KR101445387B1 - Apparatus and method for allocating resource in mobile telecommunication system - Google Patents

Abstract

A method of allocating resources in a mobile communication system, the method comprising: receiving resource allocation information for uplink transmission from a base station in a mobile communication system according to the present invention; And the resource allocation information indicates information of resources allocated by the persistent resource allocation method or the dynamic resource allocation method according to a result of comparison between the number of data transfer times and the preset number of valid persistent resource allocations.

VoIP, scheduling, persistent scheduling

Description

[0001] APPARATUS AND METHOD FOR ALLOCATING RESOURCE IN MOBILE TELECOMMUNICATION SYSTEM [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a resource allocation and apparatus and method in a mobile communication system, and more particularly, to a resource allocation apparatus and method for efficiently transmitting a packet such as Voice over IP (VoIP) in a mobile communication system.

Generally, a wireless communication system is a system developed for a case where a fixed wired network can not be connected to a terminal. Representative systems of such wireless communication systems include a wireless LAN, a wireless broadband Internet (Wibro), and a mobile ad hoc network as well as a general mobile communication system providing voice and data services.
Unlike general wireless communication, mobile communication presupposes user's mobility. The ultimate goal of mobile communication is to provide information media that transcends time and space to anytime, anywhere, and anyone by using a mobile station (MS) such as a personal data assistant (PDA) It is giving and receiving. In accordance with the rapid development of communication technology, the mobile communication system is providing a high-speed data service capable of transmitting a large amount of digital data such as moving picture as well as e-mail, still image and moving picture using a mobile phone as well as a general voice call service.

Also, there is a need for a communication system capable of efficiently providing a high-speed packet data service according to the demand of users. To meet this need, many businesses are now looking for new ways to reduce the costs associated with providing voice services without depriving users of the comfort and familiarity that existing services offer. Such cost savings are facilitating the integration of data networks and voice networks, and as data networks and voice networks become more and more integrated, the quality and reliability of voice networks are not affected Carefully designed and planned.

According to this flow, a voice over IP (VoIP) in which voice packets are transmitted through a packet network has been widely discussed.

First, the traffic characteristics of the VoIP service will be described with reference to FIG.

FIG. 1 is a diagram for explaining traffic characteristics of a Voice over IP (VoIP) service in a general mobile communication system, and shows an AMR (Adaptive Multirate Codec) vocoder for generating traffic. Depending on the vocoder type, the voice packet generation interval and the traffic size may vary, but have similar characteristics as described below. A period in which the traffic exists is referred to as a talk spurt period 101 and a period in which the traffic does not exist is referred to as a silent period 103. In the talk spurt period 101, And generates a SID (silent indicator) having a fixed size every 160 ms (104) in the silent interval 103. [ The size of a voice packet has a size of about 40 bytes even if it is a full rate. Since the size of a general Internet packet is several hundreds to several thousand bytes, the voice packet size is relatively small compared to a general Internet packet .

As described above, in order to transmit a small-sized voice packet generated every 20 ms (102), transmitting a physical downlink control channel (PDCCH) for transmitting scheduling information, which is resource allocation information, at each transmission time This can be a significant signaling overhead. Therefore, a persistent scheduling method, which is a persistent resource allocation method, has been proposed in order to efficiently support a service having the above characteristics. Hereinafter, a persistent scheduling method, which is a persistent resource allocation method, will be described with reference to FIG. 2 attached hereto.

2 is a diagram illustrating a persistent scheduling method in a general mobile communication system.

The UE is allocated a specific time and a specific resource in the entire 20 ms interval through the upper signaling or the PDCCH. FIG. 2 shows a case where a persistent resource is allocated to three transmission time intervals (TTIs). In the above, the persistent resource can inform the higher signaling at the time of call setup and inform the PDCCH through the PDCCH. In the latter case, bit information indicating whether dynamic resource allocation or persistent resource allocation is required is included in the PDCCH information. Referring to FIG. 2, it can be seen that the TTIs of 3 times (201, 202, 203) are allocated as the persistent resource allocation method at intervals of 5 ms for 20 ms intervals, and Hybrid Automatic Repeat reQuest (RTT) It can be seen that there are four transmission opportunities in total. However, in FIG. 2, three transmission opportunities are continuously allocated. In this case, even if there is no PDCCH information transmitted to the UE at the time of the reference time 201, 202 or 203, which is a specific time point at which the resource is allocated, the UE transmits a PDSCH Physical Downlink Shared Channel).

However, Persistent Scheduling, which is a general persistent resource allocation method described above, is disadvantageous in that it can not efficiently utilize the entire resources because the resources are continuously allocated for the required number of transmissions. In order to solve this problem, in a case where a resource is allocated using only the initial transmission only resource allocation method and a retransmission occurs in the transmission side because a negative acknowledgment (NACK (Not Acknowledge) message indicating that data is not received from the receiving side is not received A method of dynamic resource allocation using PDCCH is being discussed.

