JP2011188179A - Radio base station, radio communication terminal, and resource allocation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent increase of control overhead and to efficiently utilize radio resources even when a soundless state and a sounding state of UE 20 subjected to semi-persistent scheduling are repeated. <P>SOLUTION: A radio base station includes a securing section and an allocating section. The securing section secures, at predetermined time intervals, a block scheduling unit (block SPSU) constituted by continuing a plurality of scheduling units (SPSUs) as an allocation unit of radio resources to each UE 20 subjected to semi-persistent scheduling. The allocating section allocates the SPSUs constituting the block SPSUs to each UE 20 so as to share the block SPSU between the UE 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radio base station, a radio communication terminal, and a resource allocation method for performing communication using radio resources allocated by semi-persistent scheduling.

  Conventionally, semi-persistent scheduling is known as a method of assigning radio resources for transmitting and receiving packet data that occurs periodically but has a small payload size, such as VoIP (Voice over IP) data (for example, Non-patent document 1).

  Semi-persistent scheduling reduces the control overhead associated with the transmission and reception of packet data that occurs periodically but has a small payload size by allocating radio resources to a single radio communication terminal at fixed time intervals. is doing.

  Also, in semi-persistent scheduling, when a silent state (Talk Spurt OFF state) of a wireless communication terminal is detected, the use of the wireless resource is released by releasing the wireless resource fixedly assigned to the wireless communication terminal. Increases efficiency. On the other hand, when a voiced state (Talk Spurt ON state) of the wireless communication terminal is detected again, new wireless resources are fixedly allocated to the wireless communication terminal.

3GPP, TS36.321 Chapter 5.10

  However, in the above-described semi-persistent scheduling, when a silent state and a voiced state of a wireless communication terminal are repeated, a release process of a radio resource fixedly assigned to the wireless communication terminal and a new radio resource assignment process Is repeated, increasing the control overhead and reducing the utilization efficiency of radio resources.

  The present invention has been made in view of such a point, and can prevent an increase in control overhead even when a silent state and a voiced state of a semi-persistent scheduling target wireless communication terminal are repeated, and An object of the present invention is to provide a radio base station, a radio communication terminal, and a resource allocation method that can efficiently use radio resources.

  The radio base station according to the first aspect of the present invention provides a block scheduling unit configured by linking a plurality of scheduling units, which are radio resource allocation units for each radio communication terminal subject to semi-persistent scheduling, for a predetermined time. A securing unit that secures at intervals, and an allocating unit that allocates a scheduling unit constituting the block scheduling unit to each wireless communication terminal so that the block scheduling unit is shared among the wireless communication terminals. It has.

  According to this configuration, the block scheduling unit is fixedly secured at a predetermined time interval, and the block scheduling unit is shared between the radio communication terminals subject to semi-persistent scheduling. For this reason, even when a specific radio communication terminal subject to semi-persistent scheduling repeats a silent state and a voiced state, an increase in control overhead can be prevented and radio resources can be used efficiently.

  The radio communication terminal according to the second aspect of the present invention is a block that is block scheduling unit allocation information configured by continuously allocating a plurality of scheduling units, which are radio resource allocation units to a radio communication terminal subject to semi-persistent scheduling. An allocation information receiving unit that receives allocation information using a downlink control channel, a downlink data receiving unit that receives downlink data using a scheduling unit that constitutes a block scheduling unit indicated by the block allocation information, and the downlink data reception A downlink data acquisition unit that determines and acquires downlink data addressed to the terminal based on the identification information of the wireless communication terminal added to the downlink data received by the unit.

  A radio communication terminal according to a third aspect of the present invention relates to an allocation request unit that requests radio base station to allocate radio resources for transmitting uplink data, and a radio communication terminal subject to semi-persistent scheduling. An allocation information receiving unit that receives, using the downlink control channel, block allocation information that is allocation information of a block scheduling unit configured by continuously allocating a plurality of scheduling units that are radio resource allocation units, and the block allocation information indicates An uplink data transmitter that randomly selects a scheduling unit from among the scheduling units constituting the block scheduling unit, and uses the selected scheduling unit to transmit uplink data to which the identification information of the own terminal is added; Comprising.

  The resource allocation method according to the fourth aspect of the present invention provides a block scheduling unit configured by continuously allocating a plurality of scheduling units, which are radio resource allocation units for each radio communication terminal subject to semi-persistent scheduling, for a predetermined time. Securing at intervals, and allocating a scheduling unit constituting the block scheduling unit to each wireless communication terminal so that the block scheduling unit is shared among the wireless communication terminals. .

  According to the present invention, it is possible to prevent an increase in control overhead and to efficiently use radio resources even when the silent state and the voiced state of a semi-persistent scheduling target wireless communication terminal are repeated. Wireless base station, wireless communication terminal, and resource allocation method can be provided.

