Method of transmitting downlink control signal

FIELD OF THE INVENTION

The present invention relates to a mobile communication system using multiple carriers, and more particularly to a structure of a downlink control signal, and a method for its transmission. Although the present invention is suitable for a wide application, it is particularly suitable for transmitting a control signal needed for more efficient data transmission in a downward / upward direction.

BACKGROUND ART

Generally, in a mobile communication system using a multi-carrier base station transmits a downlink data packet to the user equipments (UEs) (user equipments - annotated. Translating.) Belonging to each of the at least one or more cells.

Within a cell may be a plurality of user equipments. Each UE may not be aware of when a data packet is received or what kind of a data packet is received. Therefore, when the base station transmits downlink package data to a particular user equipment (hereinafter abbreviated UE), such necessary information as an identifier (ID) of the user equipment (UE) to obtain a corresponding data packet time-frequency region for transmission of a data packet format data transport including the coding rate, modulation scheme, etc., information associated with a hybrid automatic retransmission request data (HARQ), etc., to be transmitted in the downlink direction for each downlink data packet transmission.

Conversely, to enable a user equipment (UE) to transmit a required information as a data packet in the uplink direction the base station must transmit the identifier of the user equipment (UE), which are allowed to send a data packet, a time-frequency region of the uplink for the user equipment ( UE) to transmit a data packet, the data transport format, including code rate, modulation scheme, etc., information associated with a hybrid automatic retransmission request data (HARQ), etc. in the downlink for each uplink data packet transmission.

In case of uplink data packet transmission, the base station shall transmit a respective user equipment (UE) on the downlink information on ACK / NACK (ACK / NAK - acknowledgement / non-acknowledgement) for each transmit these user equipment (UE) data packet. Moreover, the base station shall transmit information about transmission power control for each user equipment (UE) in a downward direction to maintain power transmitting / receiving uplink respective user equipment (UE) at a proper level.

For convenience of explanation, in the following description, all the information transmitted to the physical layer send and receive data between a base station and a user equipment (UE), referred to as "downlink control information". A signal carrying said information, referred to as "downlink control signals".

More details downlink control information may be categorized as follows:

1. Planning Information uplink / downlink data:

(1) Information Category A: an identifier (ID) of the user equipment (UE) for transmitting / receiving packet data, information on the allocation of time-frequency region for transferring the data packets, etc.

(2) Information Category B: data transport format, for example coding rate, modulation scheme, etc., information associated with a hybrid automatic retransmission request data (HARQ), etc.

2. The information is not associated with downstream data:

(1) Information on the ACK / NACK (ACK / NAK), power management information, etc.

For efficient operation of the system must be effectively multiplexed downlink control signal for transferring the above-mentioned control information from the data packets and the other downstream signals in the downlink time-frequency resource.

For this purpose, as follows explains the general method of transmitting a downlink signal.

First of all, the system transmitting downlink data packet can advantageously be divided into categories for localized allocation and distributed allocation.

When the localized allocation data for one user equipment unit (UE) are transmitted in a relatively limited frequency band through consecutive subcarriers. The scheduler of the base station selects a frequency band having a good frequency characteristic of a radio channel for each unit of user equipment (UE), based on the frequency response communicated to the user equipments (UEs), located within the cell of the downlink radio channel, and then transmits the data. Therefore, the transmission efficiency of the cell can be improved. For reference, when a localized allocation, the base station may, if necessary, to transfer data from one user equipment unit (UE) by subcarriers within at least two discrete frequency bands.

When the distributed allocation data for one user equipment unit (UE) are transmitted in a relatively wide frequency band within the system bandwidth by targeted distribution. Distributed allocation is suitable for the case where the scheduler of the base station is difficult to estimate the frequency response of the downlink radio channel for the user equipment (UE) or apply a frequency characteristic for scheduling downlink data packet. Since one data packet is transmitted in a wide band, the gain is obtained due to frequency diversity. Therefore, there can be improved the quality of reception of the data packet.

In the following description, downlink signal transmission system supports both localized allocation and distributed allocation for transmitting downlink data packet. Furthermore, it is assumed that the data packets transmitted by another within the same transmission time interval can be multiplexed together.

For clarity, the following description of the basic unit of time-frequency domain for transmission of the data packet is referred to as the "resource unit" (hereinafter abbreviated RB - resource block). Also it assumes that one resource block includes a plurality of sub-fields from end to end a plurality of OFDM-symbols (OFDM - Orthogonal Frequency Division Multiplexing - Orthogonal Frequency Division, n. Translating.).

1 is a diagram illustrating a structure for transmitting a downlink signal by the localized separation.

According to Figure 1, if within the system bandwidth, there are 288 subcarriers used for transmitting downlink data and, if one resource block (RB) includes 12 subcarriers within 6 OFDM-symbols, then for each 6 OFDM-symbols in downward direction, there 24 resource blocks (RBs). In this case, assuming that the resource block (RB) allocation for the localized usually called localized virtual resource block (LVRB) (localized virtual resource block), a localized virtual resource block (LVRB), as shown in Figure 1, is formed 12 successive subcarriers. From Example 1, in which the localized virtual resource blocks (LVRBs) are allocated to the user equipment UE1, it follows that the localized allocation may be accomplished by transmitting data through localized virtual resource blocks (LVRBs), consecutive to one user unit equipment (UE).

Moreover, the example in which the localized virtual resource block (LVRB) allocated to the user equipment UE2, it follows that the audio data is transmitted to the user equipments through localized virtual resource blocks (LVRBs), spaced from one another in the frequency domain. Consequently, the result is the effect of distributed allocation for gains due to frequency diversity.

2A and 2B are schematic representations of the structure to transmit the downlink signals by the distributed allocation.

Unlike Figure 1, with the proviso that localized virtual resource block (LVRB) for distributed allocation is called a distributed virtual resource block (DVRB) (distributed virtual resource block), the distributed virtual resource block (DVRB), as shown in FIG. 2A or 2B may be formed with subcarriers separated from one another in the frequency domain or time-frequency domain. In this case, according to Figure 2A and 2B, even if the data in total constituting one resource block (RB) or a small number of resource blocks (RBs), one unit is transmitted the user equipment (UE), the transmission is their distribution over a wide frequency range by using discrete subcarriers distributed virtual resource blocks (DVRBs). Thus, it may be carried distributed allocation.

DISCLOSURE OF INVENTION

TECHNICAL PROBLEM

Although the transmission scheme of the data packet in the transmission of the downlink signal, as mentioned in the foregoing description, expressly include the localized allocation and distributed system selection and combination thereof, the transmission scheme of the above downlink control signal from the downlink data packet by the localized and / or distributed no selection It was clearly concretized or proposed. Consequently, it became necessary to discuss the efficacy of a method of transmitting a control signal including scheduling information for downlink data transmission in the downlink control signals, the control signal containing scheduling information for uplink data transmission, etc. in accordance with their characteristics.

