Patent Description:
Various wireless cellular communication systems have been implemented and are being implemented. Mobile communication systems have been developed and are being developed to meet the increasing demand for communication services. With the rapid advance of technologies, the mobile communication systems have evolved to the level capable of providing high speed data communication service beyond the early voice-oriented services.

A random access (RA) procedure refers to a procedure for a terminal device to establish or reestablish a connection with a network device such as an Evolved NodeB (eNB). A contention based random access can facilitate the possibility that multiple communication devices may be interested in attempting to access the network device through the RA procedure at the same or similar point in time. Once access has been established and/or confirmed, the network device can assign resources to a particular terminal device in support of the uplink communication with the network device. <CIT> discloses a data transmission method which uses feedback to indicate whether payload data has been successfully received to improve transmission efficiency of long duty cycles and sporadic small data packets in an internet of things communication system. Configuration information is obtained which indicates communication resources used for transmitting a small data packet. The communication resources include transmission resources used for transmitting a random access preamble and payload data. The configuration information may also indicate information including a position of the resources transmitting the random access preamble and a mapping relationship between the random access preamble and the payload data block resources. The mapping relationships may be grouped into sets and each set may correspond to a particular scenario or event such as a high-speed scenario, a large path loss scenario, a large channel delay scenario, a too many data failures scenario and a large data block scenario. The terminal determines, through a predefined rule, a random access preamble and payload data block resources through the mapping which matches the scenario determined by the terminal. <CIT> discloses that a user equipment may select a coverage enhancement level based on a coverage limitation. The UE receives system information from a base station indicating an index of coverage enhancement levels and corresponding physical random access channel configurations, and the user equipment may transmit a random access preamble using the physical random access channel configuration for the selected channel enhancement level.

In general, example embodiments of the present disclosure provide a solution for information transmission in random access.

In a first aspect, there is provided a method as claimed in claim <NUM>.

In a second aspect, there is provided a method as claimed in claim <NUM>.

In a third aspect, there is provided a device as claimed in claim <NUM>.

In a fourth aspect, there is provided a device as claimed in claim <NUM>.

In a fifth aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method according to the above first aspect.

In a sixth aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method according to the above second aspect.

It is to be understood that the summary section is not intended to identify key or essential features of example embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure.

It is to be understood that these example 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.

References in the present disclosure to "one embodiment," "an example embodiment," "an example embodiment," and the like indicate that the example 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. Further, when a particular feature, structure, or characteristic is described in connection with an example 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 example embodiments whether or not explicitly described.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of example embodiments.

As used herein, the term "communication network" refers to a network following any suitable communication standards, such as 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 (<NUM>), the second generation (<NUM>), <NUM>, <NUM>, the third generation (<NUM>), the fourth generation (<NUM>), <NUM>, the future fifth generation (<NUM>) communication protocols, and/or any other protocols either currently known or to be developed in the future. Example embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should 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 refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR NB (also referred to as a 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, depending on the applied terminology and technology.

<FIG> illustrates an example communication system <NUM> in which example embodiments of the present disclosure may be implemented. The system <NUM> includes a network device <NUM> and a terminal device <NUM> served by the network device <NUM>. The serving area of the network device <NUM> is called as a cell <NUM>. It is to be understood that the number of network devices and terminal devices is only for the purpose of illustration without suggesting any limitations. The system <NUM> may include any suitable number of network devices and terminal devices adapted for implementing embodiments of the present disclosure. Although not shown, it would be appreciated that one or more terminal devices may be located in the cell <NUM> and served by the network device <NUM>.

Communications in the communication system <NUM> may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (<NUM>), the second generation (<NUM>), the third generation (<NUM>), the fourth generation (<NUM>) and the fifth generation (<NUM>) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) <NUM> 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), Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-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 system <NUM>, upon a connection is established, the network device <NUM> can communicate with the terminal device <NUM> and the terminal device <NUM> can also communicate data and control information to the network device <NUM>. A link from the network device <NUM> to the terminal device <NUM> is referred to as a downlink (DL), while a link from the terminal device <NUM> to the network device <NUM> is referred to as an uplink (UL). In DL, the network device <NUM> is a transmitting (TX) device (or a transmitter) and the terminal device <NUM> is a receiving (RX) device (or a receiver). In UL, the terminal device <NUM> is a TX device (or a transmitter) and the network device <NUM> is a RX device (or a receiver).

Typically, in order to communicate with the network device <NUM>, the terminal device <NUM> may initiate a random access (RA) procedure to establish or reestablish a connection with the network device <NUM>.