Hereinafter, the initial transmission continuous allocation method described above with reference to FIG. 3 will be described.

3 is a diagram illustrating a method of using persistent scheduling only for initial transmission in a general mobile communication system. In FIG. 3, the base station allocates resources by a continuous resource allocation method to only one TTI of the 20 ms interval as indicated by reference numerals 303 and 306.

It can be seen that the UE allocates a resource by the persistent resource allocation method at the initial point in time of 20 ms as indicated by reference numeral 303. When the UE fails to transmit the resource allocation information due to the persistent resource allocation method at this initial point, The UE transmits scheduling information, which is resource allocation information, using the PDCCH 301 as shown at 309, 310, 311, and 312, and the UE transmits the scheduling information to the UE through the PDCCH 301 at the transmission time of the UEs 309, 310, 311, 305, 307, and 308 through the resources indicated by the resource allocation information transmitted to the reference numbers 309, 310, 311, and 312 when there is the resource allocation information.

In FIG. 3, reference numerals 303 and 306 denote resource allocation by the persistent scheduling method as promised, reference numerals 309, 310, 311 and 312 denote resource allocation dynamically, And receives data through the resources 304, 305, 307, and 308 indicated by the information. However, in the method of transmitting only the initial transmission as described above with reference to FIG. 3 using the persistent resource allocation method, and allocating resources by dynamically allocating transmission resources to be transmitted next, the PDCCH which should be used as the number of retransmissions of the transmitting side increases The signaling overhead can be increased like a dynamic resource allocation scheme. If the initial BLER is low, it is difficult to keep the initial transmission BLER at a low level for the following four reasons in the case of a general system, although the number of terminals performing the retransmission is small.

1. Inaccuracy of selection of MCS (Modulation and Coding Scheme) level: When the persistent resource allocation is performed for initial transmission, not only the location and amount of radio resources but also the MCS level are fixed. In the case of downlink, (channel quality indicator) information, and the uplink is determined by the base station based on the pilot transmitted by the terminal. In this case, a measurement error may occur on the CQI, pilot strength, and the like. Also, if the mobile speed of the terminal is high, this measurement error will be considerably large. Since this value is not accurate, it is difficult to select the MCS so that the base station maintains a low BLER.

2. Power control instability: In order to maintain the scheduled MCS, it is necessary to keep the received power level constant through power control, which must also measure the CQI or pilot. However, CQI or pilot measurement error occurs due to a measurement error, a terminal speed, etc., and the power control can not be performed perfectly.

3. Adjacent cell interference: Even if the MCS level is correctly selected, if the adjacent cell interference at the time of the determination and the adjacent cell interference at the time of the actual transmission are wrong, the desired BLER will not be satisfied. In an Orthogonal Frequency Division Multiple Access (OFDM) system, it is more difficult to maintain a low initial BLER since interference is more disturbed than in a Code Division Multiple Access (CDMA) system.

4. Power shortage of UEs at cell edge: A UE at the cell edge in the uplink may not support a high data rate or a high initial transmission BLER due to power shortage. In this case, it is possible to transmit using a small transmission power if the initial transmission rate is increased and the transmission is divided several times.

The present invention provides an apparatus and method for resource allocation for transmitting a voice over IP packet in uplink or downlink in a mobile communication system.

A method according to an embodiment of the present invention is a method for allocating resources of a mobile station in a mobile communication system, the method comprising the steps of: receiving resource allocation information for uplink transmission from a base station, And information on resources allocated by the persistent resource allocation scheme or the dynamic resource allocation scheme according to a comparison result of preset effective number of persistent resource allocations.

A method according to another embodiment of the present invention is a method of allocating a resource of a base station in a mobile communication system, the method comprising the steps of: comparing a number of data transmissions with a preset effective number of persistent resource allocations; Or allocating resources by a dynamic resource allocation scheme.

An apparatus for allocating resources in a mobile communication system includes a receiver for receiving resource allocation information from a base station, wherein the resource allocation information includes a number of data transmissions and a preset persistent resource And indicates information of resources allocated by the persistent resource allocation scheme or the dynamic resource allocation scheme according to the comparison result of the allocation effective count.

According to another aspect of the present invention, there is provided an apparatus for allocating resources in a mobile communication system, the apparatus comprising: a base station for allocating resources in a mobile communication system, the base station comprising: A resource allocation controller for allocating resources according to a resource allocation scheme, and a transmitter for transmitting information on the allocated resources.

According to the present invention, when a large amount of VoIP packets are required to be retransmitted in a mobile communication system, control signaling overhead required for resource allocation can be reduced and radio resource efficiency of the network can be increased.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In order to solve the problems described in the prior art, the present invention proposes a scheme of performing persistent scheduling not only at the initial transmission but also performing persistent scheduling up to a predetermined number of retransmissions.

