WO2025208585A1

WO2025208585A1 - Random access response with orthogonal cover code utilized

Info

Publication number: WO2025208585A1
Application number: PCT/CN2024/086198
Authority: WO
Inventors: Rafhael MEDEIROS DE AMORIM; Mads LAURIDSEN; Ping Yuan; Jing Yuan Sun
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2024-04-04
Filing date: 2024-04-04
Publication date: 2025-10-09
Anticipated expiration: 2026-10-04

Abstract

Example embodiments of the present disclosure are directed to a random access response (RAR) with an orthogonal cover code (OCC) utilized. A first apparatus transmits a first message of a random access (RA) procedure, using a random access preamble and a first OCC. Based on the first OCC, the first apparatus determines at least one parameter related to reception of a second message of the RA procedure. The first apparatus receives a second message of the RA procedure using the at least one parameter. The second message includes a first RAR corresponding to the RA preamble and the first OCC.

Description

RANDOM ACCESS RESPONSE WITH ORTHOGONAL COVER CODE UTILIZED

FIELDS

Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to apparatuses, methods and computer readable storage medium for a random access response (RAR) with an orthogonal cover code (OCC) utilized.

BACKGROUND

In Release 17 and 18, the third-generation partnership project (3GPP) has introduced satellite access for New Radio (NR) users and also for enhanced machine-type communication (eMTC) and narrowband IoT (NB-IoT) devices. The technical specifications in Release 17 and 18 are functional and enable the deployment of live satellite networks for these types of devices. But due to limited spectrum available for deployments and large satellite footprints (for example, large cells) , the systems may quickly reach their capacity limit. Because of this, it was agreed that NTN systems required solutions that could enlarge the system capacity.

The need for Uplink capacity enhancement was agreed in the 3GPP Release 19. Orthogonal cover codes (OCCs) may be used in in a Random Access (RA) Procedure for this enhancement. However, there are some issues that need to be circumvented for the implementation of OCCs over a Narrowband Physical Random Access Channel (NPRACH) .

SUMMARY

In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: transmit a first message of a random access procedure, using a random access preamble and a first orthogonal cover code; determine, based on the first orthogonal cover code, at least one parameter related to reception of a second message of the random access procedure; and receive a second message of the random access procedure using the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: receive, from a first apparatus, a first message of a random access procedure, the first message transmitted by the first apparatus using a random access preamble and a first orthogonal cover code; determine, based on the first orthogonal cover code, at least one parameter related to transmission of a second message of the random access procedure; and transmit, to the first apparatus, a second message of the random access procedure based on the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In a third aspect of the present disclosure, there is provided a method. The method comprises: transmitting a first message of a random access procedure, using a random access preamble and a first orthogonal cover code; determining, based on the first orthogonal cover code, at least one parameter related to reception of a second message of the random access procedure; and receiving a second message of the random access procedure using the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In a fourth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a first apparatus, a first message of a random access procedure, the first message transmitted by the first apparatus using a random access preamble and a first orthogonal cover code; determining, based on the first orthogonal cover code, at least one parameter related to transmission of a second message of the random access procedure; and transmitting, to the first apparatus, a second message of the random access procedure based on the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for transmitting a first message of a random access procedure, using a random access preamble and a first orthogonal cover code; means for determining, based on the first orthogonal cover code, at least one parameter related to reception of a second message of the random access procedure; and means for receiving a second message of the random access procedure using the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for receiving, from a first apparatus, a first message of a random access procedure, the first message transmitted by the first apparatus using a random access preamble and a first orthogonal cover code; means for determining, based on the first orthogonal cover code, at least one parameter related to transmission of a second message of the random access procedure; and means for transmitting, to the first apparatus, a second message of the random access procedure based on the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In a seventh aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the third aspect.

In an eighth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fourth aspect.

It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments may now be described with reference to the accompanying drawings, where:

FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure may be implemented;

FIG. 2 illustrates an example structure of a medium access control (MAC) protocol data unit (PDU) including a MAC header and MAC random access responses (RARs) ;

FIGS. 3A to 3D illustrate example structures of a MAC RAR;

FIG. 4 is a signaling diagram showing an example communication process between a first apparatus and a second apparatus in accordance with some example embodiments of the present disclosure;

FIG. 5 illustrates a signalling diagram for RARs separated by different Random Access radio network temporary identifiers (RA-RNTIs) in accordance with some example embodiments of the present disclosure;

FIG. 6 illustrates a flowchart of a process for interleaving a physical downlink control channel (PDCCH) in accordance with some example embodiments of the present disclosure;

FIG. 7 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

FIG. 8 illustrates a flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

FIG. 9 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

FIG. 10 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure may now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein may be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first, ” “second, ” …, etc. in front of noun (s) and the like may be used herein to describe various elements, these elements may not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun (s) . For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or” , mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It may be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR) , Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) , the sixth generation (6G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there may of course also be future type communication technologies and systems with which the present disclosure may be embodied. It may not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may include a base station (BS) or an access point (AP) , for example, x NodeB (xNB) , such as a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) and an NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture includes a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node includes a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node) . In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

As used herein, the term “resource, ” “transmission resource, ” “resource block, ” “physical resource block” (PRB) , “uplink resource, ” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and/or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain may be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

As described above, the need for Uplink capacity enhancement for NB-IoT NTN was agreed in the 3GPP Release 19. For example, NB-IoT NTN is already being deployed live. In these early and upcoming deployments, it is clearly emerging that IoT-NTN, in particular NB-IoT, has to support massive capacity in terms of number and types of UEs, some of which with worse characteristics than others (e.g. low cost devices, wearables, etc. ) . Multiplexing of UEs by usage of orthogonal cover codes (OCCs) for Narrowband Physical Uplink Shared Channel (NPUSCH) format 1 and Narrowband Physical Random Access Channel (NPRACH) therefore needs to be studied. Therefore, in order to unlock the additional UL capacity potential, there is a need to identify approaches to de-couple the UL from the DL as much as possible.

The objective for Uplink capacity enhancement may include support of capacity enhancements for uplink. The study may specify, if beneficial, enhancements to enable multiplexing of multiple UEs (e.g. up to the min of 4 and the maximum allowed by the existing UL and DL signalling) in a single 3.75 kHz or 15 kHz subcarrier via orthogonal cover codes (OCCs) for NPUSCH format 1 and NPRACH. Multi-tone support for a 15 kHz sub-carrier space (SCS) is also considered. Impact of impairment needs to be taken into account.

There are some issues in a Random Access (RA) Procedure that need to be circumvented for the implementation of OCCs over the NPRACH. Release 19 NR NTN also defines the study of the use of OCCs. However, in NR, the study is currently limited to PUSCH only, but in a future release it may also include a Physical Random Access Channel (PRACH) .

