Patent Description:
V2X means a communication between vehicles (V2V), a communication between vehicle and pedestrian (V2P), a communication between vehicle and infrastructure (V2I) or a communication between vehicle and network (V2N). Compared with D2D (Device to Device) scenario, V2X has two different properties: <NUM>) relatively higher speed, up to <NUM>/h or even larger; <NUM>) relatively higher UE (User Equipment) density within the group. Due to the above properties, especially the second property, resource allocation has become one of critical issues discussed in 3GPP (the 3rd Generation Partner Project) so far.

Patent Application <CIT> relates to wireless communication and, in particular, to device-to-device (D2D) communication via sidelink transmission. Second control information including SCI may be received in a subframe #n and sidelink data may be transmitted in a subframe #n+k. Alternatively, the second control information and the sidelink data may be transmitted in the same subframe.

Patent Application <CIT> relates to resource allocation in direct communication between wireless devices where the resources are either allocated by a base station, or by random selection by the wireless devices. It is mentioned the possibility that an SA message can be multiplexed and transmitted together with the corresponding data.

The contribution by <NPL> relates to resource structure in V2V transmission using frequency multiplexing of SA and data. In "contiguous SA and data allocation", the SA messages can be transmitted in any frequency resource, and data and SA messages are distributed over the whole frequency resource pool. In "non-contiguous SA and data allocation", the frequency resource pool is split into an SA pool and a data pool.

The contribution by <NPL> relates to multiplexing SA messages and data to enhance V2V communication. The frequency bandwidth is divided in N sub-channels, while the possible location of SA messages in each sub-channel is fixed. Resource elements that are foreseen for SA messages by this mechanism but not used by SA messages can be left to data.

The contribution by <NPL> relates to multiplexing SA messages and the respective data in a wireless communication. The SA messages are transmitted in the same subframe as the data they are pointing to.

The contribution by <NPL> discusses advantages of transmitting SA messages independent of the respective data and of multiplexing SA messages into data channels. A combination of both is proposed as this could make use of the advantages of both options.

The contribution by <NPL> discusses the use of one SA to indicate data for multiple SA periods.

One non-limiting and exemplary embodiment provides a resource allocation mechanism in a wireless communication network comprising multiple wireless devices capable of communicating with each other directly, such as in a V2X network.

The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered as a limitation to its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings, in which:.

In the following detailed description, reference is made to the accompanying drawings, which form a part thereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. It will be readily understood that the aspects of the present disclosure can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

In a V2X communication network, as described above, there may be many wireless devices having relatively faster speed, such as vehicles or the like, within a group, therefore, on one hand, many vehicles may collide in the same resource pool, and on the other hand, they cannot listen to others due to half duplex restriction.

In an embodiment of the present disclosure, a wireless device is provided, which is applied in a wireless communication network comprising multiple wireless devices capable of communicating with each other directly, such as in the V2X communication network or the D2D communication network. Considering the potentially crowded scheduling assignment (SA) resource pool, the wireless device according to the embodiment of the present disclosure adopts a mechanism similar to a semi-static or semi-persistent scheduling (SPS) mechanism in LTE (Long-Time Evolution), which is referred to as a SPS like mechanism throughout the specification. Hereinafter, the details of the SPS like mechanism will be described with reference to <FIG>.

<FIG> is a schematic diagram illustrating the resource allocation mechanism in the wireless device according to the present disclosure. As shown in <FIG>, there are multiple SA periods. In the first SA period, a SA message, which is indicated by a block in dots, is transmitted, and associated data, which is indicated by a block in slash, is transmitted accordingly. The SA message is used for indicating initiation of SPS like transmission. In middle SA periods such as the second SA period, there is no SA message transmitted. In the last SA period, a SA message is transmitted to indicate the termination of the SPS like transmission. Further, the SA message transmitted in the first SA period is used to indicate data transmission resource in each of the multiple SA periods.

