapped one-to-one to the preamble signature selected in Group A. Therefore, gNB 112 can determine which beam is the best DL beam for UE 110 and use that DL beam to transmit the RAR.

[0036] In one or more embodiments, the association between one or more opportunities of downlink DL broadcast channels and / or signals and a subset of RACH or PRACH resources is notified to UE 110 by gNB 112 via broadcast system information, or may be known to UE 110. Based at least in part on DL measurements and the corresponding association, UE 110 can select a subset of the PRACH preamble index. UE 110 can select one or more UE transmit (Tx) beams for one or more preamble transmissions. During a single or multiple and / or repeated preamble PRACH transmission opportunity notified by broadcast system information, UE 110 may use the same UE Tx beam, but the scope of the claimed subject matter is not limited thereto. In one or more embodiments, PRACH transmissions may occur according to the 3GPP New Radio (NR) standards (e.g., according to 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), but the scope of the claimed subject matter is not limited thereto.

[0037] In one or more embodiments, from a physical layer perspective, for the New Radio (NR) standard, it is assumed that the RACH procedure includes a RACH preamble, message 1 (Msg.1), random access response, message 2 (Msg.2), message 3, and message 4. Both IDLE mode and CONNECTED mode UE 110 support the random access procedure. For a four-step RACH procedure, the RACH transmission opportunity can be defined as transmitting the time-frequency resource containing PRACH message 1 using the configured PRACH preamble format through a single specific Tx beam.

[0038] RACH resources can also be defined as time-frequency resources used to transmit RACH preambles. UE 110 can be notified via broadcast system information whether to transmit one or more and / or repeated preambles within a subset of the RACH resources, for example, to cover gNB Rx beam scanning in the absence of Tx / Rx beam correspondence at gNB112.

[0039] At least for multi-beam operation, regardless of whether Tx / Rx beam correspondence is available at gNB 112, the following RACH procedure can be considered at least for UE 110 in idle mode. The correlation between one or more opportunities for downlink (DL) broadcast channels and / or signals and a subset of RACH resources can be communicated to UE 110 via broadcast system information, or may be known to UE 110. Based at least in part on DL measurements and corresponding correlations, UE 110 can select a subset of the RACH preamble index. UE 110 can select one or more UE Tx beams for one or more preamble transmissions. During RACH transmission opportunities for a single or multiple and / or repeated preambles communicated via broadcast system information, UE 110 can use the same UE Tx beam. The NR standard at least supports the transmission of a single message 1 before the end of the listened random access response (RAR) window.

[0040] At least for cases where there is no gNB Tx / Rx beam correspondence, the gNB 112 can configure the association between DL signals and / or channels and subsets of RACH resources and / or preamble indices to determine the Msg2 DL Tx beam. Based at least in part on DL measurements and corresponding associations, the UE 110 can select subsets of RACH resources and / or RACH preamble indices. The preamble index consists of a preamble sequence index and an orthogonal coverage code (OCC) index (if OCC is supported). It should be noted that a subset of the preamble can be indicated by the OCC index.

[0041] At least for multi-beam operation, regardless of whether Tx / Rx beam correspondence is available at gNB 112, the DL Tx beam for message 2 can be obtained at gNB 112 based on the detected RACH preamble / resource and the corresponding correlation. Uplink (UL) approval in message 2 can indicate the transmission timing of message 3. As a baseline UE 110 behavior, UE 110 assumes receiving a single RAR within a given RAR window.

[0042] At least for UE 110 in idle mode, UE 110 can determine the UL Tx beam used for message 3 transmission. UE 110 can use the same UL Tx beam used for message 1 transmission. Different PRACH configurations can be supported, for example, considering different parameter sets (numerology) and whether Tx / Rx beam correspondence is available at gNB 112.

[0043] For NR RACH message 1 retransmissions at least for multi-beam operation, NR supports power ramping. If UE 110 does not change beams, the power ramp counter can continue to increment. It should be noted that UE 110 can derive the uplink transmit power using the most recent or even more recent estimate of the path loss. Whether UE 110 performs UL beam switching during retransmissions 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.

[0044] Now refer to Figure 4 The diagrams illustrating the physical random access procedure in a non-ideal reciprocity scenario, according to one or more embodiments, will be discussed. Figure 4 The image shows an example of PRACH transmission in two Orthogonal Frequency Division Multiplexing (OFDM) symbols. Furthermore, UE 110 can measure the BRS received power and determine the two optimal BRSAPs in symbols #2 410 and #3 412, as shown. Figure 4 As shown. Based at least in part on a one-to-one association, UE 110 can repeat PRACH in three different PRACH slots within slots #2 and #3 of the configured time slots. This transmission scheme can enhance PRACH detection performance under non-ideal reciprocity conditions.