TECHNICAL SOLUTION

Accordingly, the present invention is directed to a structure of a downlink control signal and a method of transmission that substantially obviate one or more problems due to limitations and disadvantages of the prior art.

The present invention is to provide a structure of a downlink control signal transmission method by which the localized allocation and distributed allocation effectively used in transmitting the downlink control signal.

Additional features and advantages of the invention will be set forth in the description which follows and in part will be obvious from the description or may be learned by its implementation. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the present specification and claims thereto, as well as the appended drawings.

To achieve these and other advantages and in accordance with the purpose of the present invention as shown in the examples of its implementation and broadly described, a method for transmitting a downlink control signal including scheduling information to transmit uplink data and transmitted by the base station according to the present invention includes the steps of multiplexing the downlink control signal, when being transferred downlink data given user equipment (UE), by applying a localized allocation to transmit a downlink control signal including scheduling information uplink data transmission of the user equipment (UE), and applying a distributed allocation to another transmission of a downlink control signal, and transmitting multiplexed downlink control signal.

Preferably, the downlink control signal is multiplexed and transmitted through the use of distributed allocation for one, at least, OFDM-symbol of the available first OFDM-symbol, and the localized allocation to other OFDM-symbols following the one, at least, OFDM-symbol.

More preferably, the downlink control signal is allocated distributed allocation is isolated as a distributed unit group of a predetermined number of consecutive subcarriers, the received value by suitably used for transmitting the uplink data resource block (RB) or a multiple of this value.

Preferably, the downlink control signal transmitted by using a localized allocation, partial transfer area resource block (RB), the carrier downlink data to the user equipment (UE).

More preferably the amount of at least one OFDM-symbol to be used for distributed allocation and the number-OFDM symbols used for the localized allocation is sent to all user equipments (UEs), located within the cell, as a general downlink.

More preferably, the top-down control signal transmitted from the distributed release includes scheduling information transmission downlink data given to the user equipment (UE), the top-down control signal includes an indicator indicating tolerated if scheduling information uplink data transmission for user equipment (UE) within the resource carrying the downlink data to the user equipment (UE).

Preferably, the scheduling information is uplink data transmission included in the downlink control signal indicates a group of resource blocks used for a scheduled uplink data transmission.

Preferably subcarrier giving malfunction when transferring downlink control signal related to the subcarriers within at least one OFDM-symbol set to enable the transfer of the downlink control signal carries downlink data.

More preferably, the base station notifies the amount of time frequency resources for the transfer of the downlink control signal, at least one OFDM-symbol set to enable the transfer of the downlink control signal.

Moreover, the base station and all user equipments (UEs), located within the same cell and serviced by said base station, known information about the transmission scheme of the descending control signal previously adopted in accordance with the amount of time-frequency resources bearing the downstream control signal.

In this case, a transmission scheme previously adopted by downlink control signal in accordance with the amount of time-frequency resource, downlink carrier control signal is used to transmit a downlink control signal in the sequence of characters beginning with the first available OFDM-symbol.

More preferably, the base station notifies the amount of time-frequency resources bearing the downlink control signal, at least one OFDM-symbol set to enable the transfer of the downlink control signal as well as the amount of time-frequency resource that is not used for transmission the downlink control signal, and for transmitting downlink data.

More preferably, the base station notifies the amount of time-frequency resource, downlink data carrier of at least one OFDM-symbol set to enable the transfer of the downlink control signal.

Preferably the amount of uplink data packets that can be transmitted within a transmission time interval (TTI) (transmit time interval), and the number of downlink data packets that can be transmitted within a transmission time interval (TTI), is set smaller than the maximum amount of uplink data packets that can be transmitted within a transmission time interval (TTI), and the maximum number of downlink data packets that can be transmitted within a transmission time interval (TTI), respectively.

Preferably, the number of pieces of information about the scheduling uplink data transmission that may be transmitted within a transmission time interval (TTI), the number of pieces of information about the scheduling of transmission downlink data, and the total amount resulting from adding the previous amounts set smaller than the maximum number of pieces of information on planning, which can be transmitted within a transmission time interval (TTI).

Preferably, the information indicating a selection, a distributed or localized, used by each user equipment (UE) to receive downlink control signal is received before a period of time longer than the transmission time interval (TTI), wherein the base station previously informs information intended for each user equipment (UE), the respective user equipment (UE) by signaling via radio resource control (RRC-signaling).

Preferably, the corresponding user equipment (UE) searches the specified area of ​​the resource having the quality of a downward radio channel, reported that it is good, by the information on the quality of the descending control signal, cell broadcast messages relevant user equipment (UE), the downlink control signal transmitted by localized allocation.

Preferably, the base station informs the bit format of the area resource information, downlink carrier control signal using the localized release all user equipment units (UEs) within the cell.

Preferably, the transmission format downlink control signal pre-assigned to each user equipment (UE) for a period longer than one transmission time interval (one TTI), and the base station previously informs the transmission format of the downlink control signal to each user equipment (UE) by signaling radio resource control channel (RRC-signaling).

It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention.

Useful results

Accordingly, the present invention provides the following effects or advantages.

First of all, a method for transmitting a downlink control signal in accordance with one embodiment of the present invention takes into account the advantages and disadvantages of the localized allocation and the distributed allocation, thereby contributing to both the efficiency of transmission at the localized allocation and the resulting gains due to frequency diversity when the distributed allocation.

Secondly, the structure of the downlink control signal transmitted by the localized allocation and distributed allocation of signal transmission through general distributed resource allocation is provided at the front end of one transmission time interval (TTI), and the signal transmission by the localized separation is provided at the rear end of a respective slot transmission (TTI). Consequently, the present invention can flexibly cope with the magnitude of the control signal.

Thirdly, the indicator for control information taken into account for localized allocation, or something like that is included in part by a distributed resource allocation can thus be increased reception performance.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included herein to further understanding of the invention and forming an integral part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

In the drawings:

Figure 1 shows a diagram of a structure for transmitting a downlink signal by the localized allocation;

2A and 2B are diagrams showing the structure of a downlink signal for transmission by the distributed allocation;

3A and 3B are diagrams showing the structure for transmitting the downlink control signal for the first-available OFDM symbol by a distributed allocation in accordance with one embodiment of the present invention;

Figure 4 shows a diagram of a structure for transmitting a downlink control signal by the localized allocation after-OFDM symbol by a distributed allocation in accordance with one embodiment of the present invention;

Figure 5 shows a circuit structure for transmission of downlink data resource blocks that the control signal is not transmitted within OFDM-symbol for transmitting downlink control signal in accordance with one embodiment of the present invention;

Figure 6 shows a diagram of a general structure for transmission of the downlink control signal channel in connection with Figures 4 and 5, according to one embodiment of the present invention;

Figure 7 shows a diagram of volume change of time-frequency resource necessary to transmit the signal in different formats scheduling transmission scheduling information;

8A and 8B schematically show examples of how the user equipments (UEs), having different transfer formats assigned to them information about the planning, scheduling signals search performed in accordance with one embodiment of the present invention; and

9 schematically shows an example of how the user equipments (UEs), having assigned to them a transmission format shall seek scheduling signals if the different transmission formats scheduling information for different priority.

