JP5174554B2 - Mobile communication method, mobile station and radio base station - Google Patents

Description

  The present invention relates to a mobile communication method, a mobile station, and a radio base station.

  In the LTE (Long Term Evolution) mobile communication system defined by 3GPP, the mobile station UE is transmitted from the radio base station eNB after the connection state is established with the radio base station eNB. It is configured to control the transmission power of the data signal based on the propagation loss in the downlink estimated based on the common pilot signal and the parameter related to the power control in the physical uplink shared channel notified by the radio base station eNB. ing.

  Here, the parameter relating to the power control is determined based on, for example, interference power in a frequency band in which the physical uplink shared channel is transmitted and target quality of a data signal on the physical uplink shared channel.

  For example, the transmission power of the physical uplink shared channel is determined by the following equation (see Non-Patent Document 1, for example).

Here, P _MAX : Maximum transmission power of mobile station UE M _PUSCH : Number of resource blocks of physical uplink shared channel P _{O_PUSCH} : Parameter related to power control notified from radio base station eNB α: Designated by radio base station eNB Parameter PL: Propagation loss (path loss, Pathloss)
Δ _TF : Offset value set for each transmission format TF: Index of transmission format
f (i): Offset value for adjustment.
i: Index indicating the sub-frame number
j: Flag indicating whether dynamic scheduling is applied or persistent scheduling is applied

Note that the parameter P _{O_PUSCH} related to power control notified from the radio base station eNB described above includes a value commonly used by mobile stations in a cell and a value individually used by each mobile station UE. It is considered that a value commonly used by the mobile stations in the cell is notified by SIB (System Information Block) -n transmitted at a period of 80 ms or more.

  As for the physical uplink control channel, similarly to the physical uplink shared channel described above, the propagation loss in the downlink estimated based on the common pilot signal transmitted from the radio base station eNB, and the radio base station eNB The transmission power is configured to be controlled based on the notified parameter relating to power control in the physical uplink control channel.

  Here, the parameter related to the power control is determined based on, for example, interference power in a frequency band in which the physical uplink control channel is transmitted and target quality of a control signal on the physical uplink control channel.

  For example, the transmission power of the physical uplink control channel is determined by the following equation (see Non-Patent Document 1, for example).

Here, P _MAX : Maximum transmission power of mobile station UE P _{O_PUCCH} : Parameter relating to power control notified from radio base station eNB PL: Propagation loss (path loss, Pathloss)
_{ΔTF_PUCCH} : Offset value set for each transmission format of the control signal TF: Index of the transmission format of the control signal
g (i): Offset value for adjustment.
i: Index indicating the sub-frame number

Note that the above-described parameter P _{O_PUCCH} related to power control notified from the radio base station eNB includes a value commonly used by mobile stations in a cell and a value used individually by each mobile station UE. It is considered that a value commonly used by the mobile stations in the cell is notified by SIB (System Information Block) -n (n indicates an index of the SIB) transmitted at a period of 80 ms or more.
TS 36.213, v 8.2.0, E-UTRA Physical layer procedures, 5.1 Uplink power control

  In the LTE mobile communication system, as described above, the transmission power of the physical uplink shared channel is a parameter related to the power loss in the physical uplink shared channel notified by the radio base station eNB and the propagation loss in the downlink. It is comprised so that it may be controlled based on. Here, the parameter relating to the power control is determined based on, for example, interference power in a frequency band in which the physical uplink shared channel is transmitted and target quality of a data signal on the physical uplink shared channel. That is, the transmission power of the physical uplink shared channel includes the propagation loss in the downlink, the interference power in the frequency band in which the physical uplink shared channel is transmitted, and the target quality of the data signal on the physical uplink shared channel. It is comprised so that it may be controlled based on.

  Here, the interference power in the frequency band in which the physical uplink shared channel is transmitted is generally a time-varying value. For example, most of the interference power is interference power from an adjacent cell, which is large when the congestion degree of the adjacent cell is large and is small when the congestion degree of the adjacent cell is small. Therefore, for example, during the day when the congestion level increases during the day, the interference power increases, and during the late night and early morning when the congestion level decreases, the interference power decreases.

  Therefore, in order to perform transmission power control more accurately, when the interference power in the frequency band in which the physical uplink shared channel is transmitted changes, the above-described interference power is changed based on the changed interference power. It is desirable to perform transmission power control. That is, in order to perform transmission power control more accurately, the mobile station UE desirably performs transmission power control based on the latest parameters related to power control.

  Since the present invention relates to transmission power control during the random access procedure or after the random access procedure, in the following description, it is assumed that the mobile station UE is in the IDLE state before performing the random access procedure.

  In order to perform transmission power based on the above-described parameters related to the latest power control, the mobile station UE receives the above-described SIB-n after determining to perform the random access procedure, and parameters related to the latest power control. It is conceivable to obtain the method. However, in this case, since SIB-n is transmitted with a period of 80 ms or more, a large delay may occur. For example, when the transmission cycle of SIB-n is 80 ms and the timing at which the random access procedure is determined is immediately after the transmission timing of SIB-n, a delay of 80 ms occurs. Such a delay is extremely problematic because it leads to an increase in connection delay.

  Alternatively, in order to perform transmission power based on the latest power control parameters, the mobile station UE receives the SIB-n at a certain period and obtains the latest power control parameters in advance. A method of performing is conceivable. For example, a method of receiving the SIB-n at a frequency of about once every 10 minutes and acquiring parameters related to the latest power control is conceivable. In this case, the problem of increased connection delay as described above does not occur. Further, when the fluctuation of the interference power is not abrupt, transmission power control based on appropriate interference power can be performed. However, when the mobile station UE in the IDLE state receives the SIB-n at a frequency of about once every 10 minutes as described above, the power consumption of the mobile station increases, resulting in a standby time. The problem of shortening arises.