It is a block diagram of the radio | wireless communications system which concerns on this embodiment. It is a figure which shows the example of the conventional allocation of the radio | wireless resource with respect to the radio | wireless communication terminal of the conventional and semi-persistent scheduling object concerning this embodiment. It is a functional block diagram of eNB and UE which concern on this embodiment. It is a figure for demonstrating the downlink data which concern on this embodiment. It is a figure for demonstrating the conventional SPSU allocation information and the block allocation information which concerns on this embodiment. It is a figure for demonstrating the block allocation information which concerns on this embodiment. It is a figure for demonstrating the uplink data which concern on this embodiment. It is a sequence diagram which shows the transmission operation | movement of the downlink data which concerns on this embodiment. It is a sequence diagram which shows the transmission operation | movement of the uplink data which concerns on this embodiment. It is a figure which shows the ensuring operation | movement of block SPSU for downlink data transmission which concerns on this embodiment. It is a figure which shows the ensuring operation | movement of block SPSU for downlink data transmission which concerns on this embodiment. It is a figure which shows the allocation operation | movement of SPSU which comprises the block SPSU for downlink data transmission which concerns on this embodiment. It is a figure which shows the allocation operation | movement of SPSU which comprises the block SPSU for downlink data transmission which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

<Overall schematic configuration of wireless communication system>
FIG. 1 is a configuration diagram of a wireless communication system according to the present embodiment. As shown in FIG. 1, a radio communication system includes an eNB (NodeB) 10 that is a radio base station that supports various radio communication schemes such as the LTE (Long Term Evolution) scheme and the LTE-Advanced scheme, a mobile phone terminal, and a notebook. It is comprised from UE20a thru | or 20e which are radio | wireless communication terminals, such as a personal computer and a portable game machine. The eNB 10 transmits and receives packet data (for example, VoIP data) that is periodically generated but has a small payload size to and from the UEs 20a to 20e belonging to the cell C formed by the own station.

  Specifically, in the downlink, the eNB 10 allocates radio resources (PDSCH: Physical Downlink Shared Channel) for transmitting downlink data to the UEs 20a to 20e subject to semi-persistent scheduling, and assigns radio resource allocation information to the PDCCH. The UE 20a to 20e is notified using (Physical Downlink Control Channel). UE 20a thru | or 20e receive the downlink data addressed to an own terminal based on the allocation information notified by PDCCH.

  On the other hand, in the uplink, the eNB 10 allocates a radio resource (PUSCH: Physical Uplink Shared Channel) for transmitting uplink data in response to a radio resource allocation request from the UE 20a to the UE 20e subject to semi-persistent scheduling. The UE 20a to 20e is notified of radio resource allocation information using the PDCCH. UE20 transmits uplink data based on the allocation information notified by PDCCH.

  In FIG. 1, UE 20 a to UE 20 e all have the same configuration, and therefore are collectively referred to as UE 20 when they are not distinguished. In FIG. 1, five UEs 20 are illustrated, but the number of UEs 20 is not limited to this. Further, the eNB 10 may be a radio base station that supports a new radio communication scheme following the LTE scheme and the LTE-Advanced scheme described above.

  Next, allocation of radio resources to the UE 20 subject to semi-persistent scheduling in the radio communication system according to the present embodiment will be described in detail. FIG. 2 is a diagram showing an example of radio resource allocation to radio communication terminals subject to conventional and semi-persistent scheduling according to the present embodiment.

  As shown in FIG. 2A, in the conventional radio resource allocation method, a semi-persistent scheduling unit (hereinafter referred to as “Semi Persistent Scheduling”) is provided for each of the UEs 20a to 20e to be subjected to semi-persistent scheduling. Are fixedly assigned at predetermined time intervals.

  Here, the SPSU is a radio resource allocation unit for the UE 20 subject to semi-persistent scheduling, and one SPSU is composed of one subframe (10 ms) in the time direction and one or more resource blocks continuous in the frequency direction. Composed.

  For example, in FIG. 2A, for the UE 20a, the SPSU at the time T1 corresponding to the transmission request for downlink or uplink data and a predetermined time interval TI from the time T1 (for example, 20 TTI (Transmission Time Interval) = 20 ms. ) SPSU of time T3 later is allocated. Similarly, the SPSU is assigned to the UE 20b and the UE 20c.

  Moreover, since the silence state is detected after the lapse of time T2 for the UE 20d, the SPSU assigned to the UE 20d is released. For this reason, UE 20e instead of UE 20d is assigned to SPSU at time T5 after a predetermined time interval TI from time T2.

  On the other hand, as shown in FIG. 2B, in the radio resource allocation method according to the present embodiment, a block SPSU composed of a plurality of consecutive SPSUs has a predetermined time interval TI (20 TTI in FIG. 2). Secured in a fixed manner. Further, the block SPSU is allocated to the UEs 20a to 20e so that the block SPSU is shared by the UEs 20a to 20e subject to semi-persistent scheduling.

  Here, the block SPSU is composed of a plurality of consecutive SPSUs, and is shared between UEs 20 subject to semi-persistent scheduling. As shown in FIG. 2, one block SPSU is composed of a plurality of SPSUs that are continuous in the frequency direction in one time domain (for example, one subframe (10 ms)). Although not shown, one block SPSU may be composed of a plurality of SPSUs continuous in the time direction in one frequency domain, or from a plurality of SPSUs continuous in both the time direction and the frequency direction. It may be configured.

