JP2011211268A - Radio communication device in radio communication system and transmission power control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication device capable of evading communication interruption no matter at what timing the interference of an individual channel and a common channel occurs, and its transmission power control method.SOLUTION: The radio communication device includes: closed loop control units (102, 202) for measuring the SIR of signals received from the other radio communication devices (100, 200) through the individual channel (DPCH) and controlling the transmission power of the other radio communication devices using TPC bits so that the measured SIR approaches an SIR target value (105); and common channel confirmation control units (103, 203) for confirming the presence/absence of the interference of the individual channel and the common channel when the measured SIR is higher than the SIR target value, and suppressing the transmission of the TPC bits for lowering the transmission power of the other radio communication devices to the closed loop control units when CPICH-RSCP is equal to or higher than a predetermined value and CPICH-Ec/No is equal to or lower than a predetermined threshold when the interference occurs.

Description

  The present invention relates to a radio communication system having a transmission power control function, and more particularly to a radio communication apparatus and a transmission power control method thereof in a base station and a mobile station.

  In a 3rd Generation Partnership Project (3GPP: 3rd Generation Partnership Project) mobile communication system, transmission power control is performed so that necessary communication quality can be ensured between a base station and a mobile station. Specifically, a signal power to interference power ratio (SIR) of a received signal of a dedicated physical channel (DPCH) is measured, and the measured SIR approaches the SIR target value in the base station. As described above, the transmission side is requested to increase / decrease the power by a predetermined step by using a transmission power control (TPC) bit. Such transmission power control is called an inner loop or a closed loop.

  Hereinafter, 3GPP closed loop power control will be briefly described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, it is assumed that a base station (BTS: Base Transceiver Station) performs DPCH transmission power control for each mobile station (UE: User Equipment) using a TPC bit. The TPC bit is defined in an uplink (UL: Up Link) and a downlink (DL: Dedicated Control Channel), and is transmitted and received by each BTS and UE. Here, the case where the mobile station UE controls the downlink DPCH transmission power from the base station by observing the downlink DPCH quality (SIR) and transmitting the uplink TPC bit to the base station BTS is illustrated. For example, the mobile station UE compares the SIR target value notified from the base station BTS with the measured SIR, and determines whether the transmission power of the downlink DPCH is increased or decreased. Then, the mobile station UE transmits a TPC bit instructing increase or decrease in transmission power to the base station BTS using the uplink. The base station BTS receives the TPC bit and changes the downlink DPCH transmission power accordingly.

  The same applies when the base station BTS controls the uplink DPCH transmission power from the mobile station UE. That is, the base station BTS measures the SIR of the uplink DPCH and determines whether the transmission power of the uplink DPCH is increased or decreased compared with the SIR target value. Then, the base station BTS transmits a TPC bit instructing increase or decrease in transmission power to the mobile station UE using the downlink. The mobile station UE receives the TPC bit and changes the transmission power of the uplink DPCH accordingly.

  As shown in FIG. 2A, the DPCH is a slot obtained by dividing a 10 ms radio frame into 15 slots, and includes a dedicated physical control channel (DPCCH) and a dedicated physical data channel (DPDCH: Dedicated Physical Data Channel). The DPCCH is a channel for transmitting DPCH control information, a transmission format information (TFCI) bit for notifying a combination of data units, and a pilot signal (Pilot Bit) that is information for timing synchronization. ), Feedback information (FBI), and TPC bits. The DPDCH is a channel that transmits data of a link layer or higher.

  In the TPC bit, as shown in FIG. 2B, a transmission power increase request (1 dB up request) and a transmission power reduction request (1 dB down request) are defined.

  Thus, in the closed-loop power control in the 3GPP mobile station, each controls the other party's DPCH transmission power using the DPCCH so that the transmission power is desired by both the base station BTS and the mobile station UE.

  Next, SIR that is a reference for transmission power control will be described. SIR is defined as:

SIR = (RSCP / ISCP) * SF
Here, RSCP (Received Signal Code Power) is the power of DPCH that can be extracted by despreading, ISCP (Interference Signal Code Power) is the interference power for DPCH, and SF (Spreading Factor) is the number of spreading chips used in DPCCH.