In other words, the embodiment of the present invention proposes a method of variably setting the case where the persistent resource allocation is valid. The number of available persistent resource allocation in a given duration (Nper) may be set for each UE, and the number of valid resources for the persistent resource allocation can be set in consideration of the average number of transmissions to be operated on a cell-by-cell basis. When the terminal is set differently, it can be set considering the channel status, the moving speed or the transmission power situation of each terminal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A detailed description of embodiments of the present invention will be given in the following embodiments. For the sake of convenience, the present invention will be described by taking the case of downlink VoIP service transmission as an example, but the basic idea of the present invention can also be applied to the uplink as well. In addition, although a resource allocation method for transmitting a VoIP packet is exemplified in the present specification, the present invention is not limited thereto, and may be applied to a resource allocation method for transmitting and receiving general data packets. In addition, when the present invention is applied to an uplink, a base station allocates resources to a mobile station, and the mobile station transmits data in an uplink through the allocated resources

First, a process of allocating a dynamic resource and a persistent resource according to an embodiment of the present invention will be described with reference to FIGS. 4, 5A, and 5B. 4 to 5B are proposed schemes for allocating dynamic resources according to an embodiment of the present invention.
4 is a diagram illustrating a case where a packet to be retransmitted is transmitted asynchronously while transmitting and receiving a VoIP packet in a mobile communication system according to an embodiment of the present invention.

That is, FIG. 4 illustrates a case where resources are allocated to the initial transmission and the first retransmission by the persistent resource allocation scheme according to the embodiment of the present invention.

If the entire system is a synchronous HARQ, the retransmission time will be determined naturally at a predetermined time interval. If the entire system is an asynchronous HARQ, a resource allocation and a retransmission Although it is possible to set it more variably than the time point is decided, it is defined considering the round trip time (RTT) of the HARQ after the initial transmission.
In other words, if the total number of HARQ processes is 5 in the case of the synchronous HARQ process, if the initial transmission is transmitted to the reference number 403, since the retransmission is performed at the reference time 404, which is the sixth TTI, In the case of allocation, the resources at the time of transmission of 403 and 404 are continuously allocated.
On the other hand, in case of asynchronous HARQ, resources may be allocated at the time of reference numbers 403 and 404, but it is also possible to allocate the retransmission time to the 7th TTI or the 8th TTI other than the 6th TTI at the time of reference numeral 404.

Referring to FIG. 4, if the UE receives initially transmitted data at the first transmission point 403 continuously allocated through the PDSCH 402 and the UE fails to demodulate at the first transmission point 403, And transmits the PDCCH 401 using the persistent resource allocation information at the time of reference numeral 404 without the PDCCH 401 resource allocation information. When the first retransmission 404 also fails to transmit, the BS transmits a second retransmission. To this end, the BS transmits resource allocation information using the PDCCH 401 as indicated by reference numeral 409. The UE receives the resource allocation information through the PDCCH 401 as shown in reference numeral 409 and can determine whether or not a second retransmission 405 is allocated. That is, since the UE does not know when the scheduling information is to be transmitted through the PDCCH, the UE must always monitor the PDCCH 401. Since the initial transmission 403 and the first retransmission 404 are continuously allocated, the asynchronous HARQ can be performed from the second retransmission 405 although the transmission time is fixed. Therefore, retransmission data can be transmitted in any TTI after the RTT It is possible to transmit.

Referring to FIG. 4, if transmission is not successful within the allocated number of sustain resources, the BS transmits retransmission data through dynamic resource allocation at the next retransmission time. For this, dynamic scheduling information, which is dynamic resource allocation information, is transmitted through the PDCCH 401 as indicated by reference numeral 409, and retransmission is transmitted as indicated by reference numeral 405. In the case of the HARQ scheme using chase combining, the retransmission data may be the same coded data as the initial transmission. In case of the HARQ scheme implemented with Incremental Reduction (IR), the information data is the same, May be transmitted.
Reference numerals 403 and 404 denote data that can be demodulated and decoded through persistent scheduling information, which is persistent resource allocation information that has been transmitted in advance. Reference numeral 405 denotes dynamic resource allocation information transmitted through the PDCCH 401 And demodulates and decodes the data transmitted through the PDSCH through the dynamic scheduling information.

That is, FIG. 4 shows an asynchronous HARQ transmission scheme. Therefore, when data retransmission is required using a dynamic resource, a time interval between a time at which a dynamic resource is allocated and a retransmission time at which the dynamic resource is allocated is earlier than an initial transmission And may be allocated to have a time interval different from the time interval between the first retransmissions.