BEST EXAMPLE OF THE INVENTION

Will now be discussed in detail preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In the following description, a signal scheduling is mainly used as a top-down control signal. However, it is obvious that the present invention can be applied also to other downlink control signals.

In the following description, details are included to ensure complete understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without these details. For a better understanding of the invention, well-known structures and devices are omitted or represented as block diagrams for the basic functions of the structures and devices. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

A method of multiplexing the downlink control signal using both properly localized allocation and distributed allocation according to one embodiment of the present invention is explained as follows.

First of all, a tacit agreement with the above downlink data packet transmission of the downlink scheduling signal, which is a control signal carrying the scheduling information for downlink data, can be transmitted through a localized allocation or distributed allocation.

For example, when transmitting the data packet given to the user equipment (UE), if the downlink data packet transmitted by the localized allocation in a particular frequency band received as having good characteristics of the downlink radio channel for the respective user equipment (UE), it is possible to improve reception performance scheduling signal so that the signal transmission for scheduling downlink data packet is transmitted in the same frequency band (i.e. in that part of the band in which the downlink data packet is transmitted).

In contrast, in the case when a data packet is transmitted by the distributed allocation of a user equipment (UE), downlink radio channel characteristics is difficult to estimate or which hardly reflected in the transmission of the downlink data packet scheduling signal transmitted by a broad band distribution. Consequently, when receiving a signal scheduling gain may be obtained, due to the frequency diversity. Furthermore, it may be necessary to transmit scheduling signals corresponding to the above downlink data packet transmission by the distributed allocation in accordance with the operational requirement from another system without regard to the method for transmitting downlink packet data.

However, distributed allocation is mainly suitable for the transmission planning downlink signal containing information about scheduling uplink data transmission. If the transfer downlink data packets given user equipment (UE) occurs rarely, and transmitting an uplink data packets that the user equipment (UE) is performed frequently, the base station may have difficulty in estimating the characteristics of the downlink radio channel a user equipment (UE). In the case where the base station transmits a downlink data packet given to the user equipment (UE) by a localized discharge at the time point when a predetermined user equipment (UE) should transmit the uplink data packet, the base station has the opportunity to know the characteristics of the downlink radio channel a user equipment (UE). In this case, to obtain higher transmission efficiency is beneficial to downlink scheduling signal for uplink data of the user equipment (UE) is transmitted in the frequency band used to carry downlink data packet.

Given above are explained advantages and disadvantages, and in accordance with one embodiment of the present invention, when transmitting the downlink control signal including scheduling information transmitting an uplink / downlink data packet will be supported as a localized allocation and distributed allocation. However, if there is downlink data transmission to a particular user equipment (UE), for transmitting a downlink control signal including scheduling information uplink data transmission of a particular user equipment (UE), the localized allocation is used. Otherwise, the downlink control signal is multiplexed and transmitted by the distributed allocation.

In particular, in accordance with one embodiment of the present invention, which discusses the transfer scheme downlink control signal if the basic time interval for transmitting a signal scheduling and packet data in the downlink direction to each user equipment (UE) is defined as a TTI (transmit time interval - the interval transmission time) for transmitting a downlink signal scheduling at least one or more slots OFDM-symbols in a range from the first OFDM-symbol within a transmission time interval (TTI) or second OFDM-symbol in the case of the first OFDM-symbol for another purpose (hereinafter represented as "first available symbol"), to a predetermined OFDM symbol used-distributed allocation. Then, the downlink control signal is transmitted by the localized separation of OFDM-symbol following the specified OFDM symbol, if necessary.

In the explained embodiment, distributed allocation is normally used to transmit a downlink control signal, and a localized allocation is used for a specific case where downlink data is transmitted corresponding to the user equipment (UE). As mentioned earlier in the description, this gives more flexibility to multiplex the downlink control signal using a transmission scheme downlink control signal using block-OFDM symbols. Moreover, the presence or absence of the multiplexed by the localized separation or the like of the control signal can be produced using the provided in front of the transmission time interval (TTI) of the indicator control signal multiplexed by the distributed allocation. Therefore, there can be reduced the magnitude of the control signal multiplexed by the distributed resource allocation.

3A and 3B are diagrams transmitting downlink control signal for the first-available OFDM symbol by a distributed allocation in accordance with one embodiment of the present invention.

As mentioned in the foregoing description, when transmitting the downlink control signal by the distributed allocation interval in the range from the first available OFDM-symbols to a predetermined symbol number of scheduling signals may be multiplexed by distributing and allocating at least one or more OFDM-symbols into Within one transmission time interval (TTI), to transmit the scheduling information on several data packets transmitted in the uplink or downlink direction during a respective transmission time interval (TTI).

In particular, the scheduling signals including a control signal 1 and pilot signal 2 as shown in Figure 3, can be suitably distributed using a subcarrier block. Alternatively, the scheduling signals including a control signal 1 and pilot signal 2, as shown in Figure 3B may be respectively allocated using a group unit comprising several subcarriers contiguous in a frequency domain. 3B shows that the four successively arranged in the frequency domain subcarriers constitute one group.

In the case where the downlink control signal, as shown in Figure 3B, is distributed over the frequency domain using a block group of subcarriers, if the number of subcarriers within the band is set equal to the number of subcarriers allocated to one resource block (RB) for the transfer of a data packet (e.g., 12 subcarriers in the case of localized virtual resource block (LVRB), shown in Figure 1), or an integer multiple of set when the signal occupies a portion of the planning zone of the resource block (RB) is used for transmitting packet data in accordance with one preferred embodiment of the present invention, advantage is that a smaller amount of real resource block (RB) may be equally appropriate.

4 is a diagram of transmitting a downlink control signal by the localized allocation after-OFDM symbol by a distributed allocation in accordance with one embodiment of the present invention.

