CN108632004B - Method and device for data transmission using multiple transmission time intervals - Google Patents

Abstract

The present application proposes a method for data transmission using multiple transmission time intervals (TTIs), which is characterized by comprising: a user equipment UE detects scheduling grant SAs of other UEs within a detection window based on multiple TTI lengths on a resource pool, and based on The SA measures the received power of the scheduled data channel, and detects the received energy of each sub-channel of each subframe; the UE selects resources for data transmission based on the detected SA, the received power and the received energy; the UE transmits The SA indicates the selected resource, and data transmission is performed through the resource. By adopting the method of the present invention, collision between UEs using TTIs of different lengths is avoided as much as possible, resource utilization is improved, and transmission performance of TTIs of different lengths is guaranteed.

Description

Method and device for data transmission using multiple transmission time intervals

technical field

The present invention relates to wireless communication system technology, and in particular, to a method and device for data transmission using transmission time intervals (TTIs) of various lengths in a V2X system.

Background technique

In the Long Term Evolution (LTE)-based V2X (Vehicle to Vehicle/Perdestrian/Infrastructure/Network) system of the 3GPP standardization organization, there are two structures for configuring the PSCCH resource pool and the PSSCH resource pool. The PSCCH may be located in the same subframe as a PSSCH scheduled by it; alternatively, the PSCCH may not be located in the same subframe as any PSSCH scheduled by the PSCCH. The PSCCH resource pool and the PSSCH resource pool occupy the same set of subframes. One PSCCH is fixedly mapped to 2 PRBs (resource blocks). The allocation granularity of frequency resources is sub-channel, one sub-channel contains consecutive PRBs, and the number of PRBs is configured by high-layer signaling. The resources of a device may occupy one or more consecutive sub-channels. When the PSCCH and the PSSCH are located in the same subframe, the PSCCH and the PSSCH may occupy consecutive PRBs. In one or more consecutive subchannels occupied by the resources of one device, two PRBs, for example, the two PRBs with the lowest frequency are used to carry PSCCH, and the other PRBs are used to carry PSSCH. The actual number of PRBs occupied by the PSSCH also needs to be a power of 2, 3 and 5. When the PSCCH and the PSSCH are located in the same subframe, the PRBs of the PSCCH and the PRBs of the PSSCH may also be discontinuous. At this time, the starting PRB positions of the PSCCH resource pool and the PSSCH resource pool may be configured respectively. The PSSCH resource pool still allocates resources with sub-channel granularity. For a device, the index of the occupied PSCCH is equal to the minimum subchannel index of the occupied PSSCH.

In the V2X system, the collision problem and the in-band leakage problem can be solved based on Sensing. A basic assumption here is that the resource occupation by the device is semi-persistent scheduling (SPS), that is, the resources occupied by the device are periodic within a period of time. As shown in Figure 1, the moment when the device selects the PSCCH/PSSCH resource is subframe n. The device first detects the resources in its resource pool in the time period from subframe na to subframe nb, and determines which time-frequency resources are occupied and Which time-frequency resources are free; then select PSCCH/PSSCH resources in subframe n, note that PSCCH is transmitted in subframe n+c, PSSCH is transmitted in subframe n+d, and reserved resources are in subframe n+e; then Next, the PSCCH is transmitted in subframe n+c, the PSSCH is transmitted in subframe n+d, and the next PSSCH is transmitted in subframe n+e in the reserved resource. In particular, when c is equal to d, PSCCH and PSSCH are located in the same subframe. The interval between subframe n+e and subframe n+d is equal to the reserved interval P. The reserved interval P is equal to P _step ·k. For example, P _step is equal to 100, that is, it supports a delay of no more than about 100ms. The value range of k can be the set of all integers from 1 to 10 or a subset thereof. The value of k The value range can be configured by high-level. When performing resource selection, the device can select K resources located in different subframes, that is, each data can be repeatedly sent K times, and K is greater than or equal to 1, for example, K is equal to 2, so as to avoid the limitation of half-duplex operation. As a result, some devices cannot receive this data. When K is greater than 1, each PSSCH may indicate all the above K resources.

的PRB与上述资源Y的PRB重叠时，R_x,y对设备A不可用，即从集合S_A排除R_x,y，j＝0,1,...C-1，C是设备A当前需要按照周期P_A预留资源的周期数。接下来，判断S_A的剩余资源是否达到总资源的比特R，例如20％(203)。如果比例小于R，则把门限升高3dB(204)并重新从步骤201开始执行；否则，继续执行步骤205。在步骤205中，是估计上述S_A的剩余资源的接收能量，把接收能量最小的资源移动到集合S_B，直到S_B的资源的比例为R。对一个包含多个子信道的资源，这个资源的接收能量是其包含的各个子信道上的接收能量的平均值。接下来，从S_B的资源中选择用于数据传输的资源(206)并用于数据传输(207)。这里，当一个数据是传输两次时，UE首先在S_B内选择一个用于数据传输的资源，然后，在满足时延要求并在SA的指示范围之内，如果存在可用的资源，则UE选择另一个用于数据传输的资源。Figure 2 is a flow chart of performing resource selection based on detection. Assuming that resource selection is performed in subframe n, the current reservation interval of the device's reserved resources is P _A , and the number of cycles that need to reserve resources is C. The device may select resources within the selection window [n+T ₁ , n+T ₂ ] and reserve _C consecutive cycles at interval PA. T1 and T2 depend _on the implementation of the _UE , eg, _T1≤4 , _{20≤T2≤100} . T ₁ depends on the influence of the processing delay from the time when the UE selects resources to when it can start sending scheduling allocation signaling (SA) and data, and T ₂ mainly depends on the delay characteristics that can be tolerated by the current service. First, all resources within the set selection window are in set _SA (201). Next, according to the correctly received SA, it is assumed that the SA indicates that resources continue to be reserved after subframe n, the received power of the data channel scheduled by the SA is measured, and when the received power exceeds the corresponding threshold, _a part of the candidate resources of the SA is excluded (202 ). Specifically, when the received power exceeds a corresponding threshold, the resource Y reserved after subframe n according to SA is unavailable. The above threshold is based on the priority of the device performing resource selection and the priority indicated by the correctly received SA. Jointly determined. Let R _x,y represent a single subframe resource within the selection window [n+T ₁ ,n+T ₂ ], R _x,y is located in subframe y, and includes one or more consecutive subframes starting from subchannel x channel, then, when

