JP2010081171A - Transmission and reception apparatus, mobile station device, mobile communication system, and power control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cause an initial preamble transmitting power to approach an appropriate value. <P>SOLUTION: A received power determination section 103 measures a receiving power of an announcement signal received from a base station apparatus 200, and a base station information acquirement section 104 acquires a transmitting power and a desired receiving power from the announcement signal. A transmitting power calculation section 105 adds the transmitting power, the desired receiving power and a transmitting power correction value stored in a correction value storing section 106 and subtracts the receiving power from the result to calculate a transmitting power of its own device. A transmission section 108 transmits a transmission signal to the base station apparatus 200 with the calculated transmitting power, and a response signal reception section 109 receives a response signal in response to the transmission signal. In the case where the response signal indicates transmission failure, or in the case where no response signal is received, the transmission signal is retransmitted using a power obtained by adding a ramp-up power to a previous transmitting power as a transmitting power. In the case of the response signal indicating transmission success, a transmitting power correction value is determined based on the number of transmission failures of the transmission signal, and the value is registered in the correction value storing section 106. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transmission / reception device, a mobile station device, a mobile communication system, and a power control method, and more particularly to a transmission / reception device, a mobile station device, a mobile communication system, and a power control method for performing open-loop transmission power control.

  In uplink communication of a mobile communication system, when a mobile station apparatus transmits a signal with the same transmission power, a transmission signal of a mobile station apparatus close to the base station apparatus is more transmitted in a base station apparatus than a transmission signal of a distant mobile station apparatus Received with large signal power. For this reason, the transmission signal of the near mobile station apparatus becomes a strong interference wave with respect to the transmission signal of the far mobile station apparatus, which hinders reception of the transmission signal of the far mobile station apparatus. Therefore, in order to correctly demodulate each transmission signal in the base station apparatus, it is necessary to align the signal reception level in the base station apparatus. Therefore, conventionally, uplink communication from a mobile station apparatus to a base station apparatus using a random access physical channel (PRACH: Physical Random Access Channel), which is a common channel of a mobile phone system called LTE (Long Term Evolution) When transmitting a preamble (reference signal), transmission power control based on open loop transmission power control is used (for example, Non-Patent Document 1). The preamble is a signal for synchronizing reception when starting random access communication.

A conventional random access communication method will be described below.
When starting the random access communication with the base station apparatus, the mobile station apparatus transmits a preamble to the base station with a transmission power value calculated based on information obtained from the broadcast signal transmitted from the base station apparatus. The broadcast signal is a signal including information indicating transmission power Tx _eNB [dBm] and desired received power DRx _eNB [dBm] of the base station apparatus. Mobile station apparatus determines the transmission power value _Tx UE of the apparatus [dBm] by calculating the _{Tx UE = DRx eNB + Pathloss +} n × Step.

However, Pathloss [dBm] is a downlink transmission line loss value, and is obtained by subtracting the reception power Rx _UE of the broadcast signal in the mobile station apparatus from the transmission power Tx _eNB of the base station apparatus. N indicates the number of retransmissions of the preamble. Step [dBm] indicates the ramp-up power at the time of preamble retransmission.
Accordingly, the transmission power is increased every time the retransmission of the preamble is repeated (for example, Non-Patent Document 2).

However, since the desired received power DRx _eNB is common to the mobile station apparatuses in the cell, the set value is not necessarily an appropriate value for each terminal, and unnecessary preamble retransmission occurs. As a technique for solving this problem, the technique of Patent Document 1 is disclosed.
According to Patent Document 1, the difference between the initial transmission power of the preamble and the transmission power when the preamble transmission is successful is used as a correction value, and the value obtained by adding the correction value to the initial transmission power value at the start of the next random access communication is Transmission is performed as the initial transmission power value. Thereby, since it can transmit with big transmission power at the time of next preamble transmission, the frequency | count of resending can be reduced.
JP 2007-97055 A 3GPP TS36.213 V8.3.0 (2008-05), “Physical layer procedures” R1-080159, “L1 eNB measurements on PRACH resources”, 3GPP, TSG RAN WG1 Meeting # 51, Seville, Spain, January 14-January 18, 2008

  However, since the technique described in Patent Document 1 does not take into consideration that correction is performed with the transmission line loss at each time when the preamble is retransmitted, optimal power control cannot be performed.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a transmission / reception device, a mobile station device, a mobile communication system, and a power control method for bringing the initial preamble transmission power close to an optimum value. is there.

