Patent Description:
Random access is performed by a terminal device, e.g., User Equipment (UE), in New Radio (NR) and Long Term Evolution (LTE) networks for accessing a new cell. Once a random access procedure is completed, a terminal device can be connected to a network device, e.g., evolved NodeB (eNB) or (next) generation NodeB (gNB), and communicate with the network device using dedicated transmissions.

A four-step random access procedure has been defined for NR. <FIG> shows a signaling sequence of a four-step random access procedure. As shown, at <NUM>, a UE detects a Synchronization Signal (SS) from a gNB. At <NUM>, the UE decodes Master Information Block (MIB) and System Information Block (SIB) (i.e., Remaining Minimum System Information (RMSI) and Other System Information (OSI), which may be distributed over multiple physical channels such as Physical Broadcast Channel (PBCH) and Physical Downlink Shared Channel (PDSCH), to acquire random access transmission parameters. At <NUM>, where the UE transmits a Physical Random Access Channel (PRACH) preamble, or Message <NUM>, to the gNB. The gNB detects the Message <NUM> and responds with a Random Access Response (RAR), or Message <NUM>, at <NUM>. At <NUM>, the UE transmits a Physical Uplink Shared Channel (PUSCH), or Message <NUM>, to the gNB in accordance with configuration information for PUSCH transmission carried in the RAR. At <NUM>, the gNB transmits a Contention Resolution Message, or Message <NUM>, to the UE.

In order to minimize the number of channel accesses, which is important for e.g. operations in unlicensed frequency bands where Listen Before Talk (LBT) is required before transmission, a two-step random access procedure has also been proposed for NR. Instead of using the four steps <NUM>∼<NUM>, the two-step random access procedure completes random access in only two steps, also referred to as Message A and Message B. <FIG> shows a signaling sequence of a two-step random access procedure. As shown, the steps <NUM>~<NUM> in <FIG> are the same as the steps <NUM>∼<NUM> in <FIG>. At <NUM>, the UE transmits a PRACH preamble and a PUSCH in one message (i.e., Message A) to the gNB. The PUSCH may include higher layer data such as Radio Resource Control (RRC) connection request, possibly with some small additional payload. At <NUM>, the gNB transmits Message B to the UE, including UE identifier assignment, timing advance information and CRM, etc..

A DeModulation Reference Signal (DMRS) is transmitted with the PUSCH (Message <NUM> in <FIG> or Message A in <FIG>), for use by the gNB to estimate an uplink channel so as to demodulate the PUSCH.

<CIT> discloses apparatuses, systems and methods for two-element Random Access Channel (PRACH) transmission in an unlicensed spectrum.

The above and other objects, features and advantages will be more apparent from the following description of embodiments with reference to the figures, in which:.

As used herein, the term "wireless communication network" refers to a network following any suitable communication standards, such as NR, LTE-Advanced (LTE-A), LTE, Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), and so on. Furthermore, the communications between a terminal device and a network device in the wireless communication network may be performed according to any suitable generation communication protocols, including, but not limited to, Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), and/or other suitable <NUM> (the first generation), <NUM> (the second generation), <NUM>, <NUM>, <NUM> (the third generation), <NUM> (the fourth generation), <NUM>, <NUM> (the fifth generation) communication protocols, wireless local area network (WLAN) standards, such as the IEEE <NUM> standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, and/or ZigBee standards, and/or any other protocols either currently known or to be developed in the future.

The term "network node" or "network device" refers to a device in a wireless communication network via which a terminal device accesses the network and receives services therefrom. The network node or network device refers to a base station (BS), an access point (AP), or any other suitable device in the wireless communication network. The BS may be, for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), or gNB, a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node such as a femto, a pico, and so forth. Yet further examples of the network device may include multi-standard radio (MSR) radio equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes. More generally, however, the network device may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a terminal device access to the wireless communication network or to provide some service to a terminal device that has accessed the wireless communication network.