When the PRB of the resource Y overlaps with the PRB of the above resource Y, R _x,y is unavailable to device A, that is, R x, _y is excluded from the set S _A , j=0,1,...C-1, C is the current device A _The number of cycles for which resources need to be reserved according to the cycle PA. Next, it is judged whether the remaining resources of SA reach the bit _R of the total resources, eg, 20% (203). If the ratio is less than R, the threshold is raised by 3dB (204) and the execution starts from step 201; otherwise, the execution of step 205 is continued. In step 205, the received energy of the remaining resources of _SA is estimated, and the resource with the smallest received energy is moved to the set _SB until the ratio of the resources of _SB is R. For a resource containing multiple sub-channels, the received energy of this resource is the average value of the received energy on each sub-channel it contains. Next, a resource for data transmission is selected from the resources of _SB (206) and used for data transmission (207). Here, when a piece of data is transmitted twice, the UE first selects a resource for data transmission in S _B , and then, if the delay requirement is met and within the range indicated by SA, if there are available resources, the UE will Select another resource for data transfer.

To enhance the performance of V2X systems, one direction is to use shorter transmission time intervals (TTIs). Short TTI (sTTI) is beneficial to reduce transmission delay, and sTTI is beneficial to avoid the problem of inability to receive data from other UEs caused by half-duplex. How to effectively support the data transmission of one UE on multiple carriers is an urgent problem to be solved.

SUMMARY OF THE INVENTION

The present application provides a method and device for data transmission using multiple transmission time intervals, and provides sTTI mapping structure, resource pool configuration strategy, resource allocation mechanism and resource selection process, thereby improving UE transmission performance.

To achieve the above object, the application adopts the following technical solutions:

A method for data transmission using multiple transmission time intervals TTI, comprising:

The user equipment UE detects the scheduling grant SA of other UEs within the detection window based on multiple TTI lengths on a resource pool, measures the received power of the scheduled data channel based on the SA, and detects the received energy of each subchannel of each subframe;

The UE selects resources for data transmission based on the SA, received power and received energy detected above;

The UE transmits the SA indicating the selected resource, and performs data transmission through the resource.

Preferably, a long TTI (lTTI) is divided into a plurality of short TTIs (sTTI), the automatic gain control AGC is set at the beginning of each sTTI, and the interval GAP is set at the end part, and the AGC and GAP of the sTTI are equal to the length of the lTTI; Alternatively, the AGC of the first sTTI is the same length as the 1TTI, the GAP of the last sTTI is the same as the 1TTI, and the other AGCs and/or GAPs of the sTTI are shorter than the 1TTI length.

Preferably, one 1TTI is divided into multiple sTTIs, and AGC is set at the beginning of each sTTI, but GAP is only set at the end of the last sTTI, and the GAP is the same length as the GAP of the 1TTI, and the AGC of the sTTI is equal to the length of the 1TTI; Alternatively, the AGC of the first sTTI is the same length as the lTTI, and the AGC of the other sTTIs is shorter than the lTTI length.

Preferably, one lTTI is divided into multiple sTTIs, the first sTTI is set with AGC and is the same as the lTTI, the last sTTI is set with GAP and is the same as the lTTI, and a shorter GAP and AGC are inserted between two adjacent sTTIs.

Preferably, one lTTI is divided into multiple sTTIs, and the first and last OFDM symbols of the sTTI transmit data on one subcarrier every N subcarriers, where N is a constant.

Preferably, when data transmission is performed based on TTIs of various lengths, the resource pool is configured according to 1 TTI.

Preferably, when data transmission is performed based on TTIs of multiple lengths, TTIs of each length in the resource pool are configured separately.

Preferably, it is assumed that the frequency resource occupied by the SA of the sTTI is m times that of the 1TTI, and the SA of the qth sTTI occupies the SA resource q+[0,1,...m-1] of the 1TTI, q=0,1,... .M-1, M=N-m+1, N is the number of 1TTI data sub-channels.

第q个sTTI数据子信道占用lTTI数据子信道q·m+[0,1,...m-1]+Δ₂，Δ₁和Δ₂是资源位置的参数，N是lTTI数据子信道的个数。Preferably, it is assumed that the frequency resource occupied by the SA of the sTTI is m times that of the 1TTI, and the SA of the qth sTTI occupies the SA resource of the 1TTI q·m+[0,1,...m-1]+Δ ₁ , q=0 ,1,...,M-1,

The qth sTTI data subchannel occupies the lTTI data subchannel q·m+[0,1,...m-1]+Δ ₂ , where Δ ₁ and Δ ₂ are the parameters of the resource location, and N is the number of the lTTI data subchannels number.

Preferably, when receiving SAs with TTIs of different lengths, the thresholds of PSSCH-RSRP are different for different TTI lengths; or, denoting the PSSCH-RSRP threshold as Th, compare PSSCH-RSRP with Th+Δ to determine whether the resources are available, Δ is a power adjustment parameter; or, compare PSSCH_RSRP+Δ with a threshold to determine whether the resource is available, PSSCH_RSRP is the received power of the data channel, and Δ is a power adjustment parameter.

Preferably, when measuring the received energy S-RSSI according to 1TTI, measure the received energy of other symbols except the AGC and GAP symbols of 1TTI; or, measure all symbols that will not be used for GAP except the AGC and GAP symbols of 1TTI or, one 1TTI resource is divided into multiple sTTI resources, first measure the S-RSSI of each sTTI resource, and then obtain the S-RSSI of the 1TTI resource according to the S-RSSI of each sTTI resource.

Preferably, for one sTTI resource, if within the 1TTI where the sTTI resource is located, other sTTIs with the same or overlapping frequency positions are unavailable, the UE increases the probability of selecting the sTTI resource.

Preferably, when the number of SAs supported by the UE for detection is less than the total number of SAs of multiple TTIs in one 1TTI, the detected SA resources are determined according to the priorities of different TTI lengths.

Or, when the number of SAs that the UE supports to detect is less than the total number of SAs of multiple TTIs in one 1TTI, determine the number of SA resources of 1TTI and the number of SA resources of sTTI that the UE needs to detect respectively.

Preferably, the number of detected PRBs of different TTI lengths is determined according to the priorities of different TTI lengths; or, the number of PRBs of 1TTI and the number of PRBs of sTTI to be detected by the UE are determined respectively.