FIG. 5A illustrates a case where a packet to be retransmitted is transmitted in a synchronous manner while a VoIP packet is transmitted / received according to an embodiment of the present invention. In FIG. 5A, as shown in FIG. 4, the initial transmission 503 and the first retransmission 504 allocate resources in the persistent resource allocation scheme, and the second retransmission 505 allocates resources in the dynamic resource allocation scheme. However, 4 in that the second retransmission 505 time point is located at the same position as the time interval between the initial transmission 503 and the first retransmission 504 time point.

Therefore, in a system operating in a synchronous HARQ system in the entire system, since the retransmission time after the allocation of the persistent resources is fixed, the third transmissions 505 and 508 are also transmitted in synchronization with the synchronous HARQ retransmission time .

However, in the synchronous HARQ, data must always be transmitted upon retransmission. However, in the present invention, when the number of transmissions (Ntx) of a VoIP packet transmitted in the persistent resource allocation scheme exceeds the number of valid persistent allocations (Nper) , And if the receiver fails to receive the resource allocation information through the PDCCH during retransmission, it should wait without receiving the retransmission.

5A, when a retransmission of a packet is required, a time interval between a time at which a dynamic resource is allocated and a retransmission time before a time at which the dynamic resource is allocated is equal to a time interval between the initial transmission and the first retransmission of the packet, .

FIG. 5B illustrates a method of retransmitting a packet to be retransmitted during a VoIP packet transmission / reception according to an embodiment of the present invention to an HARQ process such as initial transmission according to a synchronous method within a predetermined interval, FIG.

As shown in FIG. 5B, in a system in which initial transmission is fixed every 20 ms, which is a unit in which VoIP packets are generated, if the retransmission is required after 20 ms, it may cause collision with the initial transmission of the next VoIP packet. FIG. 4 is a diagram illustrating transmission of retransmission data to be transmitted over an HARQ process different from that used in the initial transmission. FIG.
In FIG. 5B, it is assumed that the total number of HARQ processes 552 is eight.

5B, initial transmission, first retransmission, and second retransmission are performed through HARQ process # 0 as in reference numerals 553, 554, and 555 during the initial 20 ms interval. The second retransmission 557 of the VoIP # 1 packet is transmitted through the HARQ process # 2 because the VoIP # 2 packet must be transmitted through the HARQ process # 0 in the next 20 ms interval after the 20 ms interval.

That is, in FIG. 5B, during the initial 20 ms interval 570, the VoIP 1 packet is initially transmitted, and the first retransmission and the second retransmission are performed through the HARQ process # 0 as 553, 554, and 555. Since the VoIP 2 packet is to be transmitted through the HARQ process 0 in the 20 ms interval 680 after the 20 ms interval 570, the third retransmission 557 of the VoIP 1 packet is transmitted through the HARQ process 2 .

In FIG. 5B, as shown in FIG. 5A or FIG. 5A, the initial transmission and the first retransmission are allocated resources in a persistent allocation manner, such as 553 and 554, and the second retransmission is allocated as a dynamic resource. In 20 ms, HARQ process # Therefore, it is transmitted to the HARQ process # 0 as indicated by reference numeral 555. If retransmission is further required, it is necessary to transmit the HARQ process # 0 of reference numeral 556 because it is a synchronous HARQ. However, since the initial transmission time of the VoIP 2 packet to be transmitted after the VoIP 1 packet is fixed, Packet 2 must be transmitted.
Therefore, the third transmission of the previous VoIP # 1 packet is transmitted through the HARQ process # 2 as indicated by reference numeral 557. The third transmission (555) of the VoIP 1 packet exceeds the effective number of the persistent resources and is scheduled through the PDCCH (550). If a VoIP packet to be retransmitted is generated at a time point exceeding 20 ms, the location of a new HARQ process to which the VoIP packet to be retransmitted is to be transmitted may be notified to the receiver in advance by a higher signaling, ).

That is, since the VoIP 2 packet is initially transmitted through the HARQ process 0 as shown in reference numeral 556 in FIG. 5B, the first retransmission of the VoIP 2 packet is also transmitted through the HARQ process 0 as indicated by reference numeral 558. When a 20 ms interval 580 is completed and a new VoIP 3 packet is to be transmitted, the initial transmission of the VoIP 3 packet is generated through the HARQ process 0 as indicated by reference numeral 559. However, if a second retransmission (third transmission) of VoIP # 2 packet is required, it is transmitted through HARQ process # 2 as indicated by reference numeral 560. Since it is exceeded the effective number of continuous resources, it can be understood that it is allocated as a dynamic resource.

Table 1 below shows configuration information required to variably allocate the persistent resource allocation to only a part of the retransmission, not only the initial transmission according to the embodiment of the present invention.