The term "terminal device" refers to any end device that can access a wireless communication network and receive services therefrom. By way of example and not limitation, the terminal device refers to a mobile terminal, user equipment (UE), or other suitable devices. The UE may be, for example, 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, portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, tablets, personal digital assistants (PDAs), wearable terminal devices, 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) and the like. In the following description, the terms "terminal device", "terminal", "user equipment" and "UE" may be used interchangeably. As one example, a terminal device may represent a UE configured for communication in accordance with one or more communication standards promulgated by the 3rd Generation Partnership Project (3GPP), such as 3GPP's GSM, UMTS, LTE, and/or <NUM> standards. As used herein, a "user equipment" or "UE" may not necessarily have a "user" in the sense of a human user who owns and/or operates the relevant device. In some embodiments, a terminal device may be configured to transmit and/or receive information without direct human interaction. For instance, a terminal device may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the wireless communication network. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but that may not initially be associated with a specific human user.

The terminal device may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, and may in this case be referred to as a D2D communication device.

As yet another example, in an Internet of Things (IOT) scenario, a terminal device may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another terminal device and/or network equipment. The terminal device may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as a machine-type communication (MTC) device. As one particular example, the terminal device may be a UE implementing the 3GPP narrow band internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances, for example refrigerators, televisions, personal wearables such as watches etc. In other scenarios, a terminal device may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

As used herein, a downlink transmission refers to a transmission from the network device to a terminal device, and an uplink transmission refers to a transmission in an opposite direction.

In the four-step random access procedure as shown in <FIG>, the DMRS configuration, e.g., the time domain resource and frequency domain resource for DMRS transmission, is determined based on the configuration information carried in Message <NUM>. However, in the two-step random access procedure as shown in <FIG>, there is no Message <NUM> before the UE transmits the PUSCH (in Message A). In this case, it is desired to determine the DMRS configuration to be used for the PUSCH in the two-step random access procedure.

In NR, there are various configurations for DMRS.

For example, a DMRS can be a single-symbol signal or a double-symbol signal, and the latter is only used for dedicated PDSCH and PUSCH transmissions.

Further, there can be two types of frequency mappings of DMRS, referred to as Type <NUM> (or Code Division Multiplexing (CDM) group Type <NUM>) and Type <NUM> (or CDM group Type <NUM>), respectively. Type <NUM> is comb based, with <NUM> CDM groups. Type <NUM> is not comb based, with <NUM> CDM groups.

The time mapping of DMRS to symbols within a slot can be depend on a scheduling/mapping type of PUSCH, which is dynamically indicated in Downlink Control Information (DCI) that schedules the PUSCH. For PUSCH mapping Type A, which is slot based, a DMRS may start at Symbol <NUM> or <NUM> from a slot boundary, depending on a configuration indicated in Physical Broadcast Channel (PBCH). For PUSCH mapping Type B, which is a non-slot-based (or mini-slot based) scheduling, a DMRS may start in Symbol <NUM> of PUSCH. Also, one or more additional DMRS symbols could be configured within a PUSCH duration.

A number of DMRS ports can be configured. For example, up to <NUM> or <NUM> DMRS ports can be multiplexed for Type <NUM> and up to <NUM> or <NUM> ports can be multiplexed for Type <NUM>, for single-symbol and double-symbol DMRSs respectively. Frequency Division Multiplexing (FDM), Frequency Division - Orthogonal Coverage Code (FD-OCC) and/or Time Division - Orthogonal Coverage Code (TD-OCC) can be used to separate orthogonal DMRS ports.

Furthermore, a DMRS, or DMRS sequence, can be generated as specified in Sections <NUM>. <NUM> and <NUM>. <NUM> of the <NUM>rd Generation Partnership Project (3GPP) Technical Specification (TS) <NUM>, V15.

The DMRS configuration for Message <NUM> in the four-step random access procedure is also specified in TS <NUM>. According to Section <NUM>. <NUM> of TS <NUM>, for a PUSCH carrying Message <NUM>, <MAT> (for OFDM (Orthogonal Frequency Division Multiplexing)) or <MAT> (for DFT-S-OFDM (Discrete Fourier Transform-Spread OFDM)) is applied for DMRS sequence generation in Sections <NUM>. <NUM> and <NUM>. <NUM>, respectively. Type <NUM>, single-symbol based DMRS is always used in the random access procedure since these are the default DMRS configurations prior to dedicated RRC configurations.

Table <NUM>. <NUM>-<NUM> in TS <NUM>, reproduced below as Table <NUM>, defines PUSCH DMRS positions within a slot for single-symbol DMRS, with intra-slot frequency hopping disabled.

Table <NUM>. <NUM>-<NUM> in TS <NUM>, reproduced below as Table <NUM>, defines PUSCH DMRS positions within a slot for double-symbol DMRS, with intra-slot frequency hopping disabled.

