JP2010004505A - Mobile communication method, mobile station, and radio base station - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To notify a mobile station of a parameter concerning interference power in a physical random access channel as soon as possible. <P>SOLUTION: The mobile station UE is provided with: a propagation loss computing part 11 computing a propagation loss in a down link based on a common pilot signal transmitted from a radio base station eNB; a parameter acquiring part 12 acquiring the parameter concerning power control in a PRACH (physical random access channel) notified using an MIB (master information block) by the radio base station eNB; an initial transmission power determining part 13 determining the transmission power of a newly transmitted RA (random access) preamble based on the computed transmission loss in the down link and the parameter concerning power control in the PRACH notified by the radio base station eNB; and an RA preamble transmission part 14 starting the transmission of the RA preamble with the determined transmission power. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mobile communication method, a mobile station, and a radio base station that perform communication using a physical random access channel in the uplink.

  Generally, in a mobile communication system, communication using a physical random access channel (PRACH: Physical Random Access Channel) is performed in the uplink.

  More specifically, when starting communication, the radio base station and the mobile station establish a connection state between the radio base station and the mobile station by performing a communication procedure called “random access procedure”. That is, communication is set between the radio base station and the mobile station (see, for example, Non-Patent Document 1). Here, in the random access procedure, the signal that the mobile station first transmits to the radio base station is called a random access preamble.

  In an LTE (Long Term Evolution) mobile communication system defined by 3GPP, a mobile station UE uses a downlink propagation loss estimated based on a common pilot signal transmitted from a radio base station eNB, and a radio base station. The transmission power of the random access preamble to be newly transmitted is determined based on the parameter notified by the station eNB.

  In addition, the parameter notified by the radio base station eNB is determined based on, for example, interference power in a frequency band in which the random access preamble is transmitted and the target quality of the random access preamble.

  For example, the transmission power of the random access preamble is determined by the following equation (see, for example, Non-Patent Document 2).

P_last_preamble = min (P _max , PL + _{Po_pre} + Δ_preamble + (N_pre−1) × dp_rampup)
P _max : Maximum transmission power of mobile station PL: Propagation loss (path loss)
P _{o_pre} : parameter notified by the radio base station eNB Δ_preamble: power offset determined by the format of the random preamble N_pre: number of transmissions of the random preamble dp_rampup: ramping amount when performing power ramping
TS 36.300, v 8.4.0, E-UTRA and E-UTRAN Overall description, 10.1.5 Random Access Procedure R1-081166

  In an LTE mobile communication system, a radio base station eNB allows a mobile station that permits transmission of a data signal via a physical uplink shared channel of each frequency for each sub-frame (Sub-frame) of 1 ms. Since it is determined, the interference power in the physical random access channel is assumed to change frequently.

  However, in the LTE mobile communication system, it is assumed that the interference power in the physical random access channel is notified by SIB (System Information Block) -n transmitted at a period of 80 ms or more. In addition, the interference power in the physical random access channel is not accurate, and there is a possibility that the transmission power of the random access preamble to be newly transmitted cannot be determined appropriately.

  Therefore, the present invention has been made in view of the above-described problems, and provides a mobile communication method, a mobile station, and a radio base station capable of notifying a mobile station of parameters regarding interference power in a physical random access channel as soon as possible. The purpose is to provide.

  A first feature of the present invention is a mobile communication method in which communication is performed using a physical random access channel in the uplink, in which the mobile station performs downlink communication based on a common pilot signal transmitted from the radio base station. A step of calculating a propagation loss, a step of measuring the interference power in the physical random access channel by the radio base station, and the physical random number calculated by the radio base station based on the interference power using an MIB. A step of notifying a parameter related to power control in the access channel, and the mobile station calculates a new propagation loss in the downlink and a parameter related to power control in the physical random access channel notified by the radio base station. Random access preamble transmission power to be transmitted to A step of constant, the mobile station, at the determined transmission power, and summarized in that a step of starting the transmission of the random access preamble.

  According to a second aspect of the present invention, there is provided a mobile communication method for performing communication using a physical random access channel in the uplink, in which the mobile station uses the downlink in the downlink based on the common pilot signal transmitted from the radio base station. Calculating a propagation loss, a step in which the radio base station measures interference power in a physical random access channel, and the radio base station uses the physical downlink control channel to cause the interference to the mobile station. A step of notifying a parameter relating to power control in the physical random access channel calculated based on power; and the mobile station calculates the propagation loss in the downlink and the physical random access channel notified by the radio base station. Based on the parameters related to power control in the Determining a transmit power of the access preamble, the mobile station, at the determined transmission power, and summarized in that a step of starting the transmission of the random access preamble.