<FIG> shows a first example of the resource allocation mechanism, in which a SA message is transmitted in the first SA period to indicate the start of the SPS like transmission, another SA message is transmitted in the last SA period to indicate the termination of the SPS like transmission, and no SA messages are transmitted in the middle SA periods. In a second example not shown, a SA message is transmitted in the first SA period to indicate information related to the SPS like transmission, such as the time period or the like, and no SA messages are transmitted in the SA periods other than the first SA period. The SA message transmitted in the first SA period is further used to indicate data transmission resource in each of the multiple SA periods.

In either of the above examples, since no SA messages are transmitted in some of the SA periods (the middle SA periods in the first example, and the SA periods other than the first SA period in the second example), generally, quite a lot of SA messages may be saved during the SPS like transmission, thereby the SA collision may be reduced and the half duplex issue may be relaxed in SA resource pool, which means UE or vehicle has more chances to receive messages from other UEs or vehicles.

However, since a topology of the network may change often and the wireless devices may often join or leave the network, especially in the V2X scenario, in the SPS like transmission as shown in <FIG>, the wireless device newly joining in the network during the SA periods in which no SA messages are transmitted, cannot decode the data due to a lack of SA messages.

To further solve the above problem, in the present disclosure, a wireless device is provided, which is applied in a wireless communication network comprising multiple wireless devices capable of communicating with each other directly, such as in the V2X communication network or the like.

<FIG> is a block diagram schematically illustrating the wireless device according to the present disclosure.

The wireless device <NUM> can comprise a processing circuitry <NUM> operative to multiplex data with a scheduling assignment message, into transmission information; and a transmitter <NUM> operative to transmit the transmission information in a scheduling assignment period, to another wireless device in the wireless communication network. The scheduling assignment message may be used for indicating data transmission resource in the scheduling assignment period. Alternatively, the scheduling assignment message may also be used for indicating data transmission resource in a previous scheduling assignment period. That means receiving wireless device needs to buffer the data and decode it after such device has successfully received scheduling assignment message in the next scheduling assignment period, which will be described in detail with reference to <FIG>.

The wireless device <NUM> according to the present disclosure may optionally include a CPU (Central Processing Unit) <NUM> for executing related programs to process various data and control operations of respective units in the wireless device <NUM>, a ROM (Read Only Memory) <NUM> for storing various programs required for performing various process and control by the CPU <NUM>, a RAM (Random Access Memory) <NUM> for storing intermediate data temporarily produced in the procedure of process and control by the CPU <NUM>, and/or a storage unit <NUM> for storing various programs, data and so on. The above processing circuitry <NUM>, transmitter <NUM>, CPU <NUM>, ROM <NUM>, RAM <NUM> and/or storage unit <NUM> etc. may be interconnected via data and/or command bus <NUM> and transfer signals between one another.

Respective components as described above do not limit the scope of the present disclosure. According to one implementation of the disclosure, the functions of the above processing circuitry <NUM> and transmitter <NUM> may be implemented by hardware, and the above CPU <NUM>, ROM <NUM>, RAM <NUM> and/or storage unit <NUM> may not be necessary. Alternatively, the functions of the above processing circuitry <NUM> and transmitter <NUM> may also be implemented by functional software in combination with the above CPU <NUM>, ROM <NUM>, RAM <NUM> and/or storage unit <NUM> etc..

Hereinafter, the scheduling assignment mechanism adopted by the wireless device <NUM> will be described with reference to <FIG> is a schematic diagram illustrating another resource allocation mechanism in a wireless device according to the present disclosure.

As shown in <FIG>, there are multiple SA periods, similar to those in <FIG>. The difference between the present embodiment and the embodiment shown in <FIG> lies in that, there is a dedicated SA region in <FIG> for transmitting the SA message; while there may not be a dedicated SA region in the present embodiment as shown in <FIG>, in which all subframes in a scheduling assignment period can potentially transmit data. Further, the difference between the present embodiment and the embodiment shown in <FIG> lies in that, in <FIG>, the SA message is multiplexed with the data into transmission information, which is indicated by blocks filled with dark squares. The transmission information is transmitted in a SA period, for example, the second SA period as shown in <FIG>, to another wireless device.

