JP4632245B2 - Transmitting station, mobile communication system, and transmission power control method - Google Patents

Description

  The present invention relates to a mobile communication system, and more particularly to a transmission station, a mobile communication system, and a transmission power control method that divide the entire system band into a plurality of frequency blocks and allocate radio resources for each block.

  A signal propagated through a multipath environment such as mobile communication is affected by frequency selective fading. As a result, the amount of phase rotation and received power for each subcarrier varies.

  Moreover, the fluctuation | variation changes with the environment and frequency of a propagation path, and frequency selectivity is independent between users. That is, depending on the frequency, there are users who have good reception channel conditions, for example, good SIR (Signal-to-Interference Power Ratio) and bad users.

  For this reason, in a multicarrier system such as OFDM (Orthogonal Frequency Division Multiplexing) and OFCDM (Orthogonal Frequency and Code Division Multiplexing), the entire frequency band allocated to the system is divided into a plurality of frequency blocks, and each divided frequency block is divided. Frequency scheduling for allocating radio resources to the network has been studied.

  Frequency scheduling will be described with reference to FIG.

  In the frequency characteristics of the reception channel state shown in FIG. 1, the horizontal axis represents frequency, the vertical axis represents the reception channel state, and the horizontal axis is further divided into frequency blocks 1 to 4.

  According to the frequency characteristics of the reception channel state, it can be seen that the occurrence of fading differs depending on the frequency and that the occurrence of fading is independent for each user. That is, it shows that the reception channel state of each user at a certain frequency may be different.

  Therefore, in this case, frequency bands with good reception channel conditions for User1, such as frequency blocks 1 and 2, are assigned to Uesr1, and frequency bands with good reception channel conditions for User2, such as frequency blocks 3 and 4, are assigned to Uesr2. By performing frequency scheduling in this way, the throughput of the entire system can be increased.

  Of the background art described above, frequency scheduling is not known in the literature as far as the applicant knows at the time of filing.

  Further, the applicant has not been able to find prior art documents related to the present invention by the time of filing. Therefore, prior art document information is not disclosed.

  However, the background art described above has the following problems.

  There is a problem that transmission power is not efficiently distributed to frequency blocks allocated to each user.

  Accordingly, an object of the present invention is to provide a transmission station, a mobile communication system, and a transmission power control method that can efficiently allocate transmission power to frequency blocks.

This transmitting station
A transmitting station in a mobile communication system that transmits a plurality of subcarriers to a receiving station,
A transmission data classifying unit that classifies packets to be transmitted as data classes based on predetermined attributes;
When allocating radio resources to the packet to be transmitted, and a radio resource allocation unit for allocating the frequency blocks obtained by dividing a frequency band assigned to the own mobile communication system as a unit,
A required power estimation unit that estimates the required power required to transmit data with a required quality to the receiving station;
A transmission power control unit that controls transmission power to be allocated in units of frequency blocks to the frequency block to which the packet to be transmitted is allocated by the radio resource allocation unit ;
The radio resource allocation unit allocates at least one frequency block to each data class based on control information indicating a reception channel state of the frequency block to be notified from the receiving station,
The transmission power control unit equally distributes the total transmission power allocated to the transmission station to all frequency blocks, and the transmission power to be allocated to the frequency blocks allocated to a predetermined data class is the required power. after adjusting so, that determine the transmission power to be allocated to the frequency block allocated to the data class other than the predetermined data class.

  With this configuration, it is possible to distribute transmission power for each frequency block to which radio resources are allocated.

This mobile communication system
A mobile communication system comprising a transmitting station and a receiving station that receives a plurality of subcarriers transmitted from the transmitting station,
The receiving station is
A reception channel state measurement unit that measures a reception channel state in units of frequency blocks obtained by dividing a frequency band assigned to the mobile communication system;
A control information generation unit that generates control information indicating a reception channel state to be notified to the transmitting station based on the reception channel state measured by the reception channel state measurement unit;
A control information transmitting unit for transmitting the control information generated by the control information generating unit to the transmitting station;
The transmitting station is
A transmission data classifying unit that classifies packets to be transmitted as data classes based on predetermined attributes;
Based on the control information indicating the reception channel state notified the frequency blocks from the receiving station, when allocating radio resources to the packet to be transmitted, frequency blocks obtained by dividing a frequency band assigned to the own mobile communication system A radio resource allocation unit that allocates the unit as a unit;
A required power estimation unit that estimates the required power required to transmit data with a required quality to the receiving station;
A transmission power control unit that controls transmission power to be allocated in units of frequency blocks to the frequency block to which the packet to be transmitted is allocated by the radio resource allocation unit ;
The radio resource allocation unit allocates at least one frequency block to each data class based on control information indicating a reception channel state of the frequency block to be notified from the receiving station,
The transmission power control unit equally distributes the total transmission power allocated to the transmission station to all frequency blocks, and the transmission power to be allocated to the frequency blocks allocated to a predetermined data class is the required power. after adjusting so, that determine the transmission power to be allocated to the frequency block allocated to the data class other than the predetermined data class.

