WO2010016596A1

WO2010016596A1 - Base station, communication terminal, communication system, base station control method, communication terminal control method, communication system control method, control program, and recording medium

Info

Publication number: WO2010016596A1
Application number: PCT/JP2009/064069
Authority: WO
Inventors: 磊黄; 仁茂劉; 銘丁; 晨陳
Original assignee: シャープ株式会社
Priority date: 2008-08-07
Filing date: 2009-08-07
Publication date: 2010-02-11
Also published as: CN101646198B; CN101646198A

Abstract

A mobile communication system (100) which supports an LTE communication terminal (102) and an LTE-A communication terminal (103). The frequency band width of the mobile communication system (100) is divided into a main frequency band and one or more sub frequency bands. When a base station (101) receives operation width information showing an operable frequency band width of the communication terminal (102, 103) from the communication terminal (102, 103), the base station (101) sets the main frequency band and a sub frequency band selected by the base station (101) as the operation frequency band of the communication terminal to the communication terminal (102, 103), determines, out of the set operation frequency band, a sub frequency band to which PDCCH is assigned, and assigns the PDCCH of LTE to the determined sub frequency band.

Description

Base station, communication terminal, communication system, base station control method, communication terminal control method, communication system control method, control program, and recording medium

The present invention relates to a technical field of mobile communication, and in particular, a base station, a communication terminal, a communication system, a base station control method, a communication terminal control method, and a communication system to which LTE (Long-Term Evolution) -Advanced is applied. The present invention relates to a control method, a control program, and a recording medium.

April 7-8, ^{2008, 3GPP (The 3 rd Generation Partner} Project) in Shenzhen City of China organization IMT Advanced Workshop meeting is opened, possible with the requirements of the LTE-Advanced (hereinafter referred to as LTE-A) Proposals for related technologies were discussed. At this meeting, a number of companies submitted problems regarding system frequency bandwidth in LTE-A and problems related to frequency spectrum (carrier) aggregation (Carrier Aggregation). After this discussion and discussion, the chair of the meeting submitted a draft requirement for LTE-A (Non-patent Document 1).

The draft clearly states that LTE-A should support a maximum system frequency bandwidth of 100 MHz. The system frequency bandwidth of 100 MHz may be formed by one continuous frequency spectrum (continuous plural carriers), or may be formed by collecting a plurality of non-continuous frequency spectra (non-contiguous plural carriers). Also good. The draft also describes that LTE and LTE-A can coexist on the same frequency spectrum. In this case, LTE-A needs to be compatible with conventional LTE-compatible user apparatuses (communication terminals and mobile station apparatuses).

The reason why the system frequency bandwidth is made wider is to obtain a higher peak data transmission rate than expected by LTE-A. In addition, the reason why LTE-A is compatible with LTE-compatible user equipment is to make a smooth transition from LTE to LTE-A.

This also has an advantage in the construction of the LTE-A initial network. This is because, in the LTE-A initial network, the number of conventional LTE-compatible user devices is expected to be significantly greater than that of LTE-A-compatible user devices. This is because, if access is secured, a network that can be accessed by a larger number of user devices can be constructed, so that data services can be provided to a larger number of user devices.

In addition, since the system frequency bandwidth of the LTE communication system is designed to a maximum of 20 MHz, the system frequency bandwidth of the LTE-compatible user device is also 20 MHz. In the LTE-A communication system with a maximum system frequency bandwidth of 100 MHz, in order to provide a compatibility service to an LTE-compatible user apparatus with a maximum system frequency bandwidth of 20 MHz, the following problems arise. That is, LTE-A design, in particular, system frequency band segmentation, downlink broadcast channel (BCH: Broadcast CHannel) synchronization channel (SCH: Synchronization Channel) design, and system control signaling (PDCCH: Physical Downlink Control Channel) ) Issues with respect to design and the like.

Regarding the above problems, Panasonic Corporation proposed the following solution at a meeting held in Shenzhen, China in April 2008 (Non-Patent Document 2). According to this solution, the system frequency bandwidth of LTE-A is divided into a plurality of sub-frequency bands of 20 MHz (a plurality of carriers, one carrier is referred to as a component carrier CC), and the sub-frequency band of 20 MHz. Each (CC) transmits a synchronization channel SCH and a broadcast channel BCH, thereby having compatibility with a 20 MHz LTE-compatible user apparatus.

In addition, Huawei Technologies Corporation proposed another solution at the same meeting (Non-Patent Document 3). In the Huawei company method, the LTE reference signal RS (Reference Signal), the synchronization channel SCH, the broadcast channel BCH, and the control channel PDCCH are transmitted in at least some CCs of LTE-A. It is ensured that the corresponding user apparatus preferably accesses the partial CC of LTE-A. In addition, Huawei Company says that when the synchronization channel SCH and the broadcast channel BCH are transmitted in a plurality of CCs of LTE-A, the occupation rate of radio resources increases and the design of LTE-A becomes more complicated.

At the meeting in Kansas, USA in May, NTT Docomo Co., Ltd. expressed the same viewpoint as Huawei Company (Non-patent Document 4). Meanwhile, at the conference, Texas Instruments Corporation in the United States announced that it would support Panasonic's proposal (Non-Patent Document 5).

ZTE Corporation proposed another method at the same meeting (Non-patent Document 6). In the method proposed by Chukosha, the system frequency bandwidth of LTE-A is divided into multiple CCs, one of which is set as the main CC, and all other CCs are set as sub CCs. Thus, the LTE synchronization channel SCH, broadcast channel BCH, and control channel PDCCH are transmitted in both the main CC and the sub CC. In addition, LTE-A synchronization channel SCH, broadcast channel BCH, and control channel PDCCH are also transmitted in the main CC.