  A third feature of the present invention is a mobile station that performs communication using a physical random access channel in the uplink, and calculates a propagation loss in the downlink based on a common pilot signal transmitted from the radio base station. A propagation loss calculation unit configured as described above, a parameter acquisition unit configured to acquire parameters relating to power control in a physical random access channel notified by using the MIB by the radio base station, and the calculated Initial transmission power configured to determine transmission power of a random access preamble to be newly transmitted based on a propagation loss in downlink and a parameter related to power control in the physical random access channel notified by the radio base station The determination unit and the determined transmission power And summarized in that comprises a random access preamble transmitter unit configured to start the transmission of the random access preamble.

  A fourth feature of the present invention is a mobile station that performs communication using a physical random access channel in the uplink, and calculates a propagation loss in the downlink based on a common pilot signal transmitted from the radio base station. A propagation loss calculation unit configured as described above, and a parameter acquisition unit configured to acquire parameters related to power control in a physical random access channel notified by using the physical downlink control channel by the radio base station, Based on the calculated propagation loss in the downlink and parameters related to power control in the physical random access channel notified by the radio base station, the transmission power of the random access preamble to be newly transmitted is determined. The initial transmission power determination unit and the determined In serial transmission power, and summarized in that comprises a random access preamble transmitter unit configured to start the transmission of the random access preamble, the.

  A fifth feature of the present invention is a radio base station used in a mobile communication method that performs communication using a physical random access channel in the uplink, and is configured to measure interference power in the physical random access channel. And a parameter notification unit configured to notify a parameter related to power control in the physical random access channel calculated based on the interference power using an MIB. And

  A sixth feature of the present invention is a radio base station used in a mobile communication method for performing communication using a physical random access channel in the uplink, and based on a random access preamble transmitted from the mobile station, physical random In the physical random access channel calculated based on the interference power to the mobile station using an interference power measurement unit configured to measure interference power in the access channel and a physical downlink control channel The gist of the present invention is to include a parameter notification unit configured to notify a parameter related to power control.

  As described above, according to the present invention, it is possible to provide a mobile communication method, a mobile station, and a radio base station capable of notifying a mobile station of parameters regarding interference power in a physical random access channel as quickly as possible.

(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 will be 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. The process of selecting the mobile station UE 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. SIB-n, RA response (random access response), etc. are transmitted via the channel (PDSCH), and “MIB (Master Information Block)” is transmitted via the “Physical Broadcast Channel (PBCH)”. It is configured. In FIG. 1, description of the above-described uplink and downlink shared channels (UL-SCH and DL-SCH) is omitted.

  Specifically, the MIB is configured to be transmitted in a cycle of 40 ms, and is configured to be repeatedly transmitted in subframe # 0 every 10 ms. Note that the MIB is transmitted by six central physical resource blocks (PRBs) in the PBCH.

  The meaning that the MIB is transmitted at a cycle of 40 ms means that the signal content change cycle is 40 ms, and actual transmission is performed at a cycle of 10 ms.

  That is, the mobile station UE demodulates and decodes the PBCH by combining the PBCH signals transmitted four times in 40 ms. In this case, each PBCH transmitted in a cycle of 10 ms is a self-decodable signal, and MIB information can be acquired by receiving one PBCH.

  Further, SIB-1 is configured to be transmitted at a period of 80 ms, and is configured to be repeatedly transmitted in subframe # 5 every 20 ms. In addition, although SIB-1 is transmitted by DL-SCH, the number of PRBs used for transmission of SIB-1 and the frequency position of PRB can be set flexibly.

  SIB-2 to SIB-8 are configured to be mapped to system information SI (System Information) -n and transmitted at any period of 80, 160, 320, 640, 1280, 2560, 5120 ms. Yes.

  SIB-2 is configured to be mapped to SI-1, and SIB-3 to SIB-8 are configured to be flexibly mapped to any SI-n.

  Here, SIB-n is a message including specific information elements, and SI-n may be considered as a container for carrying SIB-n.

  Also, the SIB-1 is configured to broadcast the SI-n scheduling information and the transmission cycle T of each SI-n. In addition, SIB-1 to SIB-8 and SI-n mapping information is broadcast by SIB-1.