  The present invention has been made to solve the above-described problem, and is a transmission / reception apparatus that performs wireless communication with a base station apparatus that transmits a notification signal indicating transmission power and desired reception power from the own apparatus, A broadcast signal receiving unit that receives the broadcast signal, a received power measuring unit that measures received power of the received broadcast signal, and a base station that acquires the transmission power and the desired received power from the received broadcast signal An information acquisition unit, a correction value storage unit that stores a transmission power correction value calculated based on the number of transmission failures of past transmission signals, and adds the transmission power, the desired received power, and the transmission power correction value. A transmission power calculation unit that calculates transmission power from the own device by subtracting the received power, a transmission unit that transmits a transmission signal to the base station device with the calculated transmission power, and from the base station device Send A response signal receiving unit that receives a response signal to the transmitted signal, a response determining unit that determines whether the received response signal indicates successful transmission of the transmission signal, and the response signal is successful transmission of the transmission signal A ramp-up unit that transmits a transmission signal through the transmission unit using a transmission power as a power obtained by adding a predetermined ramp-up power to the transmission power, and the response signal of the transmission signal When it is determined that transmission is successful, the transmission power correction value is determined based on the transmission power correction value and the number of times that the response signal is determined not to indicate successful transmission of the transmission signal, and the correction value And a correction value calculation unit registered in the storage unit.

  Further, the response determination unit of the present invention determines that the transmission signal is not successfully transmitted when the response signal is not received.

  Further, the correction value calculation unit according to the present invention is configured so that the transmission power is based on a value obtained by subtracting a predetermined target number of retransmissions from the number of times that the response signal is determined not to indicate successful transmission of the transmission signal. A correction value is determined.

  Further, the present invention is a mobile station device equipped with the above-described transmission / reception device.

  In addition, the present invention includes a base station device that transmits a broadcast signal indicating transmission power and desired reception power from the own device, and a mobile station device that performs wireless communication with the base station. A mobile communication system.

  Also, the present invention performs wireless communication with a base station apparatus that transmits a broadcast signal indicating transmission power from the own apparatus and desired reception power, and is calculated based on the number of transmission failures of past transmission signals. A power control method using a transmission / reception device including a correction value storage unit that stores a correction value, wherein a notification signal reception unit receives the notification signal, and a received power measurement unit receives the received notification signal. The base station information acquisition unit acquires the transmission power and the desired reception power from the received broadcast signal, and the transmission power calculation unit includes the transmission power, the desired reception power, and the transmission power correction. The transmission power from the own device is calculated by adding the value and subtracting the received power, the transmission unit transmits the transmission signal to the base station device with the calculated transmission power, and the response signal receiving unit is From the base station device The response determination unit receives a response signal to the transmitted signal, the response determination unit determines whether the received response signal indicates successful transmission of the transmission signal, and the ramp-up unit determines that the response signal is the transmission signal. When the transmission signal is determined not to indicate successful transmission, a transmission signal is transmitted through the transmission unit using the transmission power plus a predetermined ramp-up power as the transmission power, and the correction value calculation unit includes the response signal. Determines that the transmission power correction value is based on the transmission power correction value and the number of times that the response signal is determined not to indicate transmission success of the transmission signal. Then, it is registered in the correction value storage unit.

  Further, the response determination unit of the present invention determines that the transmission signal is not successfully transmitted when the response signal is not received.

  Further, the correction value calculation unit according to the present invention is configured so that the transmission power is based on a value obtained by subtracting a predetermined target number of retransmissions from the number of times that the response signal is determined not to indicate successful transmission of the transmission signal. A correction value is determined.