Of the three methods described above, both the method proposed by Panasonic Corporation and the method proposed by Chukoh Co., Ltd. transmit LTE-related channels corresponding to each sub CC within a plurality of sub CCs. Any of these CCs must support access of LTE-compatible user equipment. This makes it difficult to design LTE-A and greatly increases the load on LTE-A. Considering the actual use of LTE-A, in LTE-A in which CC is several times the number of LTE, the same number of base stations as in LTE is provided when serving the same number of users as in LTE. Do not need. Therefore, when LTE-A covers the same number of user equipment as the number of user equipment in LTE, it can be covered with fewer base stations than LTE.

Also, the Huawei company's method is to transmit the LTE channel related channel by at least one sub CC. However, there is no mention of how to implement the method specifically.

As described above, there is a demand for a technology that appropriately utilizes the entire CC of LTE-A to provide a service to an LTE-A-compatible user device and also has compatibility with a conventional LTE-compatible user device. .

It is an object of the present invention to efficiently solve the problem of introducing an LTE-A-compatible user apparatus having a plurality of CCs and the compatibility of the LTE-A compatible user apparatus with LTE-A. Specifically, it is as follows. The operating system frequency bandwidth of an LTE-A capable user device that accesses an LTE-A system where the system frequency bandwidth is expected to reach 100 MHz may be less than 100 MHz. Further, it is necessary to make LTE-A compatible with a conventional user apparatus for LET. Thus, how to design and standardize for LTE-A provides a highly efficient service to LTE-capable user equipment, has an operating system frequency bandwidth greater than LTE-capable user equipment, and a plurality of An object of the present invention is to solve the problem of not adversely affecting an LTE-A compatible user apparatus having a CC.

In order to solve the above-described problem, a base station according to the present invention includes a receiving unit that receives operation width information indicating an operable frequency bandwidth of a communication terminal from a communication terminal connected to the own station; A part of the frequency bandwidth of the connected communication system to which LTE-A is applied is determined as the main frequency band of the communication system, and a portion excluding the determined main frequency band in the frequency band of the communication system is determined Dividing into one or more sub frequency bands, selecting a sub frequency band corresponding to the communication terminal based on the operation range information, and combining the selected sub frequency band and the main frequency band to perform the communication The operating frequency band of the terminal is set, the sub frequency band to which the PDCCH is allocated is determined from the set operating frequency band, and the LTE PDC is determined in the determined sub frequency band. Access control / scheduling means for performing H allocation, and transmission means for transmitting frequency band allocation information indicating an operating frequency band set by the access control / scheduling unit to the communication terminal of LTE, in the main frequency band Control signaling and channel design are both compatible with LTE, and the main frequency band includes LTE system information, LTE-A system information, and LTE broadcast by a broadcast channel compatible with LTE. -A includes downlink control channel information commonly used in -A.

Thereby, a main CC and a sub CC can be provided, and compatibility with LTE can be provided in the main CC, and a high-quality service can be provided to an LTE-compatible communication terminal. The main CC includes information for all user devices, synchronization information, and common control information, and assigns an operating system frequency bandwidth (multiple CCs) to each LTE-A compatible communication terminal. Thus, all CCs can be used effectively. Therefore, the above-described base station can easily realize compatibility with LTE-compatible communication terminals in a communication system to which LTE-A is applied, and LTE-compatible communication terminals and various LTE-A-compatible communication terminals. On the other hand, a high-speed data communication service can be provided.

In addition, in order to solve the above-described problems, the present invention is efficient for LTE-A-compatible user equipment that is compatible with LTE-compatible user equipment and has a larger operable frequency bandwidth (one CC). A method used in a mobile communication system to which LTE-A is applied and an apparatus included in the mobile communication system. In particular, the present invention provides a downlink CC configuration method in which CC is allocated when an LTE-A-compatible user apparatus accesses the mobile communication system and notified to the user apparatus by an appropriate signaling mechanism.

In order to solve the above-described problem, a downlink CC configuration method in a communication system to which LTE-A of the present invention is applied, a part of the LTE-A system frequency bandwidth is partially transferred by the base station to the main CC of LTE-A. A main CC determination step for determining a portion of the system frequency bandwidth (multiple CCs) of LTE-A excluding the main CC, and a sub CC partitioning step for partitioning into one or more sub CCs, and receiving from the user equipment Based on the information on the operable frequency bandwidth of the user device, the sub CC corresponding to the user device is selected, and the selected sub CC and the main CC are combined to set the operating frequency bandwidth of the user device. Thereafter, an allocation sub CC to which a PDCCH (Packet Data Control Channel) is allocated is determined from the operating frequency bandwidth for the user apparatus. A CC allocation step of transmitting CC allocation information indicating the allocation sub CC to the user apparatus in a signaling manner, and a transmission step of performing LTE PDCCH allocation in the allocation sub CC to which the PDCCH is allocated, The control signaling and channel design in the main CC are both compatible with LTE, and in the main CC, in addition to LTE-defined system information broadcast by a broadcast channel compatible with LTE, LTE -A includes all the information, and the main CC includes downlink control channel information commonly used in LTE-A. In the transmission step, the user equipment For the sub-CC in the operating frequency bandwidth, It performs processing for each sub-CC after sorting, is characterized by performing the PDCCH blind test defined in LTE.

In the communication system of the present invention, when the system frequency bandwidth of LTE-A is composed of a plurality of discrete CCs, the main CC is preferably located in the frequency band with the largest bandwidth.

In the communication system of the present invention, when the system frequency bandwidth of LTE-A is continuous, the main CC is preferably located in the middle of the system frequency bandwidth of LTE-A.