In accordance with the above one embodiment of the present invention, the OFDM-symbols that are transmitted in other OFDM-symbol (the other OFDM-symbols) used (i) for signal transmission planning by the distributed allocation among OFDM-symbol within a transmission time interval (TTI) transmitted by localized signal extraction planning. Sending the downlink control signal to a particular user equipment (UE) (e.g., UE1 in Figure 4) by localized allocation within such an arbitrary transmission time interval (TTI) is applicable only if there is a transfer downlink data packet corresponding to the user equipment (UE) in transmission time interval (TTI) through localized virtual resource block (LVRB). In this case, the scheduling signal, as shown in Figure 4, can be transmitted using parts zones localized virtual resource blocks (LVRBs), carrying the downstream data packets corresponding to the user equipment (UE).

This signal transmission by the distributed allocation planning is usually applied to transmit scheduling information to transmit downlink data packet using a localized virtual resource block (LVRB) or distributed virtual resource block (DVRB). However, signal transmission planning by the localized allocation is applicable to transmit scheduling information for transmitting the downlink data packet using only a localized virtual resource block (LVRB).

Furthermore, in the example of the present invention shown in Figure 4, information about how many OFDM-symbols are used for signal transmission by scheduling allocation or distributed as OFDM-symbols are used for signal transmission planning by localized allocation can be communicated to the overall downlink in each transmission time interval (TTI), or periodically as necessary.

In accordance with the above embodiment of the present invention, the scheduling information is uplink data packet transmission is carried primarily by the control signal transmission by the distributed allocation. However, in case of attempting to transmit scheduling information to transmit the uplink data packet random user equipment (UE) when transmitting downlink data packet to the same user equipment (UE) within arbitrary transmission time interval (TTI), scheduling information for uplink data packet can be transferred area resource block (RB) for the transfer of packet data to a user equipment (UE), while transferred to the user equipment (UE) information about transmission scheduling downlink data packet transmitted by the control signal transmission by the localized separation.

In the above scheme, the signal transmission scheduling information carried by the transmitted signal is distributed allocation scheduling information includes the above-mentioned category A scheduling downlink data packet transmission, at least in connection with the prior art. In addition, this information may include a category information in the scheduling, partially or completely added to the category information A for transmitting uplink data packets.

Furthermore, the transmitted signal by the localized allocation plan may include information about planning for category B, partially or completely added to the information category A.

In accordance with one preferred embodiment of the present invention, the scheduling information is transmitted by the localized allocation control signal can include an indicator indicating whether said scheduling information is scheduling information transmitting downlink data packet or the scheduling information transmitting an uplink data packet.

In the case where the scheduling information signal scheduling, transmitted by the distributed allocation is scheduling information transmitting downlink data packet, said information may include an indicator indicating tolerated if the scheduling information data in upstream respective user equipment (UE) in within the region of the resource block (RB) for the transfer of the downlink packet data channel corresponds to user equipment (UE).

In this case, as seen from the structure of a downlink control signal in accordance with one embodiment of the present invention shown in Figure 4, the advantage is that the respective user equipment (UE) is facilitated by searching the scheduling information by providing a prior OFDM-symbol according to the distributed allocation to inform about the presence or absence of the scheduling information transmitting an uplink data packet corresponding to the user equipment (UE) for subsequent OFDM-symbol interval in accordance with a localized allocation. Furthermore, the advantage is also that it can be reduced the amount of control signal transmitted by the distributed resource allocation.

Thus transmitted arbitrary user equipment (UE) information category A scheduling may include bit information specifying resource blocks (RBs), used in the transmission of downlink packet data corresponding to the user equipment (UE), or resource blocks (RBs), used to provide the user equipment (UE) ability to transmit uplink data packet. Namely, when within a transmission time interval (TTI), there are N resource blocks (RBs), each bit within the bit data of N-bit is assigned according to the established rules of the resource block (RB), existing in said transmission time interval (TTI). When this bit can provide information on whether the corresponding resource block (RB) allocated for data.

In this case, when the same transmission time interval (TTI), there are few resource blocks (RBs), may require too many bits to indicate whether the respective used resource blocks (RBs) by a bit of information. Therefore, the overhead of scheduling information may be too large.

For such a case, in accordance with one embodiment of the present invention, resource blocks (RBs) in a single transmission time interval (TTI) are grouped by a predetermined number, e.g., M, in accordance with the rules, and then schedule a group of resource blocks (RBs) reported as bit information instead of the planned resource block (RB). Therefore, the overhead of the scheduling information can be reduced. In this case, the number 'm' is an integer equal to or greater than 2, and one group of resource blocks (RBs) can include different resource blocks (RBs) in the frequency or time domain.

As explained above scheme, the user equipment (UE) in mostly trying or attempting to decode the information on planning for all possible positions of the downward control signal transmitted by the localized separation or isolation of distributed, transmitted it to read the information about planning. If present, the scheduling information comprising an identifier (ID) corresponding to the user equipment (UE), said User Equipment (UE) determines that it is transmitted scheduling information and then receives the downlink data packet or transmits uplink packet data in accordance with the information.

In this case, there may be a different number of volumes of time-frequency resource that the user equipment (UE) must try to read. This may increase the burden on the user equipment (UE). Therefore, it is preferable that the downlink control signal, which corresponds to a user equipment (UE) tries to read, has been limited, as will be explained later.

Thus, in accordance with one embodiment of the present invention, when the downlink control signal is not really transferred to OFDM-symbol (s) set for transmission of the downlink control signal, it is proposed that the downstream data should be transferred to the respective symbol (s). This is described as follows.

5 is a diagram of transmitting downlink data resource blocks that the control signal is not transmitted within OFDM-symbol for transmitting downlink control signal in accordance with one embodiment of the present invention.

First, the number of uplink and downlink packet data scheduled within one transmission time interval (TTI), can vary for each transmission time interval (TTI). Therefore, the block control signals transmitted in the downstream direction during each transmission time interval (TTI), may vary. However, if a certain number of downlink OFDM-symbols are always reserved for signaling scheduling downlink channel and then only used time-frequency resource except for the frequency domain is indeed the carrier signal scheduling within the reserved OFDM-symbol consumed in a transmission time interval (TTI ) for transmitting, for example, a small number of scheduling signals.

Therefore, in the above one embodiment of the present invention there is provided a method of transmitting downlink data packets in time-frequency domain, which is practically unable to move the scheduling signal within at least one or more OFDM-symbols, established to ensure the signal transmission planning. A structure corresponding to the downlink transmission signal is shown in Figure 5.

5, a single transmission time interval (TTI) formed 6-OFDM symbols. Here, the first of these 6-OFDM symbol set for use in transmitting a downlink control signal from the user equipment UE1 to user equipment UE3 by distributed allocation. However, Figure 5 shows that the remaining area except for the area actually planning carrier signal allocation in distributed within said OFDM-symbols allocated for transmission of downlink data packet to the user equipment UE1.