  The present invention is also a method for performing open-loop transmission power control between a mobile station apparatus and a base station apparatus having a transmission / reception apparatus for open-loop transmission power control, wherein the mobile station apparatus is connected to the base station apparatus. When starting random access communication, a transmission power value obtained by adding a correction value that can take a positive or negative value is used as the transmission power for transmitting a preamble, and the correction value is the value of the previous random access communication. It is determined according to the number of preambles transmitted at the time.

  The correction value of the present invention is characterized in that it takes a negative value when the number of random accesses is small.

  The correction value of the present invention has a maximum positive value.

  According to the present invention, the transmission power correction value is calculated based on the number of past transmission signal transmission failures, and the initial transmission power is calculated using the transmission power correction value. As a result, a transmission power correction value that does not depend on the transmission line loss can be generated, and optimal power control can be performed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic block diagram showing a configuration of a wireless communication system according to an embodiment of the present invention.
The communication system according to the present embodiment includes a transmission / reception device 100 and a base station device 200. The transmission / reception device 100 is mounted on a mobile station device that communicates with the base station device 200 and performs transmission power control. The transmission / reception apparatus 100 transmits a preamble to the base station apparatus 200 when starting random access communication. Base station apparatus 200 transmits a broadcast signal indicating transmission power and desired reception power from the base station apparatus 200.
The transmission / reception apparatus 100 includes an antenna 101, a broadcast signal reception unit 102, a reception power measurement unit 103, a base station information acquisition unit 104, a transmission power calculation unit 105, a correction value storage unit 106, and a data processing unit 107. , Transmission unit 108, response signal reception unit 109, response determination unit 110, correction value calculation unit 111, retransmission number storage unit 112, and target retransmission number storage unit 113. In addition, the component of the transmission / reception apparatus 100 may be combined with the other component of the mobile station apparatus as needed.

Broadcast signal receiving section 102 receives a broadcast signal from base station apparatus 200 via antenna 101.
Received power measuring section 103 measures the received power of the broadcast signal received by broadcast signal receiving section 102.
Base station information acquisition section 104 acquires base station information indicating transmission power and desired reception power from the notification signal received by notification signal reception section 102.
The transmission power calculation unit 105 calculates the transmission power of the preamble based on the acquired base station information, the reception power of the broadcast signal, and the transmission power correction value stored in the correction value storage unit 106.
The data processing unit 107 generates a preamble signal.
Transmitting section 108 transmits a preamble to base station apparatus 200 with transmission power calculated via antenna 101.
Response signal receiving section 109 receives a response signal from base station apparatus 200 via antenna 101.
The response determination unit 110 determines whether the received response signal indicates successful transmission of the transmission signal.
The correction value calculation unit 111 is stored in the transmission power correction value stored in the correction value storage unit 106, the retransmission number of preambles stored in the retransmission number storage unit 112, and the target retransmission number storage unit 113. A new transmission power correction value is calculated based on the target value of the number of preamble retransmissions, and is registered in the correction value storage unit 106.
The target retransmission number storage unit 113 stores a target value for a predetermined number of retransmissions.

This point will be described in detail below. The transmission power calculation unit 105 adds the transmission power acquired by the base station information acquisition unit 104, the desired reception power, and the transmission power correction value stored in the correction value storage unit 106, and the reception power measured by the reception power measurement unit 103. The transmission power of the preamble is calculated by subtracting the power.
Response signal receiving section 109 receives a response signal for the preamble from base station apparatus 200. The response determination unit 110 determines whether or not the received response signal indicates completion of preamble reception. When it is determined that the preamble reception is not completed, the transmission power calculation unit 105 retransmits the preamble via the transmission unit 108 using the power obtained by adding a predetermined ramp-up power to the previous transmission power as the transmission power. When it is determined that the preamble reception is complete, the correction value calculation unit 111 calculates a transmission power correction value based on the number of times the preamble transmission is determined to be unsuccessful, and registers the transmission power correction value in the correction value storage unit 106.
As a result, processing for bringing the initial preamble transmission power closer to the optimum value is performed.