Information Explanation Resource information Location and amount of frequency resources About MCS  Modulation and coding rate information Effective frequency of persistent resource allocation (Nper) Number of transmissions for which persistent resource allocation is valid

The following method can be used as a method of signaling the setting information as shown in Table 1 above.

- Method 1: How to inform all the setting information by high signaling

- Method 2: A method of informing the resource / MCS information through the PDCCH and informing the effective number of the persistent resource allocation by upper signaling

Method 3: The resource / MCS information is notified through the PDCCH, and the effective number of persistent resource allocation is calculated through the number of times that the same HARQ process can be transmitted within 20 ms. In order to apply this method, the resource and MCS information allocated through one PDCCH must be defined to be valid only at a transmission time within 20ms.

Hereinafter, a procedure of a base station for a preferred implementation of the present invention will be described with reference to FIG. 6 attached hereto.
6 is a flowchart illustrating a method of performing resource allocation for transmitting a VoIP packet at a base station according to an embodiment of the present invention.
If the BS transmits a VoIP packet in step 601, the BS determines in step 602 whether the number of transmissions (Ntx) of the VoIP packet exceeds the effective number of continuous resource allocation (Nper). Since Ntx is the number of transmissions, it is counted every time a packet is transmitted or received in a persistent resource mode. Nper is a predetermined value. If Ntx is less than or equal to Nper, the base station transmits a VoIP packet using a persistent resource allocation method according to persistent scheduling.

If it is determined in step 602 that Ntx does not exceed Nper, since persistent resources are allocated by Nper, there is a persistent resource.

In this case, the BS proceeds to step 606 and checks whether resource reallocation information is required. This is to reallocate resources when it is necessary to adjust the location or amount of the transmission frequency resource or the MCS level, if necessary, even when the persistent resource is allocated. If it is determined in step 606 that resource reallocation is required, the BS proceeds to step 607 to update the resource allocation and transmits the packet data on the PDSCH in step 608. In step 608, the BS may transmit the PDCCH because it can change the resource allocation information according to need even if the persistent resource allocation scheme is used.
On the other hand, if it is determined in step 606 that the resource reallocation is not required, the BS proceeds to step 609 and transmits the PDSCH using the persistent resource information. If it is determined in step 602 that the number of transmissions (Ntx) of the VoIP packet exceeds the effective number of continuous resource allocation (Nper), the BS proceeds to step 603 and allocates resources. In step 603, the BS determines whether there is a spare resource. If there is a spare resource, the BS proceeds to step 604 to perform dynamic resource allocation. In step 605, the VoIP packet is transmitted through the PDSCH using the allocated dynamic resources, and information on the allocated dynamic resources is also transmitted through the PDCCH. On the other hand, if there is no spare resource in step 603, the BS proceeds to step 610 and does not transmit the PDSCH at that time.

The method of allocating dynamic resources in step 604 of FIG. 6 is as shown in FIGS. 4, 5A, and 5B. That is, when allocating a dynamic resource in step 604, the base station firstly allocates the time interval between the initial transmission of the packet and the first retransmission, Lt; RTI ID = 0.0 > and / or < / RTI > Second, in step 604, when a base station allocates a dynamic resource, a time interval between a time when a dynamic resource is allocated and a time before a time when the dynamic resource is allocated is equal to a time interval between an initial transmission and a first retransmission Or may be assigned to have a time interval. Thirdly, in step 604, the BS retransmits the packet using a first Hybrid Automatic Repeat reQuest (HARQ) process used at the initial transmission of the packet within a predetermined interval from the generation time of the packet, And then retransmits the packet using a second HARQ process different from the first HARQ process.

Hereinafter, a procedure of a UE according to an embodiment of the present invention will be described with reference to FIG.

7 is a flowchart illustrating a method for receiving a VoIP packet at a terminal according to an embodiment of the present invention. FIG. 7 shows a process in which a UE operates in one TTI interval.

First, in step 701, the UE receives a PDCCH as shown in step 702. FIG. The reason why the UE continues to receive the PDCCH is because the BS can change the resource allocation information as needed even though the persistent resource is allocated. Of course, when the resource allocation is not changed at the initial transmission or retransmission in order to reduce the reception complexity of the UE, it is also possible to select whether or not to receive the PDCCH considering the number of effective persistent resource allocations (Nper). In step 703, the UE determines whether there is resource allocation information corresponding to the PDCCH. At this time, the UE receives the PDCCH and checks whether there is resource allocation information corresponding to the PDCCH.