  In the transmission power control of the physical uplink control channel, the same problem as the problem in the transmission power control of the physical uplink shared channel described above exists.

  Therefore, the present invention has been made in view of the above-described problems, and does not increase the power consumption of the mobile station, and the data signal on the physical uplink shared channel or the control signal on the physical uplink control channel It is an object of the present invention to provide a mobile communication method, a mobile station, and a radio base station that can appropriately set transmission power.

  A first feature of the present invention is a mobile communication method, in which a mobile station calculates a propagation loss in a downlink based on a common pilot signal transmitted from a radio base station, and the mobile station includes: A step of transmitting a random access preamble to the radio base station via a physical random access channel; and the radio base station uses a random access response to the random access preamble to transmit downlink control information and physical uplink. A step of notifying a parameter related to power control in a link shared channel; and the mobile station calculates a propagation loss in the downlink calculated by the mobile station and a parameter related to power control in the physical uplink shared channel notified by the radio base station. , A process for determining the transmission power of the data signal And a step of transmitting the data signal with the determined transmission power via the physical uplink shared channel specified by the received downlink control information. And

  A second feature of the present invention is a mobile station, a propagation loss calculating unit configured to calculate a propagation loss in a downlink based on a common pilot signal transmitted from a radio base station, and A random access preamble transmitter configured to transmit a random access preamble to a radio base station via a physical random access channel, and a random access response to the random access preamble by the radio base station A parameter acquisition unit configured to acquire a parameter related to power control in the notified physical uplink shared channel, a calculated propagation loss in the downlink and a parameter related to power control in the acquired physical uplink shared channel. On the basis of, A transmission power determining unit configured to determine transmission power of the data signal, and the transmission power determined through the physical uplink shared channel specified by the received downlink control information, And a data signal transmission unit configured to transmit a data signal.

  A third feature of the present invention is a radio base station, an interference power measurement unit configured to measure interference power in a physical uplink shared channel, and a random access preamble transmitted from a mobile station. A random access response transmission unit configured to notify a parameter related to power control and downlink control information in the physical uplink shared channel calculated based on the interference power using an access response. Is the gist.

  A fourth feature of the present invention is a mobile communication method, in which a mobile station calculates a propagation loss in a downlink based on a common pilot signal transmitted from a radio base station, and the mobile station includes: A step of transmitting a random access preamble to the radio base station via a physical random access channel; and the radio base station uses a random access response to the random access preamble to transmit downlink control information and physical uplink. A step of notifying parameters relating to power control in a link control channel, and the mobile station calculating a propagation loss in the downlink and parameters relating to power control in the physical uplink control channel notified by the radio base station. , Transmission of the physical uplink control channel Determining a force, said mobile station, via the physical uplink control channel, at the determined transmission power, and summarized in that a step of performing transmission of control signals.

  In the fourth aspect of the present invention, the control signal may be at least one of acknowledgment information for a downlink data signal, downlink quality information, and a scheduling request signal.

  A fifth feature of the present invention is a mobile station, a propagation loss calculating unit configured to calculate a propagation loss in a downlink based on a common pilot signal transmitted from a radio base station, and A random access preamble transmitter configured to transmit a random access preamble to a radio base station via a physical random access channel, and a random access response to the random access preamble by the radio base station A parameter acquisition unit configured to acquire a parameter related to power control in the notified physical uplink control channel, a calculated propagation loss in the downlink and a parameter related to power control in the acquired physical uplink control channel; On the basis of, A transmission power determination unit configured to determine transmission power of the physical uplink control channel and a transmission of the control signal with the determined transmission power via the physical uplink control channel And a control signal transmitter configured.

  In the fifth aspect of the present invention, the control signal may be at least one of acknowledgment information for a downlink data signal, downlink quality information, and a scheduling request signal.

  According to a sixth aspect of the present invention, there is provided a radio base station, an interference power measurement unit configured to measure interference power in a physical uplink control channel, and a random access preamble transmitted from a mobile station. A random access response transmitter configured to notify parameters related to power control and downlink control information in the physical uplink control channel, calculated based on the interference power using an access response. This is the gist.

  In the sixth aspect of the present invention, at least one of acknowledgment information, downlink quality information, and a scheduling request signal for a downlink data signal may be received via the physical uplink control channel.

  As described above, according to the present invention, it is possible to appropriately set the data signal on the physical uplink shared channel or the control signal on the physical uplink control channel without increasing the power consumption of the mobile station. A mobile communication method, a mobile station, and a radio base station can be provided.

(Configuration of mobile communication system according to the first embodiment of the present invention)
The configuration of the mobile communication system according to the first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, an LTE mobile communication system is described as an example, but the present invention is also applicable to other mobile communication systems.

  In such an LTE mobile communication system, the OFDMA (Orthogonal Frequency Multiple Access) scheme is used for the downlink, and the SC-FDMA (Single-Carrier Division Multiple cc) is used for the uplink. The use of “method” is being considered.

  The “OFDMA scheme” is a scheme in which a frequency band is divided into a plurality of narrow frequency bands (subcarriers) and data is transmitted on each frequency band, and the subcarriers are partially overlapped on the frequency. However, by arranging them closely without interfering with each other, it is possible to realize high-speed transmission and increase frequency utilization efficiency.

  The “SC-FDMA scheme” is a transmission scheme that can reduce interference between terminals by dividing a frequency band and performing transmission using different frequency bands among a plurality of terminals. Since the “SC-FDMA scheme” has a feature that fluctuations in transmission power are reduced, low power consumption and wide coverage of the terminal can be realized.

