Patent Description:
V2X (Vehicle to X), i.e., information exchange between vehicles and the outside world, is an essential technology of future intelligent transportation systems. The application of V2X technology enables communication between vehicles, between vehicles and pedestrians, and between vehicles and base stations, so that a series of traffic information such as real-time road conditions, road information and pedestrian information can be acquired, which can effectively improve driving safety, reduce congestion and improve traffic efficiency.

In Long Term Evolution (LTE), a User Equipment (UE) applying the V2X technology merely supports periodic services with a same data packet size. Compared with V2X of LTE, V2X of New Radio of the Fifth Generation Mobile Communication (<NUM>) further supports periodic services with different packet sizes and aperiodic services.

To better meet service requirements of NR V2X, a resource awareness method combining short-term awareness and long-term awareness is currently adopted to select time-frequency resources for transmitting control information and data on a sidelink. The sidelink refers to a radio communication protocol between UEs without participation of a base station. The resource awareness is a method of determining whether time-frequency resources are occupied by decoding control information and/or performing signal energy measurement.

However, after the above method is used to determine the time-frequency resource for transmitting control information and data on the sidelink, exiting techniques haven't provided a solution for how to determine a transmission position of sidelink control information and data on the time-frequency resources.

<CIT> discloses a signal transmission method. Specifically, an independent resource pool is assigned to the PUE in advance. For example, when the PUE falls within a coverage area of a network side device, the network side device may configure an independent resource pool or preconfigure a resource pool by using a SIB; and when the PUE falls beyond the coverage area of the network side device, the network side device may preconfigure an independent resource pool. A mapping relationship between an independent resource block or SCI resource and a data resource is designated in advance for terminals of different terminal types, to distinguish different terminal types.

<NPL> discloses discussion of physical layer structure and procedure for NR-V2X. The following proposals are given. Proposal <NUM>: Different numerology can be applied to NR-V2X sidelink. Extended CP is needed for larger SCS. Proposal <NUM>: Both CP-OFDM and DFT-s-OFDM can be supported in NR-V2X sidelink. Proposal <NUM>: Flexible DMRS pattern should be supported in NR-V2X. Proposal4: TDM structure of PSCCH and its associated PSSCH should be supported in NR-V2X. Proposal <NUM>: Both adjacent and non-adjacent of PSCCH and its associated PSSCH should be supported in NR-V2X. Proposal <NUM>: The position and size of PSCCH in both time and frequency domain should be fixed to minimize blind decoding effort in NR-V2X. Proposal <NUM>: Option 1B of TDM structure is preferred for NR-V2X. Proposal <NUM>: Comb-like resource mapping on the first and last OFDM symbol can be supported in NR-V2X. Proposal <NUM>: Resource pool enhancement needs to be studied in NR-V2X SL. Whether to introduce BWP in NR-V2X SL needs FFS.

Embodiments of the present disclosure provide solutions for how to determine a time domain position of sidelink control information on time-frequency resources.

In an embodiment of the present disclosure, a sidelink transmission method is provided, including: acquiring a time-frequency resource for transmission on a sidelink; and taking a preset position on the time-frequency resource as a time domain transmission position of sidelink control information, and transmitting the sidelink control information on the sidelink. The preset position comprises a first preset position or a second preset position, and taking a preset position on the time-frequency resource as a time domain transmission position of sidelink control information comprises:.

Optionally, a time domain length of the time-frequency resource is a resource selection time domain unit, and a frequency domain length of the time-frequency resource is at least one sub-channel, wherein the resource selection time domain unit includes one time slot, a plurality of time slots or a plurality of symbols, and the sub-channel includes at least one frequency domain resource block.

Optionally, the first preset position is first L symbols in the resource selection time domain unit, wherein L is a time domain length of the sidelink control information, and is a positive integer less than or equal to a total number of symbols in the resource selection time domain unit.

Optionally, the first preset position is the second to (L+<NUM>)th symbols in the resource selection time domain unit, wherein L is a time domain length of the sidelink control information and is a positive integer, and (L+<NUM>) is less than or equal to a total number of symbols in the resource selection time domain unit.

Optionally, the second preset position is the (W+<NUM>)th to (W+L)th symbols in the resource selection time domain unit, wherein the Wth symbol is an end symbol of a time window in the resource selection time domain unit, L is a time domain length of the sidelink control information, W and L are both positive integers, (W+L) is less than or equal to a total number of symbols in the resource selection time domain unit, the time window is a maximum length of time allowed for resource awareness in the resource selection time domain unit, and a start symbol of the time window is a start symbol of the resource selection time domain unit.