The multiplexing of the SA message and the data may be indicated by a wireless device through a broadcast channel, such as Physical Sidelink Broadcast Channel (PSBCH) or the like. The wireless device may be the present wireless device or other wireless devices in the communication network, as long as it may function as a synchronizing source.

In a possible implementation, the SA message is used for indicating data transmission resource in the present SA period, when the current data transmission resource (e.g., subframe) is allowed to transmit the transmission information.

In another possible implementation, when the current subframe is not allowed to transmit the transmission information, data may be transmitted first, for example, in a previous SA period such as the first SA period in <FIG>, and then the multiplexed SA message is transmitted, for example, in a following SA period such as the second SA period in <FIG>. In such a case, the SA message is used for indicating data transmission resource in the previous SA period. For the receiving wireless device, some subframes may be buffered, and the data may be decoded after the multiplexed SA message is detected. The start of the data may be indicated by the multiplexed SA message. In such implementation, the wireless device may transmit data quickly and the latency may be reduced.

<FIG> is a schematic diagram illustrating a further scheduling assignment mechanism according to the present disclosure. The scheduling assignment mechanism in <FIG> also adopts the SPS like mechanism, as described with reference to <FIG>. The difference between the present embodiment and the embodiment shown in <FIG> lies in that, there is no SA message transmitted in middle SA periods in <FIG>; while the SA message multiplexed with the data is transmitted in the middle SA periods in the present embodiment. It should be noted that although the transmission information is transmitted in the middle SA periods as shown in <FIG>, in another example not shown, it may be transmitted in both the middle SA periods and the last SA period. That is, the SA message is multiplexed with data into transmission information as shown, and the transmission information is transmitted in the data transmission resource of at least one SA period other than the first SA period. Each of the multiple SA periods comprises a data region. The data transmission resource in each data region is indicated by the SA message.

The SA message may be multiplexed with the data in various ways. For example, the processing circuitry may embed the resource elements of SA message into the data resource in a physical layer, to form the transmission information, in which relevant resource elements of data resource is punctured. For another example, the processing circuitry may map the SA message into a part of the data transmission resource, such as one slot of a subframe, and map the data into the other part of the data transmission resource, such as the other slot of the subframe, to form the transmission information, in which a coding rate of the data is matched within the other part, such as the other slot, transmitting the data.

Further, as shown in <FIG>, the first SA period comprises a SA region in which another SA message for indicating the data transmission resource is transmitted. Particularly, a field or a combination of several fields may be added into said another SA message to indicate parameters related to the SPS like transmission, for example, to indicate the start of the SPS like transmission, the time period of the SPS like transmission, the time/frequency resource of SPS or the like. Alternatively, a different RNTI (Radio Network Temporary Identity) may be used to indicate the SPS like transmission.

Regarding the format of the SA message multiplexed with the data in the data region, which may be referred to as the multiplexed SA message hereinafter, there may be several options. In a first option, the format of the multiplexed SA message may be the same as that of said another SA message transmitted in the first SA period, which may be referred to as the normal SA message hereinafter. For example, the Sidelink Control Information (SCI) format <NUM> may be reused.

In a second option, the format of the multiplexed SA message may be more simplified as compared to that of the normal SA message. For example, a resource allocation field in the normal SA message may be removed or reduced in size, since the position of the multiplexed SA message may reflect the position of the data.

For another example, a timing advance field in the normal SA message may be removed, since the data and the multiplexed SA message are operated in the same data resource, that is, they use the same timing advance. Particularly, the transmitter may be operative to transmit the transmission information using a downlink timing which is based on reception timing from another wireless device and has no timing advance, in both an eNode B scheduling transmission, like the mode <NUM> transmission in the D2D network, and a UE autonomous scheduling transmission, like the mode <NUM> transmission in the D2D network. Alternatively, in case of the eNode B scheduling transmission and V2X is operated in cellular carrier, a timing advance may be applied to the first SA period.