  The LTE mobile communication system is a system that performs communication by sharing one or more physical channels between a plurality of mobile stations UE in both uplink and downlink.

  A channel shared by a plurality of mobile stations UE is generally called a “shared channel”. In the LTE scheme, a shared channel in the uplink is a “Physical Uplink Shared Channel (PUSCH)”, The shared channel in the downlink is a “physical downlink shared channel (PDSCH)”.

  In addition, as a transport channel, such a shared channel is an “uplink shared channel (UL-SCH)” in the uplink, and a “downlink shared channel (DL-SCH: Downlink) in the downlink. Shared Channel) ”.

  Further, in the uplink of the LTE mobile communication system, the radio base station eNB assigns the physical uplink shared channel (PUSCH) of each frequency every subframe (1 ms in the LTE scheme), that is, Selecting a mobile station UE that permits transmission of a data signal via a physical uplink shared channel (PUSCH) of each frequency, and assigning the physical uplink shared channel (PUSCH) to the selected mobile station UE Is configured to signal.

  Further, in the downlink of the LTE mobile communication system, the radio base station eNB assigns the physical downlink shared channel (PDSCH) of each frequency every subframe (1 ms in the LTE scheme), that is, Selecting a mobile station UE that is a transmission destination of a data signal via a physical uplink shared channel (PDSCH) of each frequency, and assigning the physical downlink shared channel (PDSCH) to the selected mobile station UE And transmitting such physical downlink shared channel (PDSCH).

  The control channel used for this signaling is “physical downlink control channel (PDCCH)” or “downlink L1 / L2 control channel (DL L1 / L2 Control Channel: Downlink L1 //) in the LTE scheme. L2 Control Channel) ".

  In addition, the transmission of the data signal via the physical uplink shared channel (PUSCH) of each frequency, that is, the mobile station UE to which the physical uplink shared channel (PUSCH) of each frequency is allocated for each subframe described above is permitted. Process for selecting mobile station UE, or mobile station UE that allocates physical downlink shared channel (PDSCH) of each frequency for each subframe, that is, data signal via physical downlink shared channel (PDSCH) of each frequency The process of selecting a mobile station UE that is a transmission destination is generally called “scheduling”.

  Here, since the mobile station UE to which a shared channel is dynamically allocated is selected for each subframe, it may be referred to as “Dynamic scheduling”. Further, the above-mentioned “allocating a shared channel” may be expressed as “allocating a radio resource for a shared channel”.

  Information transmitted through the physical downlink control channel (PDCCH) includes, for example, “Downlink Scheduling Information”, “Uplink Scheduling Grant”, and the like.

  The downlink scheduling information includes, for example, downlink resource block (Resource Block) allocation information related to the downlink shared channel (DL-SCH), UE ID, and the like.

  In addition, the uplink scheduling grant includes, for example, uplink resource block (Resource Block) allocation information regarding the uplink shared channel (UL-SCH), UE ID, and the like.

  Note that the downlink scheduling information and the uplink scheduling grant described above may be collectively referred to as “downlink control information (DCI: Downlink Control Information)”.

  As shown in FIG. 1, in the mobile communication system according to the present embodiment, the radio base station eNB transmits downlink control information via a physical downlink control channel (PDCCH) in the downlink, and physical downlink sharing. An RA response (random access response) or the like is transmitted via the channel (PDSCH).

  On the other hand, as shown in FIG. 1, in the mobile communication system according to the present embodiment, the mobile station UE transmits an RA preamble (random access preamble) via a “Physical Random Access Channel (PRACH)”. The data signal is transmitted via the physical uplink shared channel (PUSCH) and the control signal is transmitted via the physical uplink control channel (PUCCH).

  As shown in FIG. 2, the mobile station UE according to this embodiment includes an RA preamble transmission unit 11, an RA response reception unit 12, a parameter acquisition unit 13, a propagation loss calculation unit 14, a transmission power determination unit 15, And a data signal / control signal transmission unit 16.

  The RA preamble transmission unit 11 is configured to transmit an RA preamble via a physical random access channel (PRACH).

  The RA response receiving unit 12 is configured to receive an RA response to the RA preamble transmitted by the RA preamble transmitting unit 11.

  The parameter acquisition unit 13 is configured to acquire a parameter related to power control in the physical uplink shared channel (PUSCH) notified by the radio base station eNB using an RA response.

  Here, the parameter relating to the power control is, for example, an interference power value itself, an offset, or the like. Alternatively, the parameter relating to the power control may be a value determined by the interference power value and the target quality. Here, the target quality may be, for example, a target SIR (Signal-to-Interference Ratio).

  Moreover, the parameter acquisition unit 13 is configured to acquire a parameter related to power control in the physical uplink control channel (PUCCH) notified by the radio base station eNB using an RA response. Here, the parameter relating to the power control is, for example, an interference power value itself, an offset, or the like. Alternatively, the parameter relating to the power control may be a value determined by the interference power value and the target quality. Here, the target quality may be, for example, a target SIR (Signal-to-Interference Ratio).

  The propagation loss calculation unit 14 is configured to calculate a propagation loss in the downlink based on the common pilot signal transmitted from the radio base station eNB.

  More specifically, the propagation loss calculation unit 14 calculates the propagation loss in the downlink from the difference between the transmission power of the common pilot signal in the radio base station eNB and the reception power of the common pilot signal in the mobile station UE. Is configured to do. Note that the common pilot signal may be referred to as a Downlink Reference (DL RS: downlink reference signal). Further, the propagation loss may be referred to as a path loss (PL).