Table <NUM>. <NUM>-<NUM> in TS <NUM>, reproduced below as Table <NUM>, defines PUSCH DMRS positions within a slot for single-symbol DMRS, with intra-slot frequency hopping enabled.

For details of Tables <NUM>-<NUM>, reference can be made to Section <NUM>. <NUM> in TS <NUM> and description thereof will be omitted here.

For PUSCH mapping Type A, one front loaded DMRS symbol plus two additional DMRS symbols can be the default DMRS configuration for the random access procedure. For PUSCH mapping Type B with frequency hopping disabled, Type B, up to two additional DMRS symbols (dmrs-AdditionalPosition=<NUM>) can be the default configuration for the random access procedure.

A list of applicable PUSCH durations scheduled by a RAR is given in Section <NUM>. <NUM> in 3GPP TS <NUM>, V15. In particular, Table <NUM>. <NUM>-<NUM> in TS <NUM>, reproduced below as Table <NUM>, gives a default PUSCH time domain resource allocation A for normal Cyclic Prefix (CP), and Table <NUM>. <NUM>-<NUM> in TS <NUM>, reproduced below as Table <NUM>, gives a default PUSCH time domain resource allocation A for extended CP.

<FIG> is a flowchart illustrating a method <NUM> according to an embodiment of the present disclosure. The method <NUM> can be performed in a terminal device, e.g., a UE.

At block <NUM>, a DMRS configuration for a PUSCH is determined.

In an example, the DMRS configuration may be determined based on one or more of the following configuration parameters:.

In an example, the DMRS configuration may include a time domain resource for DMRS. In the block <NUM>, the time domain resource for DMRS can be determined based on one or more of the following configuration parameters:.

For example, one or more of these configuration parameters can be predetermined by default. As an example, by default, the frequency hopping can be disabled, the PUSCH mapping type can be Type A, the PUSCH duration can be a fixed value, the number of symbols for DMRS can be one, the maximum number of additional DMRS symbols can be a fixed value (e.g., dmrs-AdditionalPosition=<NUM>), and the CDM group type can be Type <NUM>.

Alternatively, one or more of these configuration parameters can be determined based on a resource and/or sequence for the preamble. For example, there can be a predetermined mapping between the configuration parameters and the resource and/or sequence for the preamble, and the configuration parameters can be determined based on the predetermined mapping.

Alternatively, one or more of these configuration parameters can be received from the network device via signaling. For example, the signaling may include RRC signaling or Layer <NUM> signaling. The RRC signaling may include a system information message and/or a dedicated signaling message, and the Layer <NUM> signaling may include DCI.

In an example, the maximum number of additional DMRS symbols can be determined based on a moving speed of the terminal device. For example, when the moving speed of the terminal device is lower than a threshold (e.g., <NUM>), dmrs-AdditionalPosition=<NUM>; or otherwise dmrs-AdditionalPosition=<NUM>.

In an example, the time domain resource for DMRS can be determined based on a predetermined mapping between the time domain resource for DRMS and one or more of the above configuration parameters. For example, Tables <NUM>-<NUM> as described above can be reused. The time domain resource for DMRS can be determined by looking up these tables based on the configuration parameters.

Further, the DMRS configuration may include a DMRS port and/or a DMRS sequence. In the block <NUM>, the DMRS port and/or the DMRS sequence can be determined based on a resource and/or sequence for the preamble and/or on a resource for the PUSCH.

For example, one DMRS port (and/or one DMRS sequence) can be mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. The DMRS port can be determined as a DMRS port that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. The DMRS sequence can be determined as a DMRS sequence that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. Alternatively, a set of DMRS ports (and/or DMRS sequences) can be mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. The DMRS port can be selected randomly from the set of DMRS ports that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. The DMRS sequence can be selected randomly from the set of DMRS sequences that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. Such random selection of the DMRS port and/or the DMRS sequence reduces the probability of collision between DMRSs from different terminal devices.

In an example, the DMRS sequence can be generated by using an identifier of the preamble as an initialization parameter. In this way, the probability of collision between DMRSs from different terminal devices can be reduced. For example, in the DMRS sequence generation as specified in Section <NUM>. <NUM> of TS <NUM>, the pseudo-random sequence generator may be initialized with <MAT> where PreambleID denotes the identifier of the preamble. Alternatively, in the DMRS sequence generation as specified in Section <NUM>. <NUM> of TS <NUM>, fgh can be a function of a cell identifier and the identifier of the preamble. For example, fgh or the sequence number v can be given by: <MAT> where PreambleID denotes the identifier of the preamble.