In this case, the amount of time frequency resources that may be allocated for data transmission through one downlink resource block (RB), may be different in each transmission time interval (TTI), depending on whether part of the resource block (RB) for Signal separation with distributed scheduling. Namely, as can be seen from the example shown in Figure 5, the user equipment UE1 can not know about what area within the scheduled resource block (RB) is used to transfer the data transmitted to the user equipment UE1, if it knows that part of the descending resource blocks (RBs), allocated to the data packet transmitted to the user equipment UE1, are used for scheduling signal transmitted to another user equipment (UE2 or UE3). Thus, the user equipment UE1 can not properly take the data packet.

In accordance with one embodiment of the present invention to user equipments (UEs), located within the cell know which areas within OFDM-symbol set for use in signal transmission scheduling for an arbitrary transmission time interval (TTI) indeed used for signal transmission scheduling in each transmission time interval (TTI), the base station notifies the number of scheduling signals transmitted during a transmission time interval (TTI) to the user equipments within the cell.

In this case it is possible to decide beforehand rule area selection signal for transmission scheduling in accordance with the number of scheduling signals actually transmitted for each transmission time interval (TTI). Therefore, all those in the unit cell of the user equipment (UE) may know which areas of descending frequency-time resources used by the scheduling signals transmitted by other units of user equipment and scheduling signals transmitted by him, and what time-frequency domain is actually used for transmission data in each downlink resource block (RB) by the number of scheduling signals notified from the base station.

In particular, according to one embodiment of the present invention to increase the number of transmitted scheduling signals OFDM-symbols set for use in transmitting scheduling signals are used sequentially. For example, assuming that the OFDM-symbols are installed for use in transmitting scheduling signals by using the first OFDM-symbol within a transmission time interval (TTI), after full utilization of time-frequency resources available for signal transmission scheduling in the first OFDM-symbol, after OFDM-symbol is used according to the rules in accordance with the number of scheduling signals. Thus, an embodiment of allocating OFDM-symbols for serial transmission of control signals is shown in Figure 6. Next, detailed description will be given of the structure.

Thus, since the number of actually transmitted scheduling signals may change in each transmission time interval (TTI), it is preferable that the number of transmission for each transmission time interval (TTI) scheduling signals was transmitted broadcast on the physical channel, rather than the traffic channel signals scheduling to all user equipments (UEs) within the cell may receive a specified number of transmitted scheduling signals.

Furthermore, scheduling signal to be transmitted with high power, to ensure the implementation of its reception by the user equipment (UE), located at a great distance from the base station. In this case, even if a subcarrier can not transfer the signal within the planning-OFDM symbols carrying the scheduling signal, the largest part of the maximum transmission power provided by the base station, the scheduling signals is consumed. Therefore subcarriers can exist, which can not transmit anything.

Therefore, according to one embodiment of the present invention, the base station broadcasts the information including the aforementioned area (or the number of scheduling signals) used for signal transmission scheduling, and the region of sub-carriers (or the number of scheduling signals corresponding to said area) that can not carry that -or within the OFDM-symbol, capable of carrying a top-down control signal. In this case the user equipments (UEs) can identify the parts used for transmitting data within the OFDM symbol-carrying signal scheduling.

To achieve the same results as in the above embodiment, in another method according to an exemplary embodiment of the present invention, information about the area actually used for data transmission within a transmission time interval (TTI) within the OFDM-symbol-capable signal scheduling It may be transferred directly into the broadcast mode, instead of providing the aforementioned base station to transmit information about the signal transfer region, or scheduling a broadcast information region, the carrier signal is scheduling information and the region not carrying any information.

Therefore, in the following description, information about the area (number) mean scheduling signals domain information carrying signal scheduling and domain information, carrier, or nothing, or information about the area used for data transmission.

Thus, instead of providing the base station to broadcast the information signal region scheduling user equipments (UEs) within the cell can also transmit information about the region scheduling signals carried in the range signal scheduling downlink data packet carrying the data downstream to each user equipment (UE).

Namely, the user equipments (UEs), receiving data from the downlink direction, it is necessary to know how many time-frequency domains is actually used for transmission by a signal scheduling for a predetermined transmission time interval (TTI), as well as time-frequency domain is actually used for data transmission means. Therefore, the same goal can be achieved by, where the information about the scheduling domain signals included in the information carried by the downlink scheduling signals to each user equipment (UE). When this information region scheduling signals subjected to channel coding in conjunction with other scheduling information. Therefore, the advantage is that you can get more coding gain. However, since the same information is transmitted to each of the plurality of user equipments (UEs) within one transmission time interval (TTI), the subsequent increase in the efficiency varies with the number of scheduling signals transmitted during one transmission time interval (TTI) and the circuit channel A signal encoding planning. When transmitting information signal area planning, together with the scheduling information it is preferred that the information signal area planning has been included in the above information Category A.

In accordance with one embodiment of the present invention to reduce the burden on the user equipment (UE) when receiving a signal scheduling and efficient use of the downlink time-frequency resource of the maximum number of downlink data packets scheduled within a transmission time interval (TTI), or the maximum number of uplink packet It may be limited value smaller than the maximum number actually transmitted.

To achieve the same results as in the above embodiment, in another method according to an exemplary embodiment of the present invention may be a limit to the amount of scheduling information transmitted within the transmission time interval (TTI) downlink data packets or the amount of scheduling information transmitted within transmission time interval (TTI) uplink data packets.

Furthermore, it is possible to impose a limit on the total amount obtained by adding the amount of scheduling information transmitted within the transmission time interval (TTI) and uplink packet data volume scheduling information transmitted within the transmission time interval (TTI) downlink data packets. Above the maximum value (s) may be sent to the user equipment (UE) from a base-station via RRC signaling upper levels.

In the method of using both the signal scheduling distributed allocation and signal scheduling localized allocation according to one embodiment of the present invention, the notification scheme of the user equipments (UEs) on the number of scheduling signals and circuit limitations of scheduling signals may be applied only to a signal scheduling Distributed allocation.

In this method, if the base station broadcasts a number of scheduling signals distributed allocation for each transmission time interval (TTI), each user equipment (UE) tries to take the time-frequency region, preset to transmit scheduling signals to the distributed allocation only in accordance with said number. If this exists, the scheduling information comprising an identifier (ID) corresponding to the user equipment (UE), is user equipment (UE) should instructions such scheduling information.

However, since the scheduling signals from the localized allocation are transmitted in a frequency-time domains within the resource blocks (RBs), carrying the downstream data packets to a user equipment (UE) substantially should attempt reception for areas transmit scheduling signals for localized allocation and available in all resource blocks (RBs). Moreover, if the user equipment (UE) must be attempted methods scheduling signals both localized and distributed allocation, the load acting on the respective user equipment (UE), increases. To reduce the load acting on the user equipment (UE) when receiving a signal scheduling in one embodiment the present invention provides the following scheme.