  The transmission power determination unit 15 performs physical uplink based on the propagation loss in the downlink calculated by the propagation loss calculation unit 14 and the parameters related to power control in the physical uplink shared channel (PUSCH) acquired by the parameter acquisition unit 13. The transmission power of the data signal on the shared channel (PUSCH) is determined.

More specifically, the transmission power determination unit 15 may be configured to determine the transmission power P _PUSCH (i) of the data signal on the physical uplink shared channel (PUSCH) by the following equation.

Here, P _max is the maximum transmission power of the mobile station UE. M _PUSCH (i) is the number of resource blocks of the physical uplink shared channel. P _{o_PUSCH} is a parameter related to power control in the physical uplink shared channel (PUSCH) acquired by the parameter acquisition unit 13. PL is the propagation loss calculated by the propagation loss calculation unit 14. α is a parameter specified by the radio base station eNB. _ΔTF is an offset value set for each transmission format, and TF is an index of the transmission format. f (i) is an offset value for adjustment, and is a value determined by a transmission power control command notified from the radio base station eNB to the mobile station UE. i is an index indicating a sub-frame number. Moreover, j is a flag indicating whether dynamic scheduling is applied or persistent scheduling is applied. In other words, based on the value of j, transmission power control when dynamic scheduling is applied and transmission power control when persistent scheduling is applied can be performed separately. In other words, the transmission power control according to the present invention may be applied when dynamic scheduling is applied, or may be applied when persistent scheduling is applied.

The _{Po_PUSCH} may be simply defined as a power offset for calculating transmission power.

Further, the parameter P _{O_PUSCH} related to power control notified from the radio base station eNB includes a value commonly used by mobile stations in the cell and a value individually used by each mobile station UE. The mobile station UE uses only values commonly used by mobile stations in a cell in a state where the values used individually by each mobile station UE are not notified from the radio base station eNB to the mobile station UE, The parameter _{PO_PUSCH} regarding power control notified from the radio base station eNB may be determined. Alternatively, the mobile station UE moves in the same manner as a value commonly used by the mobile stations in the cell in a state in which values individually used by each mobile station UE are notified from the radio base station eNB to the mobile station UE. The parameter _{PO_PUSCH} related to power control notified from the radio base station eNB may be determined using both values individually used by the station UE.

  In addition, the transmission power determination unit 15 performs physical transmission based on the propagation loss in the downlink calculated by the propagation loss calculation unit 14 and the parameters related to power control in the physical uplink control channel (PUCCH) acquired by the parameter acquisition unit 13. The transmission power of the control signal on the uplink control channel (PUCCH) is determined.

More specifically, the transmission power determination unit 15 may be configured to determine the transmission power P _PUCCH (i) of the data signal on the physical uplink control channel (PUCCH) by the following equation.

Here, P _max is the maximum transmission power of the mobile station UE. P _{o_PUCCH} is a parameter related to power control in the physical uplink control channel (PUCCH) acquired by the parameter acquisition unit 13. PL is the propagation loss calculated by the propagation loss calculation unit 14. _ΔTF is an offset value set for each transmission format of the control signal, and TF is an index of the transmission format of the control signal. g (i) is an offset value for adjustment, and is a value determined by a transmission power control command notified from the radio base station eNB to the mobile station UE. i is an Inex indicating a sub-frame number.

Note that the _{Po_PUCCH} may be simply defined as a power offset for calculating transmission power.

Also, the parameter P _{O_PUCCH} related to power control notified from the radio base station eNB is configured with a value commonly used by mobile stations in the cell and a value individually used by each mobile station UE.

The mobile station UE uses only values commonly used by mobile stations in a cell in a state where the values used individually by each mobile station UE are not notified from the radio base station eNB to the mobile station UE, You may determine the parameter _{PO_PUCCH} regarding the power control notified from the radio base station eNB.

Alternatively, the mobile station UE moves in the same manner as a value commonly used by the mobile stations in the cell in a state in which values individually used by each mobile station UE are notified from the radio base station eNB to the mobile station UE. The parameter P _{O_PUCCH} related to power control notified from the radio base station eNB may be determined using both values individually used by the station UE.

  The data signal / control signal transmission unit 16 uses the downlink control information received from the radio base station eNB, that is, the transmission power determined through the physical uplink shared channel (PUSCH) specified by the uplink scheduling grant. The data signal is transmitted.

  For example, when the data signal / control signal transmission unit 16 is instructed to transmit the physical uplink shared channel (PUSCH) by the uplink scheduling grant mapped to the RA response, the physical uplink shared channel (PUSCH) ), The data signal is transmitted with the determined transmission power. Alternatively, when the data signal / control signal transmission unit 16 is instructed to transmit the physical uplink shared channel (PUSCH) by the uplink scheduling grant mapped to the PDCCH, the physical uplink shared channel (PUSCH) Then, the data signal is transmitted with the determined transmission power.

  That is, the mobile station UE described above not only for the physical uplink shared channel (PUSCH) instructed to transmit by the RA response, but also to the physical uplink shared channel (PUSCH) instructed to transmit by the normal PDCCH. The transmission power may be determined based on a parameter related to power control in the physical uplink shared channel (PUSCH) specified by the RA response and the propagation loss.

  Alternatively, the data signal / control signal transmission unit 16 is configured to transmit the control signal with the determined transmission power via the physical uplink control channel (PUCCH).

  Here, specifically, the control signal may be acknowledgment information (ACK / NACK) for the downlink shared channel, or may be downlink quality information (CQI: Channel Quality Indicator). Alternatively, it may be a scheduling request signal (SR: Scheduling Request).