There are a plurality of possible RA procedures that can be employed, such as, a two-step RA, a four-step RA, and etc. The RA procedures may be based on contention among multiple terminal devices. A fourth-step contention-based RA procedure is a typical one, which is briefly introduced below with reference to <FIG>. In a RA procedure <NUM> of <FIG>, a terminal device selects and transmits <NUM> a random access preamble (which may be referred to as "Msg1") to a network device. The network device then transmits <NUM> a random access response (which may be referred to as "Msg2") to the random access preamble. Upon receipt of the random access response, the terminal device transmits <NUM> scheduled transmission (which may be referred to as "Msg3") to the network device. The network device transmits <NUM>, depending on contention across its serving terminal devices, a contention resolution (which may be referred to as "Msg4") to the terminal device.

Currently, there is agreed to employ a two-step procedure in order to achieve quick random access. An example of the two-step RA contention-based RA procedure is also briefly introduced below with reference to <FIG>. In a RA procedure <NUM> of <FIG>, a terminal device transmits <NUM> a first message (which may be referred to as "MsgA") to a network device. The first message combines a random access preamble (for example, Msg1) and uplink data (for example, Msg3). In response to the first message, the network device transmits <NUM> a second message (which may be referred to as "MsgB") to the terminal device. The second message combines a random access response (such as Msg2) and a contention resolution (such as Msg4).

Traditional time alignment procedures require a hand-shake between the terminal device and the network device are not applicable to some RA procedures such as the two-step RA procedure. For the cases when both preamble and data are comprised in a RA message such as MsgA in the two-step procedure, it has been proposed that the resource for the data part, such as the physical uplink shared channel (PUSCH) occasion may be defined as the time-frequency resource for payload transmission. It has also been proposed that the resource for the data part in that RA message is separately configured from the resource for the RA preamble part (such as the physical random access channel (PRACH) occasion). For one PUSCH occasion, it may be derived based on reusing the resource allocation for the configured grant (such as the NR configured grant) in principle, or alternatively based on other potential configurations such as reusing the semi-static subframe format indication (SFI) and bandwidth part (BWP), reusing occasion of the PRACH, and/or the like. The association between the channel for the data and preamble parts (such as PUSCH and PRACH) for transmission of the RA message has not been proposed.

As an alternative, the relative location of the resource for the data part may be specified or configured with respect to the associated location of the resource for the RA preamble part. For example, the time/frequency relation between RA preambles in PRACH occasion(s) and PUSCH occasions may be a single specification fixed value. As another example, time/frequency relation between each RA preamble in PRACH occasion(s) to the PUSCH occasion may be single specification fixed value. In some examples, different preambles in different PRACH occasions can have different values. As a third example, time/frequency relation between RA preambles in PRACH occasion(s) and PUSCH occasions may be a single semi-statically configured value. In a further example, time/frequency relation between each RA preamble in PRACH occasion(s) to the PUSCH occasion may be a semi-statically configured value; and different preambles in different PRACH occasions can have different values. It is noted that time and frequency relation is not required to be the same alternative. However, there has no proposal to determine the mapping between the RA preamble and the resources for resources for the data part as well as the demodulation reference signal (DMRS). Further, there is no solution regarding how to potentially applying a structure to the actual transmissions when considering larger cells than what is supported within a single cyclic prefix.

In the cases when both preamble and data are comprised in a RA message such as MsgA in the two-step procedure, depending on various applicable triggers of the RA procedure, the payload size of the RA message may be different. The presence and the size of each field of data in the RA message depends on the use case as well as on the available size of the uplink resources carrying the RA message, hence the total size of the RA message could vary depending of the use cases and available resources. For instance, the required minimum size for MsgA may differ for a terminal device in the Radio Resource Control (RRC)-CONNECTED state as compared to terminal device in the RRC IDLE/INACTIVE state.

Furthermore, for the same payload size, it is possible to support different transmission configurations (such as modulation and coding schemes (MCSs) and/or the like) that the terminal can autonomously select for the RA message based on the channel conditions between the terminal device and the network device. Due to the different encoding and/or transmission parameters of a RA message transmitted from the terminal device, such as the different payload sizes, different physical resource blocks (PRBs), and/or different MCSs, it may require the network device to try multiple decode hypothesis to determine the encoding and/or transmission parameters used by the terminal device to transmit the RA message and successfully decode the data included therein. This increases the processing (for example, decoding) complexity at the network device.

An alternative solution is to notify the network device of certain control information regarding the encoding and/or transmission of the data part that is used by the terminal device. There are some possible ways to indicate such information to the network device. For example, the terminal device can use the preamble index to indicate to the network device the configuration used. For example, if there are <NUM> possible configurations for encoding/transmission of the data part, the preamble space can be divided into <NUM> sets with the preamble of each set corresponding to one of the four configurations. However, dividing the preambles into groups reduces the pooling efficiency and increases the probability of collisions.

