KR101274376B1 - Method and apparatus for allocating resource in a communication system - Google Patents

Abstract

The present invention relates to a method and apparatus for efficiently allocating resources for transmitting feedback information in a communication system. To this end, the base station of the mobile communication system allocates resources of a size necessary for each of the plurality of terminals to report the channel quality information based on the data information and the average channel state information of each terminal. Information about the size of the resource allocated to each of the plurality of terminals is transmitted to the plurality of terminals.

Resource Allocation, Padback Channel, CQI, CQICH, Slot Allocation

Description

METHOD AND APPARATUS FOR ALLOCATION IN A COMMUNICATION SYSTEM {METHOD AND APPARATUS FOR ALLOCATING RESOURCE IN A COMMUNICATION SYSTEM}

Is a diagram schematically illustrating the allocation of a CQICH by a BS to MSs in a communication system.

2 is a diagram schematically illustrating a resource allocation process of a transmitter in a communication system according to an embodiment of the present invention.

3 is a diagram schematically illustrating allocation of a CQICH by a BS to MSs in a communication system according to an embodiment of the present invention;

4 is a diagram schematically illustrating CQICH allocation information to MSs by a BS in a communication system according to an embodiment of the present invention;

5 is a diagram schematically illustrating a structure of a CQICH allocation information message to a MS by a BS in a communication system according to an embodiment of the present invention;

The present invention relates to a communication system, and more particularly, to a method and apparatus for efficiently allocating resources for transmitting feedback information in a communication system.

In the next generation communication system, active researches are being conducted to provide users with services having high quality of service (QoS: Quality of Service, hereinafter referred to as 'QoS'). In particular, in the current generation communication system, a wireless local area network (WLAN) system and a wireless metropolitan area network (WMAN) will be referred to as "WMAN". Researches are being actively conducted to support high-speed services in a form of guaranteeing mobility and QoS in a broadband wireless access (BWA) communication system such as a system). . Examples of representative communication systems include the Institute of Electrical and Electronics Engineers (IEEE) 802.16a / d communication system and the IEEE 802.16e communication system.

The IEEE 802.16a / d communication system and the IEEE 802.16e communication system, which are the BWA communication system, orthogonal frequency division multiplex (OFDM) to support a broadband transmission network on a physical channel of the WMAN system. Division Multiplexing (hereinafter, referred to as "OFDM") / Orthogonal Frequency Division Multiple Access (OFDMA) is a communication system that adopts the scheme. The IEEE 802.16a / d communication system currently considers only a single cell structure and a state in which a subscriber station (SS) (hereinafter referred to as SS) is fixed, that is, does not consider SS mobility at all. System. In contrast, the IEEE 802.16e communication system is a system that considers the mobility of the SS in the IEEE 802.16a communication system, and the SS having the mobility is referred to as a mobile terminal (MS). do.

Meanwhile, the IEEE 802.16e communication system has a frame structure, and a base station (BS) (hereinafter, referred to as a BS) of the system efficiently allocates resources of each frame to MSs. The resource allocation information is transmitted to the MSs through a MAP message. Here, the MAP message for transmitting the downlink resource allocation information is a downlink map (DL (DownLink) -MAP, hereinafter referred to as 'DL-MAP') message, and the uplink resource allocation information The MAP message to be transmitted is an uplink map (UL (UpLink) -MAP, hereinafter referred to as 'UL-MAP') message.

의 2차원 배열로 구성된다. 상기 2차원 배열의 각 엘리먼트(element)는 할당 단위인 슬럿(slot)이 된다. 예컨대 상기 주파수 영역은 서브 캐리어(subcarrier)들의 묶음인 서브 채널(subchannel) 단위로 나뉘고, 상기 시간 영역은 심벌(symbol) 단위로 나뉜다. 따라서 상기 슬럿은 하나의 서브 채널 내에서 한 심볼이 점유하는 영역을 나타낸다. 각 슬럿은 한 셀(cell)에 존재하는 MS들 중 임의의 MS에게만 할당된다. 상기 한 셀에 존재하는 MS들 각각에 할당된 슬럿들의 집합이 버스트(burst)가 된다. 이와 같이 상기 통신 시스템에서 업링크 자원은 슬럿들을 각 MS들이 분할하여 사용하는 방식으로 할당된다.In the communication system, data transmission and reception are performed in units of frames, and each frame is divided into an area for transmitting and receiving downlink data and an area for transmitting and receiving uplink data. Here, the area for transmitting and receiving the data

It consists of a two-dimensional array of. Each element of the two-dimensional array is a slot, which is an allocation unit. For example, the frequency domain is divided into subchannel units, which are a bundle of subcarriers, and the time domain is divided into symbol units. Accordingly, the slot represents an area occupied by one symbol in one subchannel. Each slot is assigned only to any of the MSs present in one cell. The set of slots assigned to each of the MSs present in the cell becomes a burst. As such, in the communication system, uplink resources are allocated in such a manner that slots are divided and used by respective MSs.