  With this configuration, it is possible to control the transmission power allocated to each frequency block to which radio resources are allocated based on the control information indicating the reception channel state of the frequency block notified from the receiving station.

This transmission power control method is
A transmission power control method in a mobile communication system comprising a transmitting station and a receiving station that receives a plurality of subcarriers transmitted from the transmitting station,
The receiving station is
A reception channel state measurement step for measuring a reception channel state in units of frequency blocks obtained by dividing a frequency band assigned to the mobile communication system;
A control information generation step for generating control information indicating a reception channel state to be notified to the transmitting station based on the reception channel state measured by the reception channel state measurement step;
A transmission step of transmitting the control information generated by the control information generation step to the transmission station;
The transmitting station is
A transmission data classification step of classifying a packet to be transmitted as a data class based on a predetermined attribute;
Based on the control information indicating the reception channel state notified the frequency blocks from the receiving station, when allocating radio resources to the packet to be transmitted, frequency blocks obtained by dividing a frequency band assigned to the own mobile communication system Radio resource allocation step for allocating as a unit,
A required power estimation step for estimating a required power required to transmit data with a required quality to the receiving station;
With respect to the frequency block packet to be the transmission by the radio resource allocation step is assigned, have a transmission power control step of controlling transmission power to be allocated a frequency block as a unit,
The radio resource allocation step allocates at least one frequency block to each data class based on control information indicating a reception channel state of the frequency block to be notified from the receiving station,
The transmission power control step distributes the total transmission power allocated to the transmitting station equally to all frequency blocks, and the transmission power to be allocated to the frequency blocks allocated to a predetermined data class is the required power. Then, the transmission power to be allocated to the frequency blocks allocated to data classes other than the predetermined data class is determined .

  By doing so, it is possible to control the transmission power allocated to each frequency block to which the radio resource is allocated based on the control information indicating the reception channel state of the frequency block notified from the receiving station.

  According to the embodiments of the present invention, it is possible to realize a transmission station, a mobile communication system, and a transmission power control method that can efficiently allocate transmission power to frequency blocks.

Next, embodiments of the present invention will be described with reference to the drawings.
In all the drawings for explaining the embodiments, the same reference numerals are used for those having the same function, and repeated explanation is omitted.

  A mobile communication system according to an embodiment of the present invention includes a transmitting station and a receiving station, and transmits transmission data addressed to a plurality of receiving stations held in the transmitting station by a transmitting station to a plurality of frequency sub-bands in a system frequency band. Transmit using a carrier. Further, as shown in FIG. 2A, the transmitting station divides a plurality of frequency subcarriers in the system frequency band into a plurality of subcarrier blocks (frequency blocks) including one or more subcarriers. In addition, the transmission station assigns frequency subcarriers to transmission data and allocates transmission power to frequency subcarriers for each transmission cycle, with subcarrier blocks as allocation units.

  As a result, as shown in FIG. 2B, the transmitting station allocates transmission power to transmission data addressed to a plurality of receiving stations A, B, and C in addition to time and frequency allocation. For example, the transmission station assigns transmission power to each subcarrier block so that the sum is within the total transmission power assigned to the transmission station.

  A transmitting station 100 according to the present embodiment will be described with reference to FIG.

  The transmitting station 100 includes an antenna array 102, a transmission / reception control unit 104 connected to the antenna array 102, a reception quality correction calculation unit 106 connected to the transmission / reception control unit 104, an arrival direction and propagation distance estimation unit 112, and an array. Weight generation and modulation unit 126, reception quality information storage unit 108 connected to reception quality correction calculation unit 106, transmission priority calculation unit 110 connected to reception quality information storage unit 108, and transmission priority calculation unit 110 The antenna pattern and transmission data determination unit 118 as a transmission power control unit, transmission data classification unit, allocation unit and required power estimation unit, a packet QoS detection unit 120 as a QoS detection unit, and a transmission waiting time detection unit 122 Interference power estimation connected to the antenna pattern and transmission data determination unit 118. Part 116, and a position information storage unit 114 and the transmission waiting buffer 124.

  The arrival direction and propagation distance estimation unit 112 is connected to the position information storage unit 114, and the transmission waiting buffer 124 is connected to the packet QoS detection unit 120, the transmission wait time detection unit 122, and the array weight generation and modulation unit 126, and the antenna pattern and Transmission data determination unit 118 is connected to array weight generation and modulation unit 126.

  A control signal including control information from each receiving station is received by the antenna array 102 and input to the transmission / reception control unit 104.

  The transmission / reception control unit 104 inputs the control signal to the reception quality correction calculation unit 106 and the arrival direction and propagation distance estimation unit 112.

  The reception quality correction calculation unit 106 collects reception quality, for example, reception channel state information for each frequency block in the receiving station, based on the input control information, corrects it as necessary, and receives the reception quality information storage unit 108. To store.

  On the other hand, the arrival direction and propagation distance estimation unit 112 estimates the position of the receiving station by estimating the arrival direction and propagation distance of the control signal based on the input control information. The position information indicating the position is stored in the position information storage unit 114.