In addition, the reliability of the control information regarding the encoding and/or transmission of the data part impacts performance of the RA message significantly. Therefore, the transmission of the control information is desired to be of high reliability and robustness.

According to some example embodiments of the present disclosure, there is proposed a solution for information transmission in RA. The solution is related to the RA where a RA preamble and data information are transmitted together in a RA message. One example of such RA procedure is a two-step RA procedure. It would be appreciated that any other RA procedures may also be applicable. According to the solution, a plurality of RA preamble available for transmission are divided into a plurality of subsets, each being mapped to one of a plurality of different predefined sequences. Upon selecting one of the RA preambles, a terminal device selects one or more predefined sequences that are associated with the selected RA preamble based at least in part on a predetermined association between the subsets of RA preambles and a plurality of predefined sequences. A selected predefined sequence is used to modulate the control information. The terminal device transmits the selected RA preamble and the modulated control information as well as the data information in a RA message to the network device. In this way, it is possible to improve the reliability of control information.

Some example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. As briefly discussed above, the RA message to be transmitted to the network device includes a RA preamble, data information, and a predefined sequence indicating control information for the data information. Before discussing example embodiments of transmitting such RA message, some example structures of this RA message are first introduced with reference to <FIG>. As shown in <FIG>, a RA message <NUM> comprises a preamble part <NUM> and a data part <NUM>. The preamble part <NUM> may include a RA preamble selected by the terminal device. The data part <NUM> is split into two sections, including control resource elements carrying control information <NUM> and data resource elements carrying data information <NUM>. In some example embodiments of the present disclosure as discussed below, the control information <NUM> may be associated to a part of the data information <NUM>, such as a part <NUM> of the data information <NUM>. <FIG> shows another example where the control information <NUM> is illustrated to be associated with a different part <NUM> of the data information <NUM>.

The control information <NUM> is used to assist a receiver of the RA message <NUM> in detecting the data information <NUM>. The data information <NUM> may include any type of UL data. The type of data and the size of each type of data may depend on the use cases and the triggers for a RA procedure including this RA message <NUM>. For example, the data information <NUM> may include a unique identity (ID) in order to allow for contention resolution in a response message to the message <NUM>, such as MsgB in a two-step RA procedure. The ID may be different in different cases of the RA procedures. For example, for state transition and/or data transmission in the RRC IDLE/INACTIVE states, the ID may be the RRC message (or part of it) transmitted by the terminal device, which is regarded as "UE Contention Resolution Identity" in, for example, the medium access control (MAC) layer. The ID may be a <NUM>-bit length in a specific example. For data transmission in the RRC CONNECTED state, the ID may be the Cell-Radio Network Temporary Identifier (C-RNTI) MAC control element (CE), which may have a length of <NUM> bits plus MAC subheader.

In some examples, the data information <NUM> may include a RRC connection request or a RRC resume request, buffer status report (BSR), and/or a power headroom report (PHR). Alternatively, or in addition, the data information <NUM> may include data payload, such as the data transmission in the RRC CONNECTED state.

The presence and the size of each type of data information may depend on the use cases and/or on the available size of the resources for carrying the RA message. Therefore, the size of the data information <NUM> and hence the total size of the RA message <NUM> may vary depending of the use cases and available resources.

Reference is now made to <FIG>, which shows a process <NUM> for information transmission in RA according to an example embodiment of the present disclosure. For the purpose of discussion, the process <NUM> will be described with reference to <FIG>. The process <NUM> may involve the terminal device <NUM> and the network device <NUM> as illustrated in <FIG>.

In the process <NUM>, the terminal device <NUM> selects <NUM> one of a plurality of RA preambles and selects <NUM> at least one predefined sequence associated with the selected RA preamble. A predefined sequence is associated with control information to be transmitted in a RA message.

For better understanding, the control information is first introduced. The control information indicates a configuration of data information to be transmitted, which may be used to assist the network device <NUM> in detecting and decoding the data information. The data information and the control information are to be transmitted in a RA message together with a RA preamble to the network device <NUM>. In some examples, the control information and data information may be mapped to different resource elements (REs) when being transmitted.