Optionally, the second preset position is the (W+<NUM>)th to (W+L+<NUM>)th symbols in the resource selection time domain unit, wherein (W+L+<NUM>) is less than or equal to a total number of symbols in the resource selection time domain unit, L is a time domain length of the sidelink control information, and W and L are both positive integers.

Optionally, the sidelink transmission method further includes: transmitting sidelink data corresponding to the sidelink control information at a start time of the preset position.

Optionally, the sidelink transmission method further includes: transmitting sidelink data corresponding to the sidelink control information at an end time of the preset position.

In an embodiment of the present disclosure, a terminal is provided, including: an acquiring circuitry configured to acquire a time-frequency resource for transmission on a sidelink; and a first transmitting circuitry configured to: take a preset position on the time-frequency resource as a time domain transmission position of sidelink control information, and transmit the sidelink control information on the sidelink. The preset position comprises a first preset position or a second preset position, and the first transmitting circuitry is configured to determine that the preset position is the first preset position or the second preset position based on a time when the time-frequency resource is successfully acquired, wherein a start position of the first preset position is earlier than a start position of the second preset position in a time domain,
wherein the first transmitting circuitry is configured to: if the time when the time-frequency resource is successfully acquired is later than a start time of the first preset position, determine that the preset position is the second preset position; or if the time when the time-frequency resource is successfully acquired is earlier than or is the start time of the first preset position, determine that the preset position is the first preset position,
wherein the terminal further comprises a second transmitting circuitry configured to: when the preset position is the second preset position, transmit sidelink data corresponding to the sidelink control information at a start time of a first symbol or a second symbol after the time-frequency resource is successfully acquired within a time window where the time-frequency resource is acquired.

Optionally, the terminal further includes a third transmitting circuitry configured to transmit sidelink data corresponding to the sidelink control information at a start time of the preset position.

Optionally, the terminal further includes a fourth transmitting circuitry configured to transmit sidelink data corresponding to the sidelink control information at an end time of the preset position.

In an embodiment of the present disclosure, a computer readable storage medium having computer instructions stored therein is provided, wherein when the computer instructions are executed, any one of the above methods is performed.

In embodiments of the present disclosure, the preset position on the time-frequency resource for transmission on the sidelink serves as the time domain position for transmitting the sidelink control information, so that a receiving terminal can determine a specific transmission position of the sidelink control information on the time-frequency resource. Further, a transmitting terminal transmits the sidelink control information at a fixed position on the time-frequency resource, so that the receiving terminal does not need to blindly detect the sidelink control information at every possible moment of successful short-term awareness. Therefore, complexity of blind detection of the receiving terminal may be reduced, reception efficiency may be improved, and power consumption of the receiving terminal may be reduced.

In V2X of LTE, a semi-static resource selection method of long-term awareness is mainly adopted to acquire transmission resources. In NR V2X, due to increase of service types, the existing long-term awareness method cannot meet service requirements well. Therefore, it has been proposed to adopt a semi-static resource selection method combining short-term awareness and long-term awareness to determine time-frequency resources for transmitting control information and data on the sidelink.

However, after the time-frequency resources are determined using a combination of short-term awareness and long-term awareness, exiting techniques haven't provided a solution for how to set a time domain transmission position of the sidelink control information and data on the determined time-frequency resources.

In embodiments of the present disclosure, a sidelink transmission method is provided.

The preset position on the time-frequency resource for transmission on the sidelink serves as the time domain position for transmitting the sidelink control information, so that a receiving terminal can determine a specific transmission position of the sidelink control information on the time-frequency resource. Further, the receiving terminal does not need to blindly detect the sidelink control information at every possible moment of successful short-term awareness. Therefore, complexity of blind detection of the receiving terminal may be reduced, reception efficiency may be improved, and power consumption of the receiving terminal may be reduced.

<FIG> is a flow chart of a sidelink transmission method according to an embodiment. Referring to <FIG>, the method may include <NUM> and <NUM>.

In <NUM>, a time-frequency resource for transmission on a sidelink is acquired.

In some embodiments, the time-frequency resource for transmission on the sidelink may be acquired through various ways which are not limited.

In some embodiments, to better meet service requirements of NR V2X, a combination of short-term awareness and long-term awareness is adopted to acquire the time-frequency resource for transmission on the sidelink. Detailed description is given below with reference to <FIG>.