  The SIR calculation is performed in the pilot portion of the DPCH where the expected data pattern is known in advance. That is, the fluctuation factors of SIR are the DPCH received power amount (RSCP) and the DPCH interference component amount (ISCP). Based on this ratio, convergence is made to a desired communication quality using a closed loop. Specifically, if the SIR is worse than the target value (if it is low), control is performed to request an increase in DPCH transmission power with the TPC bit to increase the RSCP, and if the SIR is higher than the target value ( The SIR is converged to the target value by controlling to lower the RSCP by requesting the reduction of the DPCH transmission power with the TPC bit (if higher).

  Another example of transmission power control is described in Patent Literatures 1-3. The transmission power control method disclosed in Patent Document 1 considers the reception power of a common pilot channel (CPICH). Specifically, the mobile station estimates the difference in propagation loss from the base station from the measurement result of the reception quality of CPICH transmitted by the base station at a predetermined transmission power, and the offset power determined according to the difference. Only the transmission power of the uplink DPCH is added.

  Patent Document 2 or Patent Document 3 discloses a control method for determining the CPICH reception quality and changing the SIR target value according to the CPICH reception quality.

JP 2004-080235 A JP 2006-319462 A JP 2008-172664 A

  However, in the transmission power control method described in the above-described patent document, there is a case where the transmission power of the DPCH cannot be appropriately controlled depending on the timing of other channels other than the DPCH. This will be specifically described below.

  As shown in FIG. 3A, the DPCH format on the downlink side is slightly different from that on the uplink side, and DPDCH / DPCCH are on the same phase and mapped on the time axis. The pilot bit is at the end of the format. FIG. 3B shows an example of the timing of another channel having interference (with correlation) with the DPCH on the downlink side. That is, here, it is assumed that a channel with interference is set at a DPCH communication timing other than pilot bits. When the DPCH communication timing with interference deviates from the pilot bits in this way, as described below, a situation may occur in which transmission power decreases and reception of data on the downlink DPCH becomes impossible.

  That is, as described above, RSCP and ISCP that are the basis of SIR calculation are calculated in the pilot part of DPCH. Therefore, when there is no component that interferes with the pilot portion as shown in FIG. Especially in a good communication environment (normal communication state) where the radio wave propagation distance between the base station BTS and the mobile station UE is short (normal communication state) (step 1), the SIR becomes high (RSCP> ISCP), and the mobile station UE sets the uplink TPC bit. To request a reduction in DPCH transmission power (step 2). Here, when interference by other channels as exemplified in FIG. 3B occurs, when the DPCH transmission power is reduced by control using SIR, DPDCH in which data of the link layer or higher is contained. The portion cannot receive data due to interference (step 3). As a result, although it is determined that the communication environment is good, data communication is not established and communication is disconnected.

  Therefore, an object of the present invention is to provide a wireless communication apparatus and its transmission power control method capable of avoiding communication disconnection regardless of the timing at which interference between an individual channel and a common channel, which is the above-described problem, occurs.

  A radio communication apparatus according to the present invention is a radio communication apparatus in a radio communication system having a common channel and an individual channel provided for each radio communication apparatus, and a signal power of a signal received from another radio communication apparatus through the individual channel. An interference power ratio (hereinafter referred to as SIR) is measured, the measured SIR is compared with a preset SIR target value, and a transmission power control signal is used so that the measured SIR approaches the SIR target value. Closed loop control means for controlling the transmission power of the other wireless communication device, and when the measured SIR is higher than the SIR target value, the presence or absence of interference between the dedicated channel and the common channel is confirmed, and the interference occurs. When the reception power of the common channel is equal to or greater than a predetermined value and the total reception power amount including noise is Common channel confirmation control for suppressing transmission of a transmission power control signal for reducing the transmission power of the other wireless communication device to the closed loop control means if the ratio of the received power amount of the channels is equal to or less than a predetermined threshold And means.

  A transmission power control method according to the present invention is a transmission power control method for a wireless communication apparatus in a wireless communication system having a common channel and a dedicated channel provided for each wireless communication apparatus, from another wireless communication apparatus through the dedicated channel. A signal power to interference power ratio (hereinafter referred to as SIR) of the received signal is measured, the measured SIR is compared with a preset SIR target value, and the measured SIR is transmitted so as to approach the SIR target value. Closed loop control step for controlling the transmission power of the other wireless communication device using a power control signal, and if the measured SIR is higher than the SIR target value, check whether there is interference between the dedicated channel and the common channel However, when the interference occurs, the reception power of the common channel is not less than a predetermined value and all reception including noise is received. If the ratio of the received power amount of the common channel to the power amount is equal to or less than a predetermined threshold, transmission of a transmission power control signal for reducing the transmission power of the other wireless communication device is suppressed with respect to the closed loop control step. And a common channel confirmation control step.