According to the Random Access Procedure, as specified in the 3GPP standards, such as 3GPP TS 36.331 and TS 36.321, a network may configure a number of Random Access occasions and Random Access preambles in system information. A UE attempting to access the system (or make a request) may start the Random Access procedure as follows. Regarding Message 1 (MSG 1) from a UE to a base station (BS) , the UE randomly selects one of a subset of available Random Access Preambles (when contention based RA is used) , and transmits the preamble in one of the UL resources reserved as a RA occasion. The UE starts monitoring for physical downlink control channel (PDCCH) resources scrambled with a Random Access radio network temporary identifier (RA-RNTI) that allocates a Physical Downlink Shared Channel (PDSCH) with a RAR. As an RA-RNTI depends only on the RACH occasion it corresponds to (e.g., a system frame number (SFN) of the occasion where the preamble was transmitted) , multiple UEs may monitor and decode the same RA-RNTI.

Regarding Message 2 (MSG 2) from the base station to the UE, the network (NW) sendsa Random Access Response (RAR) to the received Random Access attempts containing: power control information, a timing advance command, uplink (UL) scheduling of MSG 3, a temporary Cell Radio Network Temporary Identifier (C-RNTI) (e.g., a temporary UE identifier (ID) ) . As mentioned above, multiple UEs may monitor the same RA-RNTI. Several UEs may attempt RA in the same RA occasion and be awaiting for a RAR. To separate its RAR from the RAR sent to other UEs that tried different preambles in the same RA occasion, the UE needs to identify in a medium access control (MAC) Subheader that carries the RAR whether a random access preamble ID (RAPID) is the same as chosen by the UE when MSG 1 was sent. Upon reading the MAC subheader with the corresponding RAPID, the UE locates the corresponding MAC payload (i.e. the MAC RAR) and read the corresponding fields. If the UE is already in a connected mode, e.g., if the UE has already an assigned C-RNTI, it ignores the temporary C-RNTI field and proceeds with the next steps (or with the connection in case of contention-free RA) . The RAR content may depend on the device type and PRACH format.

Regarding Message 3 (MSG 3) from the UE to the base station, when MSG 3 is needed (contention-based RA) , it is transmitted by the UE using the information contained in the scheduling provided in MSG 2. The message is scrambled by the UE temporary C-RNTI (or T-CRNTI) . Message 4 (MSG 4) from the BS to the UE is utilized to resolve for contention-based procedure when needed. If the contention is resolved successfully for this UE in MSG4, the UE adopts the T-CRNTI as C-RNTI, used to identify the UL/DL resources addressed by/from this UE and scramble the information.

Regarding PDCCH search space to schedule RARs, for eMTC UE, Type-2 common search space is defined for MPDCCH scrambled by the RA-RNTI in the 3GPP standards such as TS 36.321. During the RA procedure, the UE monitors the MPDCCH for a RAR in the occurrence starting in subframe K as defined for Type-2 common search space.

If a UE is configured by higher layers to decode a Machine-Type Communication (MTC) PDCCH (MPDCCH) with a CRC scrambled by a Random Access radio network temporary identifier (RA-RNTI) , the UE decodes the MPDCCH and the corresponding PDSCH according to any of the combinations defined in Table 1, for example as specified in TS 36.321, Table 7.1-3A. The scrambling initialization of a PDSCH corresponding to these MPDCCHs is by RA-RNTI.

Table 1 MPDCCH and PDSCH configured by RA-RNTI

For MPDCCH UE-specific search space, Type0-MPDCCH common search space, Type1A-MPDCCH common search space, Type2-MPDCCH common search space and Type2A-MPDCCH common search space locations of starting subframe k are given by k=k_b where k_b is the b th consecutive Bandwidth reduced low complexity (BL) /coverage enhancement (CE) downlink (DL) subframe from subframe k0, and b=u·rj, andand j∈ {1, 2, 3, 4} . Subframe k0 is a subframe satisfying the conditionwhere T=r_max·G.

For MPDCCH UE-specific search space and Type0-MPDCCH common search space, G is given by the higher layer parameter mPDCCH-startSF-UESS, except for MPDCCH candidates associated with PUR-RNTI in which case it is given by the higher layer parameter mpdcch-startSF-UESS-r16 in PUR-Config. For Type1A-MPDCCH common search space, G is given by the higher layer parameter mpdcch-startSF-SC-MCCH. For Type2-MPDCCH common search space, G is given by the higher layer parameter mPDCCH-startSF-CSS-RA-r13. For Type2A-MPDCCH common search space, G is given by the higher layer parameter mpdcch-startSF-SC-MTCH.

α_offset is given by the higher layer parameter mpdcch-Offset-SC-MTCH for Type2A-MPDCCH common search space, and by the higher layer parameter mpdcch-Offset-PUR-SS-r16 in PUR-Config for MPDCCH candidates associated with PUR-RNTI, and α_offset=0 otherwise. r_max is given by the higher layer parameter mPDCCH-NumRepetition for MPDCCH UE-specific search space and Type0-MPDCCH common search space, except for MPDCCH candidates associated with PUR-RNTI in which case it is given by the higher layer parameter mpdcch-NumRepetition-r16 in PUR-Config, and mPDCCH-NumRepetition-RA for Type2-MPDCCH common search space, and mpdcch-NumRepetitions-SC-MCCH for Type1A-MPDCCH common search space, and mpdcch-NumRepetitions-SC-MTCH for Type2A-MPDCCH common search space and r1, r2, r3, r4 are given in TS 36.321, Table 9.1.5-3.

For a NB-IoT UE, similarly, type2-NPDCCH common search space for RAR is defined in TS 36.213. During the RA procedure, the UE monitors the NPDCCH for RAR in the occurrence starting in subframe K as defined for Type-2 common search space.

If a UE is configured by higher layers to decode NPDCCH with CRC scrambled by the RA-RNTI, the UE decodes the NPDCCH and the corresponding NPDSCH according to any of the combinations defined in Table 2, for example, as specified in TS 36.213, Table 16.4.1-3. The scrambling initialization of NPDSCH corresponding to these NPDCCHs is by RA-RNTI.

Table 2 NPDCCH and NPDSCH configured by RA-RNTI

For Type2-NPDCCH common search space and Type2A-NPDCCH common search space, the aggregation and repetition levels defining the search spaces and the corresponding monitored NPDCCH candidates are listed in Table 16.6-3 by substituting the value of R_max with the higher layer configured parameter npdcch-NumRepetitions-RA for Type2-NPDCCH common search space; or with the higher layer configured parameter npdcch-NumRepetitions-SC-MTCH for Type2A-NPDCCH common search space.

The locations of starting subframe k are given by k=k_bwhere k_b is the bth consecutive NB-IoT DL subframe from subframe k0, excluding subframes used for transmission of SI messages, and b=u·R, andSubframe k0 is a subframe satisfying the conditionwhere T=R_max·G, T ≥4.