In the communication system of the present invention, the LTE-A system information preferably includes LTE-A frequency point information and sub-frequency bandwidth information.

In the communication system of the present invention, it is preferable that the base station assigns a sub CC to the user apparatus based on the operable frequency bandwidth of the user apparatus.

In the communication system of the present invention, it is preferable that the base station allocates a sub frequency band to the user apparatus based on the operable frequency bandwidth of the user apparatus and the load state of each sub CC.

In the communication system of the present invention, it is preferable that signaling in a higher layer in the first subframe scheduled by the base station for the user apparatus in the frequency band allocation information is transmitted from the base station to the user apparatus.

In the communication system of the present invention, it is preferable that the first subframe scheduled for the user apparatus is located in the main CC.

In the communication system of the present invention, it is preferable that the main CC determination step and the sub CC classification step are performed in the initialization process of the system.

In the communication system of the present invention, it is preferable that the frequency band allocation step is performed in a random access process of the user apparatus.

In the communication system of the present invention, in the frequency band allocation step, the user apparatus preferably transmits operable frequency bandwidth information of the user apparatus to the base station according to RRC access billing information in a random access process.

In the communication system of the present invention, in the frequency band allocation step, the frequency band allocation information is preferably transmitted from the base station to the user equipment by contention resolution signaling in a random access process.

In order to solve the above problems, the base station of the present invention determines a part of the LTE-A frequency bandwidth as the main frequency band of LTE-A, and excludes the main frequency band in the LTE-A frequency band. Control signaling in the main frequency band, including an access control / scheduling unit that divides the portion into one or more sub-frequency bands, and a transmission / reception unit that receives information on the operable frequency bandwidth from the user apparatus. And the channel design are both compatible with LTE, and within the main frequency band, all system information defined in LTE-A, as well as system information defined by LTE, broadcasted by a broadcast channel compatible with LTE are included. Information is included, and the main frequency band includes downlink signals commonly used in LTE-A. Control channel information is included, and the access control / scheduling unit selects a sub-frequency band corresponding to the user apparatus based on information on an operable frequency band range of the user apparatus received from the user apparatus. Then, the selected sub frequency band and the main frequency band are combined and set as the operating frequency band of the user apparatus, and then the sub frequency band to which the PDCCH is allocated from the operating frequency band is set for the user apparatus. The transmission / reception unit transmits frequency band allocation information to the user apparatus in a signaling manner, and the transmission / reception unit performs LTE-defined PDCCH allocation in a sub-frequency band to which the PDCCH is allocated. Yes.

In the base station of the present invention, it is preferable that the access control / scheduling unit allocates a sub CC to the user apparatus based on the operable frequency band range of the user apparatus.

In the base station of the present invention, it is preferable that the access control / scheduling unit allocates a sub frequency band to the user apparatus based on an operable frequency band range of the user apparatus and a current load state of each sub CC. .

In the base station of the present invention, it is preferable that the transmission / reception unit transmits the frequency band allocation information to the user apparatus by higher layer signaling in the first subframe scheduled for the user apparatus.

In the base station of the present invention, it is preferable that the transmission / reception unit transmits the frequency band information to the user apparatus by contention resolution signaling in a random access process.

In order to solve the above-described problem, the user apparatus according to the present invention is a user apparatus including a transmission / reception unit and a PDCCH detection unit, and the transmission / reception unit transmits information on an operable frequency bandwidth of the user device to a base station. The PDCCH detection unit performs reordering processing on the sub CCs in the operating frequency band, and performs PDCCH blind detection defined in LTE for each sub CC after the reordering processing. .

In the user apparatus of the present invention, it is preferable that the transmission / reception unit reports information on an operable frequency band range of the user apparatus to the base station based on RRC access request information in a random access process.

As described above, in the communication system of the present invention and the base station and communication terminal included in the communication system, the main CC and the sub CC are provided, and the main CC provides compatibility with LTE. Can provide high quality service. The main CC includes system information, synchronization information, and common control information for all communication terminals. By assigning CCs by the base station and assigning an operating system frequency bandwidth to each LTE-A compatible communication terminal, all sub CCs can be used sufficiently and effectively. According to the above-described LTE-A design, it is possible to easily realize compatibility with LTE-A communication terminals of LTE-A, and various types of LTE having LTE-compatible communication terminals and various operating system frequency bandwidths. -A high-speed data communication service can be provided to A-compatible communication terminals.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. This makes the above objects, features and advantages of the present invention clearer.
1 is a schematic diagram of a mobile communication system to which LTE-A is applied. It is a block diagram of a base station included in the mobile communication system. FIG. 2 is a block diagram of an LTE-A compatible terminal included in the mobile communication system. [Fig. 11] Fig. 11 is a sequence diagram when CC allocation information is acquired in a stage where the LTE-A compatible terminal randomly accesses the mobile communication system. FIG. 10 is a sequence diagram when the LTE-A compatible terminal acquires CC allocation information by higher layer signaling. FIG. 3 is an explanatory diagram showing a state in which a PDCCH is allocated to an LTE-A compatible terminal in the mobile communication system. It is the schematic of CC structure in LTE-A. FIG. 3 is an explanatory diagram showing CCs assigned to LTE-compatible terminals and LTE-A-compatible terminals in the mobile communication system.

Hereinafter, an example of a preferred embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that details and functions that are not necessary in the present invention are omitted from the description to avoid confusing understanding of the present invention.

The following embodiment is applied to a mobile communication system to which LTE-A is applied. Note that the present invention is not limited to the applications described in these embodiments, and can be applied to other mobile communication systems.