In some example embodiments of the present disclosure, the control information may indicate at least one of a size of data information to be transmitted, the number of resource units used for transmitting the data information, or a MCS used for the data information. In some examples, the number of resource units used for transmitting the data information may also indicate the size of the data information and thus the size may be omitted from the control information. The control information may carry one, two, or more bits of information. In some example embodiments, the control information modulates a sequence. For example, the control information modulates a low peak-average power ratio (PAPR) sequence, which may be defined by a cyclic shift of a base sequence. The length of the sequence may be varied and may be extend beyond <NUM>, depending on the number of allocated PRBs. In some examples, the REs assigned to transmission of the control information may be split into two parts, one part carrying an un-modulated sequence as a phase reference, and the other part carrying a sequence modulated by the control information.

In some example embodiments, the control information may be of a predetermined size, for example, may be preconfigured as a fixed size, regardless of the size of the data information that is eventually transmitted. Thus, the resource elements for carrying the control information may also be of a predetermined size. The data information may be of a variable size, which may be changed depending on the use cases and the allocated resources. As mentioned above, in the RA message, the control information and the data information may be collectively referred to as a data part of the RA message as compared to the preamble part. Depending on the size of the data part, different sizes of resources may be needed for transmission of the data information.

In some example embodiments, the size of the data part in the RA message may be in units of "data information resource units," each data information resource unit conveying a certain amount of information (the data information and/or possible the control information). In an example, the size of the data part may include one "data information resource unit. " In this case, the "data information resource unit" is corresponding to a part of resource for transmission of the data part of the RA message (such as the data part <NUM>), and the control information may be contained in this part. In another example, the size of the data part may include two "data information resource units," including the one containing the control information and the data information and adjacent one containing data information only. In a further example, the size of the data part may include four "data information resource units," including the one containing the control information and the data information and three adjacent ones containing the data information. Other sizes of the data part are also possible in the RA message.

There may be a plurality of RA preambles available for transmission by the terminal device <NUM> to the network device <NUM> in one or more resource units for transmission of a RA preamble. The plurality of RA preambles may be divided into a plurality of subsets of RA preambles, each subset including one or more RA preambles. Each of the subset of RA preambles is mapped to at least one of a plurality of predefined sequences. In some examples, the plurality of RA preambles may be considered as a plurality of sets of RA preambles, each set associated with a resource unit for transmission of data and/or control information.

In some example embodiments, the terminal device <NUM> may be allowed to perform RA preamble selection from a plurality of RA preamble in each time/frequency resource for RA preamble transmission. The time/frequency resource unit for transmission of a RA preamble may be referred to as a PRACH occasion ("RO" for short). The plurality of RA preamble available in each RO may be the same or different. In some example embodiments, the plurality of RA preambles available in each RO may be divided into a plurality of sets of RA preambles, such as {A1, A2,. , AN}, where N represents the number of the sets of RA preambles. Each set Ai is associated with a resource unit for transmission of the data information and/or the control information (i.e., a "data information resource unit").

In some example embodiments, the set of RA preambles for each resource unit for the data information may be further divided into one or more subsets of RA preambles. For example, for a set Ai, the subsets of RA preambles may be represented as {Ai1, Ai2,. ,AiM}, where M represents the number of subsets of RA preambles divided from the set Ai. For one or more resource units for data information, all the available RA preambles may be divided and thus the plurality of subsets of RA preambles are generated.

According to example embodiments of the present disclosure, a subset of RA preambles is associated with a predefined sequence(s). In some example embodiments, the plurality of predefined sequences are different and are orthogonal or quasi-orthogonal to each other. For example, a plurality of predefined sequences may be generated as cyclic shifts of a base sequence.

As mentioned above, a portion of all the available RA preambles, such as a set Ai divided from the whole set of available RA preambles, is associated with a resource unit for transmission at least part of the data information. For different subsets of RA preambles divided from the available RA preambles for a resource unit, each is associated with a different predefined sequence. That is, for each resource unit for the data information, each subset of RA preambles may be associated with a unique predefined sequence. In some example embodiments, a subset may include one or more RA preambles. If there is one RA preamble in a subset, there is a one-to-one association between the RA preamble and a predefined sequence for this resource unit. Alternatively, if there is more than one RA preamble in a subset, there is a many-to-one association between RA preambles and the predefined sequences.

For purpose of illustration, <FIG> shows an example of association between the predefined sequence and subsets of RA preambles in a RA message <NUM>. In this example, it is supposed that there are two possible resource units (i.e., ROs) for transmission of the preamble part <NUM> of the RA message <NUM>, including RO0 <NUM> and RO1 <NUM>. In addition there are four possible resource units (sometimes referred to as PUSCH occasions (POs)) for transmission of the data part <NUM>, including PO0, PO1, PO2, and PO3. It is further supposed that there are eight RA preambles available in each RO. In each RO, the first half of RA preambles (the first four RA preambles) are associated with one resource unit (such as PO), and the second half of RA preambles (the last four RA preambles) are associated with another resource unit (such as PO).