For NPDCCH UE-specific search space, G is given by the higher layer parameter npdcch-StartSF-USS, except for NPDCCH candidates associated with PUR-RNTI in which case it is given by higher layer parameter npdcch-StartSF-USS in PUR-Config-NB. α_offsetis given by the higher layer parameter npdcch-Offset-USS, except for NPDCCH candidates associated with PUR-RNTI in which case it is given by higher layer parameter npdcch-Offset-USS in PUR-Config-NB. For NPDCCH Type2-NPDCCH common search space, G is given by the higher layer parameter npdcch-StartSF-CSS-RA, and α_offsetis given by the higher layer parameter npdcch-Offset-RA. For NPDCCH Type2A-NPDCCH common search space, G is given by the higher layer parameter npdcch- startSF-SC-MTCH, and α_offsetis given by the higher layer parameter npdcch-Offset-SC-MTCH.

Downlink control information (DCI) may be used to schedule the RAR. For eMTC coverage enhancement (CE) mode A and CE mode B, DCI format 6-1A and 6-1B may be used to schedule the RAR. For NB-IoT, DCI format N1 may be used to schedule the RAR. In DCI format 6-1A/1B and N1, when it is scrambled with a RA-RNTI, some of the DCI fields are reserved. This implies it is possible to re-define the fields when OCC is supported in PRACH.

Regarding DCI format 6-1A, as specified in the 3GPP standards, such as TS 36.212, when the format 6-1A cyclic redundancy check (CRC) is scrambled with a RA-RNTI, then the following fields among the fields above are reserved: a Hybrid Automatic Repeat Request (HARQ) process number, a new data indicator, a Downlink Assignment Index, and HARQ acknowledgement (HARQ-ACK) resource offset. Regarding DCI format 6-1B, as specified in TS 36.212, when the format 6-1B CRC is scrambled with a RA-RNTI then the following fields among the fields above are reserved: HARQ process number, a new data indicator, and a HARQ-ACK resource offset. Regarding DCI format N1, as specified in TS 36.212, when the format N1 CRC is scrambled with a RA-RNTI or a group radio network temporary identifier (G-RNTI) , then the following fields among the fields above are reserved for RA-RNTI and not present for G-RNTI: a new data indicator and a HARQ-ACK resource.

By applying OCCs over NPRACH, multiple UEs may utilize the same RA resource (and same RAPID) in parallel, such that the NW is capable of -by decoding the cover code -to separate the attempts made by the different UEs and thereby multiplex users using the same preamble. However, as mentioned above, it is not possible in the current configuration of the 3GPP standards to separate the RAR for UEs with same RAPID and different cover codes.

For example, the MAC header has no spare bits to indicate to which cover code that specific RAR corresponds to. The 6-bits of RAPID are current in use, as there are 64 different preamble IDs allowed in the 3GPP standards. Modification on the payload of the RAR (e.g., MAC Protocol Data Unit (PDU) ) may not be backwards compatible. Legacy UEs, that are not using cover codes, may have transmitted RAR with the same preamble as other UEs that are using OCCs. However, the legacy UEs are not aware of modification in the RAR content. Therefore, these UEs may misinterpret the attempt to separate the response by OCCs in the payload.

One possible solution is to divide the set of allowed preambles (or RA occasions) in resources where UEs are expected to use cover codes (non-accessible by legacy UEs) and resources where legacy RA is expected. However, this solution has an issue of further fragmentation of the preambles and resources which are already divided into multiple subgroups for different purposes, such as Contention Free Random Access (CFRA) and Contention Based Random Access (CBRA) preambles and Different Coverage Enhancement (e.g., CE levels) . There is a need for an approach to convey a RAR to UEs that attempt RA using OCCs with the same preamble in the same RACH resource.

Example embodiments of the present disclosure propose a solution for a RAR with an OCC utilized. In this solution, a first apparatus (for example, a terminal device or a UE) transmits a first message (for example, MSG 1) of a random access procedure, using a random access preamble and a first OCC. Based on the first OCC, the first apparatus determines at least one parameter related to reception of a second message of the random access procedure. The first apparatus receives the second message of the random access procedure based on the at least one parameter. The second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In this way, the second message, which carries the RAR, may be enhanced to facilitate that some UEs apply OCCs when transmitting the same RACH preamble. The solution may enable coexistence of legacy UEs and UEs applying OCCs to a same RA preamble.

FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure may be implemented.

The communication environment 100 includes a first apparatus 110 and a second apparatus 120 which may communicate with each other. In some example embodiments, the first apparatus 110 may operate as a terminal device such as a UE, and the second apparatus 120 may operate as a network device, for example, a gNB.

It is to be understood that the number and types of apparatuses are shown in FIG. 1 for the purpose of illustration without suggesting any limitation. For example, the communication environment 100 may include any suitable number of first apparatuses and second apparatuses.

In some example embodiments, a link from the first apparatus 110 to the second apparatus 120 may be referred to as an uplink (UL) , and a link from the second apparatus 120 to the first apparatus 110 may be referred to as a downlink (DL) . In UL, the second apparatus 120 is a RX device (or a receiver) and the first apparatus 110 is a TX device (or a transmitter) . In DL, the second apparatus 120 is a transmitting (TX) device (or a transmitter) and the first apparatus 110 is a receiving (RX) device (or a receiver) .

In the following, for the purpose of illustration, some example embodiments are described with the first apparatus 110 operating as a terminal device, and the second apparatus 120 operating as a network device. However, in some example embodiments, operations described with respect to a terminal device may be implemented at a network device or other devices, and operations described with respect to a network device may be implemented at a terminal device or other devices.

Communications in the communication environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) , the fifth generation (5G) , the sixth generation (6G) , and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

In the communication environment 100, the first apparatus 110 may initiate a random access procedure towards the second apparatus 120. For example, the first apparatus 110 may transmit MSG 1 (or MsgA) and then receive MSG 2 (or MsgB) from the second apparatus 120. Via MSG2, the second apparatus 120 may send a RAR which may be carried in a MAC message such as a MAC PDU.

FIG. 2 shows an example structure of a MAC PDU 200 including a MAC header and MAC RARs.

In this example, the MAC PDU 200 includes a MAC header 205 which includes a plurality of MAC subheaders 210-1, 210-2, …, 210-n where n represents a positive integer. The information in the MAC subheader is compound by the following fields. The E field is the extension field which is a flag indicating if more fields are present in the MAC header or not. The E field is set to "1" to indicate at least another set of E/T/RAPID fields follows. The E field is set to "0" to indicate that a MAC RAR or padding starts at the next byte. The T field is the Type field which is a flag indicating whether the MAC subheader contains a Random Access ID or a Backoff Indicator. The T field is set to "0" to indicate the presence of a Backoff Indicator field in the subheader (BI) . The T field is set to "1" to indicate the presence of a Random Access Preamble ID field in the subheader (RAPID) . The R field is a reserved bit, set to "0" . The BI field is the Backoff Indicator field which identifies the overload condition in the cell. The size of the BI field is 4 bits. The RAPID field is the Random Access Preamble IDentifier field which identifies the transmitted Random Access Preamble (see clause 5.1.3) . The size of the RAPID field is 6 bits.