FIG. 1 is a schematic diagram of a mobile communication system (communication system) 100 to which LTE-A is applied. The mobile communication system 100 is a network to which LTE-A is applied. The base station 101 is a service control center of the mobile communication system 100, and radio resources of user apparatuses such as an LTE compatible terminal (LTE communication terminal) 102 and an LTE-A compatible terminal (LTE-A communication terminal) 103 in the cell. Performs scheduling (resource allocation) and data transmission related to data services.

The LTE compatible terminal 102 is a user apparatus used in a network to which LTE is applied, and operates with one CC of the LTE standard according to an operation mechanism based on LTE uplink / downlink control signaling. The LTE-A compatible terminal 103 operates in accordance with an operation mechanism based on the LTE-A standard in a plurality of CCs based on the LTE-A standard. The mobile communication system 100 can provide data services corresponding to the two types of user devices (LTE compatible terminal 102 and LTE-A compatible terminal 103) described above. Note that the mobile communication system 100 shown in FIG. 1 is for explaining the schematic configuration of the present invention, and is not limited to the above configuration when the present invention is actually implemented in a mobile communication system. For example, although FIG. 1 shows one LTE-compatible terminal 102 and one LTE-A-compatible terminal 103, a plurality of base stations and a plurality of base stations may be used.

As shown in FIG. 1, the mobile communication system 100 includes at least one base station 101. In the cell of the base station 101, several LTE compatible terminals 102 and several LTE-A compatible terminals 103 are allocated. The base station 101 controls each LTE-compatible terminal 102 and LTE-A-compatible terminal 103 allocated in the cell by radio resource scheduling and control signaling.

The configuration of the base station 101 of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing a main configuration of the base station 101. As shown in FIG. 2, the base station 101 includes a transmission / reception unit (transmission unit, reception unit) 1010, an access control / scheduling unit (access control / scheduling unit) 1011, and a determination unit 1012.

The transmission / reception unit 1010 transmits / receives control signaling and user data to / from user devices in the cell. The access control / scheduling unit 1011 controls access and assigns a CC to a newly accessed user apparatus. The determination unit 1012 determines whether the user apparatus corresponds to an LTE compatible terminal or an LTE-A compatible terminal from the random access information of the user apparatus.

The configuration of the LTE-A compatible terminal 103 according to the present invention will be described with reference to FIG. FIG. 3 is a block diagram illustrating a main configuration of the LTE-A compatible terminal 103. As shown in FIG. 3, the LTE-A compatible terminal 103 includes a transmission / reception unit (transmission / reception unit) 1030, a random access unit 1031, a filter adjustment unit 1032, an information acquisition unit 1033, and a PDCCH detection unit (PDCCH detection unit) 1034. It is a configuration.

The transmission / reception unit 1030 transmits / receives control signaling and user data to / from the base station 101. The random access unit 1031 generates random access information according to the type of user device (LTE compatible terminal or LTE-A compatible terminal). The filter adjustment unit 1032 preferably adjusts the parameters (center frequency, frequency bandwidth) of the reception frequency band filter based on CC allocation information from the base station. The information acquisition unit 1033 is operable to determine whether a user apparatus that transmits and receives information via the base station 101 is an LTE compatible terminal or an LTE-A compatible terminal. System of LTE communication system broadcast by user device capability such as system frequency bandwidth and number of CCs to be supported, information on user device category information (internal information), and broadcast channel BCH (708 in FIG. 7) in main CC The system information (external information) of the mobile communication system 100 including the information and the system information of the LTE-A communication system broadcasted by the additional broadcast channel BCH-A (707 in FIG. 7) is acquired. The system information includes LTE-A communication system information such as LTE-A system frequency bandwidth, number of CCs, CC number, CC center frequency, CC frequency bandwidth, in addition to all LTE system information.

The PDCCH detection unit 1034 performs PDCCH blind detection according to the LTE standard for all CCs within the operating system frequency bandwidth. The PDCCH blind detection method is described in 3GPP related standards.

2 and 3 show specific configurations of the base station 101 and the LTE-A compatible terminal 103 according to the embodiment of the present invention. For those skilled in the art, the present invention is It is obvious that the present invention is not limited to these specific configurations, and can be matched, divided, or combined with some or all of the configurations, or can be realized by software, hardware, or a combination thereof. is there.

Next, a downlink CC configuration method of the mobile communication system 100 to which LTE-A according to the embodiment of the present invention is applied will be described in detail with reference to FIGS.

The mobile communication system 100 of the present invention shows an LTE-A CC allocation method. Here, the system frequency bandwidth of LTE-A is indicated as Ba (MHz). Specifically, the system frequency bandwidth Ba of LTE-A can be set to 100 MHz from the draft of the resolution submitted at the recently opened LTE-A conference. On the other hand, the frequency bandwidth of the LTE CC is indicated as B (MHz). According to the current LTE resolution, the range of B is 1.25 to 20 MHz. In the present embodiment, B is set to 20 MHz. Specific system frequency bandwidth, CC configuration, etc. of LTE-A are designed by a mobile phone service provider, and are notified to user devices (communication terminals) as LTE-A system information.

First, the access control / scheduling unit 1011 of the base station 101 uses B (unit: “MHz”) in the LTE-A system frequency band Ba (unit: “MHz”, which is 100 MHz in the present embodiment). The frequency bandwidth is set to the main CC. The center frequency of the main CC is on an integer multiple of 100 kHz (the channel interval of the LTE communication system, that is, the raster is 100 kHz). As shown in FIG. 7, the signal format in the main CC (703) is completely compatible with LTE. That is, within the 20 MHz frequency band, LTE broadcast channel BCH (708), synchronization channel SCH, and downlink control channel PDCCH completely follow the conventional LTE design according to 3GPP specifications. The 20 MHz main CC (703) includes an LTE-A broadcast channel BCH-A (707). The LTE-A broadcast channel BCH-A (707) is formed of an LTE broadcast channel BCH (708) and an additional broadcast channel BCH-A having system information specific to the LTE-A communication system. The common search area (Common エリア Search Space) included in the PDCCH is in the main CC (703).