In a first scheme for each user equipment (UE) to decide whether to accept the signal from the distributed allocation planning or scheduling signal localized allocation. Then, corresponding information is communicated by the base station to each user equipment (UE).

The advantage of the transmission signal given scheduling UE (UE) through a distributed or localized allocation selection depends upon such factors changes infrequently, as speed of movement of the user equipment (UE), the performance of the user equipment (UE), etc. Therefore there is no need to transmit such information often. And the information may be transmitted to each user equipment (UE) from the base station upper layer signaling without using a separate physical layer signal. In this case, an arbitrary user equipment (UE) tries to signal reception scheduling, transmitted to it by either of the distributed allocation, or by localized allocation assigned only corresponding user equipment (UE).

In the second scheme for scheduling signals transmitted by the localized allocation, user equipment (UE) attempts to reception planning localized release in a resource block (RB) (or group of resource blocks (RBs)), which was reported as about having the best channel quality or a particular number of areas of the resource block (RB) (or group of resource blocks (RBs)) in the manner reported, as having the best channel quality, taking into account information about the quality of the downward radio channel message to the base station is only the relevant user equipment (UE).

In the general case, each user equipment (UE) within the cell periodically or when necessary, the base station reports information about the quality of the downlink radio channel to assist the base station in a scheduling downlink data packets. Therefore, when transmitting downlink data packets given user equipment (UE) within the cell, the base station is operated by the desired use of the resource block (RB) (or group of resource blocks (RBs)), having the best channel quality, or one of a specific number of resource blocks (RB ) (or one of a specific number of groups of resource blocks (RBs)), selected taking into account the qualities of the downward radio channel, a message matches the user equipment (UE). If the base station transmits a scheduling allocation in the corresponding localized region of the resource block (RB) (or group of resource blocks (RBs)), corresponding to the user equipment (UE) may receive the signal from the localized allocation plan transmitted to it by the scheme explained above.

In this case, the information from the report on the quality of the downward radio channel to which should address each user equipment (UE), may be limited to a recent report information or defined as a specific number of newly reported information or the information is communicated within a specified period of time from the current time. For each of these cases, the base station must properly identify a resource block (RB) (or a group of resource blocks (RBs)), which should be used for transmitting the data packet via the downlink radio channel. Also, the base station can transmit to each user equipment (UE) by means of upper layer signaling the number of resource blocks (RBs) or groups of resource blocks (RBs), which should be provided for receiving a signal scheduling localized release of a range of information about the quality of the radio or audio information about as a radio channel to which the UE should treat (UE).

In a third scheme, the base station through a bitmap performs notification of the resource block (RB) or a group of resource blocks (RBs), the carrier signal scheduling localized release all user equipment units (UEs) within the cell for each transmission time interval (TTI).

Namely, if the number N of resource blocks (RBs) (or groups of resource blocks (RBs)) exists within one transmission time interval (TTI) in a downward direction, each bit of information about the N-bit bitmap is displayed on each of the resource blocks ( RBs) (or each of the groups of resource blocks (RBs)). Also, each bit is able to reproduce information indicating whether the signal is transferred to the localized allocation scheduling corresponding resource block (RB) (or a group of resource blocks (RBs)). Therefore, the user equipment (UE) reads the information of the bitmap for each transmission time interval (TTI), then it can try header signal scheduling localized allocation to resource blocks (RBs) (or groups of resource blocks (RBs)), are indeed transferred Signal planning localized allocation, without attempting reception planning localized release all resource blocks (RBs) (or groups of resource blocks (RBs)).

In particular, in accordance with one embodiment of the present invention, the information about the bitmap can be transmitted in the broadcast mode for each transmission time interval (TTI) by means of its coding with the information signals including the scheduling allocation in a distributed fashion.

In a fourth scheduling scheme for downlink signal transmission in the downlink direction the data is transmitted only by the distributed allocation. Scheduling for a downlink signal transmitted in the upstream direction, data transmitted by the distributed allocation, if there are no data to be transmitted in the downstream direction. Wherein scheduling for downlink signal transmission in the uplink direction data is transmitted by the localized allocation within resource blocks (RBs) (or groups of resource blocks (RBs)), if there is data to be transmitted in the downstream direction.

At least one of the above schemes is used simultaneously in the system to reduce the load on the user equipment (UE) when receiving a signal scheduling.

6 schematically shows the general structure of a downlink transmission control signal in connection with Figures 4 and 5, according to one embodiment of the present invention.

According to Figure 6 a transmission time interval (TTI) includes six OFDM-symbols. Part of the first and fifth sub-OFDM symbols carry pilot signals downstream. In the first OFDM symbol number-scheduling signals localized allocation transmitted for a transmission time interval (TTI), can be transmitted in a broadcast mode distribution audio subcarrier. In addition, information about the bitmap scheduling signals for localized release can also be transmitted in broadcast mode to the distribution of one sub-carrier in addition to the number of scheduling signals for localized release.

Scheduling signals distributed allocation may be transmitted to the distribution at the level of the subcarrier from the first OFDM-symbol. In the example shown in Figure 6, the first OFDM-symbol of the second OFDM-symbols are used for signal transmission with distributed scheduling allocation. Also, Figure 6 shows an example of how the scheduling signals downlink data packets to the user equipment UE1 are transmitted by the localized separation region through a part of the resource block (RB), transporting downstream data packets to the user equipment UE1.

Meanwhile, in one embodiment of the present invention, a circuit supporting the transmission format exchangeability scheduling information, which will be explained in the following description.

7 is a diagram of volume change of time-frequency resource necessary to transmit the signal in different formats scheduling transmission scheduling information.

7, the scheduling information in the uplink / downlink directions, transmitted in the downlink direction for each interval and the transmission timing (TTI) to each user equipment (UE), a signal is transmitted in the format of scheduling by proper coding and modulation. For better understanding and ease of coding rate (r), the modulation scheme, etc., applicable to the scheduling information, referred to as "transmission format of the scheduling information" or "transmission format signal scheduling."

In this case, the radio channel condition corresponding to the user equipments (UEs) within a cell may differ from one another. In particular, the radio channel condition may vary significantly depending on the distance of the user equipment units (UEs) from a base station, or the presence or absence of obstacles. Therefore inefficient to use the same transmission format in the transmission scheduling information for all user equipment units (UEs) within the cell. Preferably apply respectively different transmission formats for the user equipment units (UEs) according to the state of the radio channel. If a transmission format used for scheduling information is changed, the amount of time-frequency resources needed to transmit a signal to the planning can indeed be changed. Figure 7 shows the required amounts of time frequency resources corresponding to different formats of information transmission scheduling.

Thus, if the base station randomly selects a transmission format applied to the scheduling information transmitted by a given user equipment (UE) for each transmission time interval (TTI), the corresponding user equipment (UE) should attempt reception scheduling in all possible transmission formats for each transmission time interval (TTI).