  Note that, in the above-described example, the transmission power determination unit 15 relates to power control in the physical uplink shared channel (PUSCH) acquired by the propagation loss in the downlink calculated by the propagation loss calculation unit 14 and the parameter acquisition unit 13. Based on the parameters, the transmission power of the data signal on the physical uplink shared channel (PUSCH) is determined. When a predetermined time has elapsed after receiving the RA response, the broadcast information is decoded, Parameters related to power control in the latest physical uplink shared channel (PUSCH) mapped to broadcast information are acquired, propagation loss in the downlink, and power control in the latest physical uplink shared channel (PUSCH) Based on the parameters, the physical uplink Transmission power of the data signals on the shared channel (PUSCH) may be determined.

  Alternatively, in the example described above, the transmission power determination unit 15 relates to power control in the downlink transmission loss calculated by the propagation loss calculation unit 14 and the physical uplink control channel (PUCCH) acquired by the parameter acquisition unit 13. Based on the parameters, the transmission power of the control signal on the physical uplink control channel (PUCCH) is determined. When a predetermined time has elapsed since the RA response was received, the broadcast information is decoded, Parameters related to power control in the latest physical uplink control channel (PUCCH) mapped to broadcast information are acquired, propagation loss in the downlink, and power control in the latest physical uplink control channel (PUCCH) Based on the parameters, the physical uplink The transmission power of the control signal on the click Control Channel (PUCCH) may be determined.

  As illustrated in FIG. 3, the radio base station eNB according to the present embodiment includes a PRACH reception unit 21, an interference power measurement unit 22, and a PDCCH / PDSCH transmission unit 23.

  The PRACH receiving unit 21 is configured to receive the RA preamble transmitted by the mobile station UE via the physical random access channel (PRACH).

  The interference power measurement unit 22 is configured to measure interference power in the physical uplink shared channel (PUSCH).

  For example, the interference power measurement unit 22 may be configured to measure the interference power based on the thermal noise power in the frequency band of the physical uplink shared channel (PUSCH) and the signal power of the interference signal.

  In this case, for example, the interference power measurement unit 22 calculates the desired signal from the signal power including all of the thermal noise in the frequency band of the physical uplink shared channel (PUSCH), the signal power of the interference signal, and the signal power of the desired signal. Interference power in the frequency band of the physical uplink shared channel (PUSCH) may be acquired by subtracting signal power. Here, the desired signal may be, for example, a physical uplink shared channel signal actually received by the radio base station eNB.

  Alternatively, for example, the interference power measurement unit 22 may calculate the interference power in the frequency band of the physical uplink shared channel (PUSCH) based on the dispersion of the reference signal mapped to the physical uplink shared channel.

The interference power measurement unit 22 calculates a parameter P _{o_PUSCH} related to power control in the physical uplink shared channel (PUSCH) based on the interference power and the target quality of the data signal on the physical uplink shared channel. Also good. More specifically, the parameter P _{o_PUSCH} for power control in the physical uplink shared channel (PUSCH) may be calculated as follows:
P _{o_PUSCH} = (interference power) + (target quality of data signal)

  The interference power measurement unit 22 is configured to measure interference power in the physical uplink control channel (PUCCH).

  For example, the interference power measurement unit 22 may be configured to measure the interference power based on the thermal noise power in the frequency band of the physical uplink control channel (PUCCH) and the signal power of the interference signal.

  In this case, for example, the interference power measurement unit 22 calculates the desired signal from the signal power including all of the thermal noise in the frequency band of the physical uplink control channel (PUCCH), the signal power of the interference signal, and the signal power of the desired signal. Interference power in the frequency band of the physical uplink control channel (PUCCH) may be acquired by subtracting signal power. Here, the desired signal may be, for example, a physical uplink control channel signal actually received by the radio base station eNB.

  Alternatively, for example, the interference power measurement unit 22 may calculate the interference power in the frequency band of the physical uplink control channel (PUCCH) based on the dispersion of the reference signal mapped to the physical uplink control channel.

The interference power measurement unit 22 calculates a parameter P _{o_PUCCH} related to power control in the physical uplink control channel (PUCCH) based on the interference power and the target quality of the control signal on the physical uplink control channel. Also good. More specifically, the parameter P _{o_PUCCH} related to power control in the physical uplink control channel (PUCCH) may be calculated as follows:
P _{o_PUCCH} = (interference power) + (target quality of control signal)

  The PDCCH / PDSCH transmission unit 23 is configured to notify parameters related to power control and downlink control information in the physical uplink shared channel (PUSCH) using an RA response to the received RA preamble.

  Note that the PDCCH / PDSCH transmission unit 23 uses parameters related to power control when dynamic scheduling is applied as parameters related to power control in the physical uplink shared channel (PUSCH), and power control when persistent scheduling is applied. Both of the parameters may be notified, or only one of them may be notified.

  Alternatively, the PDCCH / PDSCH transmission unit 23 uses both a value commonly used by mobile stations in the cell and a value individually used by the mobile station UE as parameters relating to power control in the physical uplink shared channel (PUSCH). Notification may be performed, or only one of them may be notified.

  Further, the PDCCH / PDSCH transmission unit 23 uses the RA response to the received RA preamble, in addition to the parameters related to power control and downlink control information in the physical uplink shared channel (PUSCH), the physical uplink control channel ( It may be configured to notify a parameter related to power control in PUCCH).

(Operation of the mobile communication system according to the first embodiment of the present invention)
With reference to FIG. 4, the operation of the mobile communication system according to the first embodiment of the present invention will be described.

  As shown in FIG. 4, when it is determined in step S1001 that the mobile station UE needs to transmit an RA preamble (for example, it is necessary to transmit a data signal via a physical uplink shared channel (PUSCH)). When it occurs), an RA preamble is transmitted to the radio base station eNB via a physical random access channel (PRACH).