[0045] Now refer to Figure 5 A diagram illustrating a first option for physical random access channel frequency hopping according to one or more embodiments will be discussed. In one or more embodiments, if multiple frequency resources are configured for PRACH transmissions, UE 110 can perform frequency hopping on multiple PRACH transmissions to take advantage of the benefits of frequency diversity. Figure 5 The first option (i.e., option 1) is shown, where a constant frequency resource offset can be applied between two consecutive PRACH transmissions if L consecutive PRACH transmissions are performed. More specifically, UE 110 can randomly select a frequency resource in the first PRACH slot and apply frequency hopping on subsequent PRACH transmissions. In one example, the constant frequency resource offset could be [M / 2], where M is the total number of PRACH frequency resources configured by the higher layer. Figure 5An example of PRACH frequency hopping for Option 1 is shown. In this example, UE 110 randomly selects PRACH frequency resource #3, performs the first PRACH transmission 510 in PRACH slot 0 at 510, and performs frequency hopping on subsequent transmissions. Specifically, UE 110 sends three PRACH transmissions: transmission 512 in PRACH slot 1 of frequency resource #1, transmission 514 in PRACH slot 2 of frequency resource #3, and transmission 516 in PRACH slot 3 of frequency resource #1, but the scope of the claimed subject matter is not limited to this.

[0046] Now refer to Figure 6 A diagram illustrating a second option for physical random access channel frequency hopping according to one or more embodiments will be discussed. In the second option (i.e., option 2), UE 110 performs frequency hopping on PRACH transmissions between two PRACH frequency resources. More specifically, 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 resource may be randomly selected by UE 110, and the distance between the first and second frequency resources may be predefined or configured by a higher layer. In one example, the frequency distance may be [M / 2]. Figure 6 An example of PRACH frequency hopping for Option 2 is shown. In this example, UE 110 randomly selects PRACH frequency resource #3 for the first PRACH transmission 610 and performs frequency hopping for subsequent transmissions. Specifically, the UE sends three PRACH transmissions: transmission 612 in frequency resource #3, transmission 614 in frequency resource #1, and transmission 616 in frequency resource #1, but the scope of the claimed subject matter is not limited to this.

[0047] Now refer to Figure 7 A diagram illustrating a third option for physical random access channel frequency hopping according to one or more embodiments will be discussed. In the third option (i.e., option 3), UE 110 performs frequency hopping for multiple PRACH transmissions according to a frequency hopping pattern. Specifically, the frequency hopping pattern can be defined as a function of at least one or more of the following parameters: cell ID, frequency resources for the first PRACH transmission, symbol and / or time slot indexes for the PRACH transmission, and UE ID (e.g., Cell Radio Network Temporary Identifier (C-RNTI)). In one example, the frequency resource index for each PRACH transmission can be given by:

[0048]

[0049] in, It is the physical cell ID, nsf It is a time slot index, I freq It is a frequency resource index used for PRACH transmission. Figure 7 An example of PRACH frequency hopping for Option 3 is shown. In this example, 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, but the scope of the claimed subject matter is not limited to this.

[0050] Now refer to Figure 8 This section will discuss a diagram illustrating the physical random access channel transmission timing according to one or more embodiments. Similar to the method used in LTE, for contention-free random access, gNB 112 will assign a dedicated PRACH preamble signature for PRACH transmission. For 5G systems, an enhanced embodiment of contention-free random access can be provided as follows. In one embodiment, multiple PRACH formats can be defined in the specification. 5G PRACH format indicators can be included in the downlink control information (DCI) format via PDCCH commands to trigger contention-free PRACH transmission. In another embodiment, PRACH transmission timing and / or frequency resources can be indicated in the DCI format via PDCCH commands to trigger contention-free PRACH transmission.

[0051] The time slot structure used for PRACH transmission can be based on a self-contained time slot structure, where PDCCH can be transmitted at the beginning of a time slot and PUCCH can be transmitted at the end of a time slot. In one example, PRACH can be transmitted at the end of a time slot and multiplexed with PUCCH using frequency division multiplexing (FDM).

[0052] Furthermore, the transmission gap between the PRACH transmission timing or PDCCH command and the PRACH transmission slot can be explicitly indicated in the DCI format. As a further extension, a set of PRACH transmission timings can be predefined or configured by a higher layer. Fields in the DCI format can be used to indicate which transmission timing within that set of PRACH transmission timings is applied to the PRACH transmission. A PRACH transmission timing or gap with a value of 0 can be considered a self-contained PRACH transmission, meaning the PRACH is transmitted in the same slot as the PDCCH transmission.

[0053] Figure 8Two examples of PRACH transmission timing are shown. In the first example, a self-contained PRACH transmission is triggered, i.e., the PRACH transmission delay k = 0, where PRACH transmission 810 occurs at the end of a time slot 814, after the guard time (GT). In the second example, the gap between the PDCCH and PRACH is one time slot, i.e., k = 1, where PRACH transmission 812 occurs at the end of two time slots (time slots 814 and 816), after the guard time (GT).

[0054] In another embodiment, in the case of non-ideal reciprocity, the number of PRACH transmissions can be indicated in the DCI format via a PDCCH command to trigger contention-free PRACH transmissions. Furthermore, an indicator indicating whether PRACH frequency hopping can be applied to multiple PRACH transmissions can be included in the DCI format. In one example, bit 1 can indicate that frequency hopping for PRACH transmissions is enabled, while bit 0 can indicate that frequency hopping for PRACH transmissions is disabled.