If the resource allocation information exists in step 703, the MS moves to step 704 and receives the PDSCH using the resource allocation information acquired in step 703. FIG. That is, if the resource is allocated in the persistent resource allocation scheme, data is received via the PDSCH using the previously received persistent resource allocation scheme. If dynamic resource allocation is performed, the resource allocation information received through the PDCCH PDSCH. ≪ / RTI >

If there is no resource allocation information corresponding to the PDSCCH in step 703, the MS proceeds to step 705 and checks whether the number of times of transmission of the VoIP packet (Ntx) exceeds the effective number of persistent resource allocation (Nper). If it is determined in step 705 that Ntx does not exceed Nper (Ntx is less than or equal to Nper), the UE proceeds to step 707 to receive the PDSCH using resources allocated to the persistent resources.

If it is determined in step 705 that Ntx exceeds Nper, the MS proceeds to step 706 and waits until the next retransmission time. That is, in step 706, since the UE has not received the resource allocation information even though Ntx is larger than Nper, it knows that the packet to be retransmitted will be received by the dynamic resource allocation method instead of the continuous resource allocation method, PDCCH. ≪ / RTI > That is, in step 702, it waits until the resource allocation information is received through the PDCCH. In step 702, the PDCCH is received. If there is resource allocation information in the PDCCH in step 703, the UE receives the retransmitted packet through the dynamically allocated resources according to the embodiment of the present invention.

When Ntx is larger than Nper, there are three ways in which the packets to be retransmitted according to the embodiment of the present invention are allocated dynamic resources to be received.

First, a time interval between the time to allocate the dynamic resource and the retransmission time before the dynamic resource is allocated is allocated to have a time interval different from a time interval between the initial transmission and the first retransmission of the packet. In the asynchronous HARQ scheme, the time interval can be adjusted as desired by the scheduler.

Second, a time interval between the time at which the dynamic resource is allocated and the time at which the dynamic resource is allocated before the time at which the dynamic resource is allocated is allocated to have a time interval equal to the time interval between the initial transmission and the first retransmission of the packet.

Third, the packet is received using a first Hybrid Automatic Repeat reQuest (HARQ) process used at the initial transmission of the packet within a predetermined period from the generation time of the packet, and after the predetermined period, And receiving the packet using a second HARQ process different from the process.
In FIG. 7, if Ntx is greater than Nper in the downlink, the UE receives the packet through the dynamic allocation resource allocated through dynamic scheduling. If Ntx is less than or equal to Nper, Lt; RTI ID = 0.0 > through < / RTI > However, when the present invention is applied to an uplink, when Ntx is greater than Nper, when a UE transmits a packet on the uplink, it transmits a packet through a dynamic allocated resource allocated through dynamic scheduling. If Ntx is smaller than Nper In case of the same, the UE will transmit the packet through the persistent allocated resources allocated through persistent scheduling when transmitting the packet on the uplink.

Hereinafter, a block diagram of a base station apparatus according to an embodiment of the present invention will be described with reference to FIG.

8 is a block diagram of a base station resource allocation apparatus 800 according to an embodiment of the present invention.

PDSCH transmission controller 802 receives persistent resource allocation information and Nper from a higher layer not shown in the figure as 801 and receives resource allocation information from base station scheduler 805 to control PDSCH transmitter 803, And controls transmission.

That is, the PDSCH transmission controller 802 checks which of the TTIs of the 20-ms interval is using the persistent resource allocation information, and if the packet is to be transmitted in the TTI to which the resource is allocated as the persistent resource allocation information, And transmits resource information such as frequency information and AMC level set as information to the PDSCH transmitter 803. Upon receiving the resource information, the PDSCH transmitter 803 transmits a packet on the PDSCH according to the resource information received from the PDSCH transmission controller 802. On the other hand, when receiving new resource allocation information from the BS scheduler 805 in addition to the persistent resource allocation information, the PDSCH transmission controller 802 outputs new resource information, which is not persistent resource allocation information, to the PSDCH transmitter 803, (803) transmits a packet through the PDSCH using the input resource information.

When allocating resources through dynamic scheduling rather than a persistent resource allocation scheme, the base station scheduler 805 transmits a resource allocation information corresponding to a TTI interval of a packet to a PDCCH transmitter 804 through a PDCCH, . The PDCCH transmitter 804 transmits scheduling information, which is dynamic resource allocation information, on the PDCCH under the control of the base station scheduler 805.

PDSCH transmission controller 802 increases Ntx by "1 " every time it transmits a packet. In addition, the PDSCH transmission controller 802 compares the received Nper with the counted Ntx, and determines a PDSCH transmission resource according to the comparison result. That is, when Ntx exceeds Nper, the PDSCH transmission controller 802 receives the dynamic resource allocation information, which is new resource allocation information, from the base station scheduler 805, and transmits the packet through the PDSCH using the new resource allocation information And controls the PDSCH transmitter 803 to transmit. At this time, the PDSCH transmission controller 802 provides the resource information allocated to the PDSCH transmitter 803 to transmit the packet. If Ntx exceeds Nper, the PDSCH transmission controller 802 must transmit a packet through dynamic scheduling. Therefore, when Ntx, which is the number of times of packet transmission, exceeds Nper, the PDSCH transmission controller 802 transmits And provides the viewpoint information to the base station scheduler 805. The base station scheduler 805 receiving the transmission time information transmits a dynamic resource when Ntx exceeds Nper, thereby controlling the PDCCH transmitter 804 to transmit dynamic resource information at the time of transmission of the packet. In addition, when the present invention is applied to the uplink, the Ntx will be the number of transmissions of the packet transmitted by the UE.