The MAC PDU 200 further includes a MAC payload 215 which carries a plurality of MAC RARs 220-1, 220-2, …, 220-n. Each MAC subheader 210-1, 210-2, …, 210-n (individually or collectively referred to as MAC subheader (s) 210) indicates a MAC RAR 220-1, 220-2, …, 220-n (individually or collectively referred to as MAC RAR (s) 220) . The first apparatus 110 may identify a RAPID in the MAC subheaders 210-1, 210-2, …, 210-n to determine whether its RAR is included in the MAC PDU 200. Some example structures of a MAC RAR 220 are shown in FIGS. 3A to 3D where FIG. 3A shows an example generic structure 300A of a MAC RAR 220, FIG. 3B shows an example structure 300B of a MAC RAR 220 for PRACH enhanced coverage level 2 or 3, FIG. 3C shows an example structure 300C of a MAC RAR 220 for NB-IoT UEs, and FIG. 3D shows an example structure 300D of a MAC RAR 220 for NB-IoT UEs using PRACH preamble format 2.

In the random access procedure, the first apparatus 110 transmits a first message (e.g., MSG 1 or MsgA) to the second apparatus 120 by using a random access preamble and an OCC (referred to as a first OCC) . Then, the first apparatus 110 receives, from the second apparatus 120, the second message (e.g., MSG 2 or MsgB) which includes a first random access response corresponding to the random access preamble and the first orthogonal cover code. The first apparatus 110 may randomly select an OCC from the configured pool of codes for (at least) contention-based RA.

In various example embodiments, the first apparatus 110 determines, based on the first OCC, at least one parameter related to reception of the second message. The second message is received by the first apparatus 110 using the at least one parameter. Some example implementations may be described below with reference to FIGS. 4 to 6.

FIG. 4 is a signaling diagram showing an example communication process 400 between the first apparatus 110 and the second apparatus 120 according to some example embodiments of the present disclosure.

As shown in FIG. 4, in the process 400, the first apparatus 110 transmits (405) a first message of a random access procedure, using a random access preamble of one or more random access preambles and an orthogonal cover code of one or more orthogonal cover codes. After the second apparatus 120 receives (410) the first message, the second apparatus 120 transmits (425) a second message of the random access procedure. Correspondingly, the first apparatus 110 receives (430) the second message. The second message includes a first random access response corresponding to the random access preamble and a first orthogonal cover code that was used by the first apparatus. For example, if the first message indicates the first OCC, the second message may only include a RAR for that specific OCC.

The first and second messages may be any messages that may be communicated between the first apparatus 110 and the second apparatus 120 during the RA procedure. In some example embodiments, the first message may be MSG 1 to carry a RA preamble to initiate the RA procedure, and the second message may be MSG 2 to carry the corresponding RARs.

According to embodiments of the present disclosure, as shown in FIG. 4, the second apparatus 120 determines (415) at least one parameter related to reception of the second message. Then, the second apparatus 120 transmits (425) the second message based the determined parameter. Correspondingly, the first apparatus 110 determines (420) the at least one parameter and then receives (430) the second message based on the determined parameter.

In this way, the RARs dedicated to users with same RAPID but different OCCs may be distinguished. As such, the second apparatus 120 may respond to both the first apparatus 110 applying an OCC to a RA preamble and a legacy apparatus using the same RA preamble with no ambiguity, thereby enabling coexistence of these apparatuses in the RA procedure. Therefore, RA efficiency and network capacity may be improved.

The at least one parameter may include any parameter related to the communication of the second message. In some example embodiments, the at least one parameter may include a scrambling code associated with the second message. In some example embodiments, the scrambling code may include a scrambling code of a first scheduling message for scheduling the second message. An example of the first scheduling message may include a downlink control information (DCI) message or physical downlink control channel (PDCCH) message.

In some example embodiments, the scrambling code may include a random access radio network temporary identifier (RA-RNTI) modified based on the first OCC. For example, an OCC identifier (ID) may be used as a modifier for selecting an OCC-ID corresponded RA-RNTI sequence. This enables transmission of a RAR that is specific to a transmission based on a combination of given preamble and OCC. In this way, the OCC ID may be used to modify the scrambling patterns related to the RAR, thereby modifying RAR readability.

In an embodiment, instead of using a regular RA-RNTI which is used to scramble the legacy PDCCH message containing the RAR DCI, the first apparatus 110 (e.g., the UE) and the second apparatus 120 (e.g., the network) may use a modified version of the RA-RNTI to perform the operation. This new OCC-RA-RNTI (O-RA-RNTI) may be obtained based on the OCC ID used by the UE, such that the OCC ID maps into a different RA-RNTI (i.e. in combination with the RACH occasion) .

For example, the 3GPP standards, such as TS 36.321, defines (for NB-IoT) :
RA-RNTI=1 + floor (SFN_id/4) + 256*carrier_id (1)

where SFN_id represents an identifier (ID) of a system frame number (SFN) used by the first apparatus 110, and carrier_id represents an ID of a carrier used by the first apparatus 110. The equation (1) may be updated to:
OCC-RA-RNTI =1 + floor (SFN_id/4) + 256*carrier_id+mapping (OCC index) (2)

The mapping may e.g. be "Offset + OCC index" where an offset is used to ensure not to hit the 256*carrier_id and the floor (SFN_id/4) range; or alternatively X*OCC index. X may be any positive integer. For example, If X=1, OCC index = 1, 2, 3, 4. If X=2, OCC index = 2, 4, 6, 8) , and so forth.

In some example embodiments, just a different sequence (not multiple sequences) may be used to differentiate the new RAR message (as an example of the second message) from the legacy RAR message. For example, UEs that used OCC in the NPRACH, may expect to read the new O-RA-RNTI, where UEs using legacy NPRACH will read the legacy RA-RNTI.

FIG. 5 shows a signalling diagram 500 for RARs separated by different RA-RNTIs in accordance with some example embodiments of the present disclosure. UE1 505 and UE2 510 may act as examples of the first apparatus 110, and a base station 515 may act as an example of the second apparatus 120.

As shown in FIG. 5, in a RA occasion, UE1 505 initiates (520) a RA attempt using e.g., RAPID #7 and OCC ID #0, and UE2 510 initiates (522) a RA attempt using e.g., RAPID #7 and OCC ID#1. The random access preamble may be an example of the first message. The base station 515 decodes (524) the RA attempts. The base station 510 transmits (526) to both UE1 505 and UE2 510 an RAR scheduled with RA-RNTI X. This RA-RNTI is a version of RA-RNTI modified by OCC ID #1.

UE1 505 decodes (528) the RAR to look for RAPID #7 in the RAR. In this example, UE2 510 is not capable of decoding a RAR scrambled with RA-RNTI and keeps monitoring for a RAR within a RAR window. The base station 515 transmits (530) to UE2 510 an RAR scheduled with RA-RNTI Y which is a version of RA-RNTI modified by OCC ID #1. UE2 510 decodes (532) the RAR to look for RAPID #7 in the RAR.