[0055] Now refer to Figure 9 This paper will discuss illustrations of dynamic panel handover for Physical Random Access Channel (PRACH) transmission according to one or more embodiments. In another embodiment of the invention, when the UE is equipped with two or more subarrays or panels (e.g., panels (panel 0) 910 and panels (panel 1) 912), beam or subarray or panel indices can be indicated in the downlink control information (DCI) format via PDCCH commands to trigger contention-free PRACH transmission in a cross-beam manner. This arrangement allows for dynamic beam triggering and handover for PRACH transmission, further increasing PRACH detection performance and connectivity robustness.

[0056] Figure 9 An example of dynamic panel switching for PRACH transmission is shown. In this example, UE 110 can use two panels ((panel 0) 910 and (panel 1) 912) to measure the beam reference signal received power (B-RSRP) and report the corresponding B-RSRPs of the two panels to gNB 112. After receiving the B-RSRPs from UE 110, gNB 112 can select the panel with the stronger B-RSRP and instruct UE 110 to use that panel to transmit PRACH. Figure 9As shown, compared to the B-RSRP of beam 914 from gNB 112 at panel (panel 0) 910, panel (panel 1) 912 can have a stronger B-RSRP of beam 916 from gNB 112, where gNB 112 operates as a transmit / receive point (TRP). In this case, panel (panel 1) 912 can be indicated in the DCI and used for PRACH transmission, but the scope of the claimed subject matter is not limited thereto.

[0057] Now refer to Figure 10 The following will discuss illustrations of example components of a device according to some embodiments. Figure 10 Example components of a device 1000 according to some embodiments are shown. 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. Components of the illustrated device 1000 may be included in a UE or RAN node. In some embodiments, device 1000 may include fewer components (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 components such as memory / storage, a display, a camera, a sensor, or an input / output (I / O) interface. 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 separately included in more than one device).

[0058] Application circuitry 1002 may include one or more application processors. For example, application circuitry 1002 may include circuitry with, 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 execute instructions stored in the memory / storage to enable various applications or operating systems to run on device 1000. In some embodiments, the processor of application circuitry 1002 may process IP data packets received from the EPC.

[0059] The baseband circuit 1004 may include, for example, but not limited to, circuitry of one or more single-core or multi-core processors. The baseband circuit 1004 may include one or more baseband processors or control logic to process baseband signals received from the receive signal path of the RF circuit 1006 and generate baseband signals for the transmit signal path of the RF circuit 1006. The baseband circuit 1004 may interface with the application circuit 1002 for generating and processing baseband signals and controlling the operation of the RF circuit 1006. For example, in some embodiments, the baseband circuit 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 processors 1004D for other existing, developing, or future generations (e.g., second-generation (2G), sixth-generation (6G), etc.). The baseband circuitry 1004 (e.g., one or more of baseband processors 1004A-D) can 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 functions of the baseband processors 1004A-D may be included in modules stored in memory 1004G and executed via a central processing unit (CPU) 1004E. Radio control functions may include, but are not limited to, signal modulation / demodulation, encoding / decoding, radio frequency shifting, etc. 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 functions. Embodiments of modulation / demodulation and encoder / decoder functions are not limited to these examples, and other suitable functions may be included in other embodiments.

[0060] 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 in other embodiments may include other suitable processing elements. 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 the baseband circuitry 1004 and the application circuitry 1002 may be implemented together, for example, on a system-on-a-chip (SoC).

[0061] In some embodiments, baseband circuit 1004 can provide communication compatible with one or more radio technologies. For example, in some embodiments, baseband circuit 1004 can support communication with the Evolved Universal Terrestrial Radio Access Network (EUTRAN) or other Wireless Metropolitan Area Networks (WMAN), Wireless Local Area Networks (WLAN), or Wireless Personal Area Networks (WPAN). Embodiments in which baseband circuit 1004 is configured to support radio communication with more than one radio protocol may be referred to as multimode baseband circuits.

[0062] RF circuit 1006 enables communication with a wireless network using modulated electromagnetic radiation over a non-solid-state medium. In various embodiments, RF circuit 1006 may include switches, filters, amplifiers, etc., to facilitate communication with the wireless network. RF circuit 1006 may include a receive signal path, which may include circuitry for down-converting RF signals received from FEM circuit 1008 and providing baseband signals to baseband circuit 1004. RF circuit 1006 may also include a transmit signal path, which may include circuitry for up-converting the baseband signals provided by baseband circuit 1004 and providing RF output signals to FEM circuit 1008 for transmission.