  On the other hand, as shown in FIG. 1, in the mobile communication system according to the present embodiment, the mobile station UE is configured to transmit an RA preamble via a physical random access channel.

  As illustrated in FIG. 2, the mobile station UE according to the present embodiment includes a propagation loss calculation unit 11, a parameter acquisition unit 12, an initial transmission power determination unit 13, an RA preamble transmission unit 14, and a data signal transmission unit 15. And a PDCCH / PDSCH receiver 16.

  The propagation loss calculation unit 11 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 11 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 parameter acquisition unit 12 is configured to acquire parameters related to power control in the physical random access channel (PRACH) notified by the radio base station eNB using the MIB.

  Here, the parameter relating to power control is, for example, the interference power value itself, an offset, or the like. Alternatively, the parameter related to 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).

  Or the parameter acquisition part 12 is comprised so that the parameter regarding the power in the physical random access channel (PRACH) notified using the physical downlink control channel (PDCCH) by the radio base station eNB may be acquired.

  Here, the parameter relating to power control is, for example, the interference power value itself, an offset, or the like. Alternatively, the parameter relating to 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 parameter acquisition unit 12 transmits the power control transmitted by the radio base station eNB using the MIB or the physical downlink control channel (PDCCH) only when the valid period of the acquired parameter relating to power control has expired. The parameter regarding may be newly acquired.

  The initial transmission power determination unit 13 newly transmits the RA based on the propagation loss in the downlink calculated by the propagation loss calculation unit 11 and the parameter regarding the power control in the physical random access channel notified by the radio base station eNB. The transmission power of the preamble (random access preamble) is determined.

  Specifically, the initial transmission power determination unit 13 may be configured to determine the transmission power P_last_preamble of the RA preamble according to the following equation.

P_last_preamble = min (P _max , PL + _{Po_pre} + Δ_preamble + (N_pre−1) × dp_rampup)

Here, P _max is the maximum transmission power of the mobile station UE. PL is the propagation loss calculated by the propagation loss calculation unit 11. P _{o_pre} is a parameter related to power control in the physical random access channel acquired by the parameter acquisition unit 12. Δ_preamble is a power offset determined by the format of the random preamble. N_pre is the number of transmissions of the random preamble. For example, when performing the first transmission, N_pre = 1, and when performing the second transmission, N_pre = 2,. dp_rampup corresponds to the amount of ramping when power ramping is performed. The expression “(N_pre−1) × dp_rampup)” means that transmission is performed with a transmission power that is larger by dp_rampup than the previous transmission.

  Note that, as shown in the above formula, the initial transmission power determination unit 13 not only determines the transmission power at the time of the initial transmission of the RA preamble, but also determines the transmission power at the time of the retransmission of the RA preamble.

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

  The RA preamble transmission unit 14 is configured to start transmission of the RA preamble with the transmission power determined by the initial transmission power determination unit 13. In this case, in the first transmission of the RA preamble, the transmission power is calculated with N_pre = 1 in the above equation.

  In addition, when the RA preamble transmission unit 14 does not receive an RA response to the RA preamble, the RA preamble transmission unit 14 is configured to retransmit the RA preamble after increasing the transmission power of the RA preamble from the transmission power of the first transmission. In this case, the initial transmission power determining unit 13 calculates the transmission power as N_pre = 2, 3, 4,.

  The data signal transmission unit 15 is configured to transmit a data signal via a physical uplink shared channel (PUSCH) specified by the downlink control information received from the radio base station eNB.

  More specifically, the data signal transmission unit 15 is designated by the downlink control information addressed to the own station included in the RA response, that is, the uplink scheduling grant, acquired by the PDCCH / PDSCH reception unit 16 described later. A data signal is configured to be transmitted via a physical uplink shared channel (PUSCH).

  In this case, the physical uplink shared channel (PUSCH) may be referred to as “RACH Message 3” or “Random Access Message 3”.

  The PDCCH / PDSCH receiving unit 16 receives a PDCCH that is a downlink control channel and a shared channel in the downlink.

  More specifically, when transmitting the RA preamble, the PDCCH / PDSCH receiving unit 16 receives an RA response corresponding to the RA preamble. That is, when the downlink control information for the RA response, that is, downlink scheduling information is received and the downlink scheduling information is successfully received, the RA response specified by the downlink scheduling information is The mapped physical downlink shared channel (PDSCH) is decoded. Then, the information on the RA response after decoding is given to the parameter acquisition unit 12 and the data signal transmission unit 15.