If Ntx is greater than Nper, the PDSCH transmission controller 802 allocates a dynamic resource to be used for transmitting a packet to be retransmitted according to the following three schemes.

First, the PDSCH transmission controller 802 determines whether the time interval between the time when the dynamic resource is allocated and the time before the time when the dynamic resource is allocated is different from the time interval between the initial transmission and the first retransmission of the packet To the base station scheduler 805 so as to allocate the dynamic resources.

Second, the PDSCH transmission controller 802 has a time interval equal to the time interval between the initial transmission of the packet and the first retransmission, and the time interval between the time at which the dynamic resource is allocated and the retransmission time before the time at which the dynamic resource is allocated To the base station scheduler 805 so as to allocate the dynamic resources.

Third, the PDSCH transmission controller 802 transmits the packet using a first Hybrid Automatic Repeat reQuest (HARQ) process used at the initial transmission of the packet within a predetermined period from the generation time of the voice packet, The PDSCH transmitter 803 controls the PDSCH transmitter 803 to transmit the packet using a second HARQ process different from the first HARQ process after a predetermined interval and allocates a dynamic resource allocation Scheme to the PDCCH to provide packet transmission time information.

FIG. 9 is a block diagram of a persistent resource allocation apparatus 900 according to an embodiment of the present invention.

The PDSCH reception controller 902 receives the persistent resource allocation information and the Nper which is the number of valid persistent resource allocation times, such as reference numeral 901, from the upper layer, not shown, and determines PDSCH reception, resource information for receiving a packet to be transmitted on the PDSCH As well as to the PDSCH receiver 903. The PDSCH receiver 903 receives the packet transmitted on the PDSCH using the resource information informed by the PDSCH reception controller 902. If Ntx is greater than or equal to Nper, the PDSCH reception controller 902 controls the PDSCH receiver 903 to wait until the next retransmission time. If Ntx is less than or equal to Nper, And controls the PDSCH receiver 903 to receive the packet on the PDSCH using the persistent resource allocation information. The PDCCH receiver 904 receives the PDCCH from the base station and informs the PDSCH reception controller 902 of the resource allocation information through the PDCCH when the resource allocation information is received via the PDSCH. Lt; / RTI >

If the PDSCH reception controller 902 fails to receive the resource allocation information for receiving the packet to be retransmitted even though Ntx is larger than Nper, the packet to be retransmitted is received in the dynamic resource allocation scheme instead of the continuous resource allocation scheme . Accordingly, the PDSCH reception controller 902 controls the PDSCH receiver 903 to receive, via the PDSCH, a packet to be retransmitted through the resources allocated by the dynamic scheduling. In addition, when the PDCCH receiver 904 receives the scheduling information through the PDCCH, the PDSCH reception controller 902 controls the PDSCH 902 to receive the packet with the resource information corresponding to the scheduling information at the transmission time of the packet to be transmitted by the scheduling information, And controls the receiver 903. In the case of an uplink, the Ntx may be the number of packet transmissions transmitted by the UE.

When Ntx is greater than Nper, there are three ways in which the PDSCH reception controller 902 allocates dynamic resources for receiving packets to be retransmitted according to an embodiment of the present invention.

The first is a dynamic allocation mode in which the time interval between the time at which the dynamic resource is allocated in the asynchronous manner and the time at which the dynamic resource is allocated before retransmission is different from the time interval between the initial transmission and the first retransmission of the packet Receive packets using resources.

Second, the time interval between the time at which the dynamic resource is allocated as the synchronous mode and the time at which the dynamic resource is allocated is set to be equal to the time interval between the initial transmission and the first retransmission of the packet Receive packets using dynamic resources.

The third step is to receive the packet using a first Hybrid Automatic Repeat reQuest (HARQ) process used at the initial transmission of the packet within a predetermined interval from the generation time of the packet, And receiving the packet using a second HARQ process different from the process. On the other hand, if the present invention is applied to the uplink as described above, if the Ntx is greater than Nper, the UE will transmit the packet to the Node B through the resources allocated by the dynamic scheduling. If Ntx is less than or equal to Nper, It will send the packet to the base station via the resources allocated in the scheduling.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

1 is a diagram for explaining traffic characteristics of a Voice over IP (VoIP) service in a general mobile communication system,

2 is a diagram illustrating persistent scheduling in a general mobile communication system,

3 illustrates a method of using persistent scheduling only for initial transmission in a general mobile communication system,

4 is a diagram illustrating a case where a packet to be retransmitted is transmitted asynchronously while VoIP packets are transmitted and received in a mobile communication system according to an embodiment of the present invention;

FIG. 5A illustrates a case where a packet to be retransmitted is transmitted in a synchronous manner while VoIP packets are transmitted and received according to an embodiment of the present invention; FIG.