Then, the LTE compatible terminal 102 obtains LTE system information configured by master information MIB (Master Information Block) and multiple system information SIBs (System Information Blocks) of the LTE communication system from the broadcast channel BCH of the LTE communication system. Can be acquired. The LTE-A compatible terminal 103 combines BCH and BCH-A, that is, LTE-A communication system system information in BCH and master information MIB and system information in the LTE-A communication system in BCH-A. Combined with LTE-A related information such as SIBs, system information specific to LTE-A communication system, and frequency allocation of LTE-A system frequency bandwidth, number of CCs, CC number, CC center frequency, CC frequency bandwidth LTE-A system information configured by information and the like can be acquired.

In addition, when the system frequency bandwidth of LTE-A is configured by a plurality of CCs (non-continuous CCs) with discrete CCs, the main CC is arranged in a continuous CC having the largest frequency bandwidth. When a plurality of LTE-A CCs are continuous (continuous CC), the main CC is arranged in the center CC among the plurality of CCs of the LTE-A. The main CC is not limited to the central CC, and may be a CC near the center. Further, when the plurality of CCs are even numbers, any one of the vicinity of the two CCs in the center of the continuous CCs or a CC in the vicinity thereof may be used. However, the center frequency of the main CC is an integer multiple of 100 kHz of the frequency so that the LTE compatible terminal 102 and the LTE-A compatible terminal 103 can perform initial cell search (SCH reception) in the main CC.

Also, the access control / scheduling unit 1011 sets a portion excluding the B (MHz) portion of the LTE-A system frequency bandwidth as a sub CC. The sub CC can be divided into a plurality of sections according to the design. In this embodiment, one section is set to 10 MHz, and the LTE-A system frequency band includes a total of eight sub CCs.

Next, a flow when the LTE-A compatible terminal 103 accesses the base station 101 will be described with reference to FIG. FIG. 4 is a sequence diagram showing a first example of a flow of control signaling transmission / reception between the LTE-A compatible terminal 103 and the base station 101 when the LTE-A compatible terminal 103 accesses the base station 101. is there.

The transmission / reception unit 1030 of the LTE-A compatible terminal 103 receives the synchronization channel SCH in the main CC, and performs system synchronization between the LTE-A compatible terminal 103 and the base station 101.

Thereafter, the information acquisition unit 1033 of the LTE-A compatible terminal 103 acquires the system information of the mobile communication system 100 through the broadcast channel BCH and the additional broadcast channel BCH-A in the main CC.

Next, the LTE-A compatible terminal 103 compares the bandwidth of the mobile communication system 100 in the acquired system information with the operable frequency band range of the LTE-A compatible terminal 103. When the system frequency bandwidth of the mobile communication system 100 is equal to or smaller than the operable system frequency bandwidth of the LTE-A compatible terminal 103 (smaller or equal), the random access unit 1031 of the LTE-A compatible terminal 103 is defined by 3GPP. Random access according to the LTE standard. On the other hand, when the system frequency bandwidth of the mobile communication system 100 is larger than the operable system frequency bandwidth of the LTE-A compatible terminal 103, the LTE-A compatible terminal 103 uses the newly defined LTE-A random number as follows. Access.

That is, as shown in FIG. 4, first, the LTE-A compatible terminal 103 transmits a random access channel (RACH) through an uplink CC (uplink CC paired with the main CC) corresponding to the main CC in the LTE-A system frequency bandwidth. : Random Access CHannel), random access request information (RACH message A) is transmitted (41). Next, the base station 101 transmits random access response information (RACH message B) to the LTE-A compatible terminal 103 through the main CC (42).

The transmission / reception unit 1030 of the LTE-A compatible terminal 103 connects to RRC (Radio Resource Control) in the information (RACH message C) during the random access process through a common control channel (CCCH: Common Control Channel) in the random access channel. Information on the operable system frequency bandwidth of the LTE-A compatible terminal 103 (LTE-A compatible terminal capability or category information) is added to the billing information and transmitted to the base station 101 (43).

Then, the access control / scheduling unit 1011 of the base station 101, based on the acquired operable system frequency bandwidth of the LTE-A compatible terminal 103, the current load state of the mobile communication system 100, and the load state of each sub CC, The LTE-A system frequency bandwidth to be allocated to the LTE-A compatible terminal 103 and the main CC are determined.

FIG. 8 shows one specific example of LTE-A system frequency bandwidth allocated to the LTE-A compatible terminal 103B and main CC allocation. As a first example of allocation, for example, the operable system frequency bandwidth of the LTE-A compatible terminal 103B is 60 MHz, and in addition to including one fixed 20 MHz main CC (805) in the 60 MHz, four 10 MHz Of sub-CCs (806, 807, 808, 809). The access control / scheduling unit 1011 of the base station 101 acquires the number of user devices allocated in each sub CC, and allocates the four sub CCs with the smallest number of user devices allocated to the LTE-A compatible terminal 103 by rearrangement. . Other sub CCs may be assigned. Other methods may be used for the CC allocation method.

The base station 101 adds allocation information to the LTE-A compatible terminal 103 to contention resolution information (downlink control signaling, Contention Resolution, RACH message D), which is information during the random access process, and transmits the information to the base station. . Based on the CC allocation information from the base station, the filter adjustment unit 1032 of the LTE-A compatible terminal 103 preferably adjusts the reception frequency band filter parameters (center frequency, frequency bandwidth) and receives downlink information. To do.