  As illustrated in FIG. 3, the radio base station eNB according to the present embodiment includes an interference power measurement unit 21, a PBCH transmission unit 22, a PDCCH / PDSCH transmission unit 23, and a PUSCH reception unit 24.

  The interference power measurement unit 21 is configured to measure interference power in a physical random access channel (PRACH).

  For example, the interference power measurement unit 21 obtains signal power including all of thermal noise in the frequency band of the physical random access channel (PRACH), signal power of the interference signal, and signal power of the desired signal, thereby obtaining the interference power. May be configured to measure. Here, the desired signal may be, for example, a random preamble signal actually received by the radio base station eNB.

  Alternatively, for example, the interference power measurement unit 21 may be configured to measure the interference power by acquiring thermal noise in the frequency band of the physical random access channel (PRACH) or signal power of the interference signal. .

  In this case, for example, the interference power measurement unit 21 obtains the desired signal from the signal power including all of the thermal noise, the signal power of the interference signal, and the signal power of the desired signal in the frequency band of the physical random access channel (PRACH) described above. The signal power of thermal noise and interference signals in the frequency band of the physical random access channel (PRACH) may be acquired by subtracting the signal power of.

Then, the interference power measurement unit 21 may calculate a parameter P _{o_pre} related to power control in the physical random access channel (PRACH) based on the interference power and the target quality of the random preamble. More specifically, the interference power measurement unit 21 may calculate a parameter P _{o_pre} related to power control in the physical random access channel (PRACH) as follows.

P _{o_pre} = (interference power) + (target quality of random preamble)

  The PBCH transmission unit 22 is configured to notify parameters related to power control in the physical random access channel (PRACH) calculated by the interference power measurement unit 21, using the MIB transmitted by the six physical resource blocks of the PBCH. Has been. The PBCH is mapped to the center of the system band.

Specifically, the PBCH transmission unit 22 has a change in interference power in the physical random access channel (PRACH) measured by the interference power measurement unit 21, and as a result, a parameter P _{o_pre} related to power control has changed. Only, the contents of the MIB are updated, and the parameter P _{o_pre} related to the power control after the change is notified.

  The PDCCH transmission unit / PDSCH 23 is configured to transmit downlink control information using a physical downlink control channel (PDCCH).

  Further, the PDCCH transmission unit / PDSCH 23 is configured to transmit a data signal using a physical downlink shared channel (PDSCH).

  For example, the PDCCH transmission unit / PDSCH 23 performs the above-described scheduling according to the RA preamble from the mobile station UE, and uses the physical downlink control channel (PDCCH) to downlink control information (downlink) for RA response. Scheduling information) and an RA response is transmitted using a physical downlink shared channel (PDSCH). The RA response is mapped with an uplink scheduling grant for the physical uplink shared channel (PUSCH).

  Further, the PDCCH transmission unit / PDSCH 23 is configured to notify parameters related to power control in the physical random access channel (PRACH) calculated by the interference power measurement unit 21 using the physical downlink control channel (PDCCH). May be.

Specifically, the PDCCH transmission unit / PDSCH 23 has a change in interference power in the physical random access channel (PRACH) measured by the interference power measurement unit 21, and as a result, a parameter P _{o_pre} related to power control has changed. Only in this case, the parameter P _{o_pre} related to the power control after the change is notified using the physical downlink control channel (PDCCH).

  Here, it is assumed that a special RNTI (Radio Network Temporary Identifier) is assigned to the physical downlink control channel (PDCCH) for notifying the above-described parameters related to power control.

  The PUSCH receiving unit 24 is configured to receive a data signal transmitted from the mobile station UE via a physical uplink shared channel (PUSCH).

  For example, when an RA response is transmitted to the mobile station UE, the PUSCH receiving unit 24 receives a physical uplink shared channel (PUSCH) that specifies the transmission using the RA response.

(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, in step S1001, the mobile station UE calculates a propagation loss in the downlink based on the common pilot signal transmitted from the radio base station at a predetermined timing.

In step S1002, when the radio base station eNB detects a change in interference power in the PRACH, that is, as a result, when it becomes necessary to change the parameter P _{o_pre} related to power control, the MIB or physical downlink control is performed. A parameter related to power control in the physical random access channel (PRACH) after the change is notified using the channel (PDCCH).