For a further example, a time resource pattern (T-RPT) field in the normal SA message may be removed or reduced in size, since the multiplexed SA message may reflect certain T-RPT index, as described later with reference to <FIG>.

The SPS like transmission may be enabled or disabled by a wireless device, and may be indicated through a broadcast channel, such as PSBCH or the like. The wireless device may be the present wireless device or other wireless devices in the communication network, as long as it may function as a synchronizing source.

Additionally, by an indication of the multiplexed SA message, transmission properties, such as MCS (modulation and coding scheme) or the like, may be adapted.

Further, in the SPS like transmission, the data transmission resource may be selected by the wireless device once in the first SA period, when the transmission from the wireless device to the other wireless device is scheduled by the wireless device autonomously. That is, in a case of the UE autonomous scheduling transmission, the wireless device may transmit the normal SA message in the first SA period and the multiplexed SA message in the following SA periods, and the wireless device just selects resource (SA or data) once in the first SA period. The resource will be repeated in the following SA periods.

Alternatively, the data transmission resource may be selected by a base station when the transmission from the wireless device to the other wireless device is scheduled by the base station. That is, in a case of the eNode B based scheduling transmission, similarly, the wireless device may transmit the normal SA message in the first SA period and the multiplexed SA message in the following SA periods. However, different from that in the above case, the resource selection will follow the eNode B's guidance. Further, in an embodiment, the time position to transmit the multiplexed SA message in a SA period may be limited. <FIG> is a diagram schematically showing a position of a multiplexed SA message in time domain according to the present disclosure. As shown in <FIG>, the time position of the multiplexed SA message may be limited to first few "<NUM>" subframes the second T-RPT bitmap indicates. Particularly, in <FIG>, the value of the bitmap is, for example, "<NUM>" which means subframes #<NUM>, #<NUM>, #<NUM> and #<NUM> in slash are available for transmission. Such bitmap is repeated to the end of the SA period and a truncated bitmap is used for the last few subframes, as shown in <FIG>. The usage of the bitmap is common for all UEs so that the receiving wireless device and the transmitting wireless device know when to apply the first bitmap, the second bitmap, and so on. Those skilled in the art shall understand that the value of the bitmap shown in <FIG> is only an example, and other values of the bitmap are also possible.

As shown in <FIG>, the starting subframe to apply the T-RPT pattern is aligned between the multiplexed SA message and the data. As the timing to apply T-RPT pattern is cell-specific or group-specific, the transmitting wireless device and the receiving wireless device have the same understanding on the time to transmit the multiplexed SA message. The transmitter may be operative to transmit the transmission information in part of subframes applying time resource pattern (T-PRT) in a SA period. The part of subframes may be specified, predefined or configured depending on resource allocation mode (eNode B scheduled or UE autonomous selection). The receiver does not know the value of the bitmap in advance, so it will presume one value of bitmap (time resource pattern), for example "<NUM>", and attempt to detect the multiplexed SA message. In order to reduce the decoding complexity, it is possible to restrict part of the T-RPT patterns to transmit the multiplexed SA message.

Additionally, in frequency domain, the multiplexed SA message may be transmitted in various ways. As an example, the multiplexed SA message may be transmitted in one PRB in a subframe. As another example, the multiplexed SA message may be transmitted repeatedly in all allocated PRBs in a subframe. As a further example, the same multiplexed SA message may be transmitted across several PRBs in a subframe.