Similarly to the above, when the system frequency bandwidth of the mobile communication system 100 is larger than the operable system frequency bandwidth of the LTE-A compatible terminal 103, the LTE-A compatible terminal 103 uses the newly defined LTE- A random access is performed. FIG. 5 is a sequence diagram showing a second example of the flow of control signaling transmission / reception between the LTE-A compatible terminal 103 and the base station 101 when the LTE-A compatible terminal 103 accesses the base station 101. is there.

Since the

procedures

501, 502, and 503 shown in FIG. 5 are the same as the

procedures

41, 42, and 43 shown in FIG. 4, a detailed description thereof is omitted here.

The access control / scheduling unit 1011 of the base station 101 performs the procedure 503 based on the acquired operable system frequency bandwidth of the LTE-A compatible terminal 103, the current load state of the mobile communication system 100, and the load state of each CC. The system frequency bandwidth to be allocated to the LTE-A compatible terminals 102 and 103 (A to D) and the main CC are determined.

FIG. 8 is an explanatory diagram showing an example of assigning CCs to the LTE compatible terminal 102 and the plurality of LTE-A compatible terminals 103. A second example of assignment will be described with reference to FIG. In the example shown in FIG. 8, CC allocation states are shown for the LTE compatible terminal 102 and the four LTE-A compatible terminals 103 (A to D).

The LTE compatible terminal 102 with an operable system frequency bandwidth of 20 MHz is assigned a main CC (805) of 20 MHz. In addition, the LTE-A compatible terminal 103A having an operating system frequency band of 40 MHz is assigned two 10 MHz sub CCs (801, 802) in addition to the main CC (805). In addition, CC (803,808) may be sufficient as sub CC allocated. The LTE-A compatible terminal 103B having an operable system frequency bandwidth of 60 MHz is assigned four 10 MHz sub CCs (801, 802, 808, 809) in addition to the 20 MHz main CC (805). . Other sub CC combinations may be used. The same applies to the LTE-A compatible terminals 103 (C, D).

Thereafter, the transmitting / receiving unit 1010 of the base station 101 transmits contention resolution information (downlink control signaling, Contention Resolution, RACH message D), which is information during the random access process (504).

The access control / scheduling unit 1011 of the base station 101 performs resource allocation of CC allocation information to the LTE-A compatible terminal 103 in the first scheduling subframe through the PDCCH of the main CC, and performs scheduling information ( (Point, size, etc. information indicating the resource of CC allocation information) is transmitted (505). Further, the access control / scheduling unit 1011 performs higher layer signaling to the CC allocation information resource through the main CC, and transmits the CC allocation information of the LTE-A compatible terminal 103 (506).

In the first scheduling subframe, the PDCCH detection unit 1034 of the LTE-A compatible terminal 103 performs scheduling information on resources of CC allocation information in the PDCCH in the main CC (information such as points and sizes indicating the resources of the CC allocation information) ) To read the PDSCH data corresponding to the downlink data shared channel (PDSCH: PhysicalPhysDownlink Shared Channel) resource, and obtain the CC allocation information.

Next, the LTE-A compatible terminal 103 operates in the assigned CC in the scheduling subframe subsequent to the first scheduling subframe. In this case, the filter adjustment unit 1032 adjusts the parameters of the filter based on the acquired CC allocation information so that the information from the base station 101 can be suitably received. The CC assignment information includes CC (CC center frequency, CC number, etc.) information including a plurality of CCs assigned to the LTE-A compatible terminal 103 and PDCCH.

Similarly to the above, when the system frequency bandwidth of mobile communication system 100 is larger than the operable system frequency bandwidth of LTE-A compatible terminal 103, downlink control in mobile communication system 100 according to the embodiment of the present invention A signaling transmission method will be described.

In the LTE-A system, the common search area (Common Search Space) in the PDCCH is arranged in the main CC. Note that, as the common search area in the LTE-A PDCCH, the common search area of the LTE PDCCH can be used in multiple. In addition, an LTE-A PDCCH common search area can be newly defined in the main CC.

Hereinafter, the PDCCH allocation process of LTE-A will be described with reference to FIG. FIG. 6 is an explanatory diagram showing a state when the PDCCH is distributed to the LTE-A compatible terminal 103. FIG. 6A is a diagram illustrating a CC to which a PDCCH is allocated, and FIG. 6B is a flowchart illustrating a flow of detecting a PDCCH.

The base station 101 allocates a specific CC to the LTE-A compatible terminal 103 by a specified calculation method, and performs LTE PDCCH distribution in the specific CC.

Specifically, the PDCCH detection unit 1034 of the LTE-A compatible terminal 103 performs rearrangement processing on the sub CCs within the corresponding operating system frequency bandwidth. Here, the rearrangement processing refers to rearranging the CC processing procedures according to a certain rule, for example, rearrangement processing in the order of CC numbers.

Then, the sub CCs (601 to 603) shown in (a) of FIG. 6 are the results of rearrangement in the order of the

sub CCs

601, 602, and 603 by the rearrangement process. Also, the flow of performing PDCCH detection in this order is shown in FIG.

Then, the PDCCH detection unit 1034 performs LTE PDCCH blind detection in the newly defined downlink control information (DCI) format based on the rearranged order (S611). Specifically, first, PDCCH detection is performed on the sub CC (601) (S612), and if no PDCCH is detected (not detected in S612), detection is performed on the next sub CC (602). (S613). When the PDCCH is not detected in the sub CC (602) (not detected in S613), the PDCCH is detected in the next sub CC (603) (S614). In this way, the operation continues until the detection of PDCCH in all the sub CCs (601 to 603) is completed. In the process, when the corresponding PDCCH is detected, the PDCCH detection is terminated at that time ( S615). For example, when the PDCCH is detected in the sub CC (602) (detected in S613), the PDCCH detection is terminated as it is (S615). The flow at this time is shown by a broken line in FIG. Here, although the case where there are three sub CCs has been described, the present invention is not limited to this.