A device for data transmission using multiple transmission time intervals, comprising a detection module, a resource selection module and a transceiver module, wherein:

A detection module, used for UE to detect SAs of other UEs in a detection window based on multiple TTI lengths in a resource pool, measure the received power of the scheduled data channel based on the SA, and detect the received energy of each subchannel of each subframe;

a resource selection module, used for the UE to select resources for data transmission based on the SA, received power and received energy detected above;

A transceiver module, the UE transmits the selected resource indicated by the SA, and performs data transmission through the resource.

By adopting the method of the present invention, collision between UEs using TTIs of different lengths is avoided as much as possible, resource utilization is improved, and transmission performance of TTIs of different lengths is guaranteed.

Description of drawings

1 is a schematic diagram of detection-based resource selection;

Fig. 2 is the flow chart of resource selection based on detection;

Fig. 3 is the flow chart of the present invention;

Figure 4 is a schematic diagram of the sTTI structure;

FIG. 5 is a schematic diagram 1 of SA and data channel resources of sTTI;

FIG. 6 is a schematic diagram 2 of SA and data channel resources of sTTI;

7 is a schematic diagram of resource selection according to the present invention;

Fig. 8 is the equipment diagram of the present invention;

9 is a schematic diagram of using half an OFDM symbol as an AGC;

10 is a schematic diagram of using half an OFDM symbol as a GAP;

FIG. 11 is a schematic diagram of data channel mapping using half an OFDM symbol as AGC and GAP.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

In V2X communication, the equipment (UE) participating in the communication can be divided into various types, such as vehicle (VUE), pedestrian (PUE), and roadside unit (RSU). Assuming that the data transmission mechanism of the UE is, first, the UE sends a control channel, which is used to indicate the time-frequency resources occupied by the data channel and information such as coding and modulation scheme (MCS), hereinafter referred to as scheduling assignment signaling (SA); The UE transmits data on the scheduled data channel. For the LTE D2D/V2X system, the above SA is also called PSCCH, and the data channel is also called PSSCH. For a device, because its data is basically generated periodically within a period of time, the device can periodically reserve resources according to a certain reservation interval; and each data can be repeatedly sent K times, correspondingly K resources need to be reserved, and K is greater than or equal to 1, so as to avoid that some devices cannot receive this data due to the limitation of half-duplex operation.

Assuming that multiple transmission time interval (TTI) lengths are used, the longest TTI is recorded as 1TTI, and other TTI lengths are collectively referred to as sTTI, and there may be one or more sTTI lengths. Multiple sTTIs divided within one lTTI. Using sTTI is beneficial to reduce the delay of data transmission, especially for some services with stricter delay requirements. Within a resource pool, only one TTI length, 1TTI or sTTI, may be used; or it may also allow data transmission in which both 1TTI and sTTI exist at the same time. Preferably, the A and data channels of a UE use the same length of TTI.

Fig. 3 is the flow chart of the method for supporting multiple TTI lengths of the present invention, comprises the following steps:

Step 301: The UE detects the SAs of other UEs in a detection window based on multiple TTI lengths on a resource pool, measures the received power of the scheduled data channel based on the SA, and detects the received energy of each subchannel in each subframe.

In the above measurement of received power and received energy, the influence of the coexistence of multiple TTI lengths needs to be considered.

Step 302: The UE selects resources for data transmission based on the detected SA, received power, and received energy.

In the above resource selection process, the influence between UEs with different TTI lengths can be avoided as much as possible, thereby improving the coexistence performance.

Step 303: The UE transmits the selected resource indicated by the SA, and performs data transmission through the resource.

For multiple sTTIs divided within one 1TTI, each sTTI includes automatic gain control (AGC) symbols, DMRS and data symbols and space (GAP) symbols. The AGC symbol is used for the receiver to adjust the working point, and the AGC symbol can transmit data or not. The GAP symbol is the time interval used for the UE's transceiving transition time, as well as avoiding overlap between V2X signals and cellular network signals and avoiding overlap between V2X signals.

Further, the present invention provides the following specific embodiments to elaborate the method for supporting various TTI lengths of the present invention.

Example 1

In actual communication, it is difficult to accurately predict the distribution of UE types and services. For example, the traffic volume working according to lTTI and the traffic volume working according to sTTI are difficult to predict. Therefore, it is necessary to consider supporting the data transmission of lTTI and sTTI at the same time in the same resource pool.

Figure 4(a) shows the structure of the lTTI. The first OFDM symbol of the lTTI is used for AGC, so the data on the first OFDM symbol may not be used for decoding; the last OFDM symbol is deleted as GAP can be used to generate the UE's transceiving transition time, and, when multiplexing V2X and cellular network communications on one carrier, avoid V2X signals overlapping with cellular network signals, and avoiding overlapping V2X signals of different UEs. For example, the V2X subframe structure of LTE Release 14 adopts the 1TTI structure of FIG. 4( a ).

One lTTI can be further divided into two or more sTTIs. The lengths of AGC and GAP required by UEs supporting sTTI may be the same as UEs supporting only lTTI. Or, because the time delay requirement of the UE supporting sTTI is relatively strict, the processing capability of the AGC and the GAP is generally improved accordingly, so the lengths of the AGC and the GAP can be shortened. In addition, assuming that the cellular network transmission adopts lTTI, there is no problem of overlapping with the cellular network transmission except for the last sTTI.

As shown in Figure 4(b), AGC may be set at the beginning of each sTTI, and GAP may be set at the end. The AGC and GAP of sTTI are equal in length to lTTI. Alternatively, the AGC of the first sTTI is the same length as the 1TTI, the GAP of the last sTTI is the same as the 1TTI, and other AGCs and/or GAPs of the sTTI may be shorter than the 1TTI length. For example, the AGC of the first sTTI and the GAP of the last sTTI may include multiple OFDM symbols, while the other AGCs and/or GAPs of the sTTI include only one OFDM symbol. The above-mentioned GAP can be used as the UE's transceiving conversion time, and avoid overlapping of V2X signals of different UEs. Because of the introduction of the above-mentioned GAP, the transceiving operation of the UE in one sTTI does not affect the transceiving operation in the adjacent next sTTI. The problem with this method is that the overhead of AGC and GAP is relatively large.