  According to the present invention, communication interruption can be avoided regardless of the timing at which interference between the dedicated channel and the common channel occurs.

It is a schematic block diagram of the radio | wireless communications system for demonstrating the general transmission power control method. (A) is a data format diagram of uplink DPCH, and (B) is a diagram for explaining a bit pattern of TPC. (A) is a figure which shows the frame structure of downlink DPCH, (B) is a figure explaining an example of the timing relationship between downlink DPCH and another channel. It is a flowchart for demonstrating the situation where transmission power falls and it becomes impossible to receive DPCH data. 1 is a block diagram illustrating a schematic configuration of a wireless communication device according to an embodiment of the present invention. It is a block diagram for demonstrating operation | movement of the radio | wireless communications system which provided the radio | wireless communication apparatus by one Example of this invention. It is a timing chart for demonstrating the communication timing of each channel in 3GPP. It is a graph which shows roughly the relationship of the mobile station reception power with respect to the base station transmission power regarding CPICH-RSCP. It is a graph which shows roughly the relationship of the mobile station reception power with respect to the base station transmission power regarding RSSI. It is a graph which shows roughly the relationship of the mobile station reception power with respect to the base station transmission power regarding CPICH-Ec / No. 7 is a flowchart showing a transmission power control method in the wireless communication apparatus shown in FIG. 6. It is a schematic diagram for demonstrating the TPC bit determination criterion using CPICH-RSCP in a present Example. It is a schematic diagram for demonstrating the TPC bit criterion based on CPICH-Ec / No in a present Example.

  Embodiments and examples of the present invention will be described with reference to the accompanying drawings, which are not intended to limit the present invention. In addition, in this specification and drawing, the component with the same code | symbol shall show the mutually same function.

1. System As shown in FIG. 5, a wireless communication apparatus according to an embodiment of the present invention includes a CPU (Central Processing Unit) 10 that is a program control processor that executes transmission power control and prevention of transmission power reduction request described later. The wireless unit 11, the display unit 12, the key operation unit 13, and the storage unit 14 are controlled by the CPU 10, respectively.

  In the case of a wireless communication device mounted on a mobile phone, the wireless unit 11 transmits and receives radio waves for communication with the base station, the display unit 12 notifies the user of the operation and communication status of the mobile phone, and the key. The operation unit 13 allows the user to perform operations such as outgoing and incoming calls of the mobile phone, and the storage unit 14 temporarily stores data and stores user settings of the mobile phone when the CPU 10 operates. A program for controlling transmission power according to the present embodiment is stored. The CPU 10 executes transmission power control by the mobile phone by executing the stored program, and further recognizes control for functioning as a mobile phone, for example, input from the key operation unit 13 and controls the display unit 12. To control the state of the wireless unit 11 and control data transmission / reception with the network.

  As will be described below, the CPU 10 can execute closed loop transmission power control and common channel confirmation control when making a request for reducing the transmission power by executing a program stored in the storage unit 14. That is, in the DPCH reception power control, the DCPH reception power is prevented from being excessively lowered by the closed loop transmission power control, and the event of disconnection of the speech path due to the impossible DPCH reception is avoided. Hereinafter, a description will be given with reference to FIG.

  The wireless communication system shown in FIG. 6 includes a base station 100 and a mobile station 200, and is a system compatible with 3GPP, for example. The mobile station 200 may be not only a mobile phone or a portable information terminal, but also a mobile communication device such as a home appliance or an industrial appliance.