Also, the PDCCH includes all resource allocation information in the operating system frequency bandwidth of the LTE-A compatible terminal 103.

Also, the PDCCH in each sub CC includes corresponding PDSCH related information in the CC in the format of downlink control information (DCI) by a method compatible with LTE.

Next, channel mapping in LTE-A will be described using FIG. FIG. 7 is a schematic diagram of channel mapping in LTE-A. In FIG. 7, the vertical axis represents frequency and the horizontal axis represents time. As shown in FIG. 7, LTE-A includes a 20 MHz main CC (703) and a 10 MHz sub CC (701, 702, 704, 705). Here, although four sub CCs are shown, it is not restricted to this. The number of sub CCs is changed according to the operating system frequency bandwidth.

As shown in FIG. 7, the main CC (703) and the sub CCs (701, 702, 704, 705) all include the PDCCH in the first symbol. Further, the common search area 706 is included in the PDCCH of the main CC.

In addition, a symbol next to the symbol including the PDCCH of the main CC (703) includes an area 707 including BCH / SCH and BCH-A.

As described above, according to the downlink forming method described above, the LTE compatible terminal 102 and the LTE-A compatible terminal 103 both access the mobile communication system 100 to which LTE-A is appropriately applied, and LTE- A high-speed data service provided by A can be received. Further, the above-described design is simple and highly efficient, is not complicated in design, and satisfies the requirements of user devices.

The above-described embodiment has been described with reference to a preferred example, and those skilled in the art can make various other changes, replacements, and additions without departing from the spirit and scope of the present invention. . Therefore, the scope of the present invention should not be limited to the specific embodiments described above, but should be determined by the appended claims.

Finally, each block of the base station 101 and the LTE-A compatible terminal 103, in particular, the transmission / reception unit 1010 of the base station 101, the access control / scheduling unit 1011, the determination unit 1012, and the transmission / reception unit 1030 of the LTE-A compatible terminal 103, The random access unit 1031, the filter adjustment unit 1032, the information acquisition unit 1033, and the PDCCH detection unit 1034 may be configured by hardware logic, or realized by software using a CPU (central processing unit) as follows. Also good.

That is, the base station 101 and the LTE-A compatible terminal 103 include a CPU that executes instructions of a control program for realizing each function, a ROM (read only memory) that stores the program, and a RAM (random access memory) that develops the program. ), A storage device (recording medium) such as a memory for storing the program and various data. The object of the present invention is to enable a computer to read program codes (execution format program, intermediate code program, source program) of control programs for the base station 101 and the LTE-A compatible terminal 103, which are software for realizing the functions described above. Are supplied to the base station 101 and the LTE-A compatible terminal 103, and the computer (or CPU or MPU (microprocessor unit)) reads and executes the program code recorded on the recording medium. Can also be achieved.

Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, a CD-ROM (compact disk-read-only memory) / MO (magneto-optical) / Disc system including optical disc such as MD (Mini Disc) / DVD (digital versatile disc) / CD-R (CD Recordable), card system such as IC card (including memory card) / optical card, or mask ROM / EPROM ( A semiconductor memory system such as erasable, programmable, read-only memory, EEPROM (electrically erasable, programmable, read-only memory) / flash ROM, or the like can be used.

Alternatively, the base station 101 and the LTE-A compatible terminal 103 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, an intranet, an extranet, a LAN (local area network), an ISDN (integrated services network, digital network), a VAN (value-added network), and a CATV (community antenna) television communication. A network, a virtual private network, a telephone line network, a mobile communication network, a satellite communication network, etc. can be used. Further, the transmission medium constituting the communication network is not particularly limited. For example, IEEE (institute of electrical and electronic engineering) (1394), USB, power line carrier, cable TV line, telephone line, ADSL (asynchronous digital subscriber loop) loop Wireless such as IrDA (infrared data association) or remote control, Bluetooth (registered trademark), 802.11 wireless, HDR (high data rate), mobile phone network, satellite line, terrestrial digital network, etc. But it is available. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

According to the present invention, since a communication device that supports only LTE can be compatible with a communication system to which LTE-A is applied, it is suitable for a communication system that supports LTE-A.

100 Mobile communication system (communication system)
101 Base station 102 LTE compatible terminal (communication terminal)
103 LTE-A compatible terminal (communication terminal)
1010 Transmission / reception unit (transmission means, reception means)
1011 Access control / scheduling unit (access control / scheduling means)
1030 Transmission / reception unit (transmission / reception means)
1034 PDCCH detector (PDCCH detector)