For better illustration, the following Table <NUM> provides an example showing an association between predefined sequences and subsets of RA preambles as well as ROs for the RA preambles and resource units for the data information. This example is to show a one-to-one association between RA preambles and predefined sequence and thus the preamble index is listed. In this example, each RA preamble is associated with a unique predefined sequence in each resource unit for transmission of data information and each resource unit for transmission of a RA preamble. It would be appreciated that in other example, each subset of RA preambles may include more than one RA preamble, and each subset may be associated with more than one predefined sequence in each RO and PO.

According to such association, the terminal device <NUM> may first select a RA preamble and then determine a set of RA preambles from which this RA preamble is selected. The set of RA preambles are available for use in a RO. Based on the set of RA preambles, the terminal device <NUM> may determine in which target resource unit (for example, PO) the data information and control information are to be transmitted. Then determine a subset of RA preambles from which this RA preamble is selected, based on the predetermined association between subsets of RA preambles and predefined sequences that are specific to the PO, the terminal device <NUM> may select one or more associated predefined sequences.

As a specific example, if the terminal device <NUM> selects Preamble <NUM> in a RO0, the terminal device <NUM> may determine that in this RO0, the PO to be used for transmission of data and control information is PO1. According to the predetermined association, the terminal device <NUM> can select Predefined Sequence <NUM> for use.

It is to be understood that Table <NUM> is merely an example provided for purpose of illustration. In other example embodiments, different numbers of RA preambles, subsets of RA preambles, resource units for transmitting data information and/or RA preamble, as well as their association may be varied in different examples.

Referring back to <FIG>, the terminal device <NUM> modulates <NUM> the control information associated with one of the selected predefined sequence(s). Depending on the configuration of the data information, the terminal device <NUM> may determine the control information that indicates such configuration. In some example embodiments, the plurality of predefined sequences may be associated with different control information. The terminal device <NUM> may then modulate the control information with one of the predefined sequence(s) that is selected.

The following Table <NUM> shows an example of how the control information indicates the configuration of the data information (in this example, MCS and the size of the data information represented by the number of resource units).

In the example of Table <NUM>, different control information may indicate a different configuration combination of the number of resource units and the MCS to be used for the data information. It is to be understood that Table <NUM> is merely an example. In other examples, control information may be used to indicate more, less, or other different configurations that may be used by the terminal device <NUM>. Thus, the number of bits in the control information may be less than two bits or more than two bits. Further, in addition to the number of resource units and MCS, other parameters related to processing and/or transmission of the data information and assisting the network device <NUM> in detecting the data information may also be included and indicated using the control information. The scope of the present disclosure is not limited in this regard.

In some example embodiments, to transmit control information containing a large number of bits, such as more than two bits, the sequence selection may be used on top of modulating the sequence with the control information. As an alternative, to transmit control information with a larger number of bits, additional UL symbols, for example, a larger number of REs may be allocated to carry the control information. For example, as shown in <FIG>, three groups of symbols may be allocated to carry the control information <NUM>, where a first group <NUM> of Symbols <NUM> and a third group <NUM> of Symbols <NUM> contain sequences modulated by the control information, while a second group <NUM> of Symbols <NUM> contains one or more un-modulated symbols as a reference signal. As an alternative to convey control information with a larger number of bits, such as larger than two, the terminal device <NUM> may apply higher order modulation on the control information when transmitting. For example, a single modulated sequence can convey up to <NUM> bits with <NUM>-quadrature amplitude modulation (QAM). Of course, other number of bits for the control information and other types of modulation may also be applicable.

In some example embodiments, an indication of the association between the subsets of RA preambles and the predefined sequences may be configured at the terminal device <NUM>, for example, by the network device <NUM>, in a system information block (SIB). In some example embodiments, configuration information from the network device <NUM> may further include, for example, in the SIB, information to determine the location and number of resource units for transmission of the data information; the association between the sets of RA preambles in the resource units for transmission of RA preambles and the resource units for transmission of data information; and information about which part of resources (REs) is used for transmission of the control information and which part is used for transmission of the data information within a resource unit (such as a PUSCH occasion). The association between configurations of data information and values for different control information may also be configured by the network device <NUM>, for example, in the SIB.

In some other example, if there is one resource unit available for transmission of a RA preamble, the association between the sets of RA preambles in the resource units for transmission of RA preambles and the resource units for transmission of data information may not be required and thus in selecting the RA preamble, the target resource unit to be used for transmission of the RA preamble is not required. In some example embodiments, the location of control information is determined by the set of preambles within a resource unit for transmission of a RA preamble.