A terminal in the Internet of Vehicles initiates resource selection or reselection at time n. First, a resource selection window C1 with a time range from time (n+T1) to time (n+T2) is determined. The terminal can remove an unavailable time-frequency resource Z1 in the resource selection window C1 based on an awareness result in the time window C2, and select <NUM>% of available time-frequency resource as candidate time-frequency resources Z2, where <NUM><T1<=<NUM>, <NUM><=T2<=<NUM>, a time range of the long-term awareness time window C2 is from time (n-T4) to time (n-T3), and T4>T3><NUM>. In the embodiments of the present disclosure, for ease of description, the time window C2 is referred to as a long-term awareness time window.

Afterward, another time-frequency resource is randomly selected from the candidate time-frequency resources Z2, and short-term awareness is performed on the selected time-frequency resource. After the short-term awareness is successful, the selected time-frequency resource may be used to transmit sidelink control information and data. The terminal may generate a short-term awareness time window based on other factors such as service priority, but its length cannot exceed a maximum value of length of the short-term awareness time window.

The short-term awareness includes following steps. A value is randomly selected within the time window, and within a duration indicated by the value, the terminal performs energy measurement in a frequency domain range of the time-frequency resource randomly selected in the candidate resources Z2. During the duration, if the energy measurement values are all lower than a threshold, the selected time-frequency resource is considered to be idle and not occupied by other terminals, and the terminal may select the time-frequency resource to transmit sidelink control information and data. In the embodiments of the present disclosure, for ease of description, the time window in the short-term awareness is referred to as a short-term awareness time window.

In some embodiments, for periodic services, the terminal may reserve a currently acquired time-frequency resource and indicate it in the sidelink control information. When a next cycle arrives, the terminal may directly transmit the sidelink control information at a start time of the time-frequency resource reserved, without performing long-term awareness and short-term awareness again.

Therefore, when a value of zero is randomly selected in the short-term awareness time window, or when the acquired time-frequency resource is the reserved time-frequency resource, the terminal does not need to perform short-term awareness and can directly apply the sidelink transmission method provided in the embodiments of the present disclosure to determine the time domain transmission position of the sidelink control information and data. When a value of non-zero is randomly selected in the short-term awareness time window, and the acquired time-frequency resource is not the reserved time-frequency resource, the terminal may perform short-term awareness based on the randomly selected value, and further apply the sidelink transmission method provided in the embodiments of the present disclosure to determine the time domain transmission position of the sidelink control information and data.

It could be understood that no matter what method is used to obtain the time-frequency resource, the present disclosure is not limited thereto, and all fall within the scope of the present disclosure.

In <NUM>, a preset position on the time-frequency resource is taken as a time domain transmission position of sidelink control information, and the sidelink control information is transmitted on the sidelink.

In some embodiments, one or more fixed positions on the time-frequency resource may be taken as the time domain transmission position of the sidelink control information in advance. The preset position may be set in a variety of ways.

In some embodiments, a time domain length of the time-frequency resource may be a resource selection time domain unit, a frequency domain length of the time-frequency resource may be at least one sub-channel, and a sub-channel may consist of several frequency domain resource blocks. The resource selection time domain unit includes one time slot, a plurality of time slots or a plurality of symbols, which is specifically configured or predefined by a higher layer. In this case, a start position of the short-term awareness time window is a start position of the resource selection time domain unit.

The predetermined position includes a first predetermined position or a second predetermined position. A start position of the first preset position is before a start position of the second preset position in a time domain. In other words, a start time of the first preset position is earlier than a start time of the second preset position.

It is determined whether the preset position is the first preset location or the second preset location based on a time when the time-frequency resource is successfully acquired. Specifically, if the time when the time-frequency resource is successfully acquired is later than the start time of the first preset position, it is determined that the preset position is the second preset position. If the time when the time-frequency resource is successfully acquired is earlier than or equal to the start time of the first preset position, it is determined that the preset position is the first preset position.

In some embodiments, the first preset position and the second preset position may be set in a variety of ways which are not limited here. The terminal may adjust the time domain transmission position of the sidelink data based on the time domain transmission position of the sidelink control information. Generally, there is a corresponding relationship between the sidelink control information and sidelink data. The sidelink control information includes necessary information to successfully decode the sidelink data. The terminal may transmit the sidelink data first, or transmit the sidelink control information first.

The time domain transmission positions of the sidelink control information and the sidelink data are described in detail below in conjunction with <FIG>.