  When the mobile station UE determines that it is necessary to transmit the RA preamble (that is, when it is necessary to transmit a data signal via the physical uplink shared channel (PUSCH)), in step S1003, in step S1001 The transmission power of the RA preamble to be newly transmitted is determined based on the latest downlink propagation loss calculated in step 1 and the parameters related to power control in the latest physical random access channel (PRACH) acquired in step S1002.

  In step S1004, the mobile station UE starts transmission of the RA preamble with the determined transmission power.

  In step S1005, the radio base station eNB transmits an uplink scheduling grant using an RA response to the mobile station UE according to the received RA preamble. In this case, the uplink scheduling grant is mapped to the PDSCH.

  Thereafter, the mobile station UE transmits a data signal via the physical uplink shared channel (PUSCH) specified by the received uplink scheduling grant.

(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 immediately controls the power in the physical random access channel (PRACH) via the MIB or the physical downlink control channel (PDCCH). The parameter regarding can be notified to the mobile station UE.

(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 mobile 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.

Explanation of symbols

UE ... mobile station 11 ... propagation loss calculation unit 12 ... parameter acquisition unit 13 ... initial transmission power determination unit 14 ... RA preamble transmission unit 15 ... data signal transmission unit 16 ... PDCCH / PDSCH reception unit eNB ... radio base station 21 ... interference power Measuring unit 22 ... PBCH transmitting unit 23 ... PDCCH / PDSCH transmitting unit 24 ... PUSCH receiving unit

Claims (6)

A mobile communication method for performing communication using a physical random access channel in uplink,
The mobile station calculates a propagation loss in the downlink based on the common pilot signal transmitted from the radio base station;
The radio base station measuring interference power in a physical random access channel;
The radio base station notifying a parameter related to power control in the physical random access channel calculated based on the interference power using MIB;
The mobile station determines transmission power of a random access preamble to be newly transmitted based on the calculated propagation loss in the downlink and a parameter related to power control in the physical random access channel notified by the radio base station. When,
And a step of starting transmission of a random access preamble with the determined transmission power. A mobile communication method for performing communication using a physical random access channel in uplink,
The mobile station calculates a propagation loss in the downlink based on the common pilot signal transmitted from the radio base station;
The radio base station measuring interference power in a physical random access channel;
The radio base station notifying a parameter related to power control in the physical random access channel calculated based on the interference power to the mobile station using a physical downlink control channel;
The mobile station determines transmission power of a random access preamble to be newly transmitted based on the calculated propagation loss in the downlink and a parameter related to power control in the physical random access channel notified by the radio base station. When,
And a step of starting transmission of a random access preamble with the determined transmission power. A mobile station that performs communication using a physical random access channel in the uplink,
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 parameter acquisition unit configured to acquire parameters related to power control in the physical random access channel notified by the radio base station using MIB;
Based on the calculated propagation loss in the downlink and parameters related to power control in the physical random access channel notified by the radio base station, the transmission power of the random access preamble to be newly transmitted is determined. An initial transmission power determination unit;
A mobile station comprising: a random access preamble transmission unit configured to start transmission of a random access preamble with the determined transmission power. A mobile station that performs communication using a physical random access channel in the uplink,
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 parameter acquisition unit configured to acquire a parameter related to power control in a physical random access channel notified by the radio base station using a physical downlink control channel;
Based on the calculated propagation loss in the downlink and parameters related to power control in the physical random access channel notified by the radio base station, the transmission power of the random access preamble to be newly transmitted is determined. An initial transmission power determination unit;
A mobile station comprising: a random access preamble transmission unit configured to start transmission of a random access preamble with the determined transmission power. A radio base station used in a mobile communication method for performing communication using a physical random access channel in uplink,
An interference power measurement unit configured to measure interference power in a physical random access channel;
A radio base station comprising: a parameter notifying unit configured to notify a parameter related to power control in the physical random access channel calculated based on the interference power using MIB. A radio base station used in a mobile communication method for performing communication using a physical random access channel in uplink,
An interference power measurement unit configured to measure interference power in a physical random access channel based on a random access preamble transmitted from a mobile station;
A parameter notification unit configured to notify a parameter related to power control in the physical random access channel calculated based on the interference power to the mobile station using a physical downlink control channel; A wireless base station characterized by that.

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