In addition to the RA-RNTI, or as an alternative, in some example embodiments, the scrambling code based on the first OCC may be a group radio network temporary identifier (group RNTI or G-RNTI) which is determined based on the first message transmitted using the first OCC. In an example, the OCC ID of the first OCC may be used for selecting an OCC-ID corresponded G-RNTI for the PDCCH message (as an example of the first scheduling message) that allocates the RAR. In this way, a G-RNTI (group RNTI) which is previously configured by the network in system information may be reutilized for providing a RAR PDCCH.

In some example embodiments, scheduling availability of the RAR may be modified based on the first OCC used by the first apparatus 110. For example, the OCC ID may be used to modify the scheduling availability/information.

In some example embodiments, the at least one parameter determined (415, 420) based on the first OCC may include a resource for transmitting/receiving the second message. For example, RAR messages directed to a certain OCC ID may only be transmitted in certain resources. In this way, the availability of resources where the network can allocate the RAR is modified.

The resource (s) may include any resource that is related to the communication of the second message. In some example embodiments, the resource may include a first time window for transmitting/receiving the second message. In some example embodiments, the first time window may be different from a second time window for receiving a further second message (e.g., a legacy RAR message) which includes a second random access response unrelated to an orthogonal cover code. Generally, the RAR may be scheduled anywhere in the entire duration of an RAR Window. According to some example embodiments, in order to distinguish RAR addressed for UEs with different OCCs, some modification may be applied. In one embodiment, the network (NW) may indicate a dedicated RAR window for the OCC UE (as an example of the first apparatus 110) , in which only the UE using OCC will be scheduled.

In some example embodiments, a starting point of the first time window may be subsequent to an end point of the second time window. In one example, the NW may split the RAR window for a legacy UE and an OCC UE by indicating a dedicated RAR window for the OCC UE. The RAR for the OCC UE is not scheduled in the RAR window for the legacy UE but instead be scheduled in the dedicated RAR window for OCC UEs (i.e. no time overlap) . The RAR for legacy UE is only scheduled in the legacy RAR window hence there is no inter-operability issue even if the OCC UE is scheduled in the dedicated RAR window using a new RAR format.

In some example embodiments, the first time window may an extension of the second time window. In some example embodiments, the second apparatus 120 may transmit a factor for extending the second time window to determine the first time window. Correspondingly, the first apparatus 110 may receive this factor and then use the factor to determine the first time window.

In an example, the NW may broadcast a factor n to extend the RAR window for OCC UE. n represents any number. The legacy RAR window for the legacy UE may be defined with legacy parameter ra-ResponseWindow. The dedicated RAR window for the OCC US may be defined as (n-1) *ra-ResponseWindow, in which the dedicated window can be started upon the legacy RAR window expiry. Alternatively, the dedicated RAR window may be defined as n*ra-ResponseWindow and can be started as legacy (e.g., after PRACH transmission + offset) . But OCC UE only expect the RAR scheduling in the last (n-1) *ra-ResponseWindow duration. Alternatively, the new RAR is scheduled using the legacy parameter ra-ResponseWindow but for a new OCC RAR window information element, which is only read by the new UEs.

In some example embodiments, the resource may include a time and/or frequency resource for transmitting/receiving the second message. In some example embodiments, the time and/or frequency resource for receiving the second message may include at least one of a slot, a frame, a hyper frame, or a physical resource block. In one embodiment, the RAR resource for OCC UE may be defined by SFN -system frame number -and/or slot number.

In an example, it is considered 4 OCC IDs available to be chosen by the UE for NPRACH, with indexes 0 to 3. In this case, the NW (as an example of the second apparatus 120) may apply a modulo-operation to the slot index such that the UE (as an example of the first apparatus 110) may only expect the RAR PDCCH to come at slot X (within the RAR window -potentially the dedicated window proposed above) , where X is given by X=mod_4 (Slot index) . In this example, other network parameters (such as SFN, HFN, PRBs, etc. ) may be used instead of slot index to perform the operation. The same applies for the modulo-operation that may be replaced by different operations.

In some example embodiments, the resource may include a first search space for receiving a first scheduling message for scheduling the second message. In one embodiment, the NW may indicate a dedicated PDCCH search space for the OCC UE, in which only the UE using OCC will be scheduled.

In one example, the NW may split the PDCCH search space for legacy UEs and OCC UEs by indicating a dedicated search space for the OCC UE. The RAR for OCC UE may only be scheduled in a PDCCH occurrence in the dedicated search space and the legacy UE may not be scheduled in that search space. Therefore, there is no inter- operability issue even if the OCC UE is scheduled using a new RAR format. In an example, the dedicated search space may be defined by a set of parameters such as pdcch-StartSF-CSS-RA, pdcch-Offset-RA and pdcch-NumRepetitions-RA.

In some example embodiments, the resource (s) may be associated with a second orthogonal cover code (e.g., a DL OCC) associated with the first orthogonal cover code and/or a group of orthogonal cover codes associated with the first orthogonal cover code. In some example embodiments, the second apparatus 120 may transmit an indication of the resource to the first apparatus 110. Correspondingly, the first apparatus 110 may receive this indication. In an example, the indications may be per OCC ID or for a group of OCC IDs.

In some example embodiments, the second message may be identified based on a first scheduling message for scheduling the second message including an indication related to the first orthogonal cover code. In an example, the OCC ID may be included in the DCI, which schedules the RAR. The RAR is then provided per OCC. The scheduling DCI for the RAR has reserved bits as mentioned above. Therefore, the DCI may be enhanced with a field, which explicitly defines what OCC the RAR is for. For example, if the new field in the DCI defines '3', the RAR is for preambles, which were transmitted using OCC code #3. Such an indication may be utilized together with a different RNTI and/or search space/time domain scheduling to ensure legacy UEs do not receive the RAR which is for a specific OCC ID.

In some example embodiments, the at least one parameter based on the first OCC may include an interleaving pattern of a first scheduling message for scheduling the second message. For example, different interleaving patterns may be applied to the PDCCH message that contain the scheduling of the RAR message in DL. The PDCCH (e.g., transport block (TB) or CRC of the PDCCH) may be be interleaved according to a function based on the OCC ID used by the first apparatus 110 in the NPRACH transmission.

In an example, an interleave sequence may be generated to be used by the NW to transmit the PDCCH which schedules message 2. The sequence may be obtained from a function associated to the OCC ID. At the UE side, the UE that initiates the RA attempt, may then decode the PDCCH by de-interleaving the message using the respective sequence. This enforces that the UE will not decode RAR dedicated to other UEs (as they are interleaved with a different sequence) .

In some example embodiments, a respective interleaving pattern for each of one or more orthogonal cover codes is predefined, or preconfigured or configured for the first apparatus. For example, the interleaving pattern corresponding to different OCC can be pre-defined (e.g. hard coded in hardware as standardization in specifications) or configured from network to UE.