Referring back to <FIG>, in the process <NUM>, the terminal device <NUM> transmits <NUM> the selected RA preamble, the modulated control information, and the data information in a RA message to the network device <NUM>. The data information may be transmitted at least using the target resource unit. Depending on the size of the data information and the resource allocation, one or more additional resource units may be needed for its transmission. In addition, the modulated control information may also be transmitted using the target resource unit.

In some example embodiments, the terminal device <NUM> may transmit such RA message (such as MsgA) to initiate a two-step RA procedure. In some other example embodiments, other types of RA procedure which requires a combination of RA preamble and data information in a RA message may also be applicable. As mentioned below, although being considered as a RA message, the RA preamble is transmitted using different time and/or frequency resources from the control information and the data information.

<FIG> illustrates an example of the RA message <NUM> transmitted by the terminal device <NUM> to the network device <NUM> according to the association illustrated in <FIG>. Still using the example described with reference to Table <NUM>, the terminal device <NUM> selects Preamble <NUM> and then selects Predefined Sequence <NUM> associated with this RA preamble in RO0 and PO1. As shown in <FIG>, the RA message <NUM> includes Preamble <NUM> in the resource unit RO0 <NUM> in the preamble part <NUM>, the control information <NUM> related to Predefined Sequence <NUM> in the data part <NUM> using the resource unit PO1, and the data information <NUM> using four resource units PO0 to PO3.

In some example embodiments, if the number of resource units for transmitting the data information is larger than one, the terminal device <NUM> may map the data information to those resource units in a cyclic order started from the target resource unit. For example, the terminal device <NUM> may modulate and encode the data information to generate coded modulation symbols. The mapping order of the coded modulation symbols of the data information when it spans the plurality of resource units is such that it starts with the resource unit containing the control information (i.e., the target resource unit) and then cyclically mapped to other resource units.

In some example embodiments, in response to no enough resource units available before an end of resource allocation for the data information, the terminal device <NUM> may cyclically select one or more additional resources from a start of the resource allocation. As an example, it is supposed that there are eight resource units, represented by {A, B, C, D, E, F, G, H}, that are arranged in an ascending order of frequency. If the number of resource units used is <NUM>, and the target resource unit is G, then according to the cyclic order, the used resource units are G, H, A, B.

In some example embodiments, in response to no enough resource units available before an end of resource allocation for the data information, the terminal device <NUM> may map the data information using at least one additional resource unit before the target resource unit to satisfy the number of resource units. Still taking the set of available resource {A, B, C, D, E, F, G, H} as example, if the number of resource units used is <NUM>, and the target resource unit is G, by selecting additional resource unit(s), the used resource units are G, H, E, and F. The benefit of such cyclic is to have the resource units consecutive when it is beneficial to do so (e.g. for the DFT-s-OFDM waveform).

For example, as illustrated in <FIG>, the control information <NUM> is transmitted using the target resource unit PO1. The data information <NUM> may be mapped to all the used resource units PO0 to PO4 in a cyclic order from PO1, PO2, PO3, and PO0, as indicated by the arrow <NUM>. It is to be noted that an opposite cyclic order is also possible. The cyclic mapping order of the data information may further improve the decodability of data in the case where multiple terminal devices transmit autonomously in the same set of resources.

In some example embodiments, the network device <NUM> may determine allocation of resource units for transmission of the data information based on a location of the target resource unit and the number of resources units and allocate the resource units to the terminal device semi-statically.

At the side of the network device <NUM>, it may detect and decode the RA message on all the possible resource units. The operation of the network device <NUM> in detection and decoding the RA message may be regarded as an inverse process to that performed at the terminal device <NUM>. Specifically, the network device <NUM> detects <NUM> one of a plurality of RA preambles that is received from the terminal device <NUM>. The plurality of RA includes all the possible RA preambles that are potentially used by the terminal device <NUM>. The network device <NUM> may perform bind detection to decode the RA preamble selected and transmitted by the terminal device <NUM>.

The network device <NUM> determines <NUM> at least one predefined sequence associated with the detected random access preamble based on the predetermined association between a plurality of predefined sequences and the plurality of subsets of random access preambles and a target resource unit to be used for transmission of control information and data information from the terminal device. The network device <NUM> then detects <NUM> the control information on the target resource unit based on the at least one predefined sequence. In some examples, the network device <NUM> may perform demodulation using the determined predefined sequence(s). Upon detecting the control information, the network device <NUM> detects <NUM> the data information based on the control information. The detection of the data information may be performed on at least a target resource unit that is corresponding to the predefined sequence, which is associated with the control information.