  For example, in FIG.2 (b), SPSU which comprises the block SPSU of time T2 is allocated with respect to UE20a with UE20b and UE20d, and downlink or uplink data are transmitted using SPSU which comprises the said block SPSU. The The UE 20a is also assigned an SPSU constituting a block SPSU at a time T5 after a predetermined time interval TI from the time T2, and downlink or uplink data is transmitted using the SPSU constituting the block SPSU.

  Similarly, the SPSUs constituting the block SPSU are allocated to the UEs 20b to 20e, and downlink or uplink data is transmitted using the SPSUs constituting the block SPSU.

  As described above, in the present embodiment, the block SPSU is fixedly secured at a predetermined time interval, and the block SPSU is shared between the UEs 20 subject to semi-persistent scheduling. For this reason, even when a specific UE 20 repeats a silent state and a voiced state, an increase in control overhead can be prevented and radio resources can be used efficiently.

  Next, the structure of eNB10 and UE20 which comprises the radio | wireless communications system which concerns on this embodiment is demonstrated. The eNB 10 and the UE 20 are physically devices including an antenna, a modem, a CPU, a memory, and the like. FIG. 3 is a functional configuration diagram of the eNB 10 and the UE 20 according to the present embodiment.

<Configuration of eNB>
As shown in FIG. 3, the eNB 10 includes a radio communication unit 101, a downlink data generation unit 102, a UE-ID addition unit 103, a downlink data queue 104, a resource allocation unit 105, an allocation information generation unit 106, an SPSU blind detection unit 107, An uplink data acquisition unit 108 is provided.

  The radio communication unit 101 transmits / receives various data to / from the UE 20. Specifically, the wireless communication unit 101 transmits allocation information to be described later using the PDCCH. Also, the wireless communication unit 101 transmits downlink data to the UE 20 using PDSCH (Physical Downlink Shared Channel). Moreover, the radio | wireless communication part 101 receives the uplink data from UE20 using PUSCH (Physical Uplink Shared Channel).

  The downlink data generation unit 102 generates downlink data for the UE 20 subject to semi-persistent scheduling.

  The UE-ID adding unit 103 adds identification information of the transmission destination UE 20 of the downlink data to the downlink data generated by the downlink data generating unit 102. FIG. 4 is a diagram for explaining downlink data according to the present embodiment. As illustrated in FIG. 4, the UE-ID adding unit 103 adds an error detection code such as CRC (Cyclic Redundancy Check) to the downlink data generated by the downlink data generation unit 102, and adds the added error detection. The identification information of the UE 20 is added by calculating the exclusive OR of the code and the identification information (UE-ID) of the transmission destination UE 20.

  Note that the UE-ID adding unit 103 may add identification information of the transmission destination UE 20 to the downlink data in an area different from the CRC.

  The downlink data queue 104 stores, in a FIFO (First-In First-Out), downlink data to which the identification information of the transmission destination UE 20 is added by the UE-ID adding unit 103.

The resource allocation unit 105 secures a block SPSU composed of a plurality of SPSUs at a predetermined time interval TI (for example, 20 TTI). Specifically, the resource allocation unit 105 determines a block SPSU size N _BSPS that is the number of SPSUs constituting the block SPSU, and _reserves the block SPSU of the determined block SPSU size N BSPS at a predetermined time interval TI.

Here, the block SPSU size N _BSPS for downlink data may be a predetermined fixed value, or according to the downlink data storage number N _BUFFER which is the number of downlink data stored in the downlink data queue 104. It may be a determined value.

In addition, when the downlink data storage number N _BUFFER exceeds the block SPSU size N _BSPS of the block SPSU in which the downlink data storage number N _BUFFER is secured, the resource allocation unit 105 dynamically schedules the SPSU for transmitting downlink data that could not be allocated to the block SPSU. May be assigned.

Moreover, the resource allocation unit 105, if the state in which downlink data storage number _{N BUFFER} exceeds block SPSU size _{N BSPS} is repeated a predetermined number of times or more, depending on the downlink data storage number _{N BUFFER} at that time, the block SPSU size _NBSPS May be updated, and the updated block SPSU size _NBSPS block SPSU may be allocated at a predetermined time interval TI.

Further, the resource allocation unit 105, when the state in which the downlink data storage number N _BUFFER is 0 is repeated a predetermined number of times or more, the predetermined time interval TI so that the radio resource can be allocated to the dynamic scheduling target UE 20 or the like. The block SPSU secured in step 1 may be released. In this case, the resource allocation unit 105 reallocates the block SPSU when the downlink data is stored in the downlink data queue 104.

On the other hand, when the state in which the downlink data storage number N _BUFFER is 0 has not been repeated more than a predetermined number of times, the resource allocation unit 105 has no downlink data to prevent control overhead related to the release and re-reservation of the block SPSU. In both cases, the block SPSU may be secured.