  In step S1002, the radio base station eNB transmits a parameter related to power control and downlink control information in the physical uplink shared channel (PUSCH) to the mobile station UE by an RA response according to the received RA preamble. .

  The RA response may include parameters related to power control in the physical uplink control channel (PUCCH) in addition to parameters related to power control and downlink control information in the physical uplink shared channel (PUSCH). .

  The mobile station UE calculates the propagation loss in the downlink based on the common pilot signal transmitted from the radio base station at a predetermined timing. In step S1003, the mobile station UE calculates the latest propagation loss in the downlink and step S1002. The transmission power of the data signal to be transmitted on the physical uplink shared channel (PUSCH) is determined based on the parameters related to power control in the latest physical uplink shared channel (PUSCH) acquired in step (1).

  In step S1004, the mobile station UE transmits a data signal with the transmission power determined in step S1003 via the physical uplink shared channel (PUSCH) specified by the received downlink control information.

  In step S1004 and subsequent steps, when the mobile station UE receives an uplink scheduling grant, the mobile station UE transmits a data signal via the physical uplink shared channel (PUSCH) based on the uplink scheduling grant.

  In this case, the mobile station UE uses the calculated propagation loss in the latest downlink and the parameters related to power control in the physical uplink shared channel (PUSCH) acquired in step S1002 on the physical uplink shared channel (PUSCH). The transmission power of the data signal to be transmitted is determined, and the data signal is transmitted with the transmission power.

  In addition, when the mobile station UE transmits a control signal via the physical uplink control channel (PUCCH) after step S1004, the mobile station UE obtains the calculated propagation loss in the latest downlink and the step S1002. The transmission power of the control signal to be transmitted on the physical uplink control channel (PUCCH) is determined based on the parameters relating to the power control in the physical uplink control channel (PUCCH), and the control signal is transmitted with the transmission power.

(RA response format (example 1))
The RA response format (example 1) according to the first embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 5, the RA response may be composed of the following four information elements.
・ TA
・ UL Grant
・ Temporary C-RNTI
-Parameters related to power control in the physical uplink shared channel (PUSCH)

  Here, TA is called Timing Advance and is information for determining the transmission timing of the uplink signal. UL Grant is an uplink scheduling grant. Temporary C-RNTI is a temporarily assigned C-RNTI. C-RNTI is a parameter corresponding to UE identification information, that is, UE ID.

Or as shown in FIG. 6, RA response may be comprised by the following four information elements.
・ TA
・ UL Grant
・ Temporary C-RNTI
-Parameters related to power control in the physical uplink control channel (PUCCH)

Or as shown in FIG. 7, RA response may be comprised by the following five information elements. In this case, the RA response includes both parameters relating to power control in the physical uplink shared channel (PUSCH) and parameters relating to power control in the physical uplink control channel (PUCCH).
・ TA
・ UL Grant
・ Temporary C-RNTI
-Parameters related to power control in the physical uplink shared channel (PUSCH)-Parameters related to power control in the physical uplink control channel (PUCCH)

  In the example described above, the number of bits of the parameter related to power control in the physical uplink shared channel (PUSCH) and the parameter related to power control in the physical uplink control channel (PUCCH) is 8, but a value other than 8 is used. It may be.

  That is, for example, regarding parameters related to power control in a physical uplink shared channel (PUSCH), when both a value commonly used by mobile stations in a cell and a value individually used by each mobile station UE are specified. May be, for example, 12 bits.

  That is, for example, regarding parameters related to power control in the physical uplink shared channel (PUSCH), when both a parameter when dynamic scheduling is applied and a parameter when persistent scheduling is applied are specified, For example, it may be 16 bits (8 bits + 8 bits = 16 bits).

(RA response format (example 2))
With reference to FIG. 8, the format of the RA response according to the first embodiment of the present invention will be described.

As shown in FIG. 8, the MAC PDU including the RA response may be configured by the following information elements.
-Parameters related to power control in the physical uplink control channel (PUCCH)-Parameters related to power control in the physical uplink shared channel (PUSCH)-N subheaders-N RA responses

  Here, the N sub-headers and the N RA responses have a one-to-one correspondence. Note that the number N of subheaders and RA responses may be “1”, “2”, or any value.

  Information elements in the RA response are the same as those described in FIG.

The subheader consists of the following information elements:
・ E
・ T
・ RAPID

  Here, E is an extension field. When this value is “0”, it indicates that the subheader ends with this byte. When this value is “1”, “E / T” is added to the subsequent bits. / RAPID "or" E / T / R / R / BI ". Here, R represents a reserved bit, and BI represents a Backoff Indicator.

  T indicates whether this subheader includes “Random Access Preamble ID” or “Backoff Indicator”.

  In the example of FIG. 8, only the case where the MAC PDU includes “Random Access Preamble ID” is shown. However, when the MAC PDU includes “Backoff Indicator”, the “physical “Parameters related to power control in uplink control channel (PUCCH)” or “parameters related to power control in physical uplink shared channel (PUSCH)” may be included in the MAC PDU.

  RAPID is “Random Access Preamble ID”. That is, it indicates the ID of the RA preamble.

  In the example described above, the number of bits of the parameter related to power control in the physical uplink shared channel (PUSCH) is “8”, and the number of bits of the parameter related to power control in the physical uplink control channel (PUCCH) is “5”. However, it may be a value other than “8” or “5”.

  In addition, as for a byte including a parameter related to power control in the physical uplink control channel (PUCCH), a surplus bit is a reserved bit.