  On the other hand, when an IP packet from the network is received, packet header information such as a destination address is acquired from the received IP packet and stored in the transmission waiting buffer 124.

  In the transmission waiting buffer 124, the IP packet is classified as transmission data, for example, for each destination receiving station according to a predetermined attribute and stored as a data class.

  For example, as shown in FIG. 4, in the transmission waiting buffer 124, the transmission data transmitted to the receiving stations A, B, C, and D has a predetermined attribute, for example, the priority given as the header information of the data, the transmission Data classes are classified based on at least one of a maximum delay time allowed in data transmission, a request for delay fluctuation in transmission data (delay jitter), a request for transmission latency and a minimum transmission rate. The For example, the data is classified into data class 1 having a high priority composed of transmission data to receiving stations A and B and data class 2 having a low priority composed of transmission data to receiving stations C and D.

  In addition, the transmission waiting buffer 124 inputs transmission data of a predetermined data class to an array weight generation and modulation unit described later in accordance with an instruction from an antenna pattern and transmission data determination unit 118 described later.

  The packet QoS detection unit 120 detects a QoS request, for example, a priority, a delay request, a guaranteed rate, or the like for the IP packet stored in the transmission waiting buffer 124 and inputs it to the transmission priority calculation unit 110.

  The transmission waiting time detection unit 122 detects the transmission waiting time of the IP packet stored in the transmission waiting buffer 124 and inputs it to the transmission priority calculation unit 110.

  The transmission priority calculation unit 110 performs subcarrier blocks for each data class based on at least one of the reception quality information stored in the reception quality information storage unit 108, the QoS request of the input packet, and the transmission waiting time. Is assigned to the antenna pattern and transmission data determination unit 118. In this case, for example, when information indicating that a predetermined transmission waiting time has elapsed is input by the transmission waiting time detection unit 122, the priority for the data class is increased.

  The interference power estimation unit 116 estimates reception C / I (Carrier to Interference ratio) information of the channel in communication of the receiving station when the receiving station is communicating, and receives the receiving station when the receiving station is not communicating. The received C / I information of the pilot channel is estimated, and the result is input to the antenna pattern and transmission power determination unit 118.

  The antenna pattern and transmission data determination unit 118 is based on the position information of the receiving station, the priority, and the reception C / I information, and is assigned to the transmission data, the data class corresponding to the transmission data, the antenna pattern, and the transmission. Determine the power. Information indicating the determined transmission data, the subcarrier block to be assigned to the data class corresponding to the transmission data, the antenna pattern, and the transmission power is notified to the array weight generation / modulation unit 126 and the transmission waiting buffer 124.

  The antenna pattern and transmission data determination unit 118 determines a subcarrier block to be allocated from a data class having a high priority based on the input priority. In this case, based on the reception state of the receiving station, subcarrier blocks in which the reception state is good are assigned to each receiving station in order. For example, the receiving station measures the receiving channel state and notifies the transmitting station. Further, the receiving station may measure the reception channel state for each subcarrier block and notify the transmitting station.

  Antenna pattern and transmission data determining section 118 assigns one or more subcarrier blocks to the data class according to a predetermined ratio. For example, the assigned subcarrier block is determined based on the data amount of each data class. The ratio of the allocated subcarrier blocks is updated at a predetermined cycle.

  This will be specifically described. For example, the antenna pattern and transmission data determination unit 118 determines the ratio of one or more subcarrier blocks allocated to the classified data classes, for example, the data classes 1 and 2. Next, according to the determined ratio, subcarrier blocks are allocated from data class 1 having a high priority.

  As an example, a case where 2 subcarrier blocks are allocated to data class 1 and 4 subcarrier blocks are allocated to data class 2 will be described with reference to FIG. 5A.

  First, the antenna pattern and transmission data determination unit 118 selects a subcarrier block for transmitting data of data class 1, that is, data destined for receiving stations A and B having high priority. For example, the subcarrier blocks b and e having good reception states for the receiving stations A and B are allocated based on the reception state with respect to the frequency of each receiving station.

  Next, the antenna pattern and transmission data determination unit 118 selects a subcarrier block for transmitting data of data class 2, that is, data destined for receiving stations C and D having low priority. In this case, for example, based on the reception state with respect to the frequency of each receiving station, among the unassigned subcarrier blocks a, c, d, and f, the subcarrier blocks a and f that have a good reception state for the receiving station C The subcarrier blocks c and d having good reception status are assigned to the receiving station D.

  Further, for example, for a user of a predetermined data class, for example, a user of non-real-time traffic whose delay requirements are not strict, based on at least one of a reception channel state and a QoS request for an IP packet, a tentative frequency block The temporary allocation may be performed. By doing so, it is possible to maximize the throughput for non-real-time traffic users.

  On the other hand, frequency blocks are reassigned to users of other data classes, for example, real-time traffic with severe delay requirements based on at least one of the reception channel state and the QoS request for IP packets. For example, from among multiple frequency blocks that can satisfy the required rate, select the frequency block with the lowest user throughput of the non-real-time traffic that has already been temporarily allocated, and allocate the frequency block in real time. Change to type traffic user. Here, the real-time traffic may include a user who has a long waiting time even in non-real-time traffic and has a severe delay request.