[0063] 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 the frequency used by the mixer circuit 1006a in both the receive and transmit signal paths. In some embodiments, the mixer circuit 1006a in the receive signal path may be configured to down-convert the RF signal received from the FEM circuit 1008 based on the synthesized frequency provided by the synthesizer circuit 1006d. The amplifier circuit 1006b may be configured to amplify the down-converted signal, and the filter circuit 1006c may be a low-pass filter (LPF) or a band-pass filter (BPF) configured to remove unwanted signals from the down-converted signal to generate an output baseband signal. The output baseband signal may be provided to the baseband circuit 1004 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, the mixer circuit 1006a of the receiving signal path may include a passive mixer, but the scope of the embodiments is not limited thereto.

[0064] In some embodiments, the mixer circuit 1006a of the signal transmission path can be configured to up-convert the input baseband signal based on the synthesized frequency provided by the synthesizer circuit 1006d to generate an RF output signal for the FEM circuit 1008. The baseband signal can be provided by the baseband circuit 1004 and can be filtered by the filter circuit 1006c.

[0065] In some embodiments, the mixer circuit 1006a for the receive signal path and the mixer circuit 1006a for the transmit signal path may include two or more mixers, and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuit 1006a for the receive signal path and the mixer circuit 1006a for the transmit signal path may include two or more mixers, and may be arranged for image suppression (e.g., Hartley image suppression). In some embodiments, the mixer circuit 1006a for the receive signal path and the mixer circuit 1006a for the transmit signal path may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuit 1006a for the receive signal path and the mixer circuit 1006a for the transmit signal path may be configured for superheterodyne operation.

[0066] In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, but the scope of the embodiments is not limited thereto. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, the RF circuit 1006 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and the baseband circuit 1004 may include a digital baseband interface for communicating with the RF circuit 1006.

[0067] In some dual-mode embodiments, separate radio IC circuitry may be provided for processing signals with respect to each spectrum, but the scope of the embodiments is not limited thereto. In some embodiments, synthesizer circuitry 1006d may be a fractional-N synthesizer or a fractional-N / N+1 synthesizer, but the scope of the embodiments is not limited thereto, as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 1006d may be a Δ-Σ synthesizer, a frequency multiplier, or a synthesizer including a phase-locked loop with a frequency divider. Synthesizer circuitry 1006d may be configured to synthesize the output frequency used by mixer circuitry 1006a of RF circuitry 1006 based on the frequency input and divider control input. In some embodiments, synthesizer circuitry 1006d may be a fractional-N / N+1 synthesizer.

[0068] In some embodiments, the frequency input may be provided by a voltage-controlled oscillator (VCO), but this is not required. Depending on the desired output frequency, the divider control input may be provided by the baseband circuitry 1004 or the application processor 1002. In some embodiments, the divider control input (e.g., N) may be determined from a lookup table based on the channel indicated by the application processor 1002.

[0069] The synthesizer circuit 1006d of the RF circuit 1006 may include a divider, a delay phase-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 (e.g., based on carry) divide the input signal by N or N+1 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 cycle 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.

[0070] In some embodiments, the synthesizer circuit 1006d may be configured to generate a carrier frequency as an 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 may be used in conjunction with quadrature generator and divider circuitry to generate multiple signals having multiple different phases relative to each other at the carrier frequency. In some embodiments, the output frequency may be the LO frequency (fLO). In some embodiments, the RF circuit 1006 may include an IQ / polar coordinate converter.

[0071] FEM circuit 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 circuit 1006 for further processing. FEM circuit 1008 may also include a transmit signal path, which may include circuitry configured to amplify the signals provided by RF circuit 1006 for transmission by one or more of the one or more antennas 1010. In various embodiments, amplification via the transmit or receive signal path may be performed only in RF circuit 1006, only in FEM 1008, or in both RF circuit 1006 and FEM 1008.

[0072] In some embodiments, the FEM circuit 1008 may include a TX / RX switch to switch between transmit and receive mode operation. The FEM circuit 1008 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuit may include an LNA to amplify a received RF signal and (e.g., to RF circuit 1006) provide the amplified received RF signal as an output. The transmit signal path of the FEM circuit 1008 may include: a power amplifier (PA) for amplifying (e.g., the input RF signal provided by RF circuit 1006); and one or more filters for generating RF signals for subsequent transmission (e.g., by one or more of one or more antennas 1010).

[0073] In some embodiments, PMC 1012 can manage the power supplied to baseband circuitry 1004. Specifically, PMC 1012 can control power selection, voltage scaling, battery charging, or DC-DC conversion. PMC 1012 is often included when device 1000 can be powered by a battery (e.g., when the device is included in a UE). PMC 1012 can increase power conversion efficiency while providing the desired implementation size and thermal characteristics.

[0074] Figure 10 The diagram shows that PMC 1012 is coupled only to baseband circuitry 1004. However, in other embodiments, PMC 1012 may additionally or alternatively couple to other components (such as, but not limited to, application circuitry 1002, RF circuitry 1006, or FEM 1008) and perform similar power management operations for them.

[0075] In some embodiments, PMC 1012 can control or be part of various power-saving mechanisms of device 1000. For example, if device 1000 is in the RRC_Connected state (where it is still connected to the RAN node because it expects to receive traffic soon), it can enter a state called Discontinuous Receive Mode (DRX) after an inactive period. During this state, device 1000 can be powered down for a short time interval and thus save power.