FIG. 5B illustrates a case where a packet to be retransmitted during transmission and reception of a VoIP packet is retransmitted to an HARQ process such as initial transmission according to a synchronous method within a specific interval, and then transmitted to another HARQ process in a subsequent interval according to an embodiment of the present invention Fig.

6 is a flowchart illustrating a method of performing resource allocation for transmitting a VoIP packet at a base station according to an embodiment of the present invention.

FIG. 7 is a flowchart illustrating a method for performing VoIP packet reception in a terminal according to an exemplary embodiment of the present invention;

8 is a block diagram of a persistent resource allocation apparatus of a base station according to an embodiment of the present invention.

9 is a block diagram of an apparatus for allocating persistent resources of a terminal according to an embodiment of the present invention.

Claims (16)

A method of resource allocation of a terminal in a mobile communication system, Receiving resource allocation information for uplink transmission from a base station, Wherein the resource allocation information includes information on resources allocated by the persistent resource allocation method or the dynamic resource allocation method according to a comparison result between a number of data transmissions of the terminal and a preset effective number used for determining whether the persistent resource allocation method is valid or not The resource allocation method comprising the steps of: The method according to claim 1, Wherein the resource allocation information indicates information of a resource allocated by the persistent resource allocation scheme when the number of times of data transfer is less than or equal to the predetermined effective number of times and if the number of data transfers is greater than the predetermined effective number of times, Wherein the information of the resource allocated by the resource allocation method is indicated. The method according to claim 1, Wherein the predetermined effective number is set using a channel state of each terminal, a moving speed of each terminal, and a transmission power available for each terminal. The method according to claim 1, Wherein the preset effective number is set using an average number of data transmission times of the terminals required in each cell. A method of allocating resources of a base station in a mobile communication system, Comparing a number of data transmissions of the UE with a preset effective number used for determining whether the persistent resource allocation scheme is valid; And allocating resources according to a persistent resource allocation scheme or a dynamic resource allocation scheme according to the comparison result. 6. The method of claim 5, Wherein the allocating step comprises: Allocating resources according to the persistent resource allocation scheme when the number of data transmissions is less than or equal to the preset effective number; And allocating resources according to the dynamic resource allocation scheme when the number of times of transmission of the data is greater than the preset effective number. 6. The method of claim 5, Wherein the predetermined effective number is set using a channel state of each terminal, a moving speed of each terminal, and a transmission power available for each terminal. 6. The method of claim 5, Wherein the preset effective number is set using an average number of data transmission times of the terminals required in each cell. A terminal apparatus for allocating resources in a mobile communication system, And a receiver for receiving resource allocation information from the base station, Wherein the resource allocation information includes information on resources allocated by the persistent resource allocation method or the dynamic resource allocation method according to a comparison result between a number of data transmissions of the terminal and a preset effective number used for determining whether the persistent resource allocation method is valid or not Of the terminal device. 10. The method of claim 9, Wherein the resource allocation information indicates information of a resource allocated by the persistent resource allocation scheme when the number of times of data transfer is less than or equal to the predetermined effective number of times and if the number of data transfers is greater than the predetermined effective number of times, And information on resources allocated by the resource allocation scheme. 10. The method of claim 9, Wherein the predetermined effective number is set using a channel state of each terminal, a moving speed of each terminal, and a transmission power available for each terminal. 10. The method of claim 9, Wherein the preset effective number is set using an average number of data transmission times of the terminals required in each cell. A base station apparatus allocating resources in a mobile communication system, A resource allocation controller for comparing the number of data transmissions of the UE with a preset effective number used for determining whether the persistent resource allocation scheme is valid and allocating resources according to the persistent resource allocation scheme or the dynamic resource allocation scheme according to the comparison result; , And a transmitter for transmitting information on the allocated resource. 14. The method of claim 13, Wherein the resource allocation controller allocates resources according to the persistent resource allocation scheme when the number of data transmissions is less than or equal to the preset valid number and if the number of data transmissions is greater than the preset effective number, The base station apparatus allocating resources by the base station apparatus. 14. The method of claim 13, Wherein the predetermined effective number is set using a channel state of each terminal, a moving speed of each terminal, and a transmission power available for each terminal. 14. The method of claim 13, Wherein the preset effective number is set using an average number of data transmissions of the terminals required in each cell.

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