Further, the frequency position to transmit the multiplexed SA message in a SA period may be also limited. <FIG> is a diagram schematically showing a position of a multiplexed SA message in frequency domain according to the present disclosure. As an example, the frequency position of the multiplexed SA message may be linked with the T-RPT pattern. For example, if the T-RPT pattern is "<NUM>", the first PRB (Physical Resource Block) is used for transmitting the multiplexed SA message. If the T-RPT pattern is "<NUM>", the third PRB is used for transmitting the multiplexed SA message. That is, different T-RPT pattern is linked with different frequency position of the multiplexed SA message. Therefore, the transmitter may be operative to transmit the transmission information in a PRB of the data transmission resource, an index of the PRB being associated with a T-RPT index of the data transmission resource.

For the receiving wireless device, it may presume certain T-RPT pattern and attempt to detect the multiplexed SA message. If the multiplexed SA message is detected, the T-RPT pattern is also known accordingly. In <FIG>, a candidate <NUM> is linked with the T-RPT pattern <NUM> and a candidate <NUM> is linked with the T-RPT pattern <NUM>. For the transmitting wireless device, the frequency resource allocation should include corresponding linked PRB to transmit the multiplexed SA message. Therefore, in such example, the complexity of the receiving wireless device may be reduced, but there may be some restriction on resource allocation in frequency domain.

As another example, the frequency position of the multiplexed SA message may be fixed regardless of the T-RPT pattern. That is, the transmitter may be operative to transmit the transmission information in a fixed PRB of the data transmission resource.

For example, PRBs <NUM> and <NUM> may always be the possible candidates to transmit the multiplexed SA message. In such a case, the data resource should include one of the candidate PRBs.

It is to be noted that although the multiplexed SA message is described in a SPS like resource allocation scenario in the present embodiment, the present disclosure is not limited thereto, and may be applied to a dynamic resource allocation or even in a scenario without a SA resource pool as shown in <FIG>.

Further, it is to be noted that, in any of the above figures, the SA channel used for transmitting one SA message or the data channel used for transmitting one transport block is repeated. Between or among the repeated SA channels or the repeated data channels, a certain hopping rule may be applied. For example, in <FIG>, the SA channel is repeated twice, the data channel is repeated four times, and the multiplexed SA message is transmitted in four repeated data channels. However, it is just an example, and the present disclosure is not limited thereto. Those skilled in the art shall understand that the SA channel and the data channel may be repeated other times than those shown in the figures, and the multiplexed SA message may be transmitted in any one or more of the repeated data channels.

The resource allocation mechanisms, which have been described above with reference to <FIG>, may be applied to both the eNode B scheduled transmission, like the mode <NUM> transmission in the D2D network, and the UE autonomous transmission, like the mode <NUM> transmission in the D2D network. By multiplexing the SA message with the data and transmitting the SA message multiplexed with the data together in the data channel, the SA resource pool may be relaxed, and the newly joined UE will not miss any data transmitted in any SA period other than the first SA period.

<FIG> is a block diagram schematically illustrating a wireless device according to an embodiment of the present disclosure.

The wireless device <NUM> can comprise a receiver <NUM> operative to receive transmission information in a scheduling assignment period, from another wireless device in the communication network; and a processing circuitry <NUM> operative to de-multiplex a scheduling assignment message from the transmission information, and to decode data from the transmission information based on the scheduling assignment message. The scheduling assignment message may be used for indicating data transmission resource in the scheduling assignment period. Alternatively, the scheduling assignment message may also be used for indicating data transmission resource in a previous scheduling assignment period.

The wireless device <NUM> according to the present disclosure may optionally include a CPU (Central Processing Unit) <NUM> for executing related programs to process various data and control operations of respective units in the wireless device <NUM>, a ROM (Read Only Memory) <NUM> for storing various programs required for performing various process and control by the CPU <NUM>, a RAM (Random Access Memory) <NUM> for storing intermediate data temporarily produced in the procedure of process and control by the CPU <NUM>, and/or a storage unit <NUM> for storing various programs, data and so on. The above receiver <NUM>, processing circuitry <NUM>, CPU <NUM>, ROM <NUM>, RAM <NUM> and/or storage unit <NUM> etc. may be interconnected via data and/or command bus <NUM> and transfer signals between one another.