[0076] If there is no data service activity for the extended period, device 1000 can transition to the RRC_Idle state, in which it disconnects from the network and does not perform operations such as channel quality feedback or handover. Device 1000 enters a very low-power state and performs paging, in which it periodically wakes up again to listen to the network and then powers down again. Device 1000 may not be able to receive data in this state, and in order to receive data, it must transition back to the RRC_Connected state.

[0077] The additional power-saving mode allows devices to be unavailable from the network for periods longer than the paging interval (ranging from seconds to hours). During this time, the device is completely unreachable from the network and can be completely powered down. Any data sent during this time results in a large latency, which is assumed to be acceptable.

[0078] The processors of application circuit 1002 and baseband circuit 1004 can be used to execute elements of one or more instances of the protocol stack. For example, the processor of baseband circuit 1004 can be used individually or in combination to execute layer 3, layer 2, or layer 1 functions, while the processor of application circuit 1002 can utilize data received from these layers (e.g., packet data) and also execute layer 4 functions (e.g., Transport 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 the physical (PHY) layer of the UE / RAN node, as described in further detail below.

[0079] As used herein, the terms "circuit" or "circuit system" may refer to, be part of, or include the following: application-specific integrated circuits (ASICs), electronic circuits, processors (shared, dedicated, or grouped) and / or memories (shared, dedicated, or grouped) executing one or more software or firmware programs, combinational logic circuits, and / or other suitable hardware components that provide the described functionality. In some embodiments, the circuit may be implemented in one or more software or firmware modules, or the functionality associated with the circuit may be implemented by one or more software or firmware modules. In some embodiments, the circuit may include logic that is at least partially operable in hardware. The embodiments described herein can be implemented in a system using any suitably configured hardware and / or software.

[0080] The following are example implementations of the subject matter described herein. It should be noted that any example or variation thereof described herein can be used in any substitution or combination of any other example or variation, but the scope of the claimed subject matter is not limited thereto.

[0081] In Example 1, an apparatus for a user equipment (UE) includes: one or more baseband processors for: processing a set of reciprocity offset thresholds received from a New Radio (NR) Node B (gNB), and determining a repetition level for transmitting L times of a 5G Physical Random Access Channel (PRACH) based on the set of reciprocity offset thresholds or configuration via a higher layer; 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, and further includes: a radio transceiver for: transmitting PRACH multiple times to the gNB based on 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 configured to: select PRACH resources from a set of available PRACH resources associated with the optimal gNB transmit (Tx) beam, based at least in part on a potential message size and a measured path loss, wherein the potential message size includes data available for transmission, a Medium Access Control (MAC) header or MAC control element, or a combination thereof, and the measured path loss is 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 the 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 configured to: compare the reciprocity offsets with a list of thresholds and determine the optimal receive (Rx) beam and corresponding repetition level for PRACH transmission. Example 6 may include the subject matter of Example 1 or any of the examples described herein, wherein the one or more baseband processors are configured to: determine whether to transmit PRACH in a continuous or discontinuous manner in the time domain, and configure the PRACH to be transmitted L times in resources corresponding to L Optimal Beam Reference Signals (BRS) or Synchronization Signals (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 configured to: randomly select a PRACH preamble signature and configure the selected PRACH preamble signature for subsequent repeated PRACH transmissions, and wherein the one or more baseband processors are configured to: randomly select a PRACH preamble for repeated transmissions. Example 8 may include the subject matter of Example 1 or any of the examples described herein, wherein the one or more baseband processors are configured to: configure frequency hopping on multiple PRACH transmissions if multiple frequency resources are configured for PRACH transmissions.Example 9 may include the subject matter of Example 1 or any of the examples described herein, wherein the one or more baseband processors are configured to: apply a constant frequency resource offset 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 configured to: configure frequency hopping on a PRACH transmission between two PRACH frequency resources, and wherein the one or more baseband processors are configured to: configure a first [L / 2] PRACH transmission using a first frequency resource and configure a second [L / 2] PRACH transmission using a second frequency resource. Example 11 may include the subject matter of Example 1 or any of the examples described herein, wherein the one or more baseband processors are configured to: configure frequency hopping on multiple 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: cell identifier (ID), frequency resource for the first PRACH transmission, symbol or slot index for the PRACH transmission, cell radio network temporary identifier (C-RNTI) or UE ID, or a combination thereof.