In the communication system, when the MS receives the UL-MAP message, the MS transmits its channel quality information (CQI) (hereinafter referred to as 'CQI') to the BS (CQICH: Channel Quality Information). CHannel, hereinafter referred to as 'CQICH', confirms allocation information and transmits a CQI to the BS through the CQICH. Next, the BS will allocate the CQICH to the MS in the communication system with reference to FIG. 1.

1 is a diagram schematically illustrating allocation of a CQICH by a BS to MSs in a communication system.

Referring to FIG. 1, the BS allocates one CQICH slot to each user, that is, each MS, every frame. In more detail, the BS fixedly assigns one CQICH slot to n MSs every frame, assigns one CQICH slot of every frame to an MS having a user ID of a, and assigns one CQICH slot of every frame to an MS of b. Two CQICH slots are allocated, and N MSs are allocated N CQICH slots of every frame.

However, as mentioned above, the overhead of the system may occur because the BS fixedly allocates one CQICH slot to all MSs every frame. For example, if any MS needs more than one CQICH slot to send its CQI to the BS, resources for CQI transmission may be insufficient. In addition, if there is no CQI to be transmitted to any MS to the BS, the BS may be wasted resources by allocating a CQICH slot fixed every frame to the MS that did not transmit the CQI.

Accordingly, an object of the present invention is to provide a method and apparatus for allocating resources in a communication system.

The present invention also relates to a method and apparatus for efficiently allocating resources for transmitting feedback information in a communication system.

In addition, the present invention provides a method and apparatus for allocating resources for a receiver to transmit its channel information in a communication system.

A method for allocating a resource for reporting channel quality information by a plurality of terminals in a base station of a mobile communication system according to the present invention for achieving the above objects is based on data information and average channel state information of each terminal. And allocating a resource having a size necessary for each terminal to report channel quality information, and transmitting information on the size of the resource allocated to each of the plurality of terminals to the plurality of terminals.

An apparatus for allocating a resource for reporting channel quality information for each of a plurality of terminals in a base station of a mobile communication system according to the present invention for achieving the above objects comprises the plurality of terminals based on data information and average channel state information of each terminal. Each terminal includes a scheduler for allocating a resource having a size required for reporting channel quality information, and a transmitter for transmitting information about the size of the resource allocated to each of the plurality of terminals to the plurality of terminals.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

The present invention proposes a resource allocation method and apparatus in an IEEE 802.16 communication system, which is a communication system, for example, a broadband wireless access (BWA) communication system. do. Here, in the embodiment of the present invention to be described later, orthogonal frequency division multiplexing (OFDM) orthogonal frequency division multiple access (OFDM) in the IEEE 802.16 communication system for convenience of explanation. An example of a communication system using an Orthogonal Frequency Division Multiple Access (OFDMA) scheme) will be described as an example. However, the resource allocation method and apparatus proposed by the present invention can be applied to other communication systems.

In addition, the present invention provides a transmitter for managing a cell in a communication system, such as a base station (BS), and a plurality of receivers for receiving communication service from the transmitter, for example, a mobile terminal (MS). : When the mobile station transmits and receives data between the MSs, the receivers transmit their channel information, that is, channel quality information (CQI), to the transmitter. The present invention proposes a method and apparatus for allocating a channel (CQICH: Channel Quality Information CHannel, hereinafter referred to as 'CQICH'). In an embodiment of the present invention to be described later, a method and apparatus for adaptively allocating a CQICH every frame corresponding to information of data to be transmitted to a receiver and a CQI received from each receiver by a scheduler included in the transmitter are proposed. . At this time, the scheduler, the amount of data to be transmitted to each receiver as the information of the data, the time information waited in the buffer for the data to be transmitted to each receiver, the time information stored in the buffer and from each receiver to the previous frame The CQICH is allocated to each receiver adaptively every frame according to the received average CQI. Here, in the embodiment of the present invention, for the convenience of description, it is assumed that the scheduler is included in the transmitter. However, the scheduler may be included in a control station for controlling the BS, for example, the BS.