First, assume that a total number of symbols in the resource selection time domain unit is N, and a corresponding time range is from time t<NUM> to time tN-<NUM>. A time domain length of the sidelink control information is L symbols, where L and N are both positive integers. Following ways may be used to set the time domain transmission position of the sidelink control information and the sidelink data.

In some embodiments, referring to <FIG>, the first preset position may be first L symbols in the resource selection time domain unit, and a corresponding time range is from time t<NUM> to tL-<NUM>, where L<=N.

When the first preset position is taken as the time domain transmission position of the sidelink control information, the corresponding sidelink data may be transmitted at the start time t<NUM> of the first preset position as shown in <FIG>, or the corresponding sidelink data may be transmitted at the end time tL-<NUM> of the first preset position as shown in <FIG>. The sidelink data is transmitted through a Physical Sidelink Shared Channel (PSSCH). In the embodiments of the present disclosure, for ease of description, the sidelink data is recorded as PSSCH.

In some embodiments, referring to <FIG>, when a first symbol f1 of the resource selection time domain unit is a protection symbol and other information cannot be transmitted, the first preset position may be the second to (L+<NUM>)th symbols in the resource selection time domain unit, and a corresponding time range is from the symbol t<NUM> to tL, where L+<NUM><=N.

When the first preset position is taken as the time domain transmission position of the sidelink control information, the corresponding sidelink data may be transmitted at the start time t<NUM> of the first preset position as shown in <FIG>, or the corresponding sidelink data may be transmitted at the end time tL of the first preset position as shown in <FIG>.

In some embodiments, referring to <FIG>, the second preset position may be the (W+<NUM>)th to (W+L)th symbols in the resource selection time domain unit, and a corresponding time range is from tW-<NUM> to tW+L-<NUM>, the Wth symbol is an end symbol of a time window MAX in the resource selection time domain unit, W is a positive integer, and W+L<=N. The time window MAX is a maximum length of time allowed for resource awareness in the resource selection time domain unit, and a start symbol of the time window MAX is a start symbol of the resource selection time domain unit.

When the second preset position is taken as the time domain transmission position of the sidelink control information, the corresponding sidelink data may be transmitted at the start time tW-<NUM> of the second preset position as shown in <FIG>, or the corresponding sidelink data may be transmitted at the end time tW+L-<NUM> of the second preset position as shown in <FIG>.

In some embodiments, referring to <FIG> and <FIG>, when the (W+<NUM>)th symbol fw is a protection symbol and other information cannot be transmitted, the second preset position may be the (W+<NUM>)th to (W+L+<NUM>)th symbols in the resource selection time domain unit, and a correspond time range is from tW+<NUM> to tW+L, where W+L+<NUM><=N.

When the second preset position is taken as the time domain transmission position of the sidelink control information, the corresponding sidelink data may be transmitted at the start time tW+<NUM> of the second preset position as shown in <FIG>, or the corresponding sidelink data may be transmitted at the end time tW+L of the second preset position as shown in <FIG>.

Regardless of whether the preset position is the first preset position or the second preset position, and whether the sidelink data corresponding to the sidelink control information is transmitted at the start time or the end time of the preset position, the receiving terminal determines a reception position of the sidelink data based on the start position of the sidelink control information, without using extra bits in the sidelink control information to indicate, thereby effectively saving bits occupied by the sidelink control information to save time-frequency resources.

To improve resource utilization, when the preset position is the second preset position, the method further includes: transmit sidelink data corresponding to the sidelink control information at a start time of a first symbol or a second symbol after the time-frequency resource is successfully acquired within a time window where the time-frequency resource is acquired. For example, referring to <FIG>, the start time of the first symbol or the second symbol after the time-frequency resource is successfully acquired within the time window may be time n.

From above, with the embodiments of the present disclosure, the preset position on the time-frequency resource for transmission on the sidelink serves as the time domain position for transmitting the sidelink control information, so that the receiving terminal can determine a specific transmission position of the sidelink control information on the time-frequency resource, thereby reducing complexity of blind detection of the receiving terminal, improving reception efficiency, and reducing power consumption of the receiving terminal.

In order to enable those skilled in the art to better understand and implement the present disclosure, a device and a computer readable storage medium corresponding to the above method are described in detail below.

<FIG> is a structural diagram of a terminal <NUM> according to an embodiment. Referring to <FIG>, the terminal <NUM> may include an acquiring circuitry <NUM> and a first transmitting circuitry <NUM>.