[0082] In Example 12, an apparatus for a New Radio Interface (NR) Node B (gNB) includes: one or more baseband processors configured to: configure a set of reciprocity offset thresholds for a User Equipment (UE) and process fifth-generation (5G) Physical Random Access Channel (PRACH) received from the UE according to the set of reciprocity offset thresholds; and a memory configured to: store the repetition levels. Example 13 may include the subject matter of Example 12 or any of the examples described herein, wherein the one or more baseband processors are configured to: allocate dedicated resources for the UE under non-ideal reciprocity conditions, wherein dedicated resources under non-ideal reciprocity conditions and resources under perfect reciprocity conditions are multiplexed using Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or Code Division Multiplexing (CDM) or combinations thereof, wherein the division of dedicated resources under non-ideal reciprocity conditions and resources under perfect reciprocity conditions is predefined or 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 14 may include the subject matter of Example 12 or any of the examples described herein, wherein the one or more baseband processors are configured to: encode a PRACH format indicator, PRACH transmission timing, or PRACH time-frequency resource, or a combination thereof, in the downlink control information (DCI) format via a PDCCH command to trigger 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 configured to: encode the number of PRACH transmissions in the downlink control information (DCI) format via a PDCCH command to trigger contention-free PRACH transmission, and encode an indicator indicating whether PRACH frequency hopping will be applied to multiple PRACH transmissions. Example 16 may include the subject matter of Example 12 or any of the examples described herein, wherein the one or more baseband processors are configured to: if the UE comprises two or more subarrays or panels, encode the beam or subarray or panel index in the downlink control information (DCI) format via PDCCH commands to trigger contention-free PRACH transmission in a cross-beam manner.

[0083] In Example 17, one or more machine-readable media may store instructions thereon that, if executed by a user equipment (UE), cause: processing a set of reciprocity offset thresholds received from a New Radio Interface (NR) Node B (gNB); determining a repetition level for transmitting 5G Physical Random Access Channel (PRACH) L times based on the set of reciprocity offset thresholds or based on a configuration performed by a higher layer; and storing the repetition level in memory. Example 18 may include the subject matter of Example 17 or any of the examples described herein, wherein, if executed, the instructions further cause: a radio transceiver to transmit PRACH multiple times to the gNB according to the repetition level. Example 19 may include the subject matter of Example 17 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 20 may include the subject matter of Example 17 or any of the examples described herein, wherein, if executed, the instructions further cause: PRACH resources to be selected from the set of available PRACH resources associated with the optimal gNB transmit (Tx) beam, at least in part based on a potential message size and a measured path loss, the potential message size including data available for transmission, a Medium Access Control (MAC) header or MAC control element, or a combination thereof, and the measured path loss to be at least in part based 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 the 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 configured to: compare the reciprocity offsets with a list of thresholds and determine the optimal receive (Rx) beam and corresponding repetition level for PRACH transmission.

[0084] In Example 22, one or more machine-readable media may store instructions thereon that, if executed by a New Radio (NR) Node B (gNB), cause: a set of reciprocity offset thresholds to be configured for a User Equipment (UE); fifth-generation (5G) Physical Random Access Channel (PRACH) received from the UE according to the set of reciprocity offset thresholds; and the repetition level to be stored in a memory. Example 23 may include the subject matter of Example 22 or any of the examples described herein, wherein, if executed, the instructions further cause: dedicated resources to be allocated to the UE under non-ideal reciprocity conditions, wherein the dedicated resources under non-ideal reciprocity conditions and the resources under perfect reciprocity conditions will be multiplexed using Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or Code Division Multiplexing (CDM), or a combination thereof, wherein the division of dedicated resources under non-ideal reciprocity conditions and resources under perfect reciprocity conditions is predefined or configured by a higher layer via 5G Master Information Block (MIB), via 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, if executed, the instructions further cause: PRACH format indicator, PRACH transmission timing, or PRACH time-frequency resources, or a combination thereof, to be encoded in the downlink control information (DCI) format via PDCCH commands to trigger contention-free PRACH transmission. Example 25 may include the subject matter of Example 22 or any of the examples described herein, wherein, for non-ideal reciprocity, the one or more baseband processors are configured to: encode the number of PRACH transmissions in the downlink control information (DCI) format via PDCCH commands to trigger contention-free PRACH transmissions, and encode an indicator for indicating whether PRACH frequency hopping will be applied to multiple PRACH transmissions.

[0085] In Example 26, an apparatus for a user equipment (UE) includes: a module for processing a set of reciprocity offset thresholds received from a New Radio (NR) Node B (gNB); a module for determining a repetition level for transmitting L times of 5G Physical Random Access Channel (PRACH) based on the set of reciprocity offset thresholds or configuration via a higher layer; and a module 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 include: a module for transmitting PRACH multiple times to the gNB based on the repetition level. Example 28 may include the subject matter of Example 26 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 29 may include the subject matter of Example 26 or any of the examples described herein, and further includes: a module for selecting PRACH resources from a set of available PRACH resources associated with the optimal gNB transmit (Tx) beam, based at least in part on a potential message size and a measured path loss, the potential message size including data available for transmission, a Medium Access Control (MAC) header or MAC control element, or a combination thereof, the measured path loss being based at least in part on a beam reference signal (BRS) or synchronization signal (SS) block of the optimal gNB Tx beam. Example 30 may include the subject matter of Example 26 or any of the 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 configured to: compare the reciprocity offsets with a list of thresholds and determine the optimal receive (Rx) beam and corresponding repetition level for PRACH transmission.