Respective components as described above do not limit the scope of the present disclosure. According to one implementation of the disclosure, the functions of the above receiver <NUM> and processing circuitry <NUM> may be implemented by hardware, and the above CPU <NUM>, ROM <NUM>, RAM <NUM> and/or storage unit <NUM> may not be necessary. Alternatively, the functions of the above receiver <NUM>, processing circuitry <NUM> may also be implemented by functional software in combination with the above CPU <NUM>, ROM <NUM>, RAM <NUM> and/or storage unit <NUM> etc..

In an embodiment, the data transmission resource is in a data region of a scheduling assignment period including a SA region and the data region. The processing circuitry may be operative to try to blindly decode the scheduling assignment message from the SA region first. Then the processing circuitry may be operative to blindly decode the SA message from the data region. After decoding the SA message, the data is decoded accordingly.

In another embodiment, the data transmission resource is in at least one SA period other than the first SA period. Each SA period comprises a data region, the data transmission resource in each data region is indicated by the SA message. That is, the SPS like resource allocation as described above is applied.

In a further embodiment, the processing circuitry may be operative to decode the SA message from the SA region, when it is indicated that the SA message and the data are not multiplexed through a broadcast channel, such as the PSBCH or the like, or when it is indicated that the SPS like resource allocation is not enabled through the broadcast channel.

In a further embodiment, when the SPS like resource allocation is enabled, another SA message (the normal SA message as described above) is transmitted in the first SA period. For the wireless device which has already detected the normal SA message indicating the SPS like resource allocation in the first SA period, it may not require to detect or monitor the multiplexed SA message in the following SA periods, since it already knows the SPS like transmission from beginning based on the normal SA message in the SA resource pool. For the wireless device newly joining in the following SA periods, it will firstly detect the normal SA message in the SA resource pool, and then detect the multiplexed SA message in the data resource pool as described above.

Therefore, with the wireless device according to the present embodiment, the new joined wireless device can still decode data of the SPS like transmission correctly.

<FIG> is a flowchart illustrating a wireless communication method <NUM> according to the present disclosure.

As shown in <FIG>, first, at a block <NUM>, data is multiplexed with a scheduling assignment message, into transmission information. Then, at a block <NUM>, the transmission information is transmitted in a scheduling assignment period, to another wireless device in the communication network.

The scheduling assignment message may be used for indicating data transmission resource in the scheduling assignment period or in a previous scheduling assignment period.

The details of the wireless communication method have been described above with reference to the wireless device, and will not be repeated here.

<FIG> is a flowchart illustrating another wireless communication method <NUM> according to the present disclosure.

As shown in <FIG>, first, at a block <NUM>, transmission information is received in a scheduling assignment period, from another wireless device in the communication network.

Then, at a block <NUM>, a scheduling assignment message is de-multiplexed from the transmission information, and data is decoded from the transmission information based on the scheduling assignment message, at a block <NUM>.

With the wireless communication method as shown in <FIG> or <FIG>, the newly joined UE will not miss any data transmitted in any SA period other than the first SA period.

Claim 1:
A communication apparatus (<NUM>)
characterized by comprising:
a circuitry (<NUM>) which, in operation, determines a format for transmitting Sidelink Control Information, SCI, used for scheduling sidelink data, wherein the format is determined as a function of whether a subframe including the SCI includes the sidelink data; and
a transmitter (<NUM>) which, in operation, transmits the SCI and the sidelink data, and
wherein
the circuitry, in operation, determines a first format for transmitting the SCI when the sidelink data is transmitted in the subframe in which the SCI is transmitted, the first format not including a timing advance field, and
the circuitry, in operation, determines a second format for transmitting the SCI when the sidelink data is transmitted in a subframe that is different from the subframe in which the SCI is transmitted, the second format including the timing advance field.