In some example embodiments, the network device <NUM> may transmit <NUM> a response to the RA message. The response may include a random access response and a contention resolution. Such response may also be referred to as MsgB in the two-step RA procedure. It would be appreciated that the response may include other information in other types of RA procedures.

In some example embodiments, in detecting the data information, if the network device <NUM> determines that the control information indicates the number of resource units used for transmitting the data information and the number is larger than one, it may de-map the data information from the number of resource units in a cyclic order started from the target resource unit.

Some example embodiments of information transmission in RA have been described above. By transmitting the control information in the RA message to the example embodiments, it is possible to improve the reliability of the control information and reduce the probability of collision of control information in the case of multiple RA preamble point to the same resource unit.

<FIG> shows a flowchart of an example method <NUM> implemented at a terminal device according to some example embodiments of the present disclosure. For the purpose of discussion, the method <NUM> will be described from the perspective of the terminal device <NUM> with reference to <FIG>.

At block <NUM>, the terminal device <NUM> selects, at a terminal device, one of a plurality of random access preambles, the plurality of random access preambles being divided into a plurality of subsets of random access preambles. At block <NUM>, the terminal device <NUM> selects at least one predefined sequence associated with the selected random access preamble based on a predetermined association between a plurality of predefined sequences and the plurality of subsets of random access preambles and based on a target resource unit to be used for transmission of control information and data information. At block <NUM>, the terminal device <NUM> modulates the control information with one of the at least one predefined sequence, the control information indicating configuration of the data information. At block <NUM>, the terminal device <NUM> transmits the selected random access preamble, the modulated control information, and the data information in a random access message to the network device, the data information being transmitted using at least the target resource unit.

In some example embodiments, the plurality of predefined sequences are orthogonal or quasi-orthogonal to each other.

In some example embodiments, the transmitting comprises: in response to the number of resource units for transmitting the data information being larger than one, mapping the data information to the number of resource units in a cyclic order started from the target resource unit; and transmitting the data information using the number of resource units.

In some example embodiments, the method further comprises receiving, from the network device, allocation of resource units for transmission of the data information based on a location of the target resource unit and the number of resources units.

In some example embodiments, mapping the data information comprises: in response to no enough resource units available before an end of resource allocation for the data information, mapping the data information using at least one additional resource unit before the target resource unit to satisfy the number of resource units.

In some example embodiments, the control information indicates at least one of a size of the data information, the number of resource units used for transmitting the data information, or a modulation coding scheme used for the data information.

In some example embodiments, selecting the at least one predefined sequence comprises selecting a location of a further target resource unit to be used for transmission of the selected random access preamble; and selecting the at least one predefined sequence based on the predetermined association that is related to the location of the further target resource unit to be used for transmission of the selected random access preamble.

In some example embodiments, the control information and control resource elements carrying the control information are of predetermined sizes, and wherein the data information is of a variable size.

In some example embodiments, the plurality of random access preambles comprise a plurality of sets of random access preambles each associated with a resource unit available for transmission of the control information and the data information, each of plurality of sets of random access preambles being divided into some of the plurality of subsets of random access preambles, and wherein the method further comprises: determining the target resource unit based on the set of random access preamble from which the random access preamble is selected.

In some example embodiments, the method <NUM> further comprises receiving an indication of the predetermined association from the network device.

<FIG> shows a flowchart of an example method <NUM> implemented at a network device according to some example embodiments of the present disclosure. For the purpose of discussion, the method <NUM> will be described from the perspective of the network device <NUM> with reference to <FIG>.

At block <NUM>, the network device <NUM> detects, at a network device, one of a plurality of random access preambles that is received from a terminal device, the plurality of preambles being divided into a plurality of subsets of random access preambles. At block <NUM>, the network device <NUM> determines at least one predefined sequence associated with the detected random access preamble based on a predetermined association between a plurality of predefined sequences and the plurality of subsets of random access preambles and based on a target resource unit to be used for transmission of control information and data information from the terminal device. At block <NUM>, the network device <NUM> detects the control information on the target resource unit based on the at least one predefined sequence, the control information indicating a configuration of the data information. At block <NUM>, the network device <NUM> detects, based on the control information, the data information on at least a target resource unit.

In some example embodiments, detecting the data information comprises: in response to the control information indicating the number of resource units used for transmitting the data information and the number being larger than one, de-mapping the data information from the number of resource units in a cyclic order started from the target resource unit.

In some example embodiments, the control information and resource elements carrying the control information are of predetermined sizes, and the data information is of a variable size.

In some example embodiments, the plurality of random access preambles comprise a plurality of sets of random access preambles each associated with a resource unit available for transmission of the control information and the data information, each of plurality of sets of random access preambles being divided into some of the plurality of subsets of random access preambles.