At block <NUM>, the PUSCH using the DMRS configuration is transmitted, along with a preamble, in a random access message to a network device (e.g., a gNB). Here, the random access message can be a message in a two-step random access procedure, e.g., Message A in <FIG>.

In an example, the preamble can be selected from a set of preambles reserved for two-step random access only, or the PUSCH can be transmitted over a time-frequency resource selected from a set of time-frequency resources reserved for two-step random access only. This allows the network device to determine that the preamble is a part of a Message A in a two-step random access and then attempt to detect the PUSCH in the Message A.

<FIG> is a flowchart illustrating a method <NUM> according to an embodiment of the present disclosure. The method <NUM> can be performed in a network device, e.g., a gNB.

At block <NUM>, a preamble from a terminal device (e.g., a UE) is determined, as a part of a random access message. The random access message further includes a PUSCH. Here, the random access message can be a message in a two-step random access procedure, e.g., Message A in <FIG>.

In an example, in the block <NUM>, it can be determined that the preamble is selected from a set of preambles reserved for two-step random access only, or that the PUSCH is transmitted over a time-frequency resource selected from a set of time-frequency resources reserved for two-step random access only.

At block <NUM>, a DMRS configuration for the PUSCH is determined.

In particular, in an example, the DMRS configuration may include a time domain resource for DMRS. In the block <NUM>, the time domain resource for DMRS can be determined based on one or more of the following configuration parameters:.

For example, one or more of these configuration parameters can be predetermined by default or can be determined based on a resource and/or sequence for the preamble.

In an example, one or more of these configuration parameters can be transmitted to the terminal device via signaling. For example, the signaling may include RRC signaling or Layer <NUM> signaling. The RRC signaling may include a system information message and/or a dedicated signaling message, and the Layer <NUM> signaling may include DCI.

In an example, the maximum number of additional DMRS symbols can be determined based on a moving speed of the terminal device.

Further, the DMRS configuration may include a DMRS port and/or a DMRS sequence. In the block <NUM>, the DMRS port and/or the DMRS sequence can be determined based on a resource and/or sequence for the preamble and/or on a resource for the PUSCH. For example, the DMRS port can be determined as a DMRS port that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or the DMRS sequence can be determined as a DMRS sequence that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. Alternatively, the DMRS port can be selected randomly from a set of DMRS ports that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or the DMRS sequence can be selected randomly from a set of DMRS sequences that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH.

In an example, the DMRS sequence can be generated by using an identifier of the preamble as an initialization parameter.

The operation in the block <NUM> corresponds to the operation in the block <NUM> performed at the terminal device. Thus, for further details of the operation in the block <NUM>, reference can be made to the block <NUM> as described above.

In an example, the method <NUM> can further include a step of demodulating the PUSCH based on the DMRS configuration. In particular, the network device can detect the DMRS based on the DMRS configuration, estimate an uplink channel based on the DMRS and then demodulate the PUSCH based on the estimated channel.

Correspondingly to the method <NUM> as described above, a terminal device is provided. <FIG> is a block diagram of a terminal device <NUM> according to an embodiment of the present disclosure.

As shown in <FIG>, the terminal device <NUM> includes a determining unit <NUM> configured to determine a DMRS configuration for a PUSCH. The terminal device <NUM> further includes a transmitting unit <NUM> configured to transmit to a network device the PUSCH using the DMRS configuration along with a preamble, in a random access message.

In an embodiment, the determining unit <NUM> can be configured to determine the time domain resource for DMRS based on one or more of: a frequency hopping configuration, a PUSCH mapping type, a PUSCH duration, a number of symbols for the DMRS, a maximum number of additional DMRS symbols, or a CDM group type.

In an embodiment, the DMRS configuration may include a time domain resource for DMRS. The determining unit <NUM> can be configured to determine the time domain resource for DMRS based on one or more of: a frequency hopping configuration, a PUSCH mapping type, a PUSCH duration, a number of symbols for the DMRS, a maximum number of additional DMRS symbols, or a CDM group type.

In an embodiment, the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for DMRS, the maximum number of additional DMRS symbols or the CDM group type may be predetermined by default or determined based on a resource and/or sequence for the preamble.