  In the above-described example, only parameters when dynamic scheduling is applied are shown as parameters related to power control in the physical uplink shared channel (PUSCH). In addition, when persistent scheduling is applied. The parameters may also be specified.

  In this case, one more byte is used as a parameter for power control in the physical uplink shared channel (PUSCH).

  Further, in the above-described example, both the parameter related to power control in the physical uplink shared channel (PUSCH) and the parameter related to power control in the physical uplink control channel (PUCCH) are included in the MAC PDU. A configuration in which either one of them is included may be employed.

(RA response format (example 3))
With reference to FIG. 9, the format of the RA response according to the first embodiment of the present invention will be described.

As shown in FIG. 9, the MAC PDU including the RA response may be configured by the following information elements.
Sub-header (2 bytes in total) including parameters related to power control in the physical uplink control channel (PUCCH) and parameters related to power control in the physical uplink shared channel (PUSCH)
・ N subheaders ・ N RA responses

  Here, the N sub-headers and the N RA responses have a one-to-one correspondence. Note that the number N of subheaders and RA responses may be “1”, “2”, or any value.

  Information elements in the RA response are the same as those described in FIG.

  Information elements in subheaders other than T and P are the same as those described in FIG.

  Hereinafter, a subheader including parameters related to power control in the physical uplink control channel (PUCCH) and parameters related to power control in the physical uplink shared channel (PUSCH) will be described.

  First, T indicates whether this sub-header includes “Random Access Preamble ID” or “Backoff Indicator or parameters related to power control”.

  For example, when the value of T is “0”, this indicates that “a parameter related to Backoff Indicator or power control” is included, and when the value of T is “1”, “a parameter related to Backoff Indicator or power control” is included. The structure which shows that may be sufficient.

  Here, the parameter related to power control is a parameter related to power control in the physical uplink control channel (PUCCH) or a parameter related to power control in the physical uplink shared channel (PUSCH).

  Next, P indicates whether the subheader includes “Backoff Indicator” or a parameter related to power control. For example, when the value of P is “0”, it may indicate that “Backoff Indicator” is included, and when the value of P is “1”, it may indicate that a parameter related to power control is included. .

  Here, the parameter related to power control is a parameter related to power control in the physical uplink control channel (PUCCH) or a parameter related to power control in the physical uplink shared channel (PUSCH). In the example shown in FIG. , P and 2 bytes are used for parameters related to the power control.

  The effects of T and P are shown below.

  In the case of the format shown in FIG. 8, since the parameter related to power control is always included in the MAC PDU, there is a problem that the bit size of the MAC PDU increases.

  However, in the case of the format of FIG. 9, it is possible to select whether or not to include parameters related to power control in the MAC PDU by T and P. Therefore, the parameters related to power control are only included in the MAC PDU when necessary. Can be performed, and there is an advantage that the bit size of the MAC PDU can be suppressed.

  Although T and P described above are defined as separate fields, instead of specifying T as 2 bits, “00: RAPID, 01: BI, 10: parameters related to power control” may be specified.

  In the above-described example, the number of bits of parameters related to power control in the physical uplink shared channel (PUSCH) is 8, and the number of bits of parameters related to power control in the physical uplink control channel (PUCCH) is 5. , Values other than 8 and 5 may be used.

  In the above-described example, only parameters when dynamic scheduling is applied are shown as parameters related to power control in the physical uplink shared channel (PUSCH). In addition, when persistent scheduling is applied. The parameters may also be specified.

  In this case, one more byte is used as a parameter for power control in the physical uplink shared channel (PUSCH).

  Further, in the above-described example, both the parameter related to power control in the physical uplink shared channel (PUSCH) and the parameter related to power control in the physical uplink control channel (PUCCH) are included in the MAC PDU. A configuration in which either one of them is included may be employed.

(Operations and effects of the mobile communication system according to the first embodiment of the present invention)
According to the mobile communication system according to the first embodiment of the present invention, the radio base station eNB relates to power control in the latest physical uplink shared channel (PUSCH) for the mobile station UE using an RA response. Parameters or parameters related to power control in the latest physical uplink shared channel (PUSCH), and the mobile station UE uses the parameters related to power control in the latest physical uplink shared channel (PUSCH) or the latest physical uplink shared channel. Since it is configured to calculate the transmission power of the data signal on the physical uplink shared channel or the transmission power of the control signal on the physical uplink control channel with reference to the power control parameter in (PUSCH), the physical Data signal on uplink shared channel It is possible to appropriately set the transmission power of the transmission power of the control signal on the physical uplink control channel.

(Example of change)
The operations of the mobile station UE and the radio base station eNB described above may be implemented by hardware, may be implemented by a software module executed by a processor, or may be implemented by a combination of both. .

  The software module includes a RAM (Random Access Memory), a flash memory, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electronically Erasable and Programmable ROM, a hard disk, a registerable ROM, a hard disk). Alternatively, it may be provided in a storage medium of an arbitrary format such as a CD-ROM.

  Such a storage medium is connected to the processor so that the processor can read and write information from and to the storage medium. Further, such a storage medium may be integrated in the processor. Such a storage medium and processor may be provided in the ASIC. Such an ASIC may be provided in the mobile station UE or the radio base station eNB. Further, the storage medium and the processor may be provided as a discrete component in the mobile station UE or the radio base station eNB.