In some example embodiments, the interleaving pattern is used for interleaving at least one of: encoded bits of the first scheduling message, or a cyclic redundancy check code of the first scheduling message. For example, the interleaving can be cyclic, e.g. cyclic of the PDCCH bits. Alternatively, or in addition, the interleaving may be for the encoded bits or can be for the CRC.

In some example embodiments, the first scheduling message comprises a physical downlink control channel message for scheduling the second message, and the interleaving pattern is applied for one of: the physical downlink control channel message for scheduling the second message, and a plurality of physical downlink control channel messages during the random access procedure, the plurality of physical downlink control channel messages corresponding to the second orthogonal cover code associated with the first orthogonal cover code. For example, the interleaving may be for PDCCH in random access procedure, e.g. PDCCH for RAR, or all PDCCH in random access procedure.

FIG. 6 shows a flowchart of a process 600 for interleaving a PDCCH in accordance with some example embodiments of the present disclosure.

As shown in FIG. 6, at block 605, an interleaving pattern for each OCC code is defined and configured to a UE (as an example of the first apparatus 110) . At block 610, the UE transmit a PRACH with a OCC and detect a PDCCH/RAR. At block 615, the UE deCRCs (i.e. decodes using CRC as an example) the PDCCH according to the interleaving. At block 620, it is determined if deCRC result is successful. If yes, at block 625, the UE performs the following random access procedure steps. If no, at block 630, the UE receives other PDCCH/RARs corresponding to other OCC codes.

As one OCC code is corresponding to one specific interleaving pattern, thus only using the same interleaving pattern corresponding to the OCC may generate original PDCCH bits and have the CRC processing successful. An example interleaving process will be described below.

OCC code is represented as (1, 1, 1, 1) (-1, -1, 1, 1) , (-1, 1, -1, 1) (1, -1, 1, -1) . Then, interleaving for OCC ( (1) can be:

F (1) : divide the PDCCH to 4 part No 1, 2, 3, 4, collecting the bits as part 1, part 2, part 3, part 4;

F (2) : divide the PDCCH to 4 part No 1, 2, 3, 4, collecting the bits as part 3, part 4, part 1, part 2;

F (3) : divide the PDCCH to 4 part No 1, 2, 3, 4, collecting the bits as part 2, part 4, part 1, part 3; and

F (4) : divide the PDCCH to 4 part No 1, 2, 3, 4, collecting the bits as part 1, part 3, part 2, part 4.

As one example, PDCCH bits are as 1111 1000 0000 1000. Then, after interleaving F (1) , it changed to 1111 1000 0000 1000; after interleaving F (2) , it changed to 0000 1000 1111 1000; after interleaving F (3) , it changed to 1000 1000 1111 0000; after interleaving F (4) , it changed to 1111 0000 1000 1000.

Then only performing the interleaving and deinterleaving using the same interleaving pattern may result in that the PDCCH can be recovered and a successful CRC, or otherwise the CRC will fail. The interleaving will not be understood by legacy UEs and therefore the proposal may need to be combined with other means e.g. a different RNTI, which is only known to new UEs.

In some example embodiments, the at least one parameter is associated with a second orthogonal cover code mapped from the first orthogonal cover code. In some example embodiments, the second orthogonal cover code may be the same as the first orthogonal cover code.

For example, the OCC ID may be used to modify the DL OCC (as an example of the second OCC) . In an example, different DL OCC IDs may be applied for the different RAR messages, where the DL OCC ID may be obtained as a function of the UL OCC ID.

In an embodiment, the network is capable to provide DL OCC. As the UEs attempting RACH may be coming from IDLE/INACTIVE mode, the network may not be capable to indicate to these UEs which OCC ID it will utilize in the RAR response. In this case, the network may pre-configure (either in System Information or hard-coded in spec) DL OCC IDs to be mapped from the UL OCC ID used by the UEs. In some example embodiments, the DL OCC ID may be equal to the applied UL OCC ID.

In some example embodiments, the second message may include a field indicating both the random access preamble and the second orthogonal cover code. In some example embodiments, the field may be carried in a header of the second message.

For example, the RAPID field in the MAC subheader may be expanded such that it can cover a combination of preamble and OCC IDs. The current RAPID field is 6 bits. If it is e.g. expanded to 8 bits it can accommodate 2 bits that define the OCC ID applied by the UE. This will allow the UE to identify the corresponding MAC RAR payload.

Combination of above solutions may provide further options. For example, considering OCC ID has 2 bits, 1 bit may be used to modify an RNTI and another 1 bit may be used to modify the resource. As one alternative, a part of the bit (s) of the OCC ID may be used to modify a parameter related to the second message, while other bits of the OCC ID may be used to modify another parameter related to the second message.

FIG. 7 shows a flowchart of an example method 700 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described from the perspective of the first apparatus 110 in FIG. 1.

At block 710, the first apparatus 110 transmits a first message of a random access procedure, using a random access preamble and a first orthogonal cover code.

At block 720, the first apparatus 110 determines, based on the first orthogonal cover code, at least one parameter related to reception of a second message of the random access procedure.

At block 730, the first apparatus 110 receives a second message of the random access procedure using the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In some example embodiments, the at least one parameter includes a scrambling code associated with the second message.

In some example embodiments, the scrambling code comprises a scrambling code of a first scheduling message for scheduling the second message.

In some example embodiments, the scrambling code comprises at least one of: a random access radio network temporary identifier modified based on the first orthogonal cover code, or a group radio network temporary identifier determined based on the first message transmitted using the first orthogonal cover code.

In some example embodiments, the at least one parameter includes a resource for receiving the second message, the resource being associated with at least one of: a second orthogonal cover code associated with the first orthogonal cover code, or a group of orthogonal cover codes associated with the first orthogonal cover code.

In some example embodiments, the at least one memory and the at least one processor further cause the first apparatus to: receive an indication of the resource.

In some example embodiments, the resource comprises at least one of: a first time window for receiving the second message, a time and/or frequency resource for receiving the second message, or a first search space for receiving a first scheduling message for scheduling the second message.

In some example embodiments, the first time window is different from a second time window for receiving a further second message, the further second message including a second random access response unrelated to an orthogonal cover code.

In some example embodiments, a starting point of the first time window is subsequent to an end point of the second time window.

In some example embodiments, the first time window is an extension of the second time window.

In some example embodiments, the at least one memory and the at least one processor further cause the first apparatus to: receive a factor for extending the second time window to determine the first time window.

In some example embodiments, the first search space is different from a second search space for receiving a second scheduling message for scheduling a further second message, the further second message including a second random access response unrelated to an orthogonal cover code.

In some example embodiments, the second message is identified based on a first scheduling message for scheduling the second message including an indication related to the first orthogonal cover code.

In some example embodiments, the at least one parameter includes an interleaving pattern of a first scheduling message for scheduling the second message.

In some example embodiments, a respective interleaving pattern for each of one or more orthogonal cover codes is predefined, or preconfigured or configured for the first apparatus.