  The base station 100 includes a radio unit 101 for performing radio communication with a mobile station, a closed loop transmission power control unit 102, a common channel confirmation control unit 103, and a common channel quality measurement unit 104, and an SIR target value 105 is set. ing. The SIR target value 105 may be changeable. The closed loop transmission power control unit 102 compares the measured SIR of the received signal of the DPCH with the SIR target value 105 and uses the downlink TPC bit so that the measured SIR approaches the SIR target value 105. Control to adjust the transmission power. The common channel confirmation control unit 103 confirms the presence / absence of interference between the common channel (here, CPICH) and DPCH, and the reception power (CPICH-RSCP) and Ec / No level (CPICH-Ec / No) of the common channel. Thus, transmission of a transmission power reduction request to the closed loop transmission power control unit 102 is suppressed as will be described later. Common channel quality measurement section 104 measures the reception power (CPICH-RSCP) and Ec / No level (CPICH-Ec / No) of the common channel. Thus, when the base station 100 attempts to reduce the DPCH transmission power for the mobile station 200, not only the SIR determination result but also the interference with the common channel, the reception power of the common channel, and the Ec / No level are set. The TPC bit is determined in consideration.

  Similarly, the mobile station 200 includes a radio unit 201 for performing radio communication with the base station, a closed loop transmission power control unit 202, a common channel confirmation control unit 203, and a common channel quality measurement unit 204. The closed-loop transmission power control unit 202 compares the measured SIR of the DPCH received signal with the SIR target value 105 notified from the base station 100, and the uplink TPC bit so that the measured SIR approaches the SIR target value 105. Is used to control the transmission power of the base station 100 to be adjusted. The common channel confirmation control unit 203 confirms the presence / absence of interference between the common channel (here, CPICH) and DPCH, the reception power (CPICH-RSCP) of the common channel, and the Ec / No level (CPICH-Ec / No). As described later, the transmission of the transmission power reduction request to the closed loop transmission power control unit 202 is suppressed. The common channel quality measurement unit 204 measures the received power (CPICH-RSCP) and Ec / No level (CPICH-Ec / No) of the common channel. Thus, when the mobile station 200 attempts to reduce the DPCH transmission power with respect to the base station 100, not only the SIR determination result but also the presence / absence of interference between the common channel and the DPCH, the reception power of the common channel, and Ec The TPC bit is determined in consideration of the / No level.

  CPICH, which is a common channel, is a reference channel or a common pilot channel that is broadcast to a cell in which a mobile station is located. Unlike DPCH, transmission power does not increase or decrease. In addition, as shown in FIG. 7, in 3GPP, communication is possible with offset from the reference timing of some dedicated communication channels, but other communication channels (P-SCH, S-SCH, CPICH, P-CCPCH, S-CCPCH, AICH, and HS-SCCH) communicate at the same timing as CPICH. In FIG. 7, some channels whose timing is described as τ can be offset from the reference timing. For example, the timing of DPCH can be adjusted for each UE on the base station side. Depending on this timing, the DPCH receives interference from a common channel including the CPICH on the reference timing, as described with reference to FIG. As illustrated in FIG. 3B, when the DPCH and the common channel interfere with each other, not only the DPCH but also the reception power of the common channel decreases.

  Therefore, as described above, the common channel confirmation control unit 103 of the base station 100 and the common channel confirmation control unit 203 of the mobile station 200 perform interference between the common channel and the DPCH on the DPCH format, the reception power of the common channel, and Check the Ec / No level. If the common channel is CPICH, the presence / absence of interference between DPCH and CPICH, and the levels of CPICH-RSCP and CPICH-Ec / No are confirmed.

  CPICH-RSCP is the received power amount after despreading of CPICH and is defined as the received power of one code measured by the primary CPICH.

  CPICH-Ec / No is the amount of power including the CPICH reception level (RSCP) and the total reception power of the currently received band + thermal noise, and reception for each chip divided by the power density in the band. Defined as energy (Energy-per-Chip-to-Noise Ratio). CPICH-Ec / No is the same as CPICH-RSCP / RSSI. Here, RSSI (Received Signal Strength Indicator) is the total amount of received power including thermal noise generated in the receiver in a bandwidth limited by the pulse shaping filter of the receiver.

2. CPICH-Ec / No Level Determination The reason for considering CPICH-Ec / No is as follows. That is, as can be seen from the format shown in FIG. 3B, the presence / absence of common channel interference with the DPCH can be determined only for the channel in communication whose format is known, and the DPCH from the connected base station. -When an interference channel is broadcast from other cells other than Pilot, interference from the other cells cannot be determined. For this reason, as described with reference to FIG. 4, the possibility that the DPCH power is lowered too much and disconnection cannot be excluded. Therefore, in order to avoid this situation, according to the present embodiment, the CPICH reception power amount (CPICH-RSCP) and CPICH-Ec / No (CPICH-E for the total reception power amount including thermal noise) according to the present embodiment. RPC ratio) is used to determine the TPC bit.