Further, the resource allocating unit 105 _retrieves the number of downlink data corresponding to the block SPSU size N _BSPS from the downlink data queue 104, and uses the extracted SUSUs constituting the block SPSU secured by the resource allocating unit 105. The wireless communication unit 101 is requested to transmit the downlink data extracted from the downlink data queue 104.

Moreover, the resource allocation unit 105 determines a block SPSU size _NBSPS the number of SPSU constituting the block SPSU for uplink data, a block SPSU decision block SPSU size _{N BSPS} ensuring at predetermined time intervals TI.

Here, the block SPSU size N _BSPS for uplink data may be a predetermined fixed value, or a value determined according to the number of requests from the allocation request unit 207 of the UE 20 described later. Also good.

  Further, the resource allocation unit 105 allocates SPSUs constituting the block SPSU for uplink data to the UE 20 in response to a block SPSU allocation request for the UE 20 from the allocation request unit 207 of the UE 20 described later.

  Moreover, the resource allocation part 105 may allocate the radio | wireless resource for transmitting uplink data with respect to UE20 instruct | indicated from the SPSU blind detection part 107 mentioned later by dynamic scheduling.

  The allocation information generation unit 106 generates block allocation information. Here, block allocation information according to the present embodiment will be described in comparison with conventional SPSU allocation information. FIG. 5 is a diagram for explaining conventional SPSU allocation information and block allocation information.

  In the conventional radio resource allocation method, an SPSU is allocated to each of the UEs 20a to 20e to be subjected to semi-persistent scheduling (see FIG. 2A). Therefore, as shown in FIG. 5A, the UEs 20a to 20d SPSU allocation information is generated for each of. Here, the SPSU assignment information is information indicating the SPSU fixedly assigned to the UE 20 at a predetermined time interval TI, and is generated at the start of SPSU assignment and notified to the UE 20.

  For example, in subframe 1 in FIG. 5A, SPSU allocation information is notified using the PDCCH to each of UE 20a to UE 20d for which SPSU allocation is started in subframe 1. Also, in subframe 2, SPSU allocation information is notified using PDCCH only to UE 20e for which SPSU allocation is started in subframe 2.

  On the other hand, in the radio resource allocation method according to the present embodiment, the block SPSU is shared between the UEs 20a to 20e that are the targets of semi-persistent scheduling (see FIG. 2B). As described above, the allocation information generation unit 106 generates block allocation information. Here, the block allocation information is information indicating a block SPSU that is fixedly secured at a predetermined time interval TI, and is notified to the UE 20 to which the block SPSU is allocated.

  For example, in the subframe 1 in FIG. 5B, one block allocation information is notified using PDCCH to the UEs 20a to 20d in which the allocation of the block SPSU is started in the subframe 1. Also, in subframe 2, block allocation information is reported using PDCCH only to UE 20e for which block SPSU allocation is started in subframe 2.

  Further, the allocation information generation unit 106 adds the identification information of the destination group of the block allocation information to the block allocation information as described above. Here, the destination group is a group composed of UEs 20 allocated to the block SPSU indicated by the block allocation information.

  FIG. 6 is a diagram for explaining block allocation information according to the present embodiment. As illustrated in FIG. 6, the allocation information generation unit 106 adds an error detection code such as CRC (Cyclic Redundancy Check) to the block allocation information, and identifies the destination group identification information ( A bit string including (Group-ID) is superimposed. The superimposition means that the added error detection code and the bit string including the destination group identification information are calculated using a predetermined calculation method. As the predetermined calculation method, for example, exclusive OR is used.

  Here, the bit string superimposed on the error detection code (for example, CRC) added to the block allocation information according to the present embodiment will be described in detail. The bit string superimposed on the CRC added to the conventional SPSU allocation information (see FIG. 5A) is identification information (16 bits) of the destination UE 20 of the SPSU allocation information. On the other hand, the bit string superimposed on the CRC added to the block allocation information according to the present embodiment includes the identification information (Group-ID) of the upper x bit destination group and the UE 20 in the lower 16-x bit destination group. It is hierarchized into identification information. In addition, as shown in FIG. 6, 0 (zero) may be set in the identification information of the UE 20 in the lower 16-x bit group. This is because if the destination group identification information (Group-ID) is superimposed on the CRC of the block allocation information, the UE 20 identifies the previously identified group identification even if the UE 20 identification information is not superimposed. This is because it is possible to detect and receive whether the block allocation information is addressed to the group to which the terminal belongs, based on the information.

  In the above-described example, the bit string superimposed on the CRC added to the block allocation information is a 16-bit bit string including the destination group identification information, but is not limited to 16 bits. Further, the destination group identification information may be directly superimposed on the block allocation information, or may be added to the block allocation information as a new bit instead of being superimposed.

  Also, the allocation information generation unit 106 requests the radio communication unit 101 to transmit the block allocation information with the group identification information added as described above using the PDCCH.

  The SPSU blind detection unit 107 detects the UE 20 that is the transmission source of the uplink data received by the wireless communication unit 101 using the block SPSU for uplink data. FIG. 7 is a diagram for explaining SPSU blind detection according to the present embodiment.