The operation of the transmission / reception device 100 according to the present embodiment will be described below.
FIG. 2 is a flowchart showing the operation of the transmission / reception device 100.
First, the notification signal receiving unit 102 of the transmission / reception device 100 receives a notification signal transmitted from the base station device 200 via the antenna 101 (step S1). The broadcast signal is transmitted by broadcast (by broadcast communication) using a broadcast channel that is a one-way channel from base station apparatus 200 to transmission / reception apparatus 100. The broadcast signal includes control information such as transmission power from base station apparatus 200 and desired reception power of base station apparatus 200. When receiving the broadcast signal, the received power measuring section 103 measures the received power Rx _UE [dBm] of the received broadcast signal (step S2). When receiving the broadcast signal, the base station information acquisition unit 104 acquires base station information indicating the transmission power Tx _eNB [dBm] and the desired received power DRx _eNB [dBm] described above from the broadcast signal (step S3). .

When the base station information indicating the reception power Rx _UE and the transmission power Tx _{eNB of the} broadcast signal and the desired reception power DRx _eNB is acquired, the transmission power calculation unit 105 calculates the transmission power Tx _{UE of the} preamble (step S4). The transmission power Tx _UE [dBm] adds the transmission power Tx _eNB acquired by the data processing unit 104, the desired received power DRx _eNB, and the transmission power correction value off _UE [dBm] stored in the correction value storage unit 106. Calculation is performed by subtracting the received power Rx _UE measured by the received power measuring unit 103. That is,
Tx _UE = DRx _eNB + Tx _eNB + off _UE− Rx _UE (1)
Calculate
The uplink interference power may be estimated based on the interference power of the received broadcast signal and added to the transmission power Tx _UE .

When the transmission power is calculated, the transmission power calculation unit 105 notifies the transmission unit 108 of the transmission power Tx _UE, and notifies the data processing unit 107 of the completion of calculation of the transmission power. Upon receiving the notification of completion of transmission power calculation, the data processing unit 107 generates a preamble signal and outputs it to the transmission unit 108. When acquiring the preamble signal, the transmission unit 108 transmits the preamble to the base station apparatus 200 with the transmission power Tx _UE calculated via the antenna 101 (step S5).

  When the base station apparatus 200 receives the preamble from the transmission / reception apparatus 100, the base station apparatus 200 transmits a response signal indicating whether or not the preamble has been received to the transmission / reception apparatus 100 at a predetermined timing. That is, the base station apparatus 200 transmits ACK (Acknowledgement) when the preamble can be received. Further, when the preamble can be received but the current random access is not accepted, a NACK (Negative Acknowledgement) is transmitted. If the preamble cannot be received, no response signal is transmitted.

When the preamble is transmitted in step S5, the response signal receiving unit 109 receives the response signal from the base station apparatus 200 via the antenna 101 (step S6). When receiving the response signal from the base station apparatus 200, the response determination unit 110 determines whether or not the received response signal is ACK (step S7). When the received response signal is NACK or when the response signal cannot be received, the transmission power calculation unit 105 adds 1 to the number of retransmissions n stored in the number of retransmissions storage unit 112 (step S8). Note that the number of retransmissions n is initialized to 0 at the start of the random access procedure. Next, the transmission power calculation unit 105 adds a predetermined ramp-up power Step [dBm] to the previously calculated transmission power Tx _UE , and sets this as the preamble transmission power Tx _UE (step S9). When the transmission power Tx _UE is calculated, the process returns to step S5, and the preamble is transmitted again with the transmission power Tx _UE obtained by adding the ramp-up power.

When it is determined that the response signal received in step S7 is ACK, the correction value calculation unit 111 calculates a transmission power correction value (step S10). The correction value calculation unit 111 sets the transmission power correction value off _UE to a value obtained by subtracting the target value m of the number of retransmissions stored in the target retransmission number storage unit 114 from the number of retransmissions n stored in the retransmission number storage unit 112. It is calculated by multiplying the up power Step and adding the previous transmission power correction value off _UE ′ to the obtained value. That is,
off _UE = (n−m) × Step + off _UE ′ (2)
Calculate by calculating.
Here, the reason why the transmission power correction value off _UE is calculated using Equation (2) will be described. This equation means that transmission power is controlled so that ACK is received from the base station apparatus 200 in the (m + 1) th preamble transmission. The reason for setting the transmission success in m + 1 times is to average the preamble transmission success probabilities of all the transmitting / receiving apparatuses 100 in the cell. Here, the cell is a radio wave reachable range of the base station apparatus 200. Usually, the number of transmitting / receiving apparatuses 100 that transmit a preamble to the base station apparatus 200 is not one, but a plurality of transmitting / receiving apparatuses 100 existing in the same cell transmit the preamble.