As shown in Figure 4(c), AGC may be set at the beginning of each sTTI, but GAP is only set at the end of the last sTTI, and this GAP has the same length as that of 1TTI. The AGC of sTTI is equal to the length of lTTI. Alternatively, the AGC of the first sTTI may be the same length as the lTTI, and the AGC of the other sTTIs may be shorter than the lTTI length. For example, the AGC of the first sTTI may include multiple OFDM symbols, while the AGC of other sTTIs may include only one OFDM symbol. Because there is no GAP at the end positions of other sTTIs, it affects the transceiving operations on the adjacent next sTTI. Assuming that the UE transmits in one sTTI, the UE can use the first part of the AGC symbol of the next sTTI to complete the transition from transmit to receive, but this means that the UE can only use the remaining part of the AGC symbol to complete the AGC operation; alternatively, this The UE may not perform the receiving operation in the next sTTI. Assuming that the UE receives a signal in one sTTI, the UE can use the first part of the AGC symbol of the next sTTI to complete the transition from receive to transmit, but this means that the UE can only transmit valid for AGC in the remaining part of the AGC symbol. signal or data; or, the UE may not perform a transmission operation in the next sTTI.

As shown in Figure 4(d), AGC can be set at the beginning of the first sTTI and is the same as lTTI, and GAP is set at the end of the last sTTI and is the same as lTTI, and a shorter sTTI is inserted between two adjacent sTTIs. GAP and AGC, that is, shorter segments than the GAP and AGC of 1TTI. For example, one OFDM symbol is used to generate GAP and AGC. Because of the introduction of the above-mentioned GAP and AGC, the transceiving operation of the UE in one sTTI does not affect the transceiving operation in the adjacent next sTTI. At the same time, because the above-mentioned GAP and AGC are relatively short, the overhead of AGC and GAP is reduced.

As shown in FIG. 4(e), it is further assumed that the subcarrier spacing (SCS) adopted by sTTI is larger than that of 1TTI, so that the OFDM symbol length of sTTI is shorter than that of 1TTI. The beginning part of the first sTTI is set with AGC and is the same as lTTI, for example, OFDM symbols occupying multiple sTTIs; the end part of the last sTTI is set with GAP and the same as lTTI, for example, OFDM symbols occupying multiple sTTIs; A shorter GAP and AGC are inserted between two sTTIs, that is, shorter than the GAP and AGC of 1 TTI, for example, occupying an OFDM symbol of one sTTI respectively. Because of the introduction of the above-mentioned GAP and AGC, the transceiving operation of the UE in one sTTI does not affect the transceiving operation in the adjacent next sTTI. At the same time, because the above-mentioned GAP and AGC are relatively short, the overhead of AGC and GAP is reduced.

For the methods of Figs. 4(b) to 4(e), in the OFDM symbol used for AGC, all subcarriers can be occupied to transmit data, for example, data is transmitted in the AGC symbol with 15kHz subcarrier interval; Data may be transmitted on one subcarrier every N subcarriers, for example, N is equal to 2. With the latter method, the signals on the OFDM symbols used for AGC have a repetitive structure in time. As shown in FIG. 9 , assuming that N is equal to 2, the AGC symbol can be equally divided into 2 parts, and all data can be received only based on the latter part. The receiving end may use the first part of the AGC symbol to complete the AGC operation, and receive data on the latter part of the AGC symbol, thereby reducing the overhead of the AGC. Depending on the implementation of the device at the receiving end, data may be received by using the latter part of the AGC symbol, or data may be received without using the AGC symbol.

As shown in Figure 4(f), it is assumed that data is transmitted on one subcarrier every N subcarriers on the AGC symbol, thus having the repeating structure shown in Figure 9, and it is assumed that the OFDM symbol containing GAP is also every N subcarriers The carrier transmits data on one sub-carrier, eg N equals 2. As shown in FIG. 10 , assuming that N is equal to 2, the OFDM symbol can be equally divided into 2 parts, and all data can be received only based on the former part. The first part of this OFDM symbol can still transmit data, but stop transmission on the latter part to generate GAP, thereby reducing the overhead of GAP. The last symbol of the lTTI may use the method shown in FIG. 10 to generate the GAP, or it may not transmit any signal, so that the entire symbol is used for the GAP. Depending on the implementation of the device at the receiving end, data may be received by using the latter part of the AGC symbol, or data may be received without using the AGC symbol. Depending on the implementation of the device at the receiving end, data may be received by using the first part of the OFDM symbol containing GAP, or data may be received by not using the OFDM symbol containing GAP.

For the sTTI structure shown in Fig. 4(f), it is assumed that the first and last OFDM symbols of the sTTI transmit data on one subcarrier every N subcarriers. As shown in FIG. 11 , assuming that N is equal to 2, the total amount of data transmitted in the first OFDM symbol and the last OFDM symbol is equivalent to the amount of data transmitted in an OFDM symbol with a subcarrier spacing of 15 kHz. In FIG. 11( a ), it is assumed that the subcarriers used for data transmission of the first and last OFDM symbols of the sTTI are the same. In Fig. 11(b), it is assumed that the subcarriers used for data transmission of the first and last OFDM symbols of the sTTI are different. For the mapping structure shown in FIG. 11 , the rate matching can be processed according to the time-frequency resources in which the data channel includes an integer number of OFDM symbols. For example, in FIG. 11 , assuming that two OFDM symbols are used to carry DMRS, the number of OFDM symbols that can be used to actually transmit data is equivalent to four. That is, rate matching may be performed for data transmission by 4 OFDM symbols, but actually the modulation symbols of data are mapped onto 5 OFDM symbols for data transmission.

Embodiment 2

When the data transmission of lTTI and sTTI is supported simultaneously in one resource pool, the resource pool may still be configured or pre-configured according to the lTTI. In LTE Release 14, after removing some subframes that are not available for V2X, such as synchronization channel (SLSS) subframes, TDD downlink subframes, and reserved resources, all remaining subframes are reordered, and then reordered A bitmap is periodically applied based on the logical subframe index to define the resource pool. '1' in the above bitmap represents that the subframe belongs to this resource pool, and '0' represents that it does not belong to this resource pool.