  A specific description will be given with reference to FIG. 5B.

  The transmission priority calculation unit 110 inputs a QoS request for the IP packet to the antenna pattern and transmission data calculation unit 118.

  The antenna pattern and transmission data determination unit 118 tentatively applies to at least one of a QoS request for an input IP packet and a reception channel state, for example, a user of non-real-time traffic with the best reception state in each frequency block. Thus, the frequency block is temporarily allocated. For example, the antenna pattern and transmission data determination unit 118 performs temporary allocation of the receiving stations D, F, H, C, E, and G to the subcarrier blocks a, b, c, d, e, and f, respectively.

  Next, for the receiving stations (users) A and B having the received signal level and the data rate that can be realized in each subcarrier block (frequency block) as shown in FIG. Based on one, subcarrier blocks are allocated. Here, the users A and B are priority users and receive, for example, real-time traffic with severe delay requirements. For example, from among a plurality of frequency blocks that can satisfy the required rate, select the frequency block with the lowest throughput of the user of the non-real-time traffic that has already been temporarily allocated, that is, the subcarrier blocks b and f, The allocation of the frequency block is changed to a real-time traffic user. As a result, receiving stations B and A are allocated to subcarrier blocks b and f, respectively.

  When subcarrier blocks are allocated in a centralized manner based on priority, there is a possibility that the reception channel state is sufficiently better than the required rate depending on the subcarrier block. Therefore, in order to meet the required quality of real-time traffic with strict requirements for delay after tentatively allocating non-real-time traffic (data class) that can be accelerated according to the receiving channel state Among the necessary channel states, the frequency block with the lowest throughput of the non-real-time traffic already assigned is selected and reassigned. In this way, the allocation efficiency can be improved. This also eliminates excessive quality for real-time traffic, and for non-real-time traffic, a good reception channel state is not assigned to real-time traffic. The rate and throughput are improved.

  Next, the antenna pattern and transmission data determination unit 118 uses the received reception C / I information to obtain reception quality by a reception quality information calculation method for each reception station described later, and based on the obtained reception quality. Thus, the required power is determined such that the data to be transmitted using the subcarrier block satisfies the required quality and is transmitted to the receiving station.

  Next, the antenna pattern and transmission data determination unit 118 transmits the transmission power of the subcarrier block assigned to the specific data class to the receiving station so that the data transmitted using the subcarrier block satisfies the required quality. Decide to be. Further, surplus power, which is the difference between the total transmission power assigned to the transmitting station and the determined transmission power, is distributed to subcarrier blocks assigned to data classes other than the specific data class.

  For example, as shown in FIG. 6A, the antenna pattern and transmission data determination unit 118 allocates necessary power required for transmission with satisfying required quality to the subcarrier blocks b and e allocated to a specific data class. To do.

  In this case, for example, the distribution is performed so as to satisfy the required power in order from the subcarrier block assigned to the data class having the higher priority. Specifically, the transmission power of the subcarrier block allocated to the transmission data of data class 1 having a high priority is determined. In this way, the required power can be assigned first to the subcarrier block assigned to the transmission data of the data class that is to be transmitted reliably.

  Next, the distribution of surplus power, which is the difference between the total transmission power allocated to the transmitting station 100 and the required power allocated to the subcarrier blocks allocated to the high priority data class, will be described.

  For example, as shown in FIG. 6B, the surplus power is evenly distributed to the subcarrier blocks a, c, d, and f for which the transmission power is not allocated. By doing in this way, surplus power can be allocated with easy processing to the subcarrier block to which transmission power is not allocated.

  Also, for example, as shown in FIG. 6C, the margin for the required power for each subcarrier block is made uniform with respect to the subcarrier blocks a, c, d, and f for which the transmission power is not allocated to the surplus power. You may make it distribute.

  The required power for each subcarrier block may be different, and the surplus power can be used effectively by determining the transmission power according to the different required power. In addition, since there is a control delay between when the required power is measured and when it is actually transmitted, by providing a margin for the required minimum power, even if the required power fluctuates due to the control delay, the receiving station Thus, transmission power can be allocated so that it can be received with a required quality. By allocating the surplus power in this way, the surplus power can be used effectively, and the receiving station can receive it with a required quality.

  Also, for example, as shown in FIG. 6D, surplus power is generated from subcarrier blocks with small power requirements corresponding to each subcarrier block with respect to subcarrier blocks a, c, d, and f for which transmission power is not allocated. You may make it distribute. By doing so, surplus power can be allocated to many subcarrier blocks so as to satisfy the required power, and the number of subcarrier blocks that can be transmitted to satisfy the required quality can be increased. For this reason, a large number of receiving stations that can transmit transmission data can be set, and unnecessary power consumption can be reduced.