Therefore, in one embodiment of the present invention there is provided volume selection circuit frequency-time resource for the transmission format applicable to the scheduling information transmitted to only a specific user equipment (UE), among one or more minimum units of time-frequency domain. The term "minimum unit of time frequency region" was first proposed in US provisional patent application 60/827852 on the invention entitled "Structure of the downlink control signal in a communication system using multiple carriers", invented by the author of the present application, filed by the present applicant and which It is one of the justifications for the priority claim of the present application. The above concept of "minimum unit of time-frequency domain" accepted system of 3GPP LTE (Third Generation Partnership Project Long Term Evolution - the long-term evolution of the Third Generation Partnership Project - Note. Translation.) The notion of "control channel elements (CCE = Control Shannel Element)». This is explained in detail below with reference to 3GPP LTE system.

In the 3GPP LTE system, a plurality of control channel elements (CCE) may be transmitted through the first n OFDM-symbol of the subframe. In this case, the control channel element (CCE) can be considered as a unit for transmitting control information as proposed in one embodiment of the present invention. Control channel element (CCE) may be placed in the time-frequency region or sequentially distributed. Each control channel element (CCE) consists of a number of resource elements (RE). Thus PDCCH (physical downlink control channel - a physical downlink control channel) transmitted by an arbitrary user equipment (UE) to transmit an arbitrary subframe can be transmitted by combining with one control channel elements (CCE) and a plurality of control channel elements (CCE). In this case, depending on the number of control channel elements (CCE) required for transmitting the physical downlink control channel (PDCCH) is determined by the coding rate for the respective physical downlink control channel (PDCCH). For example, if the coding rate is 3/4 when a physical downlink control channel (PDCCH), having a certain amount of information is transmitted via one control channel element (CCE), it can be adjusted so that the coding rate when transmitting the physical downlink control channel ( PDCCH), having the same amount of information, by means of two control channel elements (CCE) is 3/8, coding rate when transmitting the physical downlink control channel (PDCCH), having the same amount of information, by means of four control channel elements (CCE) is 3/16, or so that the coding rate when transmitting the physical downlink control channel (PDCCH), having the same amount of information through eight control channel elements (CCE) is 3/32.

Control channel elements (CCE) allocated to the user equipment (UE), which is to confirm beforehand whether there is transmitted is given a physical downlink control channel (PDCCH). For example, assuming that the physical downlink control channel (PDCCH) carrying predetermined information can be transmitted at a coding rate of 3/4, 3/8, 3/16 or 3/32 by means of one control channel element (CCE), the two channel elements Control (CCE), four control channel elements (CCE) or eight control channel elements (CCE), and if the given terminal is selected for verification of control channel elements (CCE), the first through sixteenth, said terminal must perform the decoding for each element control channel (CCE), assuming a case in which the physical downlink control channel (PDCCH) transmitted at a coding rate of 3/4, 3/8, 3/16 or 3/32 for sixteen control channel elements (CCE) for each subframe. Therefore, the terminal a maximum of 30 (= 16 + 8 + 4 + 2) decodes to check whether there is a physical downlink control channel (PDCCH), transmitted to him. This corresponds to the assumption that the mapping of the physical downlink control channel (PDCCH) on a control channel element (CCE) is performed via a tree structure only through contiguous control channel elements (CCE). If the mapping of the physical downlink control channel (PDCCH) becomes more free, the number of decoding is to perform user equipment (UE), can be increments.

To reduce the operational load on the user equipment (UE) with reception and, more specifically, to facilitate the solution of such problems as the power consumption of the battery of the user equipment (UE) by reducing the number of decodes required to receive physical downlink control channel (PDCCH), like 3GPP LTE system, one example of the present invention proposes a scheme for assignment of the transmission format scheduling information applicable to signal transmission scheduling each user equipment (UE).

In this case, the transmission format of the scheduling information used for scheduling the transmission signal for each user equipment (UE), can be specifically assigned to a particular format. Alternatively, one may use a method of assigning a range of coding rate, wherein each user equipment (UE) to attempt receiving a physical downlink control channel (PDCCH), as well as the size of the destination group of control channel elements (CCE) or the like

In particular, one embodiment of the present invention provides a method for determining the maximum coding rate in the transmission format of scheduling information for each user equipment (UE) or to determine the smallest group of control channel elements (CCE).

Thus, in the case where each user equipment (UE) is declared maximum coding rate or the minimum size of control channel elements (CCE), although the allocation is performed so that a specific user equipment (UE) verifies the first through sixteenth control channel elements (CCE) in explaining the above example, if the announced that the maximum encoding rate at which the corresponding user equipment (UE) is trying to implement receiving a physical downlink control channel (PDCCH), is equal to 3/8, or that the minimum size of the group of control channel elements (CCE) has two elements control channel (CCE) corresponding to the user equipment (UE) is not necessary to decode a control channel element (CCE) (i.e., the case where the coding rate is 3/4), and it performs only 14 (= 8 + 4 + 2) decodes .

Thus, compared with the method Ad minimum coding rate or the maximum size of the group method of determining the maximum coding rate or the minimum size of the group of control channel elements (CCE) for each user equipment (UE) has the following advantages.

For example, if the user equipment (UE), having a maximum coding rate assigned to equal 3/8, as in the example explained above, when the next state of the channel deteriorates if the scheduling information is transmitted coded at a low coding rate, such as 3/16, corresponding planning information can also be found. However, in case a user equipment (UE), having a minimum code rate equal to 3/8 assigned when the next state of the channel deteriorates if the scheduling information is transmitted coded at a much lower rate coding, e.g. 3/16, it becomes difficult to detect the corresponding scheduling information . Namely, as in the present embodiment, a method for determining the maximum coding rate or the minimum size of the group of control channel elements (CCE), applicable to the transmission of scheduling information, can cope with the case of a low coding rate due to further deterioration of the channel more efficiently than the method for determining the minimum coding rate or the maximum size of the group of control channel elements (CCE).

For the same purpose as in the above embodiment, in another embodiment, the present invention provides that the base station notifies each user equipment (UE) of the maximum coding rate (or smallest dimension of the group of control channel elements (CCE)), in which corresponding to the user equipment (UE) tries to perform receiving a physical downlink control channel (PDCCH).

In particular, as mentioned in the foregoing description of the above example, even if one user equipment (UE) assigned to verify the first to sixteenth control channel elements (CCE), when announced that the maximum coding rate at which the corresponding user equipment (UE) will attempt to carry out reception of physical downlink control channel (PDCCH), is equal to 3/8 (or the minimum size of the group of control channel elements (CCE) consists of two control channel elements (CCE)) and the minimum coding rate 3/16 (or maximum group size control channel elements (CCE) consists of four control channel elements (CCE)), user equipment (UE) is not necessary to carry out decoding under the assumption that one control channel element (CCE) (the case where the coding rate is 3/4) and Decoding for Assuming eight control channel elements (CCE) (a case where the encoding rate is 3/32), and it carries only a maximum of 12 (= 8 + 4) is decoded.