或者，sTTI用二维索引(k,m)来表示，其中k是sTTI所在lTTI的索引，m是sTTI在lTTI内的索引。采用这个方法，sTTI和lTTI的预留间隔相等，即P_rsvp＝k·P_step，但是在处理资源选择和在SA中指示资源时，需要考虑二维索引(k,m)的影响。For 1TTI transmission, the resource pool may be configured on the basis of the physical subframe index, or, the resource pool may be defined on the basis of the logical subframe index according to the method of LTE Release 14. For sTTI transmission, its resource pool is still defined according to lTTI, so no additional signaling or configuration information is required. Denote that one lTTI is divided into M sTTIs, then the index of the mth sTTI in the lTTI with index k is k·M+m, k=0,1,...,K-1, m=0,1, ..., M-1, K is the maximum value of the lTTI index. Using this method, for a service, record the reserved interval when using lTTI transmission as P _rsvp =k·P _step , where P _step is the basic reserved interval, for example, 100, k is a coefficient, and the value range of k can be the upper layer Configured, in LTE release 14, the maximum set of the value range of k is [1/5, 1/2, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10], using The reserved interval of sTTI is

Alternatively, the sTTI is represented by a two-dimensional index (k, m), where k is the index of the lTTI where the sTTI is located, and m is the index of the sTTI within the lTTI. With this method, the reservation interval of sTTI and 1TTI is equal, ie P _rsvp =k·P _step , but the influence of two-dimensional index (k,m) needs to be considered when processing resource selection and indicating resources in SA.

Or, for a resource pool, after removing some time units (TUs) that cannot be used for V2X, the above TUs can be subframes, time slots or mini-slots (mini-slots), and a time slot is divided into multiple mini-slots. Time slot, the UE using 1TTI reorders the 1TTIs of all remaining TUs, and then defines the first resource pool based on the reordered logical subframe index; the UE using sTTI reorders the sTTIs of all remaining TUs, and then reorders the sTTIs of all remaining TUs. The second resource pool is defined based on the logical subframe index. In terms of time resources, the first resource pool and the second resource pool may completely overlap, or may not completely overlap.

Embodiment 3

In the case of a certain amount of transmitted data, with the shortening of the TTI, the number of frequency resources that the UE needs to occupy increases accordingly, thereby ensuring a certain transmission performance. For example, when SA is mapped to 1TTI for transmission, 2 PRBs are occupied. Suppose that one 1TTI is divided into 2 sTTIs, and about 4 PRBs need to be occupied when SA is transmitted in one sTTI. In addition, taking Figure 4(b) as an example, 8 OFDM symbols in 1TTI carry data; because of the additional overhead of AGC and GAP, there are only 5 OFDM symbols in sTTI that carry DMRS and data, assuming two OFDM symbols As a DMRS, only 3 OFDM symbols carry data. In this way, under the condition that the coding rate of SA remains unchanged, the required number of PRBs is 16/3. By reducing the number of bits of the SA of the sTTI, the required number of PRBs can be reduced.

For a resource pool, according to 1TTI, its data channel is divided into N sub-channels, and resources are allocated by sub-channels. Correspondingly, the SA resource pool is also divided into N SA resources, which correspond to the N data subchannels one-to-one. Due to the change of the length of the TTI, the number of divided data subchannels of the sTTI may be the same as or more than the number of divided data subchannels of the lTTI.

It is assumed that the number of PRBs of the sTTI data subchannel is the same as that of the 1TTI, and it is assumed that the frequency resources occupied by the SA of one sTTI are m times that of the 1TTI. As shown in FIG. 5 , the SA of the qth sTTI may be the SA resource q+[0,1,...m-1] occupying 1TTI, q=0,1,...M-1, M=N- m+1. The SA of the qth sTTI may start from the data subchannel q, and allocate data subchannels with a granularity of n consecutive subchannels. For example, n may be 1 or m, and n may be configured or pre-configured by higher layer signaling. Using n greater than 1 is beneficial to reduce the overhead of indicating sub-channel resources in the SA.

第q个sTTI数据子信道可以是占用lTTI数据子信道q·m+[0,1,...m-1]+Δ₂。当m不能整除N时，上述Δ₁和Δ₂可以调整sTTI的SA在SA资源池中占用的SA资源的位置，以及sTTI数据子信道在数据资源池中占用的子信道的位置。Δ₁和Δ₂可以相等或者不相等。例如，Δ₁和Δ₂都等于0。从而，对sTTI来说，SA资源与数据子信道一一对应。第q个sTTI的SA可以是调度从sTTI数据子信道q开始的连续一个或者多个sTTI数据子信道。采用这个方法有利于降低在SA中指示子信道资源的开销。Alternatively, it is assumed that the frequency resource occupied by the SA of one sTTI is m times that of the 1TTI, and the number of PRBs of one sTTI data subchannel is also m times that of the 1TTI. As shown in FIG. 6 , the SA of the qth sTTI may be the SA resource q·m+[0,1,...m-1]+Δ ₁ occupied by lTTI, q=0,1,...,M- 1,

The qth sTTI data subchannel may be occupied 1TTI data subchannel q·m+[0,1,...m-1]+ _Δ2 . When m is not divisible by N, the above Δ1 and _Δ2 can adjust the position _of the SA resource occupied by the SA of the sTTI in the SA resource pool, and the position of the subchannel occupied by the sTTI data subchannel in the data resource pool. _Δ1 and _Δ2 may or may not be equal. For example, _Δ1 and _Δ2 are both equal to zero. Therefore, for sTTI, SA resources correspond to data subchannels one-to-one. The SA of the qth sTTI may be scheduling one or more consecutive sTTI data subchannels starting from the sTTI data subchannel q. Adopting this method is beneficial to reduce the overhead of indicating sub-channel resources in the SA.

Embodiment 4

When the data transmission of the 1TTI and the sTTI is supported simultaneously in a resource pool, the resource selection of the UE needs to consider the influence of the data transmission of the 1TTI and the data transmission of the sTTI.