  As illustrated in FIG. 7, each uplink data received using the block SPSU for uplink data includes identification information (UE-ID) of the UE 20 that is the transmission source of each uplink data, similarly to the downlink data illustrated in FIG. 4. ) Is added. The SPSU blind detection unit 107 reversely calculates the CRC added to each uplink data received using the block SPSU in turn using the identification information of the UE 20 assigned to the block SPSU. The SPSU blind detection unit 107 detects that the UE 20 from which the error detection code has been correctly extracted is the uplink data transmission source.

  The SPSU blind detection unit 107 determines that there is a collision of uplink data between the UEs 20 when the uplink data block SPSU does not detect uplink data having the UE 20 assigned to the block SPSU as a transmission source. Then, the resource allocation unit 105 may be requested to allocate the SPSU for transmitting uplink data from the UE 20 by dynamic scheduling.

  The uplink data acquisition unit 108 performs error detection processing based on the extracted CRC for each uplink data whose transmission source is detected by the SPSU blind detection unit 107. The uplink data acquisition unit 108 acquires each uplink data on which error detection processing has been performed.

<Configuration of UE 20>
As illustrated in FIG. 3, the UE 20 includes a radio communication unit 201, an allocation information detection unit 202, an SPSU blind detection unit 203, a downlink data acquisition unit 204, an uplink data generation unit 205, a UE-ID addition unit 206, and an allocation request unit 207. , SPSU random assignment unit 208 is provided.

  The wireless communication unit 201 transmits / receives various data to / from the eNB 10. Specifically, the radio communication unit 201 receives block allocation information using the PDCCH. Also, the wireless communication unit 201 receives downlink data using PDSCH. Moreover, the wireless communication part 201 transmits uplink data using PUSCH.

  The allocation information detection unit 202 detects block allocation information addressed to the own group from the block allocation information received by the wireless communication unit 201. Specifically, the allocation information detection unit 202 determines block allocation information addressed to its own group depending on whether or not the group identification information added to the block allocation information matches the group identification information notified from the eNB 10 in advance. To detect.

  For example, the allocation information detection unit 202 performs a reverse operation on the CRC added to the block allocation information as shown in FIG. 6 using a bit string composed of group identification information and 0 (zero) notified in advance from the eNB 10, It is detected that the block allocation information from which the CRC is correctly extracted from the bit string is addressed to the own group. The allocation information detection unit 202 notifies the SPSU blind detection unit 203 and the SPSU random allocation unit 208 of the block SPSU indicated by the acquired block allocation information.

  The SPSU blind detection unit 203 detects downlink data destined for the own terminal based on the identification information of the UE 20 added to the downlink data received by the wireless communication unit 201. For example, the SPSU blind detection unit 203 reverse-calculates the CRC added to each downlink data in order with the identification information (UE-ID) of the own terminal in the same manner as the uplink data of FIG. In this case, it is detected that the downlink data from which the CRC is correctly extracted is addressed to the own terminal.

  The downlink data acquisition unit 204 performs error detection processing based on the extracted CRC for the downlink data detected by the SPSU blind detection unit 203 as being addressed to the own terminal. The downlink data acquisition unit 204 acquires downlink data on which error detection processing has been performed.

  The uplink data generation unit 205 generates uplink data subject to semi-persistent scheduling.

  UE-ID adding section 206 adds identification information of the terminal itself to the uplink data generated by uplink data generating section 205. For example, the UE-ID adding unit 206 adds an error detection code such as CRC to the uplink data, similarly to the downlink data of FIG. 4, and adds the error detection code and identification information (UE-ID) of the terminal itself. ) And an exclusive OR.

  The allocation request unit 207 requests the resource allocation unit 105 of the eNB 10 to allocate the block SPSU when the uplink data block SPSU is not allocated to the terminal itself. Specifically, the allocation request unit 207 instructs the radio communication unit 201 to transmit a block SPSU allocation request to the resource allocation unit 105 of the eNB 10.

  The SPSU random assignment unit 208 randomly selects an SPSU from among the SPSUs constituting the block SPSU assigned to the terminal by the resource assignment unit 105 of the eNB 10. The SPSU random assignment unit 208 instructs the radio communication unit 201 to transmit the uplink data to which the CRC is added by the UE-ID addition unit 206 and the UE-ID is superimposed using the selected SPSU.

<Operation of wireless communication system>
Next, the operation of the wireless communication system according to this embodiment configured as described above will be described.

(1) Downlink Data Transmission Operation A downlink data transmission operation according to the present embodiment will be described with reference to FIG. FIG. 8 is a sequence diagram showing a downlink data transmission operation according to the present embodiment.

  As illustrated in FIG. 8, the downlink data generation unit 102 of the eNB 10 generates downlink data to be subjected to semi-persistent scheduling such as VoIP data (step S101). As described with reference to FIG. 4, the UE-ID adding unit 103 adds the identification information of the UE 20 that is the destination of the downlink data to the generated downlink data, and downloads the downlink data to which the identification information of the UE 20 is added. The data is stored in the data queue 104 by FIFO (step S102).