  Next, the total transmission power allocated to the transmitting station is uniformly distributed to all subcarrier blocks, and then the transmission power allocated to the subcarrier blocks allocated to a predetermined specific data class is allocated to the subcarriers. Distribute to meet the power requirements of the block. As a result, when the total temporarily allocated transmission power exceeds the total transmission power allocated to the transmitting station and becomes insufficient, the transmission power temporarily allocated to the subcarrier blocks allocated to other than the specific data class is reduced. . On the other hand, when the total of the allocated transmission power is equal to or less than the total transmission power temporarily allocated to the transmitting station, the transmission power allocated to the subcarrier blocks allocated other than the specific data class is increased.

  For example, when transmission power is insufficient, transmission power temporarily allocated to subcarrier blocks having a large margin for required power among subcarrier blocks assigned to other than a specific data class is reduced.

  This will be specifically described with reference to FIG.

  First, the total transmission power allocated to the transmitting station is temporarily provisionally distributed to all subcarrier blocks.

  Next, when the power allocated to a specific data class, for example, a subcarrier block assigned to a high priority data class, for example, subcarrier blocks b and e, is insufficient for the required power , Increase the power allocated to the subcarrier block.

  For example, the transmission power is increased so that the required power is obtained. Thus, in a specific data class, the required power is larger than the temporarily allocated power, and when the allocated power is increased, the total of the temporarily allocated transmission power is the total allocated to the transmitting station. Adjustment is performed by reducing the transmission power temporarily allocated to the other subcarrier blocks so that the transmission power is less than or equal to the transmission power. For example, adjustment is performed by reducing the transmission power temporarily allocated to the subcarrier block having the largest margin for the required power, for example, d.

  In this case, among the subcarrier blocks allocated to other than the specific data class, the temporarily allocated power reduces the transmission power temporarily allocated to the subcarrier blocks that are insufficient with respect to the required power. You may make it adjust by.

  For example, as shown in FIG. 8, when the total transmission power allocated to the transmitting station is temporarily provisionally distributed to all subcarrier blocks, the subcarrier blocks temporarily allocated to specific data classes b and e are allocated. When the transmission power is insufficient, among the subcarrier blocks allocated to other than the specific data class, the temporarily allocated power is temporarily allocated to the subcarrier block where the required power is insufficient, for example, f By reducing the transmitted power, the transmission power allocated to the specific subcarrier block is increased.

  By doing in this way, it is possible to distribute the transmission power allocated to the subcarrier blocks so as to satisfy the required power within the range of the total transmission power allocated to the transmitting station 100.

  On the other hand, for example, when the total transmission power allocated to the transmitting station 100 is temporarily allocated to all the subcarrier blocks, the subcarrier block in which the temporarily allocated transmission power is allocated to a predetermined specific data class. If the required power exceeds the required power, that is, if surplus power is generated with respect to the required power, among the subcarrier blocks allocated to other than the specific data class, the subcarrier with a small or insufficient margin for the required power You may make it redistribute the surplus electric power which is the difference of the transmission power and the required electric power temporarily allocated with respect to the block.

  This will be specifically described with reference to FIG.

  For example, the total transmission power allocated to the transmission station 100 is temporarily provisionally distributed to all subcarrier blocks. Next, when the temporarily allocated power is excessive with respect to the required power for a subcarrier block assigned to a specific data class, for example, a high priority data class, for example, subcarrier blocks b and e. Reduces the power allocated to the subcarrier block.

  For example, the transmission power is reduced so that the required power or the required power with a predetermined margin is expected. The resulting surplus power is redistributed to subcarrier blocks allocated to other than the specific data class for subcarrier blocks with a small or insufficient margin for required power, for example, subcarrier block f. .

  In addition, among the subcarrier blocks allocated to other than a specific data class, when the margin for the required power is small or when the surplus power is redistributed to the subcarrier block that is insufficient, the required power is not reached May be redistributed to subcarrier blocks excluding this subcarrier block.

  This will be specifically described with reference to FIG.

  For example, the total transmission power allocated to the transmitting station is temporarily provisionally distributed to all subcarrier blocks. Next, the power temporarily allocated to a specific data class, for example, a subcarrier block assigned to a high priority data class, for example, subcarrier blocks b and e, exceeds the required power, that is, surplus to the required power. When power is generated, the power allocated to the subcarrier block is decreased.

  For example, the power to be distributed is reduced so that the required power or the required power with a margin is expected. The resulting surplus power is redistributed to subcarrier blocks allocated to other than the specific data class for subcarrier blocks with a small or insufficient margin for required power, for example, subcarrier block f. However, if the required power is not reached, it is redistributed to subcarrier blocks a, c, d and e allocated to other than the specific data class other than the subcarrier block f.

  In this way, it is possible to distribute the transmission power to all the subcarrier blocks so as to be equal to or higher than the required power. For this reason, the receiving station can receive the signal with the required quality.

  The transmission waiting buffer 124 takes out the transmission data designated by the antenna pattern and transmission data determination unit 118 and inputs it to the array weight generation and modulation unit 126.

  The array weight generation / modulation unit 126 assigns the subcarrier block specified by the antenna pattern and the transmission data determination unit 118 to the input transmission data, performs encoding / modulation processing, and the transmission / reception control unit 104. Is transmitted to each receiving station.