In an embodiment, the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for DMRS, the maximum number of additional DMRS symbols or the CDM group type may be received from the network device via signaling.

In an embodiment, the signaling may include RRC signaling or Layer <NUM> signaling. The RRC signaling may include a system information message and/or a dedicated signaling message, and the Layer <NUM> signaling may include DCI.

In an embodiment, the maximum number of additional DMRS symbols may be determined based on a moving speed of the terminal device.

In an embodiment, the time domain resource for DMRS may be determined based on a predetermined mapping between the time domain resource for DRMS and the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for DMRS, the maximum number of additional DMRS symbols or the CDM group type.

In an embodiment, the DMRS configuration may include a DMRS port and/or a DMRS sequence. The determining unit <NUM> can be configured to determine the DMRS port and/or the DMRS sequence based on a resource and/or sequence for the preamble and/or on a resource for the PUSCH.

In an embodiment, the determining unit <NUM> can be configured to determine the DMRS port as a DMRS port that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or determine the DMRS sequence as a DMRS sequence that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. Alternatively, the determining unit <NUM> can be configured to select the DMRS port randomly from a set of DMRS ports that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or select the DMRS sequence randomly from a set of DMRS sequences that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH.

In an embodiment, the determining unit <NUM> can be configured to generate the DMRS sequence by using an identifier of the preamble as an initialization parameter.

In an embodiment, the random access message may be a message in a two-step random access procedure.

In an embodiment, the preamble may be selected from a set of preambles reserved for two-step random access only, or the PUSCH may be transmitted over a time-frequency resource selected from a set of time-frequency resources reserved for two-step random access only.

The units <NUM> and <NUM> can be implemented as a pure hardware solution or as a combination of software and hardware, e.g., by one or more of: a processor or a micro-processor and adequate software and memory for storing of the software, a Programmable Logic Device (PLD) or other electronic component(s) or processing circuitry configured to perform the actions described above, and illustrated, e.g., in <FIG>.

<FIG> is a block diagram of a terminal device <NUM> according to another embodiment of the present disclosure.

The terminal device <NUM> includes a transceiver <NUM>, a processor <NUM> and a memory <NUM>. The memory <NUM> contains instructions executable by the processor <NUM> whereby the terminal device <NUM> is operative to perform the actions, e.g., of the procedure described earlier in conjunction with <FIG>. Particularly, the memory <NUM> contains instructions executable by the processor <NUM> whereby the terminal device <NUM> is operative to: determine a DMRS configuration for a PUSCH; and transmit to a network device the PUSCH using the DMRS configuration along with a preamble, in a random access message.

In an embodiment, the operation of determining the DMRS configuration may be based on one or more of: a frequency hopping configuration, a PUSCH mapping type, a PUSCH duration, a number of symbols for the DMRS, a maximum number of additional DMRS symbols, or a CDM group type.

In an embodiment, the DMRS configuration may include a time domain resource for DMRS. The operation of determining the DMRS configuration may include determining the time domain resource for DMRS based on one or more of: a frequency hopping configuration, a PUSCH mapping type, a PUSCH duration, a number of symbols for the DMRS, a maximum number of additional DMRS symbols, or a Code Division Multiplexing (CDM) group type.

In an embodiment, the signaling may include Radio Resource Control (RRC) signaling or Layer <NUM> signaling. The RRC signaling may include a system information message and/or a dedicated signaling message, and the Layer <NUM> signaling may include Downlink Control Information (DCI).

In an embodiment, the DMRS configuration may include a DMRS port and/or a DMRS sequence. The operation of determining the DMRS configuration may include determining the DMRS port and/or the DMRS sequence based on a resource and/or sequence for the preamble and/or on a resource for the PUSCH.

In an embodiment, the operation of determining the DMRS port and/or the DMRS sequence may include: determining the DMRS port as a DMRS port that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or determining the DMRS sequence as a DMRS sequence that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. Alternatively, the operation of determining the DMRS port and/or the DMRS sequence may include: selecting the DMRS port randomly from a set of DMRS ports that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or selecting the DMRS sequence randomly from a set of DMRS sequences that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH.

In an embodiment, the operation of determining the DMRS sequence may include: generating the DMRS sequence by using an identifier of the preamble as an initialization parameter.