  Although the present invention has been described in detail using the above-described embodiments, it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

1 is an overall configuration diagram of a mobile communication system according to a first embodiment of the present invention. FIG. 3 is a functional block diagram of a mobile station according to the first embodiment of the present invention. FIG. 3 is a functional block diagram of a radio base station according to the first embodiment of the present invention. FIG. 3 is a sequence diagram showing an operation of the mobile communication system according to the first embodiment of the present invention. It is a figure which shows the format (example 1) of RA response used with the mobile communication system which concerns on the 1st Embodiment of this invention. It is a figure which shows the format (example 1) of RA response used with the mobile communication system which concerns on the 1st Embodiment of this invention. It is a figure which shows the format (example 1) of RA response used with the mobile communication system which concerns on the 1st Embodiment of this invention. It is a figure which shows the format (example 2) of RA response used with the mobile communication system which concerns on the 1st Embodiment of this invention. It is a figure which shows the format (example 3) of RA response used with the mobile communication system which concerns on the 1st Embodiment of this invention.

Explanation of symbols

UE ... Mobile station 11 ... RA preamble transmitter 12 ... RA response receiver 13 ... Parameter acquisition unit 13 ... Transmission power determiner 15 ... Propagation loss calculator 16 ... Data signal / control signal transmitter eNB ... Radio base station 21 ... PRACH Receiving unit 22 ... interference power measuring unit 23 ... PDCCH / PDSCH transmitting unit

Claims (9)

The mobile station calculates a propagation loss in the downlink based on the common pilot signal transmitted from the radio base station;
The mobile station transmitting a random access preamble to the radio base station via a physical random access channel;
The radio base station, using a random access response to the random access preamble, notifying parameters related to power control in downlink control information and physical uplink shared channel;
The mobile station determining transmission power of the data signal based on the calculated propagation loss in the downlink and a parameter related to power control in the latest physical uplink shared channel notified by the radio base station; ,
The mobile station via the designated the physical uplink shared channel by the downlink control information received, at the determined transmission power, and chromatic and performing transmission of the data signal,
Parameter Po _{_PUSCH} to power control in the physical uplink shared channel, Po _{_PUSCH} = (interference power) + mobile communication method characterized in that it is calculated by (the target quality of the data signal). Based on the common pilot signal transmitted from the radio base station, a propagation loss calculation unit configured to calculate the propagation loss in the downlink,
A random access preamble transmitter configured to transmit a random access preamble to the radio base station via a physical random access channel;
A parameter acquisition unit configured to acquire a parameter relating to power control in the physical uplink shared channel notified by the radio base station using a random access response to the random access preamble;
A transmission power determining unit configured to determine the transmission power of the data signal based on the calculated propagation loss in the downlink and the parameter regarding power control in the acquired latest physical uplink shared channel;
A data signal transmission unit configured to transmit the data signal with the determined transmission power via the physical uplink shared channel specified by the received downlink control information,
The physical parameter Po _{_PUSCH} about power control in the uplink shared channel, the mobile station, characterized in that it is calculated by (the target quality of the data signal) Po _{_PUSCH} = (interference power) +. An interference power measurement unit configured to measure interference power in the physical uplink shared channel;
Using a random access response for a random access preamble transmitted from a mobile station, configured to notify parameters related to power control and downlink control information in the physical uplink shared channel calculated based on the interference power A random access response transmission unit ,
The interference power measurement section, the physical parameters Po _{_PUSCH} about power control in the uplink shared channel, the radio base station and calculates the (target quality of the data signal) Po _{_PUSCH} = (interference power) +. The mobile station calculates a propagation loss in the downlink based on the common pilot signal transmitted from the radio base station;
The mobile station transmitting a random access preamble to the radio base station via a physical random access channel;
The radio base station, using a random access response to the random access preamble, notifying parameters related to power control in downlink control information and physical uplink control channel;
The mobile station determines the transmission power of the physical uplink control channel based on the calculated propagation loss in the downlink and the parameter related to power control in the latest physical uplink control channel notified by the radio base station. And a process of
The mobile station transmitting a control signal with the determined transmission power via the physical uplink control channel; and
The parameter P _{o_PUCCH} related to power control in the physical uplink control channel is calculated by _{Po_PUCCH} = (interference power) + (target quality of control signal). The control signal is
5. The mobile communication method according to claim 4, wherein the mobile communication method is at least one of acknowledgment information for downlink data signals, downlink quality information, and scheduling request signals. Based on the common pilot signal transmitted from the radio base station, a propagation loss calculation unit configured to calculate the propagation loss in the downlink,
A random access preamble transmitter configured to transmit a random access preamble to the radio base station via a physical random access channel;
A parameter acquisition unit configured to acquire a parameter related to power control in a physical uplink control channel notified by using a random access response to the random access preamble by the radio base station;
A transmission power determining unit configured to determine the transmission power of the physical uplink control channel on the basis of the calculated propagation loss in the downlink and the acquired parameter relating to power control in the latest physical uplink control channel. When,
A control signal transmitting unit configured to transmit a control signal with the determined transmission power via the physical uplink control channel,
A parameter P _{o_PUCCH} related to power control in the physical uplink control channel is calculated by _{Po_PUCCH} = (interference power) + (target quality of control signal). The control signal is
The mobile station according to claim 6, wherein the mobile station is at least one of acknowledgment information, downlink quality information, and a scheduling request signal for a downlink data signal. An interference power measurement unit configured to measure interference power in the physical uplink control channel;
It is configured to notify parameters related to power control and downlink control information in the physical uplink control channel, which are calculated based on the interference power, using a random access response to a random access preamble transmitted from a mobile station. A random access response transmission unit,
The radio base station, wherein the interference power measurement unit calculates a parameter P _{o_PUCCH} relating to power control in the physical uplink control channel by _{Po_PUCCH} = (interference power) + (target quality of control signal). Via the physical uplink control channel,
9. The radio base station according to claim 8, wherein at least one of delivery confirmation information for downlink data signals, downlink quality information, and scheduling request signals is received.

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