Although it is preferable that the number of preamble transmissions is small, it is not good to succeed once. When the transmission power correction value off _UE is set such that the number of preamble transmissions is successful once, the transmission power correction value off _UE increases. When all the transmission / reception apparatuses 100 in the cell increase the transmission power correction value off _UE , the collision probability of random access increases, and as a result, the average value of the success probability of preamble transmission in the cell decreases. Therefore, in view of the situation in the cell, in order to set the number of trials to increase the average value of the success probability, and to distribute and average the occurrence of transmission of the preamble, the transmission power correction value off _UE is set using the above-described equation. calculate.

Next, the transmission power correction value will be specifically described.
FIG. 3 and FIG. 4 are diagrams illustrating the relationship between the number of preamble retransmissions at the time of successful random access and the initial preamble transmission power in the next random access.
Hereinafter, a case where the target value m = 2 of the number of retransmissions and the transmission power correction value off _UE = 0 will be described.

FIG. 3A shows a case where an ACK is received from the base station apparatus 200 in the first preamble transmission, that is, the number of retransmissions n = 0. At this time, as shown in FIG. 3A, the transmission / reception device 100 receives an ACK from the base station device 200 in the first preamble transmission.
However, since the target value m of the number of retransmissions is 2, the transmission power from the transmission / reception device 100 at this time is excessive. Therefore, it is necessary to set the transmission power correction value in the direction of decreasing the transmission power so that the ACK is received from the base station apparatus 200 by the second preamble retransmission at the start of the next random access. At this time, since n = 0 and m = 2, nm is −2, and the transmission power correction value off _UE is a negative value. Thereby, as shown to Fig.3 (a), the transmission power at the time of preamble transmission at the time of the next random access start can be made small.

FIG. 3B shows a case where ACK is received from the base station apparatus 200 in the first preamble retransmission, that is, the number of retransmissions n = 1. At this time, as shown in FIG. 3B, the transmission / reception device 100 fails to transmit the first preamble, and performs the first preamble retransmission with power obtained by adding ramp-up power to transmission power.
However, since the target value m of the number of retransmissions is 2, the transmission power from the transmission / reception device 100 at this time is excessive. Therefore, it is necessary to set the transmission power correction value in the direction of decreasing the transmission power so that the ACK is received from the base station apparatus 200 by the second preamble retransmission at the start of the next random access. At this time, since n = 1 and m = 2, nm is −1, and the transmission power correction value off _UE is a negative value. Thereby, as shown in FIG.3 (b), the transmission power at the time of preamble transmission at the time of the next random access start can be made small.

FIG. 4A shows a case where ACK is received from the base station apparatus 200 in the second preamble retransmission, that is, the number of retransmissions n = 2. At this time, as shown in FIG. 4A, the transmission / reception apparatus 100 fails to transmit the first preamble, and performs the first preamble retransmission with the power obtained by adding the ramp-up power to the transmission power. The first preamble retransmission also fails, and the second preamble retransmission is performed with power obtained by further adding ramp-up power to the transmission power at the time of the first preamble retransmission.
At this time, since the target value m = 2 is set, the transmission power from the transmitting / receiving apparatus 100 at this time is appropriate. Therefore, the preamble transmission at the start of the next random access needs to be transmitted with the same transmission power. At this time, since n = 2 and m = 2, nm is 0, and the transmission power correction value off _UE is 0. As a result, as shown in FIG. 4A, it is possible to transmit with appropriate transmission power even during preamble transmission at the start of the next random access.