The UE detects the SAs of other UEs, and measures the PSSCH-RSRP of the received data channel scheduled by the SA, so as to process resource selection according to the above-mentioned PSSCH-RSRP. The UE needs to detect the SA of the lTTI and the SA of the sTTI. When the currently detected PSSCH-RSRP exceeds the threshold, the corresponding data channel resource is unavailable. For different TTI lengths, the thresholds of PSSCH-RSRP may be different. For different TTI lengths, the thresholds of PSSCH-RSRP may be separately configured or pre-configured. Alternatively, in the case that the TTI lengths of the detected other UE and the detected UE are the same or different, respectively configure or pre-configure the PSSCH-RSRP threshold. Or, denote the PSSCH-RSRP threshold as Th. When a UE detects an SA that schedules TTIs of the same length, it compares PSSCH_RSRP with the threshold Th to determine whether resources are available; when a UE detects an SA that schedules TTIs of different lengths, it sets PSSCH-RSRP to RSRP is compared with Th+Δ to determine whether the resource is available, Δ is a power adjustment parameter, Δ is a constant, or is related to the priority of the detected other UE and/or the detected UE. For example, the PSSCH-RSRP threshold corresponding to scheduling SAs with different TTI lengths may be smaller than the PSSCH-RSRP threshold corresponding to scheduling SAs with the same length TTI, so that the resources occupied by other UEs with different TTI lengths are preferentially removed, and the use of different TTI lengths is avoided as much as possible. Collision between UEs of TTI length. Alternatively, denote the PSSCH-RSRP threshold as Th. When a UE detects an SA that schedules TTIs of the same length, it compares PSSCH_RSRP with the threshold Th to determine whether resources are available; when a UE detects an SA that schedules TTIs of different lengths, it can The PSSCH-RSRP measured by SA is corrected, that is, PSSCH_RSRP+Δ is compared with the threshold Th to determine whether the resource is available, Δ is a power adjustment parameter, Δ is a constant, or, compared with the detected other UEs and/or the execution detection related to the priority of the UE. For example, Δ may be a negative value to preferentially remove resources occupied by other UEs using the same TTI length, thereby allowing more collisions between UEs using different TTI lengths. In the case of transmitting the same amount of data, using sTTI will occupy more frequency resources, using lTTI will occupy more time resources, and UEs using the two transmission methods will not 100% collide, so UEs using different TTI lengths will occupy more time resources. Partial overlap of resources has relatively little impact on data reception to a certain extent. The above method for removing resources according to PSSCH-RSRP can be used only when the UE performing detection adopts 1TTI; or, it can only be used when the UE performing detection adopts sTTI; The TTI length of the UE performing the detection is used for the UE performing the detection.

The UE may also measure the S-RSSI of the resources, and select several resources with the smallest S-RSSI to obtain the set _SB . The TTI length of the above resource is the same as the TTI length that the UE needs to occupy. In order to obtain the S-RSSI of one 1TTI resource, it is assumed that the S-RSSI is measured according to the 1TTI. For one 1TTI, the UE may obtain the S-RSSI by measuring other symbols except the AGC and GAP symbols of the 1TTI. Or, for one lTTI, considering that the lTTI is divided into multiple sTTIs, each sTTI may have its own GAP symbol, and the UE may be on all symbols that will not be used for GAP except the AGC and GAP symbols of the lTTI Measure S-RSSI. For example, with the exception of the AGC and GAP symbols of 1TTI, for the method of Fig. 4(b), the GAP symbol of the first sTTI is not used to measure S-RSSI; for the method of Fig. 4(d), the first sTTI GAP is not used to measure S-RSSI; for Figure 4(e), the GAP symbol of the first sTTI is not used to measure S-RSSI. The UE may also measure the S-RSSI only on a subset of the time resources determined according to the above rules. With this method, since the GAP symbols of sTTI are not used to measure S-RSSI, the strength of the interfering signal can be estimated more accurately, thereby reducing collisions. In order to obtain the S-RSSI of an sTTI resource, it is assumed that the S-RSSI is measured according to the sTTI. For an sTTI, the UE may obtain the S-RSSI by measuring other symbols except the AGC and GAP symbols of the sTTI. For an 1TTI resource, it is assumed that it is divided into N sTTI resources s _n in time, n=0, 1...N-1, and the s _n frequency resource is the same as the above 1TTI resource, in order to obtain the above 1TTI resource S- For RSSI, the UE may first measure the S-RSSI of each _sTTI resource sn, and then obtain the S-RSSI of the above-mentioned 1TTI resource according to the S-RSSI of each sTTI resource _sn . For example, the S-RSSI of the above-mentioned 1TTI resource may be the maximum value, the average value, or the weighted average value of the S-RSSI of each _sTTI resource sn. The above method for measuring S-RSSI may only be used when the UE performing detection adopts 1TTI; or, it may only be used when the UE performing detection adopts sTTI; The TTI length of the detected UE, used for the detected UE.

Next, the UE selects resources in set _SB . The UE may randomly select resources in set _SB . Or, for a UE using sTTI, for an sTTI resource in _SB , if other sTTIs with the same frequency location or overlapping are not available within the 1TTI where this sTTI resource is located, the UE can select such an sTTI resource with a high probability. By adopting this method, the sTTI UEs try to use the same or adjacent PRBs in one 1TTI, so that more 1TTI resources may be reserved for the 1TTI UEs, thereby avoiding collisions between UEs with different TTI lengths. As shown in Figure 7, assuming that resources 702 and 711 are unavailable, the other four resources 701, 712, 703, 713 are all available, because resources 703 and 713 are located in the same PRB, making them less probabilities of being selected by UEs of sTTI than resources 701 and 712, thereby facilitating the selection of the 1TTI resource composed of resources 703 and 713 by UEs of other 1TTIs.

For a resource pool, the SA resources of N 1TTIs are divided into one 1TTI, and the SA resources of M sTTIs are divided into one sTTI. In the time period of one 1TTI, the total number of SAs that the UE needs to detect is L=N+m · M, m is the number of sTTIs divided into one lTTI. The number of SAs that the UE can detect in one 1TTI period depends on the capability of the UE. For a UE with a particularly strong capability, that is, the number of SAs that can be detected is greater than or equal to L, the UE can detect every possible SA resource. Assuming that the capability of the UE is limited, that is, the number of SAs that can be detected is less than or equal to L, it may be a rule that defines the SA that the UE selects and detects. A possible rule is to define different detection priorities for different TTI lengths. For example, the UE first guarantees to detect SA resources of all 1TTIs, and then the remaining capacity is used to detect SA resources of sTTIs. For example, it is assumed that the security-related V2X messages are sent through the 1TTI, so the SA resources of the 1TTI need to be detected preferentially. Alternatively, another rule is to separately determine the number of 1TTI SA resources L _L and the number of sTTI SA resources L _S that the UE needs to detect. The above-mentioned parameters L _L and L _S may be configured by the base station, pre-configured, or predefined in a standard corresponding to a UE capability. Or, record the maximum number of SAs that the UE supports to detect in one 1TTI as L _max , another rule is to determine the number of SA resources L _L of the 1 TTI that the UE needs to detect, then the remaining SA detection capability is L _max -L _L SA resources for handling sTTI. The above-mentioned parameter _LL may be configured by the base station, pre-configured, or predefined in a standard corresponding to a UE capability.