  Next, a packet data transmission scheduling method performed by the antenna pattern and transmission data determination unit 118 will be described with reference to FIG.

  First, the position information of each receiving station is acquired from the position information storage unit 114 (step S1102).

  Also, the received C / I information estimated from interference power estimation section 116 is input (step S1104), and the priority information for the assignment of subcarrier blocks to each data class is input from transmission priority calculation section 110. (Step S1106).

  Next, the antenna pattern and transmission data determination unit 118 ranks the transmission priorities of all connected receiving stations (step S1108).

  Next, the antenna pattern and transmission data determination unit 118 determines the required power based on the received C / I information, and determines the number and direction of directional beams according to the procedure described later (step S1110).

  Next, the antenna pattern and transmission data determination unit 118 determines the number of multiplexed users of each directional beam (step S1112).

  Next, transmission processing is performed (step S1114).

  Next, reception quality calculation processing of each receiving station performed in the antenna pattern and transmission data determination unit 118 will be described with reference to FIG.

  First, the antenna pattern and transmission data determination unit 118 determines whether or not the receiving station is communicating (step S1202).

  When the receiving station is communicating (step S1202: YES), the interference power estimation unit 116 inputs the received C / I information of the channel in communication of the receiving station (step S1204). The antenna pattern and transmission data determination unit 118 calculates the reception quality information of the receiving station based on the received reception C / I information of the channel in communication of the receiving station (step S1212).

  On the other hand, when the receiving station is not communicating (step S1202: NO), the interference power estimation unit 116 inputs the received C / I information of the pilot channel of the receiving station.

  Further, the position information of the receiving station is input from the position information storage unit 114 (step S1208). Next, the antenna pattern and transmission data determination unit 118 estimates the gain when the directional beam is directed based on the position information of the receiving station (step S1210).

  Next, antenna pattern and transmission data determination section 118 calculates reception quality information of the receiving station based on the received C / I information of the pilot channel of the receiving station and the gain when the estimated directional beam is directed. (Step S1212).

  Next, a method of determining the number and direction of directional beams performed by the antenna pattern and transmission data determination unit 118 will be described with reference to FIG.

  First, the position information of each receiving station is input from the position information storage unit 114 (step S1302).

  The antenna pattern and transmission data determination unit 118 determines to form a beam in the direction of the receiving station with the highest priority based on the position information of each receiving station (step S1304).

Next, the antenna pattern and transmission data determination unit 118 determines whether or not there is a receiving station in a direction separated by a predetermined angle θ ₀ degrees or more based on the position information of each receiving station (step S1306).

When the receiving station exists in a direction away from the predetermined angle θ ₀ degrees or more (step S1306: YES), the antenna pattern and transmission data determination unit 118 determines to add a beam (step S1308), and returns to step S1306. .

On the other hand, if there is no receiving station in a direction away from the predetermined angle θ ₀ ° or more (step S1306: NO), the process ends.

  Next, another directional beam number / direction determination method performed by the antenna pattern and transmission data determination unit 118 will be described with reference to FIG.

  First, the position information of each receiving station is input from the position information storage unit 114 (step S1402).

  The antenna pattern and transmission data determination unit 118 determines to form a beam in the direction of the receiving station with the highest priority based on the position information of each receiving station (step S1404).

  Next, the antenna pattern and transmission data determination unit 118 determines whether or not a beam can be added in the direction of the receiving station of the next priority based on the position information of each receiving station (step S1406).

  If a beam can be added in the direction of the receiving station of the next priority (step S1406: YES), the antenna pattern and transmission data determination unit 118 determines to add a beam (step S1408), and the process returns to step S1406. .

  On the other hand, if it is not possible to add a beam in the direction of the receiving station of the next priority (step S1406: NO), the antenna pattern and transmission data determining unit 118 determines whether there are other receiving stations (step S1406). S1410).

  If there is another receiving station (step S1410: YES), the process returns to step S1406.

  On the other hand, when there is no other receiving station (step S1410: NO), the process is terminated.

  Next, the configuration of the receiving station according to the present embodiment will be described with reference to FIG.

  The receiving station 200 according to this embodiment is connected to the RF receiving circuit 200-1, the subcarrier signal separating unit 200-2 connected to the RF receiving circuit 200-1, and the subcarrier signal separating unit 200-2. Channel estimation unit 200-3, one or more reception channel state measurement units 200-4 connected to subcarrier signal separation unit 200-2 and channel estimation unit 200-3, and one or more reception channel state measurement units 200-4, a feedback data generation unit 200-5 as a control information generation unit, an encoding / modulation unit 200-6 connected to the feedback data generation unit 200-5, and an encoding / modulation unit 200- 6, an RF transmission circuit 200-7 connected to 6, one or a plurality of demodulation units 200-8 connected to the subcarrier signal separation unit 200-2, One or a plurality of decoding units 200-9 respectively connected to the plurality of demodulation units 200-8, a parallel-serial conversion unit 200-10 connected to the one or more decoding units 200-9, and a parallel-serial conversion unit 200 And IP packet restoration unit 200-11 connected to -10.