For the same purpose as in the above embodiment, in another embodiment, the present invention provides that the base station notifies each user equipment (UE) about whether to attempt a corresponding user equipment (UE) perform receiving a physical downlink control channel (PDCCH) with a maximum coding rate (or smallest dimension of the group of control channel elements (CCE)) at which the corresponding user equipment (UE), will attempt to perform receiving a physical downlink control channel (PDCCH), and a given number of coding rates which are lower than a previous coding rate ( or a given number of group size greater than the smallest size of the group of control channel elements (CCE)).

In particular, as mentioned in the foregoing description of the above example, even if one user equipment (UE) assigned to verify the first to sixteenth control channel elements (CCE), when the two-stage coding rate, including the maximum coding rate 3/8 and code rate over 3 / 8, at which the corresponding user equipment (UE) to attempt receiving a physical downlink control channel (PDCCH) (or two-stage group of control channel elements (CCE)), further declared subject to investigation by the user equipment (UE), said user equipment (UE ) is not necessary to carry out decoding under the assumption that one control channel element (CCE) (the case where the coding rate is 3/4) and decoding assuming eight control channel elements (CCE) (the case where the coding rate is 3/32), and it It performs only a maximum of 12 (= 8 + 4) decoding.

Using the methods explained above, it is possible to reduce the number of trial decodings for a user equipment (UE) receiving the physical downlink control channel (PDCCH). Therefore, there can be solved a problem such as power consumption of the battery of the user equipment (UE), etc.

In the above explained embodiments, the transmission format of the scheduling information to each of the user equipments (UEs) do not require frequent changes. Therefore, this information may be communicated by the base station to each user equipment (UE) by means of upper layer signaling, located above the physical layer. Furthermore, each of the user equipments (UEs) may attempt to reception scheduling assuming a transmission format that is assigned to the respective user equipment (UE). Wherein the user equipment (UE) searches for a frequency-time domain downstream direction, signal that carries scheduling, planning for the specified signal by the unit volume of time-frequency resource determined for the transmission format scheduling information to the user equipment (UE).

In accordance with a detailed embodiment of the present invention, the operation of the user equipment (UE) when receiving a signal scheduling may be greater simplified by destination volume time-frequency resource used for transmitting scheduling information in different transmission formats, to an integer multiple of the smallest amount of time-frequency resource used to transmit scheduling information.

In this case, the volume of the smallest time-frequency resource, used for transmission of scheduling information may correspond explained above the control channel element (CCE). Namely, in the present embodiment serves to set the amount of time-frequency resource used in the scheduling information, different transmission format for a block of control channel elements (CCE). As mentioned in the foregoing description, the control channel element (CCE) may comprise a portion of sequential time-frequency domain, or it may have a shape distributed on the time-frequency domain.

8A and 8B schematically show examples of how the user equipments (UEs), having different transmission formats scheduling information assigned to them, to search for signals planning in accordance with one embodiment of the present invention.

In particular, Figures 8A and 8B show examples where two user equipments (UEs), which are assigned to the different formats of transmission scheduling information, search for the scheduling signals via circuits explained above in the case where scheduling signals transferred subcarriers adjacent to the frequency axis for the arbitrary symbols, or in the case where scheduling signals transmitted distributed subcarrier block.

According 8A and 8B, the user equipment UE1 and the user equipment UE2 respectively receive their assigned transmission formats scheduling information, and then they try to exercise respectively receiving signals in possible scheduling of time-frequency areas. In particular, the user equipment UE1 receives a single frequency region, said one gap 8, and then it attempts to implement the scheduling signal reception. A user equipment UE2 receives a single frequency domain, said two portions 8B, and then tries to reception planning. In this case, the user equipment UE1 in the example shown in Figure 8, to complete the search for the signal readout signal scheduling plan transmitted to it during the fourth search.

In the method in which the base station broadcasts the number of scheduling signals distributed allocation actually transmitted for each transmission time interval (TTI), in accordance with one embodiment of the present invention explained above operation may be supported by using the least amount of frequency- time resource used for transmitting scheduling signals distributed allocation, as a unit volume, instead of using the number of scheduling signals distributed allocation, and then by subsequent notification of the number of time-frequency resources reaching the predetermined unit amount used for transmission of scheduling signals distributed selection.

In another method in accordance with one embodiment of the present invention can reduce the load on the user equipment (UE) when receiving a signal scheduling by notifying the number of scheduling signals distributed allocation actually transmitted for each transmission time interval (TTI), which must be allocated to each scheduling signal having a different transmission format. In this case, priority is assigned to the allocated frequency-time domain signal for each scheduling transmission format of the scheduling information.

Figure 9 schematically shows an example in which the user equipments (UEs), having assigned to them a transmission format shall seek scheduling signals if the different transmission formats scheduling information are prioritized.

According to Figure 9, there are two transmission formats: format 1 transmission and a transmission format 2. The signal scheduling transmission format 1 has priority over the other signal transmission format in planning the allocation of two time-frequency domain. In this case, as shown in Example 9, the three signals transmitted scheduling transmission format 1 signal and two scheduling format 2.

If the periodic transmission of scheduling signals according to the rule of the example shown in Figure 9, if the user equipment (UE) known in advance about the rule, or if the base station notifies the number of scheduling signals transmitted in a transmission format corresponding to a user equipment (UE) detects a time-frequency domain signal is transferred to the planning in the same transmission format assigned to it. Therefore, the corresponding user equipment (UE) may try to carry out reception planning only in the relevant field.

Industrial Applicability

Consequently, in accordance with one embodiment of the present invention, a method for transmitting a downlink control signal helps to ensure the efficiency of transmission through the localized allocation, and the gain due to frequency diversity in distributed allocation by taking into account the advantages and disadvantages of the localized allocation and distributed allocation.

Moreover, due to the structure of the transmitting the downlink control signal using a localized allocation and distributed allocation is provided a signal transmission through general allocation allocating to the front of a single transmission time interval (TTI), and provides the transmission signal by localized exposure to the rear of the corresponding transmission time interval ( TTI). Consequently, the present invention is to flexibly cope with the size of the control signal. When the indicator of the control information included in distributed allocation, or the like, included in part by the localized allocation, whereby reception performance can be improved.

The present invention has been described and illustrated herein with reference to preferred embodiments thereof. Those skilled in the art will appreciate that there can be produced various modifications and changes without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers such modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.