[0086] In Example 31, an apparatus for a New Radio Interface (NR) Node B (gNB) includes: a module for configuring a set of reciprocity offset thresholds for a User Equipment (UE); a module for processing fifth-generation (5G) Physical Random Access Channel (PRACH) received from the UE according to the set of reciprocity offset thresholds; and a module for storing the repetition levels. Example 32 may include the subject matter of Example 31 or any of the examples described herein, and further includes: a module for allocating dedicated resources for the UE under non-ideal reciprocity conditions, wherein dedicated resources under non-ideal reciprocity conditions and resources under perfect reciprocity conditions will be multiplexed using Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or Code Division Multiplexing (CDM), or a combination thereof, wherein the division of dedicated resources under non-ideal reciprocity conditions and resources under perfect reciprocity conditions is predefined or 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 33 may include the subject matter of Example 31 or any of the examples described herein, and further includes: a module for encoding a PRACH format indicator, PRACH transmission timing, or PRACH time-frequency resource, or a combination thereof, in a downlink control information (DCI) format via a PDCCH command to trigger contention-free PRACH transmission. Example 34 may include the subject matter of Example 31 or any of the examples described herein, and further includes: a module for encoding the number of PRACH transmissions in a downlink control information (DCI) format via a PDCCH command to trigger contention-free PRACH transmission, and encoding an indicator indicating whether PRACH frequency hopping will be applied to multiple PRACH transmissions. In Example 35, the machine-readable storage may include machine-readable instructions that, when executed, implement the means described in any of the preceding claims.

[0087] In the description and / or claims herein, the terms “coupled” and / or “connected” and their derivatives may be used. In certain 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 indicate that two or more elements are in direct physical and / or electrical contact. However, “coupled” may also indicate that two or more elements may not be in direct contact with each other, but can still cooperate and / or interact with each other. For example, “coupled” may indicate that two or more elements are not in contact with each other, but are indirectly joined together via another element or an intermediate element. Finally, the terms “on,” “above,” and “over” may be used in the following description and claims. “On,” “above,” and “over” may be used to indicate that two or more elements are in direct physical contact with each other. However, it should be noted that “over” may also indicate that two or more elements are not in direct contact with each other. For example, “over” may indicate that one element is on top of another element but not in contact with each other, and there may be one or more other elements between the two elements. Furthermore, the term "and / or" can mean "and," it can mean "or," it can mean "exclusive or," it can mean "one," it can mean "some, but not all," it can mean "none of," and / or it can mean "both," but the scope of the claimed subject matter is not limited thereto. In the description and / or claims herein, the terms "comprising" and "including," and their derivatives, may be used and are intended to be synonyms with each other.

[0088] While the claimed subject matter has been described in a degree of detail, it should be recognized that those skilled in the art can modify its elements without departing from the spirit and / or scope of the claimed subject matter. It should be understood from the foregoing description that the subject matter relates to enhanced physical random access channel transmission in new air interface standards and many of their adjuncts, and it will be apparent that various changes can be made in the form, construction, and / or arrangement of its components without departing from the scope and / or spirit of the claimed subject matter, or without sacrificing all its material advantages; the forms described above are merely illustrative embodiments, and / or do not constitute material changes. The claims are intended to encompass and / or include these changes.

Claims

1. An apparatus for a user equipment (UE), comprising: Memory; as well as One or more baseband processors are coupled to the memory and configured to: Receive a set of reciprocity offset thresholds from the base station via higher-layer signaling; The repetition level L for PRACH transmissions on the Physical Random Access Channel is determined based on the aforementioned set of reciprocity offset thresholds; and The PRACH transmission is provided L times based on the repetition level L.

2. The apparatus of claim 1, wherein, The one or more baseband processors are further configured to determine the optimal receive Rx beam by comparing the reciprocity offset with the set of reciprocity offset thresholds.

3. The apparatus as claimed in claim 1 or 2, wherein, The set of reciprocity offset thresholds is configured by higher layers via the 5G Master Information Block (MIB), the 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling.

4. The apparatus as claimed in claim 1 or 2, wherein, The one or more baseband processors are further configured to select PRACH resources from a set of available PRACH resources associated with the Tx beam transmitted by the optimal base station, based at least in part on a potential message size and a measured path loss, wherein the potential message size includes data available for transmission, a Medium Access Control (MAC) header or MAC control element, or a combination thereof, and the measured path loss is based at least in part on a beam reference signal (BRS) or synchronization signal (SS) block of the Tx beam transmitted by the optimal base station.

5. The apparatus of claim 2, wherein, The reciprocity offset is beam-specific.

6. The apparatus as claimed in claim 1 or 2, wherein, The one or more baseband processors are further configured to determine whether to transmit PRACH in the time domain in a continuous or discontinuous manner, and to configure PRACH to be transmitted L times in resources corresponding to L optimal beam reference signals BRS or synchronization signals SS block antenna ports AP.

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

8. The apparatus as claimed in claim 1 or 2, wherein, The one or more baseband processors are further configured to configure frequency hopping on multiple PRACH transmissions if multiple frequency resources are configured for PRACH transmissions.