The acquiring circuitry <NUM> is configured to acquire a time-frequency resource for transmission on a sidelink; and the first transmitting circuitry <NUM> is configured to: take a preset position on the time-frequency resource as a time domain transmission position of sidelink control information, and transmit the sidelink control information on the sidelink.

The preset position includes a first preset position or a second preset position, and the first transmitting circuitry <NUM> is configured to determine that the preset position is the first preset position or the second preset position based on a time when the time-frequency resource is successfully acquired, wherein a start position of the first preset position is earlier than a start position of the second preset position in a time domain.

In some embodiments, a time domain length of the time-frequency resource is a resource selection time domain unit, and a frequency domain length of the time-frequency resource is at least one sub-channel, wherein the resource selection time domain unit includes one time slot, a plurality of time slots or a plurality of symbols, and the sub-channel includes at least one frequency domain resource block.

In some embodiments, the first preset position is first L symbols in the resource selection time domain unit, wherein L is a time domain length of the sidelink control information, and is a positive integer less than or equal to a total number of symbols in the resource selection time domain unit.

In some embodiments, the first preset position is the second to (L+<NUM>)th symbols in the resource selection time domain unit, wherein L is a time domain length of the sidelink control information and is a positive integer, and (L+<NUM>) is less than or equal to a total number of symbols in the resource selection time domain unit.

In some embodiments, the second preset position is the (W+<NUM>)th to (W+L)th symbols in the resource selection time domain unit, wherein the Wth symbol is an end symbol of a time window in the resource selection time domain unit, L is a time domain length of the sidelink control information, W and L are both positive integers, (W+L) is less than or equal to a total number of symbols in the resource selection time domain unit, the time window is a maximum length of time allowed for resource awareness in the resource selection time domain unit, and a start symbol of the time window is a start symbol of the resource selection time domain unit.

In some embodiments, the second preset position is the (W+<NUM>)th to (W+L+<NUM>)th symbols in the resource selection time domain unit, wherein (W+L+<NUM>) is less than or equal to a total number of symbols in the resource selection time domain unit, L is a time domain length of the sidelink control information, and W and L are both positive integers.

The first transmitting circuitry <NUM> is configured to: if the time when the time-frequency resource is successfully acquired is later than a start time of the first preset position, determine that the preset position is the second preset position; or if the time when the time-frequency resource is successfully acquired is earlier than or is the start time of the first preset position, determine that the preset position is the first preset position.

The terminal <NUM> further includes a second transmitting circuitry <NUM> configured to: when the preset position is the second preset position, transmit sidelink data corresponding to the sidelink control information at a start time of a first symbol or a second symbol after the time-frequency resource is successfully acquired within a time window where the time-frequency resource is acquired.

In some embodiments, the terminal <NUM> further includes a third transmitting circuitry (not shown) configured to transmit sidelink data corresponding to the sidelink control information at a start time of the preset position.

In some embodiments, the terminal <NUM> further includes a fourth transmitting circuitry (not shown) configured to transmit sidelink data corresponding to the sidelink control information at an end time of the preset position.

In an embodiment of the present disclosure, a computer readable storage medium having computer instructions stored therein is provided, wherein when the computer instructions are executed, any one of the above sidelink transmission methods is performed.

In some embodiments, the computer readable storage medium may include a Read Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk.

Claim 1:
A sidelink transmission method, comprising:
acquiring (<NUM>) a time-frequency resource for transmission on a sidelink; and
taking (<NUM>) a preset position on the time-frequency resource as a time domain transmission position of sidelink control information, and transmitting the sidelink control information on the sidelink,
characterized in that the preset position comprises a first preset position or a second preset position, and taking (<NUM>) a preset position on the time-frequency resource as a time domain transmission position of sidelink control information comprises:
determining that the preset position is the first preset position or the second preset position based on a time when the time-frequency resource is successfully acquired, wherein a start position of the first preset position is earlier than a start position of the second preset position in a time domain,
wherein determining that the preset position is the first preset position or the second preset position based on a time when the time-frequency resource is successfully acquired comprises: if the time when the time-frequency resource is successfully acquired is later than a start time of the first preset position, determining that the preset position is the second preset position; or if the time when the time-frequency resource is successfully acquired is earlier than or is the start time of the first preset position, determining that the preset position is the first preset position,
wherein when the preset position is the second preset position, the method further comprises: transmitting sidelink data corresponding to the sidelink control information at a start time of a first symbol or a second symbol after the time-frequency resource is successfully acquired within a time window where the time-frequency resource is acquired.