  The resource allocation unit 105 determines whether or not a downlink data block SPSU is secured (step S103). When the block SPSU for downlink data is not secured (step S103; No), the resource allocation unit 105 secures a block SPSU composed of a predetermined number of SPSUs at a predetermined time interval TI (step S104).

The resource allocation unit 105 determines whether or not it is the reserved time T _BSPS reserved as the block SPSU (step S105). If it is not the reserved time T _BSPS (step S105; No), the resource allocation unit 105 waits for a predetermined time and then returns to step S105.

On the other hand, when the block SPSU reservation time T _BSPS is _reached (step S105: Yes), the resource allocation unit 105 sets the SPSU that forms the block SPSU to the UE 20 that is the destination of the downlink data stored in the downlink data queue 104. Is assigned (step S106).

  The resource assignment unit 105 determines whether or not the UE 20 assigned to the SPSU constituting the block SPSU for the first time is included in the UE 20 assigned to the SPSU constituting the block SPSU (step S107).

  When the UE 20 assigned for the first time to the SPSU constituting the block SPSU is included (step S107; Yes), the assignment information generation unit 106 generates block assignment information for the UE 20, and identifies the destination group in the generated block assignment information. Information is added (step S108).

  The wireless communication unit 101 transmits the block allocation information added with the group identification information by the allocation information generation unit 106 using the PDCCH (step S109).

  The radio communication unit 101 extracts the downlink data for the UE 20 assigned to the SPSU constituting the block SPSU from the downlink data queue 104 and transmits the downlink data using the assigned SPSU (step S110).

  The allocation information detection unit 202 of the UE 20 determines whether the group identification information added to the block allocation information received using the PDCCH matches the identification information of the own group, thereby determining the block addressed to the own group. Allocation information is detected (step S111). Specifically, the allocation information detection unit 202 performs reverse calculation of the CRC using the group identification information notified from the eNB 10 in advance, and acquires the block allocation information that the CRC was correctly extracted.

  The SPSU blind detection unit 203 detects downlink data destined for the own terminal from the downlink data received by the wireless communication unit 201 using the block SPSU indicated by the block allocation information (step S112). Specifically, as shown in FIG. 7, the SPSU blind detection unit 203 reverse-calculates the CRC added to each downlink data in order with the identification information of the own terminal, and can correctly extract the CRC with the identification information of the own terminal. It detects that the downlink data is addressed to its own terminal.

  The downlink data acquisition unit 204 performs error detection processing based on the extracted CRC for the downlink data detected by the SPSU blind detection unit 203 as being addressed to the own terminal. The downlink data acquisition unit 204 acquires downlink data on which error detection processing has been performed (step S113).

(2) Uplink Data Transmission Operation With reference to FIG. 9, the uplink data transmission operation according to the present embodiment will be described. FIG. 9 is a sequence diagram showing an uplink data transmission operation according to the present embodiment.

  The uplink data generation unit 205 of the UE 20 generates uplink data to be subjected to semi-persistent scheduling such as VoIP data (step S201). The UE-ID adding unit 103 adds the identification information of the own terminal to the generated uplink data, similarly to the downlink data of FIG. 4 (step S202).

  The allocation request unit 207 determines whether or not the SPSUs constituting the uplink data block SPSU are allocated to the own terminal (step S203). When the SPSU is not assigned to the own terminal (step S203; No), the assignment requesting unit 207 requests the resource assigning unit 105 of the eNB 10 to assign the SPSU constituting the block SPSU to the own terminal (step). S204).

  The resource allocation unit 105 of the eNB 10 allocates an SPSU that constitutes a block SPSU to the UE 20 in response to a request from the allocation request unit 207 of the UE 20 (Step S205).

  The allocation information generation unit 106 generates block allocation information for the UE 20 and adds group identification information to the generated block allocation information (step S206). The wireless communication unit 101 transmits the block allocation information to which the group identification information is added by the allocation information generation unit 106 using the PDCCH (step S207).

  The allocation information detection unit 202 of the UE 20 determines whether the group identification information added to the block allocation information received using the PDCCH matches the identification information of the own group, thereby determining the block addressed to the own group. Allocation information is detected (step S208). Specifically, the allocation information detection unit 202 performs reverse calculation of the CRC using the group identification information notified from the eNB 10 in advance, and acquires the block allocation information that the CRC was correctly extracted.

The SPSU random assignment unit 208 determines whether or not it is the reserved time T _BSPS of the block SPSU assigned to the UE 20 (step S209). On the other hand, when it is not the reserved time T _BSPS of the block SPSU (step S209; No), this operation waits for a predetermined time and returns to step S209.

On the other hand, when it is the block SPSU reservation time T _BSPS (step S209; Yes), the SPSU random assignment unit 208 randomly selects an SPSU from the SPSUs constituting the block SPSU assigned to the UE 20 (step S210). ).

  Using the SPSU selected by the SPSU random assignment unit 208, the radio communication unit 201 transmits uplink data to which the identification information of the UE 20 is added in step S202 to the eNB 10 (step S211).