9. The apparatus of claim 8, wherein, The one or more baseband processors are further configured to apply a constant frequency resource offset between two consecutive PRACH transmissions.

10. The apparatus of claim 8, wherein, The one or more baseband processors are further configured to configure frequency hopping on PRACH transmission between two PRACH frequency resources, and to configure the transmission of a first [L / 2] PRACH using a first frequency resource and to configure the 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 further configured to configure frequency hopping on multiple 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: cell identifier ID, frequency resources for the first PRACH transmission, symbol or time slot index for the PRACH transmission, cell radio network temporary identifier C-RNTI or UE ID, or a combination thereof.

12. An apparatus for a base station, comprising: Memory; as well as One or more baseband processors are coupled to the memory and configured to: A set of reciprocity offset thresholds is provided for transmissions to the User Equipment (UE) via higher-layer signaling, and the set of reciprocity offset thresholds is used by the UE to determine the repetition level L for physical random access channel (PRACH) transmissions. as well as The PRACH transmission is received L times based on the repetition level L.

13. The apparatus of claim 12, wherein, The one or more baseband processors are further configured to allocate dedicated resources to the UE under non-ideal reciprocity conditions, wherein the dedicated resources under non-ideal reciprocity conditions and the resources under perfect reciprocity conditions will be multiplexed using Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or Code Division Multiplexing (CDM), or a combination thereof, wherein the division of the dedicated resources under non-ideal reciprocity conditions and under perfect reciprocity conditions is predefined or configured by a higher layer via the 5G Master Information Block (MIB), via the 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 further configured to encode PRACH format indicators, PRACH transmission timing, or PRACH time and frequency resources, or combinations thereof, in the downlink control information (DCI) format via PDCCH commands to trigger contention-free PRACH transmission.

15. The apparatus of claim 12 or 13, wherein, For non-ideal reciprocity, the one or more baseband processors are further configured to encode the number of PRACH transmissions in the downlink control information (DCI) format via PDCCH commands to trigger contention-free PRACH transmissions, and to encode an indicator for indicating whether PRACH frequency hopping will be applied to multiple PRACH transmissions.

16. The apparatus of claim 12 or 13, wherein, The one or more baseband processors are further configured to encode the beam or subarray or panel index in the downlink control information (DCI) format via PDCCH commands if the UE includes two or more subarrays or panels, thereby triggering contention-free PRACH transmission in a cross-beam manner.

17. An apparatus for a user equipment (UE), comprising: A module for processing a set of reciprocity offset thresholds, wherein the set of reciprocity offset thresholds is received from the base station via higher-layer signaling; A module for determining the repetition level L for the Physical Random Access Channel (PRACH) based on the set of reciprocity offset thresholds; as well as A module for sending the PRACH transmission L times based on the repetition level L.

18. The apparatus of claim 17, further comprising a module for determining an optimal receiving Rx beam by comparing a reciprocity offset with the set of reciprocity offset thresholds.

19. The apparatus of claim 17 or 18, wherein, The set of reciprocity offset thresholds is configured by higher layers via the 5G Master Information Block (MIB), the 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling.

20. The apparatus of claim 17 or 18, further comprising a module for selecting PRACH resources from a set of available PRACH resources associated with the Tx beam transmitted by the optimal base station, based at least in part on a potential message size and a measured path loss, wherein the potential message size includes data available for transmission, a Medium Access Control (MAC) header or MAC control element, or a combination thereof, and the measured path loss is based at least in part on a beam reference signal (BRS) or synchronization signal (SS) block of the Tx beam transmitted by the optimal base station.

21. The apparatus of claim 18, wherein, The reciprocity offset is beam-specific.

22. An apparatus for a base station, comprising: A module for sending a set of reciprocity offset thresholds to a user equipment (UE) via higher-layer signaling, the set of reciprocity offset thresholds being used by the UE to determine the repetition level L for physical random access channel (PRACH) transmissions. as well as A module for processing the PRACH transmissions L times based on the repetition level L.

23. The apparatus of claim 22, further comprising: A module for allocating dedicated resources to the UE under non-ideal reciprocity conditions, wherein the dedicated resources under non-ideal reciprocity conditions and the resources under perfect reciprocity conditions are multiplexed using Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or Code Division Multiplexing (CDM), or a combination thereof. The division of the dedicated resources under non-ideal reciprocity conditions and under perfect reciprocity conditions is predefined or configured by a higher layer via the 5G Master Information Block (MIB), via the 5G System Information Block (SIB), or via Radio Resource Control (RRC) signaling.

24. The apparatus of claim 22 or 23 further includes a module for encoding a PRACH format indicator, PRACH transmission timing, or PRACH time and frequency resources, or a combination thereof, in the downlink control information (DCI) format via a PDCCH command to trigger contention-free PRACH transmission.

25. The apparatus of claim 22 or 23, further comprising a module for encoding the number of PRACH transmissions in the downlink control information (DCI) format via a PDCCH command to trigger contention-free PRACH transmissions, and for encoding an indicator for indicating whether PRACH frequency hopping will be applied to multiple PRACH transmissions.

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