  The transmission signal transmitted from the transmission station 100 is received by the RF reception circuit 200-1. The RF reception circuit 200-1 inputs the reception signal to the subcarrier signal separation unit 200-2. Subcarrier signal separation section 200-2 separates the received signal into signals for each subcarrier, and separates the signals for each subcarrier into one or more demodulation sections 200-8 for each subcarrier, and for each subcarrier. The data is input to one or a plurality of reception channel state measurement units 200-4. Subcarrier signal separation section 200-2 inputs the separated signal for each subcarrier to channel estimation section 200-3.

  Each demodulator 200-8 demodulates the input signal for each subcarrier, and inputs the demodulated signal to one or a plurality of decoders 200-9 for each demodulated signal. Each decoding unit 200-9 decodes the input signal and inputs the decoded signal to the parallel-serial conversion unit 200-10. The parallel-serial conversion unit 200-10 performs parallel-serial conversion on the input signal and inputs the input signal to the IP packet restoration unit 200-11. The IP packet restoration unit 200-11 restores the input signal.

  On the other hand, channel estimation section 200-3 performs channel estimation using pilot symbols for each subcarrier, and inputs a channel estimation value for each subcarrier to one or a plurality of reception channel state measurement sections 200-4.

  Each reception channel state measurement unit 200-4 measures a reception channel state, for example, SIR based on the input signal and channel estimation value for each subcarrier, and inputs the measurement value to the feedback data generation unit 200-5. To do. The feedback data generation unit 200-5 generates feedback data (control information) indicating the reception channel state of the frequency block based on the input measurement value of the reception channel state, and encodes / modulates the generated feedback data Enter 200-6. The encoding / modulation unit 200-6 encodes / modulates the input feedback data and inputs it to the RF transmission circuit 200-7. The RF transmission circuit 200-7 feeds back food back data to the transmission station 100 as control information.

  The transmission station, mobile communication system, and transmission power control method according to the present invention can be applied to a mobile communication system that divides the entire system band into a plurality of frequency blocks and allocates radio resources for each block.

It is explanatory drawing which shows frequency scheduling. It is explanatory drawing which shows the distribution method of transmission power. It is explanatory drawing which shows the distribution method of transmission power. It is a partial block diagram which shows the transmitter concerning one Example of this invention. It is explanatory drawing which shows a data class. It is explanatory drawing which shows the allocation method of a subcarrier block. It is explanatory drawing which shows the allocation method of a subcarrier block. It is explanatory drawing which shows the distribution method of transmission power. It is explanatory drawing which shows the distribution method of transmission power. It is explanatory drawing which shows the distribution method of transmission power. It is explanatory drawing which shows the distribution method of transmission power. It is explanatory drawing which shows the distribution method of transmission power. It is explanatory drawing which shows the distribution method of transmission power. It is explanatory drawing which shows the distribution method of transmission power. It is explanatory drawing which shows the distribution method of transmission power. It is a flowchart which shows transmission scheduling of packet data. It is a flowchart which shows the calculation method of the reception quality information of each receiver. It is a flowchart which shows the determination method of a directional beam number and direction. It is a flowchart which shows the determination method of a directional beam number and direction. It is a partial block diagram which shows the receiver concerning one Example of this invention.

Explanation of symbols

100 transmitting station 200 receiving station

Claims (10)