의 2차원 배열로 구성된다. 상기 2차원 배열의 각 엘리먼트(element)는 할당 단위인 슬럿(slot)이 된다. 예컨대 상기 주파수 영역은 서브 캐리어(subcarrier)들의 묶음인 서브 채널(subchannel) 단위로 나뉘고, 상기 시간 영역은 심벌(symbol) 단위로 나뉜다. 따라서 상기 슬럿은 하나의 서브 채널 내에서 한 심볼이 점유하는 영역을 나타낸다. 각 슬럿은 한 셀(cell)에 존재하는 MS들 중 임의의 MS에게만 할당된다. 상기 한 셀에 존재하는 MS들 각각에 할당된 슬럿들의 집합이 버스트(burst)가 된다. 그러면 여기서, 도 2를 참조하여 본 발명의 실시 예에 따른 통신 시스템에서 자원 할당 과정을 구체적으로 설명하기로 한다.Meanwhile, in a communication system according to an exemplary embodiment of the present invention, data transmission and reception are performed in units of frames, and each frame is divided into an area for transmitting and receiving downlink data and an area for transmitting and receiving uplink data. Here, the area for transmitting and receiving the data

It consists of a two-dimensional array of. Each element of the two-dimensional array is a slot, which is an allocation unit. For example, the frequency domain is divided into subchannel units, which are a bundle of subcarriers, and the time domain is divided into symbol units. Accordingly, the slot represents an area occupied by one symbol in one subchannel. Each slot is assigned only to any of the MSs present in one cell. The set of slots assigned to each of the MSs present in the cell becomes a burst. Next, a resource allocation process in the communication system according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a diagram schematically illustrating a resource allocation process of a transmitter in a communication system according to an embodiment of the present invention.

Referring to FIG. 2, in step 201, the transmitter receives CQI and data information of each MS. For example, a BS receives a CQI from each receiver, i.e. MSs, and receives information of data to be sent to each receiver, i.e. MSs, over any current nth frame. In step 201, the transmitter receives the amount of data to be transmitted to each receiver as the information of the data and the time information waited in the buffer for transmitting the data to each receiver, that is, the time information stored in the buffer. Signal to Interference and Noise Ratio (SINR) for each channel as the CQI of the channel assigned to the receivers from the previous frames, i.e., the n-1th frame, to be referred to as " SINR " Receive.

Then, in step 203, the transmitter determines the size of the CQICH to be allocated to each receiver according to the information of the data received in step 201 and the CQI. More specifically, in step 203, the transmitter transmits data rate for each channel of each receiver in previous frames using SINR for each channel allocated to the receivers as CQIs from each receiver in step 201. After calculating, the average value for the maximum value of the calculated data rate is calculated to identify the average CQI received from each of the receivers up to the previous frame, that is, the n-1 th frame. In addition, the transmitter, as information of the data, the amount of data present in the downlink transmission buffer and the time information waited in the downlink transmission buffer to transmit data to each receiver in the current frame, that is, the nth frame, namely Check the time information stored in the transmission buffer. The size of the CQICH to be allocated to each receiver is determined according to the average CQI and data information thus identified.

Next, in step 205, the transmitter corresponds to the maximum value of the data rate and the transmission buffer according to the allocation order of channels for each receiver in the current frame, and the SINR of each receiver for the corresponding channel calculated in step 203. The CQICH is allocated from the receivers having the maximum amount of data present. Then, the transmitter broadcasts a message including the CQICH allocation information of each receiver to each receiver. Next, an example of a resource in a communication system according to an exemplary embodiment of the present invention will be described below with reference to FIGS. 3 to 5.

3 is a diagram schematically illustrating allocation of a CQICH to MSs by a BS in a communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the BS allocates a CQICH slot to each user, that is, each MS, in accordance with the CQI received from each MS and information of data to be transmitted to each MS as described above.
More specifically, the BS adaptively allocates a CQICH slot to n MSs every frame. For example, in the Mth frame, the CQICH slots 1 and 2 are allocated to the MS having the user ID a, and the 3 CQICH slots are allocated to the MS having the user ID b. In the next frame, M + 1, the CQICH slot is not allocated to the MS having the user ID a, and the CQICH slots 1, 2, and 3 are allocated to the MS having the user ID b. In the M + kth frame, one CQICH slot is allocated to an MS having a user ID of d, and two and three CQICH slots are allocated to an MS having a user ID of a.

Thus, in the communication system according to the embodiment of the present invention, the BS, that is, the transmitter, performs a CQICH slot corresponding to the information of the CQI received from each MS, i.e., each receiver from the previous frame and the data to be transmitted to the receivers in the current frame. Adaptive allocation That is, a transmitter according to an embodiment of the present invention adaptively allocates a different number of CQICH slots to respective transmitters every frame, and also adaptively allocates CQICH slots to each receiver every frame. Assign.

4 schematically illustrates CQICH allocation information to MSs by a BS in a communication system according to an embodiment of the present invention. 4 is a diagram illustrating CQICH allocation information when the BS allocates CQICH to MSs as shown in FIG. 3.