Claims

Receiving means for receiving operation width information indicating an operable frequency bandwidth of the communication terminal from a communication terminal connected to the own station;
A part of the frequency bandwidth of the communication system to which LTE-A is applied including its own station is determined as the main frequency band of the communication system, and the determined main frequency band is excluded from the frequency bandwidth of the communication system The portion is divided into one or more sub-frequency bands, a sub-frequency band corresponding to the communication terminal is selected based on the operation width information, and the selected sub-frequency band and the main frequency band are combined. An access control / scheduling unit configured to set an operating frequency band of the communication terminal, determine a sub-frequency band to which a PDCCH is allocated from the set operating frequency band, and perform LTE PDCCH allocation in the determined sub-frequency band;
Transmitting means for transmitting frequency band allocation information indicating an operating frequency band set by the access control / scheduling means to the communication terminal,
The control signaling and channel design in the main frequency band are both compatible with LTE,
The main frequency band includes LTE system information broadcast by a broadcast channel compatible with LTE, LTE-A system information, and downlink control channel information commonly used in LTE-A. A base station characterized by
The access control / scheduling means, when the frequency band of the communication system is configured by a plurality of discrete frequency bands, has the highest bandwidth among the plurality of discrete frequency bands. The base station according to claim 1, wherein the base station is determined within a large frequency band.
The access control / scheduling means determines the main frequency band as a central frequency band among the plurality of frequency bands of the communication system when a plurality of frequency bands of the communication system are continuous. The base station according to claim 1.
The LTE-A system information includes an LTE-A system frequency bandwidth, the number of frequency bands, a frequency band number, a center frequency of the frequency band, and a bandwidth of the frequency band. The listed base station.
The access control / scheduling means selects a sub frequency band to be allocated to the communication terminal based on an operable frequency bandwidth of the communication terminal and a load state of the sub frequency band. Base station.
The said transmission means transmits the said frequency band allocation information to the said communication terminal by the signaling of the higher layer in the 1st sub-frame which the said access control / scheduling means selected. base station.
The base station according to claim 1, wherein the transmission means transmits the frequency band allocation information to the communication terminal by contention resolution signaling in a random access process.
The base station according to claim 6, wherein the transmission means arranges the first subframe in the main frequency band.
The base station according to claim 1, wherein the access control / scheduling means determines the main frequency band and classifies the sub frequency band at a stage of establishing a connection between the local station and the communication terminal. Bureau.
The base station according to claim 1, wherein the transmitting means transmits the frequency band allocation information in a random access process of the communication terminal.
Information indicating the operable frequency band range of the own terminal is transmitted to a base station connected to the own terminal and included in a communication system to which LTE-A is applied, and the operating frequency band of the own terminal is transmitted from the base station. Transmitting and receiving means for receiving the indicated information;
Reordering processing is performed on a plurality of sub-frequency bands in the operating frequency band indicated by the operating frequency band information received by the transmission / reception means, and LTE PDCCH blind detection is performed on each sub-frequency band after the reordering process. And a PDCCH detecting means for detecting PDCCH by performing the communication terminal.
12. The communication terminal according to claim 11, wherein the transmission / reception means transmits information on an operable frequency band range of the terminal to the base station based on RRC (Radio Resource Control) access request information in a random access process. .
A communication system including the base station according to any one of claims 1 to 10 and the communication terminal according to claim 11 or 12.
A base station control program for operating the base station according to any one of claims 1 to 10, for causing a computer to function as each means described above.
A communication terminal control program for operating the communication terminal according to claim 11 or 12, for causing a computer to function as each of the above means.
A computer-readable recording medium recording at least one of the base station control program according to claim 14 and the communication terminal control program according to claim 15.
A receiving step of receiving operation width information indicating an operable frequency bandwidth of the communication terminal from a communication terminal connected to the own station;
A part of the frequency bandwidth of the communication system to which LTE-A is applied, including the local station, is determined as the main frequency band of the communication system, and the determined main frequency band is excluded from the frequency band of the communication system Are divided into one or more sub-frequency bands, and based on the operation width information, a sub-frequency band corresponding to the communication terminal is selected, and the selected sub-frequency band and the main frequency band are combined to An access control / scheduling step for setting an operating frequency band of a communication terminal, determining a sub-frequency band to which a PDCCH is allocated from the set operating frequency band, and performing LTE PDCCH allocation in the determined sub-frequency band;
Transmitting the frequency band allocation information indicating the operating frequency band set in the access control / scheduling step to the communication terminal, and
The control signaling and channel design in the main frequency band are both compatible with LTE,
The main frequency band includes LTE system information broadcast by a broadcast channel compatible with LTE, LTE-A system information, and downlink control channel information commonly used in LTE-A. A control method for a base station.
A transmission step of transmitting information on the operable frequency bandwidth of the own terminal to a base station included in a communication system to which LTE-A is applied, connected to the own terminal;
A receiving step of receiving the operating frequency band of the terminal from the base station;
PDCCH detection for detecting PDCCH by performing rearrangement processing on sub-frequency bands in the operating frequency band received in the reception step, and performing LTE PDCCH blind detection on each sub-frequency band after the rearrangement processing And a communication terminal control method.
A receiving step of receiving operating range information indicating an operable frequency bandwidth of the communication terminal from a communication terminal connected to the base station;
A part of a frequency bandwidth of a communication system to which LTE-A is applied including a base station is determined as a main frequency band of the communication system, and a portion excluding the determined main frequency band in the frequency band of the communication system Are divided into one or more sub-frequency bands, and based on the operation width information, a sub-frequency band corresponding to the communication terminal is selected, and the selected sub-frequency band and the main frequency band are combined to An access control / scheduling step for setting an operating frequency band of a communication terminal, determining a sub-frequency band to which a PDCCH is allocated from the set operating frequency band, and performing LTE PDCCH allocation in the determined sub-frequency band;
Transmitting the frequency band allocation information indicating the operating frequency band set in the access control / scheduling step to the communication terminal, and
The control signaling and channel design in the main frequency band are both compatible with LTE,
The main frequency band includes LTE system information broadcast by a broadcast channel compatible with LTE, LTE-A system information, and downlink control channel information commonly used in LTE-A. And
A reordering process is performed on sub frequency bands in the operating frequency band received by the communication terminal in the transmission step, and a PDCCH is detected by performing LTE PDCCH blind detection on each sub frequency band after the reordering process. And a PDCCH detection step for detecting the communication system.