In addition, the total number of PRBs that the UE can decode also depends on the capabilities of the UE. The above-mentioned total number of PRBs may specifically refer to the total number of PRBs of the data channel, or may also be the total number of PRBs including the SA and the data channel. It can be the ability to define the number of PRBs that the UE can detect only according to one TTI length, for example, 1TTI, and the above-mentioned ability can be converted into the ability of other TTI lengths. Alternatively, it may also be the ability to define the number of PRBs that the UE can detect according to each TTI length. The ability to define the number of PRBs that the UE can detect according to a TTI length may only be used to detect PRBs of this TTI length; or, the ability to define the number of PRBs that the UE can detect according to a TTI length may also be Converted to PRBs for detection of other TTI lengths. For example, denote the total number of PRBs that the UE can detect in one 1TTI as N. Correspondingly, the number of PRBs that the UE can detect in one sTTI can be defined as c·N, where c is a coefficient, which can be compared with the relative relationship between sTTI and 1TTI. Length is related, e.g. c is equal to 2. Assuming that the capability of the UE is limited, it may be a rule that defines the number of PRBs detected by the UE according to different TTI lengths. A possible rule is to define different detection priorities for different TTI lengths. For example, the UE first guarantees to detect PRBs of all 1TTIs, and then the remaining capacity is used to detect PRBs of sTTIs. For example, it is assumed that security-related V2X messages are sent through 1TTI, so the PRB of 1TTI needs to be detected preferentially. Alternatively, another rule is to respectively determine the number of 1TTI PRB sources L _L and the number of sTTI PRBs L _S that the UE needs to detect. The above-mentioned parameters L _L and L _S may be configured by the base station, pre-configured, or predefined in a standard corresponding to a UE capability. Alternatively, assuming that the maximum number of PRBs that the UE supports to detect in 1TTI is L _max , another rule is to determine the number of 1TTI PRBs that the UE needs to detect, L _L , then the remaining detection capability is used to process the sTTI PRBs, that is, corresponding to L The detection capability of _max -L _L lTTI PRBs is used to process sTTI PRBs. The above-mentioned parameter _LL may be configured by the base station, pre-configured, or predefined in a standard corresponding to a UE capability.

Corresponding to the above method, the present application also discloses a device that can be used to implement the above method. As shown in FIG. 8 , the device includes a detection module, a resource selection module and a transceiver module, wherein:

A detection module, used for UE to detect SAs of other UEs in a detection window based on multiple TTI lengths in a resource pool, measure the received power of the scheduled data channel based on the SA, and detect the received energy of each subchannel of each subframe;

a resource selection module, used for the UE to select resources for data transmission based on the SA, received power and received energy detected above;

The transceiver module is used for the UE to transmit the selected resource indicated by the SA, and to perform data transmission through the resource.

Those skilled in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium, and the program can be stored in a computer-readable storage medium. When executed, one or a combination of the steps of the method embodiment is included.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing module, or each unit may exist physically alone, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware, and can also be implemented in the form of software function modules. If the integrated modules are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium.

The above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, and the like.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the present application. within the scope of protection.

Claims (29)

1. A method performed by a user equipment, UE, in a communication system, comprising:

receiving control information on a PSCCH, wherein the control information comprises information of resources scheduled by the PSCCH for the PSSCH;

determining Reference Signal Received Power (RSRP) of PSSCH;

determining a set of resources for data transmission based on the RSRP and a threshold;

transmitting data through the resource set;

wherein the threshold is determined based on a length of a TTI of the PSSCH.

2. The method of claim 1, further comprising:

one long tti (ltti) divides a plurality of short ttis (stti);

setting Automatic Gain Control (AGC) at the beginning part of each sTTI; and

setting a GAP at the ending part;

the length of AGC of each sTTI is equal to that of AGC of the lTTI, and the length of GAP of each sTTI is equal to that of GAP of the lTTI; or,

the length of AGC of the first sTTI is the same as that of AGC of the l TTI, the length of GAP of the last sTTI is the same as that of GAP of the l TTI, and the lengths of AGC or GAP of other sTTI are shorter than that of AGC or GAP of the l TTI; or

The length of AGC and GAP for each other sTTI is shorter than the length of AGC and GAP for the tti, respectively.

3. The method of claim 1, wherein the data is transmitted on a subset of the set of resources, wherein the subset is identified based on a length of a TTI used for data transmission.

4. The method of claim 1, wherein one tti divides a plurality of ttis, the first sTTI is configured with AGC and same as the tti, the last sTTI is configured with GAP and same as the tti, and a shorter GAP and AGC are inserted between two adjacent sTTI.

5. The method of claim 1, wherein an tti divides a plurality of sTTI, wherein the first and last OFDM symbols of the sTTI are each transmitted on one subcarrier every N subcarriers, and wherein N is a constant.

6. The method of claim 1, wherein when data transmission is performed based on TTIs of various lengths, the resource pool is configured according to lTTI; alternatively, the resource pool is configured for each TTI of length.

7. The method according to claim 1, wherein the scheduling assignment signaling SA of the sTTI is assumed to occupy M times of frequency resources of the tti, and the SA of the qth sTTI occupies SA resources q + [0, 1.. M-1], q ═ 0, 1.. M-1, M ═ N-M +1, and N is the number of tti data subchannels.

8. The method of claim 1, wherein the SA of the qth sTTI occupies m times of frequency resources of the tti and the SA of the qth sTTI occupies q · m + [0, 1.. m-1] of SA resources of the tti]+Δ ₁ ，q＝0,1,...,M-1，

The qth sTTI data subchannel occupies the lTTI data subchannel q · m + [0, 1.. m-1]]+Δ ₂ ，Δ ₁ And Δ ₂ Is a parameter of resource location, and N is the number of ttis data subchannels.

9. The method of claim 1, wherein the PSSCH-RSRP thresholds are different for different TTI lengths when SAs of different TTI lengths are received; or, recording the PSSCH-RSRP threshold as Th, comparing the PSSCH-RSRP with Th + delta to judge whether the resource is available, wherein delta is a power regulation parameter; or comparing PSSCH-RSRP + delta with a threshold to judge whether the resource is available, wherein PSSCH-RSRP is the received power of the data channel, and delta is the power adjusting parameter.