A transmitting station in a mobile communication system that transmits a plurality of subcarriers to a receiving station,
A transmission data classifying unit that classifies packets to be transmitted as data classes based on predetermined attributes;
When allocating radio resources to the packet to be transmitted, and a radio resource allocation unit for allocating the frequency blocks obtained by dividing a frequency band assigned to the own mobile communication system as a unit,
A required power estimation unit that estimates the required power required to transmit data with a required quality to the receiving station;
A transmission power control unit that controls transmission power to be allocated in units of frequency blocks to the frequency block to which the packet to be transmitted is allocated by the radio resource allocation unit ;
The radio resource allocation unit allocates at least one frequency block to each data class based on control information indicating a reception channel state of the frequency block to be notified from the receiving station,
The transmission power control unit equally distributes the total transmission power allocated to the transmission station to all frequency blocks, and the transmission power to be allocated to the frequency blocks allocated to a predetermined data class is the required power. after adjusted to the transmitting station, characterized that you determine the transmission power to be allocated to the frequency block allocated to the data class other than the predetermined data class. In the transmitting station according to claim 1,
The transmission power control unit determines transmission power to be allocated to the frequency block to which the packet to be transmitted is allocated by the radio resource allocation unit, and the total transmission power is equal to or less than the transmission power allocated to the transmission station. A transmitting station that is controlled to be In the transmitting station according to claim 1 or 2 ,
The transmission data classification unit includes a priority given to the packet to be transmitted as data header information, a maximum delay time allowed in transmission of the transmission packet, a request for fluctuation in delay time in transmission of the transmission packet, transmission A transmitting station that classifies based on at least one of a request for a waiting time and a minimum transmission rate. In the transmitting station of any one of Claim 1 thru | or 3 ,
The transmission station, wherein the radio resource allocation unit allocates at least one frequency block based on a data amount of each data class. The transmission station according to any one of claims 1 to 4 ,
A QoS detector for detecting a QoS request required for the packet to be transmitted;
A priority determining unit that determines priority for allocation of frequency blocks to each data class based on at least one of the reception channel state and the QoS request;
The transmission station, wherein the radio resource allocation unit allocates at least one frequency block to each data class based on the priority determined by the priority determination unit. In the transmitting station according to claim 5 ,
A transmission waiting time detecting unit for detecting a transmission waiting time of the packet to be transmitted,
The transmission apparatus according to claim 1, wherein the priority determination unit determines a priority for the allocation of the frequency block to each data class based on the transmission waiting time detected by the transmission waiting time detection unit. The transmission station according to any one of claims 1 to 4 ,
A QoS detection unit for detecting a QoS request required for the packet to be transmitted;
The radio resource allocation unit
Assigning at least one frequency block to a predetermined data class based on at least one of the QoS request detected by the QoS detection unit and the reception channel state of the frequency block to be notified from the receiving station;
The at least one frequency block assigned to the predetermined data class is determined based on at least one of a QoS request detected by the QoS detection unit and a reception channel state of the frequency block to be notified from a receiving station. A transmission station that performs reallocation to a data class other than the data class. In the transmitting station according to claim 7 ,
The radio resource allocation unit
Allocating at least one frequency block to a data class having a predetermined delay request based on at least one of the QoS request detected by the QoS detection unit and the reception channel state of the frequency block to be notified from the receiving station;
Of the frequency blocks assigned to the data class having the predetermined delay request, a frequency satisfying the required rate when the throughput is less than a predetermined value and the data block is assigned to a data class having a delay requirement stricter than the predetermined delay request. A transmitting station, wherein blocks are reallocated to a data class having a delay requirement that is stricter than the predetermined delay requirement. A mobile communication system comprising a transmitting station and a receiving station that receives a plurality of subcarriers transmitted from the transmitting station,
The receiving station is
A reception channel state measurement unit that measures a reception channel state in units of frequency blocks obtained by dividing a frequency band assigned to the mobile communication system;
A control information generation unit that generates control information indicating a reception channel state to be notified to the transmitting station based on the reception channel state measured by the reception channel state measurement unit;
A control information transmitting unit for transmitting the control information generated by the control information generating unit to the transmitting station;
The transmitting station is
A transmission data classifying unit that classifies packets to be transmitted as data classes based on predetermined attributes;
Based on the control information indicating the reception channel state notified the frequency blocks from the receiving station, when allocating radio resources to the packet to be transmitted, frequency blocks obtained by dividing a frequency band assigned to the own mobile communication system A radio resource allocation unit that allocates the unit as a unit;
A required power estimation unit that estimates the required power required to transmit data with a required quality to the receiving station;
A transmission power control unit that controls transmission power to be allocated in units of frequency blocks to the frequency block to which the packet to be transmitted is allocated by the radio resource allocation unit ;
The radio resource allocation unit allocates at least one frequency block to each data class based on control information indicating a reception channel state of the frequency block to be notified from the receiving station,
The transmission power control unit equally distributes the total transmission power allocated to the transmission station to all frequency blocks, and the transmission power to be allocated to the frequency blocks allocated to a predetermined data class is the required power. after adjusted to a communication system characterized that you determine the transmission power to be allocated to the frequency block allocated to the data class other than the predetermined data class. A transmission power control method in a mobile communication system comprising a transmitting station and a receiving station that receives a plurality of subcarriers transmitted from the transmitting station,
The receiving station is
A reception channel state measurement step for measuring a reception channel state in units of frequency blocks obtained by dividing a frequency band assigned to the mobile communication system;
A control information generation step for generating control information indicating a reception channel state to be notified to the transmitting station based on the reception channel state measured by the reception channel state measurement step;
A transmission step of transmitting the control information generated by the control information generation step to the transmission station;
The transmitting station is
A transmission data classification step of classifying a packet to be transmitted as a data class based on a predetermined attribute;
Based on the control information indicating the reception channel state notified the frequency blocks from the receiving station, when allocating radio resources to the packet to be transmitted, frequency blocks obtained by dividing a frequency band assigned to the own mobile communication system Radio resource allocation step for allocating as a unit,
A required power estimation step for estimating a required power required to transmit data with a required quality to the receiving station;
With respect to the frequency block packet to be the transmission by the radio resource allocation step is assigned, have a transmission power control step of controlling transmission power to be allocated a frequency block as a unit,
The radio resource allocation step allocates at least one frequency block to each data class based on control information indicating a reception channel state of the frequency block to be notified from the receiving station,
The transmission power control step distributes the total transmission power allocated to the transmitting station equally to all frequency blocks, and the transmission power to be allocated to the frequency blocks allocated to a predetermined data class is the required power. A transmission power control method characterized by determining transmission power to be allocated to frequency blocks allocated to a data class other than the predetermined data class after adjustment to be performed .

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