Referring to FIG. 4, when the BS allocates CQICH slots to MSs as described with reference to FIG. 3, the BS configures CQICH allocation information including the number of CQICH slots allocated to the receivers in each frame. That is, the BS sequentially allocates one CQICH slot to two CQICH slots to an MS having a user ID of a in the Mth frame, and a CQICH slot allocated to an MS having a user ID of a for an MS having a user ID of b. Information indicating that one CQICH slot of is allocated, and one CQICH slot is allocated to the MS having the user ID d in the M + kth frame, and the MS having the user ID d is assigned to the MS having the user ID a. Configures information indicating that three CQICH slots after the CQICH slot have been allocated.

5 is a diagram schematically illustrating a CQICH allocation information message structure of a BS to MSs in a communication system according to an embodiment of the present invention. FIG. 5 is a diagram illustrating a CQICH allocation information message structure when the BS allocates CQICH to MSs as shown in FIGS. 3 and 4.

Referring to FIG. 5, when the BS allocates CQICH slots to MSs in every frame as described with reference to FIGS. 3 and 4, the BS determines the number of CQICH slots allocated for each receiver, that is, a user ID and the user ID. The CQICH allocation information message is configured by arranging the CQICH slots of the receivers in order, and the configured CQICH allocation information message is broadcasted to each receiver.
More specifically, since the BS has allocated the CQICH slots from the MS having the user ID a in the M-th frame, the BS first allocated the CQICH slots from the number of CQICH slots allocated to the user ID a and the MS having the user a. A CQICH allocation information message is constructed by listing the user ID e indicating that the user ID e is assigned to the MS and the number of CQICH slots allocated to the MS having the user ID e. In this manner, the BS composes a message according to CQICH allocation information allocated to each MS adaptively every frame, and then broadcasts the configured message to each MS.

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 to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

The present invention as described above, by adaptively allocating a channel for receiving feedback information from each receiver in a communication system corresponding to channel information received from each receiver and information of data to be transmitted to each receiver. This reduces overhead and makes efficient use of limited resources.

Claims (16)

In a method for allocating resources by a base station in a mobile communication system, It is necessary to report the channel quality information to each of the plurality of terminals based on the data rate of each terminal and the average data rate calculated by the maximum data rate among the data rates of each channel for each frame transmitted by the base station. Allocating resources of size, And transmitting information about the size of the resource allocated to each of the plurality of terminals to each of the plurality of terminals. delete The method of claim 1, The data information includes the information on the amount of data to be transmitted to the base station to each terminal and the information on the time the data waits in the buffer for transmission to each terminal. The method of claim 3, The process of allocating the resource of the required size, Assigning a resource allocation order to each of the plurality of terminals in consideration of the average data rate and the amount of data to be transmitted; And allocating a resource having a size necessary for reporting the channel quality information to each of the plurality of terminals according to the assigned resource allocation order. 5. The method of claim 4, The data information and the average data rate is reported using the resources previously allocated from each terminal, and the resource of the required size is allocated in units of frames. The method of claim 5, The information on the size of the resource allocated to each of the plurality of terminals includes resource identification information of each terminal and information on the number of slots corresponding to the size of the resource allocated to each terminal. Way. The method of claim 6, Information on the size of the resource allocated to each of the plurality of terminals is included in the resource allocation information message and transmitted, and the size of the allocated resource is recorded in the resource allocation information message according to the resource allocation order. Resource allocation method. A base station for allocating resources in a mobile communication system, Size required for reporting channel quality information to each of a plurality of terminals based on the data rate of each terminal and the average data rate calculated by the maximum data rate among the data rates of each channel for each frame transmitted by the base station. A scheduler that allocates resources for And a transmitter configured to transmit information about a size of a resource allocated to each of the plurality of terminals to each of the plurality of terminals. delete 9. The method of claim 8, The data information base station, characterized in that the information on the amount of data to be transmitted to the base station to each terminal and information on the time the data waits in the buffer for transmission to each terminal. The method of claim 10, wherein the scheduler, In order to assign a resource allocation order to each of the plurality of terminals in consideration of the average data rate and the amount of data to be transmitted, and to report the channel quality information to each of the plurality of terminals according to the assigned resource allocation order. A base station for allocating resources of size. 12. The method of claim 11, The data information and the average data rate is reported using the previously allocated resources from each terminal, the base station, characterized in that the resource of the required size is allocated in units of frames. The method of claim 12, The base station, characterized in that the information on the size of resources allocated to each of the plurality of terminals includes the identification information of each terminal and information on the number of slots corresponding to the size of the resources allocated to each terminal. 14. The method of claim 13, Information about the size of the resource allocated to each of the plurality of terminals is included in the resource allocation information message and transmitted, and the size of the allocated resource is recorded in the resource allocation information message according to the resource allocation order. Base station. delete delete

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