  The SPSU blind detection unit 107 of the eNB 10 detects the transmission source of the uplink data received by the wireless communication unit 101 using the block SPSU (Step S212). Specifically, the SPSU blind detection unit 203 reversely calculates the CRC added to each uplink data in order with the identification information of each UE 20 assigned to the same block SPSU as shown in FIG. The source UE 20 is detected depending on whether it can be taken out.

  The uplink data acquisition unit 108 performs error detection processing based on the extracted CRC for the uplink data whose transmission source is detected by the SPSU blind detection unit 107. The uplink data acquisition unit 108 acquires uplink data on which error detection processing has been performed (step S213).

  On the other hand, the SPSU blind detection unit 107 detects a collision of uplink data between the UEs 20 when the uplink data having the UE 20 assigned to the block SPSU as a transmission source cannot be detected (step S214). In such a case, the resource allocation unit 105 allocates an SPSU to the UE 20 that has collided by dynamic scheduling in accordance with an instruction from the SPSU blind detection unit 107.

  As shown in FIG. 5A, the allocation information generation unit 106 generates SPSU allocation information indicating the SPSU allocated to the UE 20 by dynamic scheduling, and the radio communication unit 101 converts the generated SPSU allocation information into PDCCH (Step S215).

  The radio communication unit 201 of the UE 20 transmits the uplink data in which the collision has occurred using the SPSU indicated by the SPSU allocation information transmitted in step S215 (step S216).

(3) Securing operation of block SPSU for downlink data transmission The securing operation of the block SPSU for downlink data according to this embodiment will be described in detail with reference to FIGS. 10 to 11 are diagrams illustrating operations for securing a block SPSU for downlink data according to the present embodiment.

As illustrated in FIG. 10, the resource allocation unit 105 of the eNB 10 has a downlink data storage number N _BUFFER that is the number of downlink data stored in the downlink data queue 104 at ₀ in the reservation time T _BSPS reserved as the block SPSU. Even in some cases, if the state has not been repeated a predetermined number of times or more, the block SPSU is continuously secured.

For example, in FIG. 10, the resource allocation unit 105 has a downlink data storage number N _BUFFER of 0 in the reservation time T _BSPS3 , but in order to prevent a control overhead related to the release and re-reservation of the block SPSU, Continue to secure SPSU.

On the other hand, as shown in FIG. 11, the resource allocation unit 105 of the eNB 10 repeats the state where the downlink data storage number N _BUFFER is 0 for a predetermined number S or more in the reserved time T _BSPS reserved as the block SPSU, The block SPSU reserved at a predetermined time interval TI may be released so that radio resources can be allocated to the UE 20 or the like subject to dynamic scheduling. In this case, the resource allocation unit 105 reallocates the block SPSU when the downlink data is stored in the downlink data queue 104.

For example, in FIG. 11, the resource allocation unit 105 _{repeats the state} in which the downlink data storage number N _BUFFER is 0 at the reserved time T _BSPS3 for a predetermined number of times S (for example, 3) or more. , Release block SPSU. _Further , the block SPSU is re-secured at the secure time T _BSPS5 .

(4) SPSU Assignment Operation Constructing Downlink Data Transmission Block SPSU With reference to FIG. 12 to FIG. 13, the SPSU assignment operation constituting the downlink data block SPSU according to the present embodiment will be described in detail. 12 to 13 are diagrams showing an assignment operation of SPSUs constituting the block SPSU for downlink data according to the present embodiment. 12 and 13, it is assumed that the resource allocation unit 105 of the eNB 10 secures the block SPSU at a predetermined time interval TI.

As illustrated in FIG. 12, the resource allocation unit 105 of the eNB 10 includes the SPSU size N _{BSPS in} which the downlink data storage number N _BUFFER is the number of SPSUs constituting the block SPSU before the reserved time T _BSPS reserved as the block _SPSU. In the case of exceeding SPSU, the SPSU may be allocated by dynamic scheduling to the UE 20 that cannot allocate the SPSU constituting the block SPSU.

  For example, in FIG. 12, the resource assignment unit 105 can assign SPSUs constituting the block SPSU to the UE 20a, UE 20d, and UE 20b. On the other hand, the resource allocating unit 105 allocates SPSUs by dynamic scheduling because the SPSUs constituting the block SPSUs cannot be allocated to the UEs 20e and 20c.

In addition, as illustrated in FIG. 13, the resource allocation unit 105 of the eNB 10 continues the state where the downlink data storage number N _BUFFER exceeds the SPSU size N _{BSPS a} predetermined number of times S by the reserved time T _BSPS reserved as the block SPSU. In this case, the number of SPSUs constituting the block SPSU may be increased.

For example, in FIG. 13, since the resource allocation unit 105 _{repeats a state} in which the downlink data storage number N _BUFFER is larger than the block SPSU size N _{BSPS at} the reserved time T _BSPS3 by a predetermined number of times S (for example, 3) or more, In the reserved time T _BSPS3 , the block SPSU size _NBSPS is updated from 3 to 5 in accordance with the downlink data storage number N _BUFFER , and the updated block SPSU size _NBSPS block SPSU is allocated at a predetermined time interval TI.