In some example embodiments, the interleaving pattern is used for interleaving at least one of: encoded bits of the first scheduling message, or a cyclic redundancy check code of the first scheduling message.

In some example embodiments, the first scheduling message comprises a physical downlink control channel message for scheduling the second message, and the interleaving pattern is applied for one of: the physical downlink control channel message for scheduling the second message, and a plurality of physical downlink control channel messages during the random access procedure, the plurality of physical downlink control channel messages corresponding to the second orthogonal cover code associated with the first orthogonal cover code.

In some example embodiments, the at least one parameter is associated with a second orthogonal cover code mapped from the first orthogonal cover code.

In some example embodiments, the second orthogonal cover code is the same as the first orthogonal cover code.

In some example embodiments, the second message includes a field indicating both the random access preamble and the second orthogonal cover code.

In some example embodiments, the field is carried in a header of the second message.

FIG. 8 shows a flowchart of an example method 800 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 800 will be described from the perspective of the second apparatus 120 in FIG. 1.

At block 810, the second apparatus 120 receives, from a first apparatus, a first message of a random access procedure, the first message transmitted by the first apparatus using a random access preamble and a first orthogonal cover code.

At block 820, the second apparatus 120 determines, based on the first orthogonal cover code, at least one parameter related to transmission of a second message of the random access procedure.

At block 830, the second apparatus 120 transmits, to the first apparatus, a second message of the random access procedure based on the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In some example embodiments, the scrambling code comprises at least one of: a random access radio network temporary identifier modified based on the second orthogonal cover code associated with the first orthogonal cover code, or a group radio network temporary identifier determined based on the first message transmitted using the first orthogonal cover code.

In some example embodiments, the at least one parameter includes a resource for transmitting the second message, the resource being associated with at least one of: a second orthogonal cover code associated with the first orthogonal cover code, or a group of orthogonal cover codes associated with the first orthogonal cover code.

In some example embodiments, the at least one memory and the at least one processor further cause the second apparatus to: transmit an indication of the resource to the first apparatus.

In some example embodiments, the resource comprises at least one of: a first time window for transmitting the second message, a time and/or frequency resource for transmitting the second message, or a first search space for transmitting a first scheduling message for scheduling the second message.

In some example embodiments, the first time window is different from a second time window for transmitting a further second message, the further second message including a second random access response unrelated to an orthogonal cover code.

In some example embodiments, the at least one memory and the at least one processor further cause the second apparatus to: transmit a factor for extending the second time window to determine the first time window.

In some example embodiments, the first search space is different from a second search space for transmitting a second scheduling message for scheduling a further second message, the further second message including a second random access response unrelated to an orthogonal cover code.

In some example embodiments, the at least one parameter is indicated in a first scheduling message for scheduling the second message including an indication of a second orthogonal cover code associated with the first orthogonal cover code.

In some example embodiments, a respective interleaving pattern for each of one or more orthogonal cover codes is predefined, or preconfigured or configured by the second apparatus for the first apparatus.

All operations and features related to the first apparatus 110 and the second apparatus 120 as described above with reference to FIGS. 1 to 6 are likewise applicable to the methods 700 and 800 and have similar effects.

In some example embodiments, a first apparatus capable of performing the method 700 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

In some example embodiments, the first apparatus comprises means for transmitting a first message of a random access procedure, using a random access preamble and a first orthogonal cover code; means for determining, based on the first orthogonal cover code, at least one parameter related to reception of a second message of the random access procedure; and means for receiving a second message of the random access procedure using the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

In some example embodiments, a second apparatus capable of performing the method 800 (for example, the second apparatus 120 in FIG. 1) may comprise means for performing the respective operations of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included the second apparatus 120 in FIG. 1.

In some example embodiments, the second apparatus comprises means for receiving, from a first apparatus, a first message of a random access procedure, the first message transmitted by the first apparatus using a random access preamble and a first orthogonal cover code; means for determining, based on the first orthogonal cover code, at least one parameter related to transmission of a second message of the random access procedure; and means for transmitting, to the first apparatus, a second message of the random access procedure based on the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.

FIG. 9 is a simplified block diagram of a device 900 that is suitable for implementing example embodiments of the present disclosure. The device 900 may be provided to implement a communication device, for example, the first apparatus 110 or the second apparatus 120 as shown in FIG. 1. As shown, the device 900 includes one or more processors 910, one or more memories 920 coupled to the processor 910, and one or more communication modules 940 coupled to the processor 910.

The communication module 940 is for bidirectional communications. The communication module 940 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 940 may include at least one antenna.

The processor 910 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 900 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 920 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 924, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , an optical disk, a laser disk, and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random-access memory (RAM) 922 and other volatile memories that will not last in the power-down duration.

A computer program 930 includes computer executable instructions that are executed by the associated processor 910. The instructions of the program 930 may include instructions for performing operations/acts of some example embodiments of the present disclosure. The program 930 may be stored in the memory, e.g., the ROM 924. The processor 910 may perform any suitable actions and processing by loading the program 930 into the RAM 922.

The example embodiments of the present disclosure may be implemented by means of the program 930 so that the device 900 may perform any process of the disclosure as discussed with reference to FIG. 1 to FIG. 6. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 930 may be tangibly contained in a computer readable medium which may be included in the device 900 (such as in the memory 920) or other storage devices that are accessible by the device 900. The device 900 may load the program 930 from the computer readable medium to the RAM 922 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory, ” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM) .

FIG. 10 shows an example of the computer readable medium 1000 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1000 has the program 930 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A first apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:

transmit a first message of a random access procedure, using a random access preamble and a first orthogonal cover code;

determine, based on the first orthogonal cover code, at least one parameter related to reception of a second message of the random access procedure; and

receive a second message of the random access procedure using the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.
The first apparatus of claim 1, wherein the at least one parameter includes a scrambling code associated with the second message.
The first apparatus of claim 2, wherein the scrambling code comprises a scrambling code of a first scheduling message for scheduling the second message.
The first apparatus of claim 2 or 3, wherein the scrambling code comprises at least one of:

a random access radio network temporary identifier modified based on the first orthogonal cover code, or

a group radio network temporary identifier determined based on the first message transmitted using the first orthogonal cover code.
The first apparatus of any of claims 1 to 4, wherein the at least one parameter includes a resource for receiving the second message, the resource being associated with at least one of:

a second orthogonal cover code associated with the first orthogonal cover code, or

a group of orthogonal cover codes associated with the first orthogonal cover code.
The first apparatus of claim 5, wherein the at least one memory and the at least one processor further cause the first apparatus to:

receive an indication of the resource.
The first apparatus of claim 5 or 6, wherein the resource comprises at least one of:

a first time window for receiving the second message,

a time and/or frequency resource for receiving the second message, or

a first search space for receiving a first scheduling message for scheduling the second message.
The first apparatus of claim 7, wherein the first time window is different from a second time window for receiving a further second message, the further second message including a second random access response unrelated to an orthogonal cover code.
The first apparatus of claim 8, wherein a starting point of the first time window is subsequent to an end point of the second time window.
The first apparatus of any of claims 8 to 9, wherein the first time window is an extension of the second time window.
The first apparatus of claim 10, wherein the at least one memory and the at least one processor further cause the first apparatus to:

receive a factor for extending the second time window to determine the first time window.
The first apparatus of claim 7, wherein the first search space is different from a second search space for receiving a second scheduling message for scheduling a further second message, the further second message including a second random access response unrelated to an orthogonal cover code.
The first apparatus of any of claims 1 to 12, wherein the second message is identified based on a first scheduling message for scheduling the second message including an indication related to the first orthogonal cover code.
The first apparatus of any of claims 1 to 13, wherein the at least one parameter includes an interleaving pattern of a first scheduling message for scheduling the second message.
The first apparatus of claim 14, wherein a respective interleaving pattern for each of one or more orthogonal cover codes is predefined, or preconfigured or configured for the first apparatus.
The first apparatus of claim 14 or 15, wherein the interleaving pattern is used for interleaving at least one of:

encoded bits of the first scheduling message, or

a cyclic redundancy check code of the first scheduling message.
The first apparatus of any of claims 14 to 16, wherein the first scheduling message comprises a physical downlink control channel message for scheduling the second message, and the interleaving pattern is applied for one of:

the physical downlink control channel message for scheduling the second message, and

a plurality of physical downlink control channel messages during the random access procedure, the plurality of physical downlink control channel messages corresponding to the second orthogonal cover code associated with the first orthogonal cover code.
The first apparatus of any of claims 1 to 17, wherein the at least one parameter is associated with a second orthogonal cover code mapped from the first orthogonal cover code.
The first apparatus of claim 18, wherein the second orthogonal cover code is the same as the first orthogonal cover code.
The first apparatus of any of claims 18 to 19, wherein the second message includes a field indicating both the random access preamble and the second orthogonal cover code.
The first apparatus of claim 20, wherein the field is carried in a header of the second message.
A second apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to:

receive, from a first apparatus, a first message of a random access procedure, the first message transmitted by the first apparatus using a random access preamble and a first orthogonal cover code;

determine, based on the first orthogonal cover code, at least one parameter related to transmission of a second message of the random access procedure; and

transmit, to the first apparatus, a second message of the random access procedure based on the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.
The second apparatus of claim 22, wherein the at least one parameter includes a scrambling code associated with the second message.
The second apparatus of claim 23, wherein the scrambling code comprises a scrambling code of a first scheduling message for scheduling the second message.
The second apparatus of claim 23 or 24, wherein the scrambling code comprises at least one of:

a random access radio network temporary identifier modified based on the second orthogonal cover code associated with the first orthogonal cover code, or

a group radio network temporary identifier determined based on the first message transmitted using the first orthogonal cover code.
The second apparatus of any of claims 22 to 25, wherein the at least one parameter includes a resource for transmitting the second message, the resource being associated with at least one of:

a second orthogonal cover code associated with the first orthogonal cover code, or

a group of orthogonal cover codes associated with the first orthogonal cover code.
The second apparatus of claim 26, wherein the at least one memory and the at least one processor further cause the second apparatus to:

transmit an indication of the resource to the first apparatus.
The second apparatus of claim 26 or 27, wherein the resource comprises at least one of:

a first time window for transmitting the second message,

a time and/or frequency resource for transmitting the second message, or

a first search space for transmitting a first scheduling message for scheduling the second message.
The second apparatus of claim 28, wherein the first time window is different from a second time window for transmitting a further second message, the further second message including a second random access response unrelated to an orthogonal cover code.
The second apparatus of claim 29, wherein a starting point of the first time window is subsequent to an end point of the second time window.
The second apparatus of any of claims 29 to 30, wherein the first time window is an extension of the second time window.
The second apparatus of claim 31, wherein the at least one memory and the at least one processor further cause the second apparatus to:

transmit a factor for extending the second time window to determine the first time window.
The second apparatus of claim 29, wherein the first search space is different from a second search space for transmitting a second scheduling message for scheduling a further second message, the further second message including a second random access response unrelated to an orthogonal cover code.
The second apparatus of any of claims 22 to 33, wherein the at least one parameter is indicated in a first scheduling message for scheduling the second message including an indication of a second orthogonal cover code associated with the first orthogonal cover code.
The second apparatus of any of claims 22 to 34, wherein the at least one parameter includes an interleaving pattern of a first scheduling message for scheduling the second message.
The second apparatus of claim 35, wherein a respective interleaving pattern for each of one or more orthogonal cover codes is predefined, or preconfigured or configured by the second apparatus for the first apparatus.
The second apparatus of claim 35 or 36, wherein the interleaving pattern is used for interleaving at least one of:

encoded bits of the first scheduling message, or

a cyclic redundancy check code of the first scheduling message.
The second apparatus of any of claims 35 to 37, wherein the first scheduling message comprises a physical downlink control channel message for scheduling the second message, and the interleaving pattern is applied for one of:

the physical downlink control channel message for scheduling the second message, and

a plurality of physical downlink control channel messages during the random access procedure, the plurality of physical downlink control channel messages corresponding to the second orthogonal cover code associated with the first orthogonal cover code.
The second apparatus of any of claims 22 to 38, wherein the at least one parameter is associated with a second orthogonal cover code mapped from the first orthogonal cover code.
The second apparatus of claim 39, wherein the second orthogonal cover code is the same as the first orthogonal cover code.
The second apparatus of any of claims 39 to 40, wherein the second message includes a field indicating both the random access preamble and the second orthogonal cover code.
The second apparatus of claim 41, wherein the field is carried in a header of the second message.
A method comprising:

transmitting a first message of a random access procedure, using a random access preamble and a first orthogonal cover code.

determining, based on the first orthogonal cover code, at least one parameter related to reception of a second message of the random access procedure.

receiving a second message of the random access procedure using the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.
A method comprising:

receiving, from a first apparatus, a first message of a random access procedure, the first message transmitted by the first apparatus using a random access preamble and a first orthogonal cover code.

determining, based on the first orthogonal cover code, at least one parameter related to transmission of a second message of the random access procedure.

transmitting, to the first apparatus, a second message of the random access procedure based on the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.
A first apparatus comprising:

means for transmitting a first message of a random access procedure, using a random access preamble and a first orthogonal cover code;

means for determining, based on the first orthogonal cover code, at least one parameter related to reception of a second message of the random access procedure; and

means for receiving a second message of the random access procedure using the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.
A second apparatus comprising:

means for receiving, from a first apparatus, a first message of a random access procedure, the first message transmitted by the first apparatus using a random access preamble and a first orthogonal cover code;

means for determining, based on the first orthogonal cover code, at least one parameter related to transmission of a second message of the random access procedure; and

means for transmitting, to the first apparatus, a second message of the random access procedure based on the at least one parameter, wherein the second message includes a first random access response corresponding to the random access preamble and the first orthogonal cover code.
A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 43 or the method of claim 44.