10. The method of claim 9, wherein RSRP of the PSSCH is less than or equal to the threshold, and wherein the set of resources for data transmission includes resources for the PSSCH; the RSRP of the PSSCH is greater than the threshold, and the set of resources for data transmission does not include resources for the PSSCH.

11. The method of claim 1, the determining a set of resources for data transmission comprising:

for one sTTI resource, if other sTTI with the same frequency position or overlapping frequency position is unavailable in the lTTI where the sTTI resource is located, the UE increases the probability of selecting the sTTI resource.

12. The method of claim 1, the determining resources for data transmission comprising:

when the number of the SAs supported by the UE to be detected is less than the total number of the SAs of various TTIs with different lengths in the lTTI, determining the detected SA resources according to the priority of the TTIs with different lengths; or,

and when the number of the SAs supported and detected by the UE is less than the total number of the SAs of the plurality of TTIs with different lengths in the lTTI, respectively determining the number of the SA resources of the lTTI and the number of the SA resources of the sTTI which need to be detected by the UE.

13. The method of claim 1, the determining a set of resources for data transmission comprising:

determining the number of detected resource blocks PRB of the TTIs with different lengths according to the priorities of the TTIs with different lengths; or respectively determining the PRB number of lTTI and the PRB number of sTTI which are required to be detected by the UE.

14. The method of claim 1, the control information is received based on a length of a plurality of TTIs.

15. An apparatus performed by a User Equipment (UE) in a communication system, comprising a detection module, a resource selection module, and a transceiving module, wherein:

a detection module, configured to receive control information on a PSCCH, where the control information includes information of resources for the PSCCH scheduled by the PSCCH; determining Reference Signal Received Power (RSRP) of PSSCH;

a resource selection module to determine a set of resources for data transmission based on the RSRP and a threshold;

the transceiving module is used for carrying out data transmission through the resource set;

wherein the threshold is determined based on a length of a TTI of the PSSCH.

16. The apparatus of claim 15, wherein:

one long tti (ltti) divides a plurality of short ttis (stti);

setting automatic gain control AGC at the beginning part of each sTTI; and

setting a GAP at the ending part;

the length of AGC of each sTTI is equal to that of AGC of the l TTI, and the length of GAP of each sTTI is equal to that of GAP of the l TTI; or,

the length of AGC of the first sTTI is the same as that of AGC of the l TTI, the length of GAP of the last sTTI is the same as that of GAP of the l TTI, and the lengths of AGC or GAP of other sTTI are shorter than that of AGC or GAP of the l TTI; or

The length of AGC and GAP for each other sTTI is shorter than the length of AGC and GAP for the tti, respectively.

17. The apparatus of claim 15, wherein the data is transmitted on a subset of the set of resources, wherein the subset is identified based on a length of a TTI used for data transmission.

18. The apparatus of claim 15, wherein an tti divides a plurality of sTTI, a first sTTI is configured with AGC and same as the tti, a last sTTI is configured with GAP and same as the tti, and a shorter GAP and AGC are inserted between two adjacent sTTI.

19. The apparatus of claim 15, wherein an tti divides a plurality of sTTI, wherein the first and last OFDM symbols of the sTTI are each to transmit data on one subcarrier every N subcarriers, and wherein N is a constant.

20. The apparatus of claim 15, wherein when data transmission is performed based on TTIs of various lengths, the resource pool is configured according to lTTI; alternatively, the resource pool is configured for each TTI of length.

21. The apparatus according to claim 15, wherein the SA of sTTI occupies M times of frequency resources of lti, the SA of qth sTTI occupies q + [0, 1.. M-1], q ═ 0, 1.. M-1, M ═ N-M +1, and N is the number of lti data subchannels.

22. The apparatus of claim 15, wherein the SA of the qth sTTI occupies m times of frequency resources of the tti and the SA of the qth sTTI occupies q · m + [0, 1.. m-1] of SA resources of the tti]+Δ ₁ ，q＝0,1,...,M-1，

The qth sTTI data sub-channel occupies the lttti data sub-channel q · m + [0, 1.. m-1]]+Δ ₂ ，Δ ₁ And Δ ₂ Is a parameter of resource location, and N is the number of ttis data subchannels.

23. The apparatus of claim 15, wherein when SA of different length TTIs are received, the PSSCH-RSRP thresholds are different for different TTI lengths; or, recording the PSSCH-RSRP threshold as Th, comparing the PSSCH-RSRP with Th + delta to judge whether the resource is available, wherein delta is a power regulation parameter; or comparing PSSCH-RSRP + delta with a threshold to judge whether the resource is available, wherein PSSCH-RSRP is the received power of the data channel, and delta is the power adjusting parameter.

24. The device of claim 23, wherein RSRP of the PSSCH is less than or equal to the threshold, and wherein the set of resources for data transmission comprises resources for the PSSCH; the RSRP of the PSSCH is greater than the threshold, and the set of resources for data transmission does not include resources for the PSSCH.

25. The apparatus of claim 15, the determining a set of resources for data transmission comprising:

for one sTTI resource, if other sTTI with the same frequency position or overlapping frequency position is unavailable in the lTTI where the sTTI resource is located, the UE increases the probability of selecting the sTTI resource.

26. The device of claim 15, the resource selection module to determine resources for data transmission comprises:

when the number of the SAs supported by the UE to be detected is less than the total number of the SAs of various TTIs with different lengths in the lTTI, determining the detected SA resources according to the priority of the TTIs with different lengths; or,

and when the number of the SAs supported and detected by the UE is less than the total number of the SAs of the plurality of TTIs with different lengths in the lTTI, respectively determining the number of the SA resources of the lTTI and the number of the SA resources of the sTTI which need to be detected by the UE.

27. The device of claim 15, the resource selection module to determine the set of resources for data transmission comprises:

determining the number of PRBs of TTIs with different lengths according to the priorities of the TTIs with different lengths; or respectively determining the PRB number of lTTI and the PRB number of sTTI which are required to be detected by the UE.

28. The apparatus of claim 15, the control information is received based on a length of a plurality of TTIs.

29. A user device, comprising:

a transceiver; and

a processor coupled to the transceiver and configured to perform the method of any of claims 1-14.

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