<Action and effect>
According to the radio communication system according to the present embodiment, the block SPSU is fixedly secured at a predetermined time interval, and the block SPSU is shared between the UEs 20 subject to semi-persistent scheduling. For this reason, even when a specific UE 20 subject to semi-persistent scheduling repeats a silent state and a voiced state, an increase in control overhead can be prevented and radio resources can be used efficiently.

[Other Embodiments]
Although the present invention has been described in detail using the above-described embodiments, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

DESCRIPTION OF SYMBOLS 10 ... eNB, 20, 20a thru | or 20e ... UE, 101 ... Radio | wireless communication part, 102 ... Downlink data generation part, 103 ... UE-ID addition part, 104 ... Downlink data queue, 105 ... Resource allocation part, 106 ... Assignment information generation 107: SPSU blind detection unit, 108 ... uplink data acquisition unit, 201 ... wireless communication unit, 202 ... assignment information detection unit, 203 ... SPSU blind detection unit, 204 ... downlink data acquisition unit, 205 ... uplink data generation unit, 206 ... UE-ID addition unit, 207 ... Allocation request unit, 208 ... SPSU random allocation unit

Claims (11)

A securing unit that secures a block scheduling unit constituted by a plurality of continuous scheduling units, which are radio resource allocation units for each radio communication terminal subject to semi-persistent scheduling, at a predetermined time interval;
An allocating unit for allocating a scheduling unit constituting the block scheduling unit to each wireless communication terminal so that the block scheduling unit is shared between the wireless communication terminals;
A radio base station comprising:   To the block allocation information which is the allocation information of the block scheduling unit, identification information of a group composed of radio communication terminals to which the scheduling unit constituting the block scheduling unit is allocated is added, and the identification information of the group is added The radio base station according to claim 1, further comprising an allocation information transmitting unit that transmits the block allocation information that has been transmitted using a downlink control channel.   Using the scheduling unit in which identification information of the wireless communication terminal is added to downlink data for the wireless communication terminal, and the downlink data to which the identification information of the wireless communication terminal is added is assigned to the wireless communication terminal The radio base station according to claim 2, further comprising a downlink data transmission unit that transmits the data. A storage unit for storing downlink data for the wireless communication terminal;
The radio base station according to claim 3, wherein the allocating unit allocates a scheduling unit constituting the block scheduling unit to a radio communication terminal that is a destination of downlink data stored in the storage unit.   When the number of downlink data stored in the storage unit by the reserved time reserved as the block SPSU exceeds the number of scheduling units constituting the block scheduling unit, the allocating unit configures the block scheduling unit 5. The radio base station according to claim 4, wherein a scheduling unit is allocated using dynamic scheduling to a radio communication terminal to which no scheduling unit is allocated.   When the state in which the number of downlink data stored in the storage unit in the storage unit exceeds the number of scheduling units is continued a predetermined number of times by the reservation time, the reservation unit configures the scheduling that constitutes the block scheduling unit. The radio base station according to claim 5, wherein the number of units is increased.   If the state in which the number of downlink data stored in the storage unit is zero in the storage unit by the reservation time is continued a predetermined number of times, the reservation unit reserves the block scheduling reserved at the predetermined time interval. The radio base station according to claim 5 or 6, wherein the unit is released. An uplink data receiving unit for receiving uplink data using a scheduling unit constituting the block scheduling unit;
2. The wireless communication terminal identification information added to the uplink data received by the uplink data reception unit, and further comprising a detection unit that detects a transmission source of the uplink data. The radio base station described in 1. Allocation information for receiving block allocation information, which is block scheduling unit allocation information configured by continuously allocating a plurality of scheduling units, which are radio resource allocation units for radio communication terminals subject to semi-persistent scheduling, using a downlink control channel A receiver,
A downlink data receiving unit that receives downlink data using a scheduling unit that constitutes a block scheduling unit indicated by the block allocation information;
A downlink data acquisition unit that determines and acquires downlink data addressed to the terminal based on identification information of the wireless communication terminal added to the downlink data received by the downlink data reception unit;
A wireless communication terminal comprising: An allocation requesting unit for requesting radio base stations to allocate radio resources for transmitting uplink data;
Allocation information for receiving block allocation information, which is block scheduling unit allocation information configured by continuously allocating a plurality of scheduling units, which are radio resource allocation units for radio communication terminals subject to semi-persistent scheduling, using a downlink control channel A receiver,
Uplink data transmission for randomly selecting a scheduling unit from among the scheduling units constituting the block scheduling unit indicated by the block allocation information, and transmitting the uplink data to which the identification information of the terminal is added using the selected scheduling unit And
A wireless communication terminal comprising: Securing a block scheduling unit formed by a plurality of continuous scheduling units, which are radio resource allocation units for each radio communication terminal subject to semi-persistent scheduling, at a predetermined time interval;
Allocating a scheduling unit constituting the block scheduling unit to each wireless communication terminal so that the block scheduling unit is shared between the wireless communication terminals;
A resource allocation method comprising:

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