Next, the case where ACK is received from the base station apparatus 200 in the third and subsequent preamble retransmissions will be described.
FIG. 4B shows a case where ACK is received from the base station apparatus 200 by the third preamble retransmission, that is, the number of retransmissions n = 3. At this time, as shown in FIG. 4B, the transmission / reception device 100 fails in the first preamble transmission and the first and second preamble retransmissions, and increases the ramp-up power to the transmission power during the second preamble retransmission. Further, the third preamble retransmission is performed with the added power.
At this time, since the target value m = 2 of the number of retransmissions is set, the transmission power from the transmission / reception device 100 at this time is too small. Therefore, it is necessary to set the transmission power correction value in the direction of increasing the transmission power so that the ACK is received from the base station apparatus 200 by the second preamble retransmission at the start of the next random access. At this time, since n = 3 and m = 2, nm is 1, and the transmission power correction value off _UE is a positive value. Thereby, as shown in FIG.4 (b), the transmission power at the time of preamble transmission at the time of the next random access start can be enlarged. Similarly, when n> 3, it is possible to increase the transmission power at the time of preamble transmission at the start of the next random access.

  Thus, according to the present embodiment, the transmission power correction value is calculated based on the number of transmission failures of the past transmission signal, and the initial transmission power is calculated using the transmission power correction value. As a result, a transmission power correction value that does not depend on the transmission line loss can be generated, and optimal power control can be performed.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to
For example, in the present embodiment, when the transmission power correction value off _UE is calculated, the correction value calculation unit 111 calculates the off _UE using the equation (2) of off _UE = (n−m) × Step + off _UE ′. As explained, but not limited to this, the maximum transmission power correction value off _max is defined so as not to increase the initial transmission power too much,
off _UE = min (off _max , (nm) × Step + off _UE ′) (3)
(3) may be used. Note that min (A, B) indicates that the smaller one of A and B is selected.

In the present embodiment, when the transmission power correction value off _UE is calculated, the correction value calculation unit 111 calculates the off _UE by using the equation (2) of “off _UE = (nm) × Step + off _UE ′”. However, the present invention is not limited to this. For example, when m = 0, that is, when setting is made so that ACK is received from the base station apparatus 200 in the first preamble transmission, the correction value does not become a negative value in the above equation. That is, even when the transmission power Tx _UE is excessive, it cannot be corrected in the direction of decreasing the transmission power Tx _UE . Therefore, when n = 0,
off _UE = −1 × Step + off _UE ′ (4)
And if n ≧ 1,
off _UE = n × Step + off _UE ′ (5)
Thus, an equation for calculating the transmission power correction value off _UE in the direction of decreasing the transmission power Tx _UE when the ACK is received from the base station apparatus 200 in the first preamble transmission may be used.
Moreover, the success probability of preamble transmission is lowered by taking a negative correction value. Therefore, when n = 0, for example, off _UE = −1 × (Step / 2) + off _UE ′ (6)
The degree of decrease may be moderated by using the equation.

  In the present embodiment, the case where the target value m of the number of retransmissions is a predetermined value has been described. However, the present invention is not limited to this. For example, the base station apparatus 200 includes the target value m in the broadcast signal and transmits it. Alternatively, the transmission / reception apparatus 100 may automatically determine based on the history of the number of retransmissions in the past.

FIG. 1 is a schematic block diagram showing a configuration of a wireless communication system according to an embodiment of the present invention. 3 is a flowchart showing the operation of the transmission / reception device 100. It is a figure which shows the relationship between the frequency | count of preamble resending at the time of succeeding in random access, and the first preamble transmission power in the next random access. It is a figure which shows the relationship between the frequency | count of preamble resending at the time of succeeding in random access, and the first preamble transmission power in the next random access.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Transmission / reception apparatus 101 ... Antenna 102 ... Communication part 103 ... Reception power measurement part 104 ... Data processing part 105 ... Transmission power calculation part 106 ... Memory | storage part 107 ... Data processing part 108 ... Transmission part 109 ... Response signal receiving part 110 ... Response Determination unit 111 ... Correction value storage unit 112 ... Retransmission count storage unit 113 ... Target retransmission count storage unit 200 ... Base station apparatus

Claims (11)