Correspondingly to the method <NUM> as described above, a network device is provided. <FIG> is a block diagram of a network device <NUM> according to an embodiment of the present disclosure.

As shown in <FIG>, the network device <NUM> includes a detecting unit <NUM> configured to detect a preamble from a terminal device, as a part of a random access message the random access message further including a PUSCH. The network device <NUM> further includes a determining unit <NUM> configured to determine a DMRS configuration for the PUSCH.

In an embodiment, the network device <NUM> may further include a transmitting unit configured to transmit the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for DMRS, the maximum number of additional DMRS symbols or the CDM group type to the terminal device via signaling.

In an embodiment, the determining unit <NUM> can be configured to determine the DMRS port as a DMRS port that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or determine the DMRS sequence as a DMRS sequence that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. Alternatively, the determining unit <NUM> can be configured to determine the DMRS port randomly from a set of DMRS ports that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or determine the DMRS sequence randomly from a set of DMRS sequences that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH.

In an embodiment, the random access message may be a message in a two-step random access procedure. The detecting unit <NUM> can be configured to determine that the preamble is selected from a set of preambles reserved for two-step random access only, or that the PUSCH is transmitted over a time-frequency resource selected from a set of time-frequency resources reserved for two-step random access only.

In an embodiment, the network device <NUM> may further include a demodulating unit configured to demodulate the PUSCH based on the DMRS configuration.

<FIG> is a block diagram of a network device <NUM> according to another embodiment of the present disclosure.

The network device <NUM> includes a transceiver <NUM>, a processor <NUM> and a memory <NUM>. The memory <NUM> contains instructions executable by the processor <NUM> whereby the network device <NUM> is operative to perform the actions, e.g., of the procedure described earlier in conjunction with <FIG>. Particularly, the memory <NUM> contains instructions executable by the processor <NUM> whereby the network device <NUM> is operative to detect a preamble from a terminal device, as a part of a random access message, the random access message further including a PUSCH; and determine a DMRS configuration for the PUSCH.

In an embodiment, the DMRS configuration may include a time domain resource for DMRS. The operation of determining the DMRS configuration may include determining the time domain resource for DMRS based on one or more of: a frequency hopping configuration, a PUSCH mapping type, a PUSCH duration, a number of symbols for the DMRS, a maximum number of additional DMRS symbols, or a CDM group type.

In an embodiment, the memory <NUM> may further contain instructions executable by the processor <NUM> whereby the network device <NUM> is operative to transmit the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for DMRS, the maximum number of additional DMRS symbols or the CDM group type to the terminal device via signaling.

In an embodiment, the operation of determining the DMRS port and/or the DMRS sequence may include: determining the DMRS port as a DMRS port that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or determining the DMRS sequence as a DMRS sequence that is mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH. Alternatively, the operation of determining the DMRS port and/or the DMRS sequence may include: determining the DMRS port randomly from a set of DMRS ports that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH, and/or determining the DMRS sequence randomly from a set of DMRS sequences that are mapped to the resource and/or sequence for the preamble and/or to the resource for the PUSCH.

In an embodiment, the random access message may be a message in a two-step random access procedure. The operation of detecting the preamble as a part of the random access message may include: determining that the preamble is selected from a set of preambles reserved for two-step random access only, or that the PUSCH is transmitted over a time-frequency resource selected from a set of time-frequency resources reserved for two-step random access only.

In an embodiment, the memory <NUM> may further contain instructions executable by the processor <NUM> whereby the network device <NUM> is operative to demodulate the PUSCH based on the DMRS configuration.

The present disclosure also provides at least one computer program product in the form of a non-volatile or volatile memory, e.g., a non-transitory computer readable storage medium, an Electrically Erasable Programmable Read-Only Memory (EEPROM), a flash memory and a hard drive. The computer program product includes a computer program. The computer program includes: code/computer readable instructions, which when executed by the processor <NUM> causes the terminal device <NUM> to perform the actions, e.g., of the procedure described earlier in conjunction with <FIG>; or code/computer readable instructions, which when executed by the processor <NUM> causes the network device <NUM> to perform the actions, e.g., of the procedure described earlier in conjunction with <FIG>.

The computer program product may be configured as a computer program code structured in computer program modules. The computer program modules could essentially perform the actions of the flow illustrated in <FIG>.