In some example embodiments, the method <NUM> further comprises transmitting an indication of the predetermined association to the terminal device.

In some example embodiments, an apparatus capable of performing any of the method <NUM> (for example, the terminal device <NUM>) may comprise means for performing the respective steps of the method <NUM>. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises: means for selecting, at a terminal device, one of a plurality of random access preambles, the plurality of random access preambles being divided into a plurality of subsets of random access preambles; means for selecting at least one predefined sequence associated with the selected random access preamble based on a predetermined association between a plurality of predefined sequences and the plurality of subsets of random access preambles and based on a target resource unit to be used for transmission of control information and data information; means for modulating the control information with one of the at least one predefined sequence, the control information indicating configuration of the data information; and means for transmitting the selected random access preamble, the modulated control information, and the data information in a random access message to the network device, the data information being transmitted using at least the target resource unit.

In some example embodiments, the means for transmitting comprises: means for in response to the number of resource units for transmitting the data information being larger than one, mapping the data information to the number of resource units in a cyclic order started from the target resource unit; and transmitting the data information using the number of resource units.

In some example embodiments, the apparatus further comprises: means for receiving, from the network device, allocation of resource units for transmission of the data information based on a location of the target resource unit and the number of resources units.

In some example embodiments, means for mapping the data information comprises: means for in response to no enough resource units available before an end of resource allocation for the data information, mapping the data information using at least one additional resource unit before the target resource unit to satisfy the number of resource units.

In some example embodiments, means for selecting the at least one predefined sequence comprises: means for selecting a location of a further target resource unit to be used for transmission of the selected random access preamble; and means for selecting the at least one predefined sequence based on the predetermined association that is related to the location of the further target resource unit to be used for transmission of the selected random access preamble.

In some example embodiments, the control information and control resource elements carrying the control information are of predetermined sizes, and the data information is of a variable size.

In some example embodiments, the apparatus further comprises means for receiving an indication of the predetermined association from the network device.

In some example embodiments, the means in the apparatus comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

In some example embodiments, an apparatus capable of performing any of the method <NUM> (for example, the network device <NUM>) may comprise means for performing the respective steps of the method <NUM>. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises: means for detecting, at a network device, one of a plurality of random access preambles that is received from a terminal device, the plurality of preambles being divided into a plurality of subsets of random access preambles, and a subset of random access preambles being associated with one of a plurality of predefined sequences; means for determining at least one predefined sequence associated with the detected random access preamble based on a predetermined association between a plurality of predefined sequences and the plurality of subsets of random access preambles and based on a target resource unit to be used for transmission of control information and data information from the terminal device; means for detecting the control information on the target resource unit based on the at least one predefined sequence, the control information indicating a configuration of the data information; and means for detecting, based on the control information, the data information on a target resource unit corresponding to the predefined sequence associated with the control information.

In some example embodiments, the means for detecting the data information comprises: means for in response to the control information indicating the number of resource units used for transmitting the data information and the number being larger than one, de-mapping the data information from the number of resource units in a cyclic order started from the target resource unit.

In some example embodiments, the apparatus further comprises means for transmitting an indication of the predetermined association to the terminal device.

<FIG> is a simplified block diagram of a device <NUM> that is suitable for implementing embodiments of the present disclosure. The device <NUM> may be provided to implement a communication device, for example the terminal device <NUM> or the network device <NUM> as shown in <FIG>. As shown, the device <NUM> includes one or more processors <NUM>, one or more memories <NUM> coupled to the processor <NUM>, and one or more communication modules <NUM> coupled to the processor <NUM>.

The example embodiments of the present disclosure may be implemented by means of the program <NUM> so that the device <NUM> may perform any method/process of the present disclosure as discussed with reference to <FIG>. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the methods/ processes as described above with reference to <FIG>. 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.

Claim 1:
A device, comprising:
means for selecting, at a terminal device (<NUM>), one of a plurality of random access preambles (<NUM>), the plurality of random access preambles being divided into a plurality of subsets of random access preambles;
means for selecting at least one predefined sequence associated with the selected random access preamble based on a predetermined association between a plurality of predefined sequences and the plurality of subsets of random access preambles and based on a target resource unit (PO) to be used for transmission of control information (<NUM>) and data information (<NUM>);
means for modulating the control information with one of the at least one predefined sequence, the control information indicating configuration of the data information; and
means for transmitting the selected random access preamble, the modulated control information, and the data information in a random access message (<NUM>) to a network device (<NUM>), the data information being transmitted using at least the target resource unit.