A transmitting / receiving apparatus that performs wireless communication with a base station apparatus that transmits a notification signal indicating transmission power and desired reception power from the own apparatus,
A notification signal receiver for receiving the notification signal;
A received power measuring unit for measuring received power of the received broadcast signal;
A base station information acquisition unit that acquires the transmission power and the desired reception power from the received notification signal;
A correction value storage unit for storing a transmission power correction value calculated based on the number of transmission failures of past transmission signals;
A transmission power calculation unit that adds the transmission power, the desired reception power, and the transmission power correction value, and subtracts the reception power to calculate transmission power from the own device;
A transmission unit for transmitting a transmission signal to the base station apparatus with the calculated transmission power;
A response signal receiving unit that receives a response signal to the transmitted transmission signal from the base station device;
A response determination unit for determining whether or not the received response signal indicates successful transmission of the transmission signal;
A ramp-up unit that transmits a transmission signal via the transmission unit using a power obtained by adding a predetermined ramp-up power to the transmission power as transmission power when it is determined that the response signal does not indicate successful transmission of the transmission signal When,
When it is determined that the response signal indicates successful transmission of the transmission signal, the transmission power correction is performed based on the transmission power correction value and the number of times that the response signal is determined not to indicate successful transmission of the transmission signal. A correction value calculation unit that determines a value and registers the value in the correction value storage unit;
A transmission / reception apparatus comprising:   The transmission / reception apparatus according to claim 1, wherein the response determination unit determines that the transmission signal is not successfully transmitted when the response signal is not received.   The correction value calculation unit determines the transmission power correction value based on a value obtained by subtracting a predetermined retransmission target value from the number of times that the response signal is determined not to indicate successful transmission of the transmission signal. The transmission / reception apparatus according to claim 1, wherein the transmission / reception apparatus is a transmission apparatus.   A mobile station apparatus comprising the transmitting / receiving apparatus according to any one of claims 1 to 3. A base station device that transmits a broadcast signal indicating transmission power and desired reception power from the own device;
The mobile station apparatus according to claim 4, which performs radio communication with the base station;
A mobile communication system comprising: Correction for storing a transmission power correction value calculated based on the number of transmission failures of past transmission signals by performing wireless communication with a base station device that transmits a broadcast signal indicating transmission power and desired reception power from the own device A power control method using a transmission / reception device including a value storage unit,
The notification signal receiving unit receives the notification signal,
The received power measuring unit measures the received power of the received notification signal,
The base station information acquisition unit acquires the transmission power and the desired reception power from the received notification signal,
The transmission power calculation unit adds the transmission power, the desired reception power, and the transmission power correction value, and calculates the transmission power from the own device by subtracting the reception power,
The transmission unit transmits a transmission signal to the base station apparatus with the calculated transmission power,
The response signal receiving unit receives a response signal for the transmitted signal transmitted from the base station device,
The response determination unit determines whether or not the received response signal indicates successful transmission of the transmission signal,
When it is determined that the response signal does not indicate successful transmission of the transmission signal, the ramp-up unit transmits the transmission signal via the transmission unit as transmission power obtained by adding a predetermined ramp-up power to the transmission power. Send
When it is determined that the response signal indicates successful transmission of the transmission signal, the correction value calculation unit determines the transmission power correction value and the number of times that the response signal is determined not to indicate successful transmission of the transmission signal. Based on the transmission power correction value and registering in the correction value storage unit,
A power control method characterized by the above.   The power control method according to claim 6, wherein the response determination unit determines that the transmission signal is not successfully transmitted when the response signal is not received.   The correction value calculation unit determines the transmission power correction value based on a value obtained by subtracting a predetermined retransmission target value from the number of times that the response signal is determined not to indicate successful transmission of the transmission signal. The power control method according to claim 6 or 7, wherein: A method for performing open loop transmission power control between a mobile station apparatus and a base station apparatus having a transmission / reception apparatus for open loop transmission power control,
When the mobile station device starts random access communication with the base station device, the mobile station device uses a transmission power value to which a correction value that can take a positive or negative value is added as transmission power for transmitting a preamble, The correction value is determined according to the number of preambles transmitted in the previous random access communication.   The method according to claim 9, wherein the correction value takes a negative value when the number of random accesses is small.   The method of claim 10, wherein the correction value has a maximum positive value.

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