The processor may be a single CPU (Central Processing Unit), but could also comprise two or more processing units. For example, the processor may include general purpose microprocessors; instruction set processors and/or related chips sets and/or special purpose microprocessors such as Application Specific Integrated Circuits (ASICs). The processor may also comprise board memory for caching purposes. The computer program may be carried by a computer program product connected to the processor. The computer program product may comprise a non-transitory computer readable storage medium on which the computer program is stored. For example, the computer program product may be a flash memory, a Random Access Memory (RAM), a Read-Only Memory (ROM), or an EEPROM, and the computer program modules described above could in alternative embodiments be distributed on different computer program products in the form of memories.

With reference to <FIG>, in accordance with an embodiment, a communication system includes a telecommunication network <NUM>, such as a 3GPP-type cellular network, which comprises an access network <NUM>, such as a radio access network, and a core network <NUM>. The access network <NUM> comprises a plurality of base stations 812a, 812b, 812c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 813a, 813b, 813c. Each base station 812a, 812b, 812c is connectable to the core network <NUM> over a wired or wireless connection <NUM>. A first UE <NUM> located in a coverage area 813c is configured to wirelessly connect to, or be paged by, the corresponding base station 812c. A second UE <NUM> in a coverage area 813a is wirelessly connectable to the corresponding base station 812a.

An intermediate network <NUM> may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network <NUM>, if any, may be a backbone network or the Internet; in particular, the intermediate network <NUM> may comprise two or more sub-networks (not shown).

The host computer <NUM> further comprises a processing circuitry <NUM>, which may have storage and/or processing capabilities. The host application <NUM> may be operable to provide a service to a remote user, such as UE <NUM> connecting via an OTT connection <NUM> terminating at the UE <NUM> and the host computer <NUM>.

In the embodiment shown, the hardware <NUM> of the base station <NUM> further includes a processing circuitry <NUM>, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions.

The hardware <NUM> of the UE <NUM> further includes a processing circuitry <NUM>, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions.

It is noted that the host computer <NUM>, the base station <NUM> and the UE <NUM> illustrated in <FIG> may be similar or identical to the host computer <NUM>, one of base stations 812a, 812b, 812c and one of UEs <NUM>, <NUM> of <FIG>, respectively.

In <FIG>, the OTT connection <NUM> has been drawn abstractly to illustrate the communication between the host computer <NUM> and the UE <NUM> via the base station <NUM>, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

Wireless connection <NUM> between the UE <NUM> and the base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE <NUM> using the OTT connection <NUM>, in which the wireless connection <NUM> forms the last segment. More precisely, the teachings of these embodiments may improve the radio resource utilization and thereby provide benefits such as reduced user waiting time.

The measurement procedure and/or the network functionality for reconfiguring the OTT connection <NUM> may be implemented in software <NUM> and hardware <NUM> of the host computer <NUM> or in software <NUM> and hardware <NUM> of the UE <NUM>, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection <NUM> passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which the software <NUM>, <NUM> may compute or estimate the monitored quantities.

In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer <NUM>'s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that the software <NUM> and <NUM> causes messages to be transmitted, in particular empty or 'dummy' messages, using the OTT connection <NUM> while it monitors propagation times, errors etc..

<FIG> is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment.

<FIG> is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment.

<FIG> is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment.

<FIG> is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment.

Claim 1:
A method (<NUM>) in a terminal device, comprising:
determining (<NUM>) a DeModulation Reference Signal, DMRS, configuration for a Physical Uplink Shared Channel, PUSCH; and
transmitting (<NUM>) to a network device the PUSCH using the DMRS configuration along with a preamble, in a random access message, wherein the random access message is a message A in a two-step random access procedure,
wherein the DMRS configuration comprises a DMRS sequence and the determining the DMRS configuration comprises generating the DMRS sequence by using an identifier of the preamble as an initialization parameter; and
wherein the DMRS configuration further comprises a time domain resource for DMRS and said determining the DMRS configuration further comprises determining the time domain resource for the DMRS based on one or more of:
a number of symbols for the DMRS,
a maximum number of additional DMRS symbols, or
a Code Division Multiplexing, CDM, group type;
wherein the number of symbols for the DMRS and the maximum number of additional DMRS symbols are received from the network device via signaling, the CDM group type is predetermined by default and
wherein the signaling comprises Radio Resource Control, RRC, signaling, the RRC signaling comprising a system information message and/or a dedicated signaling message.