  The reason for using CPICH-Ec / No is as follows. First, reception characteristics on the reception side regarding CPICH-RSCP, RSSI, and CPICH-Ec / No will be described with reference to FIGS.

  As shown in FIG. 8, CPICH-RSCP is the received power of the common channel transmitted from the base station, and noise and interference components are difficult to enter in the 3GPP system. Therefore, the transmission power from the base station and the reception power received by the mobile station maintain a proportional relationship.

  As shown in FIG. 9, RSSI indicates the amount of power including thermal noise in addition to the amount of power of the common channel and the dedicated channel, as described above. Since the mobile station UE is an electronic device, the influence of thermal noise always appears at a low electric field. Therefore, the RSSI received by the mobile station UE does not decrease below a certain amount in a weak electric field even when the transmission power of the base station decreases.

  8 and 9, CPICH-RSCP and RSSI show an approximate gradient on the assumption that there is no strong electric field + interference from other base stations, but there is a difference in gradient characteristics in an environment where there is interference from other base stations. Arise. Although it cannot be determined uniquely, as an example, when it is away from a communicating base station in the state of receiving interference from another base station and approaches the other base station, CPICH-RSCP is as shown by a dotted line in FIG. As the interference gradually increases, the slope becomes somewhat steep. On the other hand, as shown by the dotted line in FIG. 9, the RSSI has a gentle slope because the interference power increases.

  Since CPICH-Ec / No is a value expressed by CPICH-RSCP / RSSI as described above, it reflects the characteristics of CPICH-RSCP in FIG. 8 and the RSSI characteristics in FIG. 9 as shown in FIG. Show properties. Therefore, by using CPICH-Ec / No, it is possible to determine the amount of interference with CPICH that is difficult to determine with CPICH-RSCP alone. In this embodiment, in addition to checking the reception power of the common channel and the presence or absence of interference between the common channel and the DPCH, the TPC bit is determined by the determination using the CPICH-Ec / No, thereby improving the transmission power control performance. Further improvement is possible.

3. Transmission Power Control Transmission power control performed by the base station 100 and the mobile station 200 will be described with reference to FIG. However, as already described, the transmission power control performed by the base station 100 and the mobile station 200 is basically the same.

  First, when the base station 100 and the mobile station 200 are in communication (step 301), the common channel quality measurement unit 104/204 measures the SIR and outputs it to the closed loop transmission power control unit 102/202. Common channel communication quality CPICH-RSCP and CPICH-Ec / No are observed (steps 302 and 303).

  The closed-loop transmission power control unit 102/202 determines that the transmission power of the uplink / downlink DPCH needs to be reduced because the measured SIR is good with respect to the SIR target value 105 of the base station 100. (Step 304).

  In this case, the common channel confirmation control unit 103/203 determines the presence or absence of timing interference from the common channel and DPCH timing offset and format (step 305). If the common channel confirmation control unit 103/203 determines that there is interference between the common channel and the DPCH (step 305: interference), the common channel reception power (CPICH-RSCP) and a predetermined value set in advance Are compared to determine whether DPCH-RSCP is within a predetermined coverage area (step 306). This predetermined value is set based on the radio sensitivity of the base station 100 or the mobile station 200.

  Common when CPICH-RSCP is equal to or greater than a predetermined value, that is, when DPCH-RSCP is determined to be within a predetermined coverage area (step 306: in the area) or when it is determined that interference is not present at step 305 The channel confirmation control unit 103/203 compares the measured CPICH-Ec / No level with a predetermined threshold (step 307), and if the CPICH-Ec / No level is higher than the predetermined threshold (step 307: from the threshold) High), a TPC bit for requesting a reduction in DPCH transmission power is returned to the transmission side (mobile station / base station) under the control of the closed loop transmission power control unit 102/202 (step 308).

  On the other hand, when it is determined that CPICH-RSCP is lower than the predetermined value, that is, DPCH-RSCP is outside the predetermined receivable area (step 306: out of area), or the CPICH-Ec / No level is predetermined. When it is determined that the threshold value is less than or equal to the threshold value (step 307: less than or equal to the threshold value), the common channel confirmation control unit 103/203 transmits the TPC bit that requests the closed loop transmission power control unit 102/202 to reduce the DPCH transmission power. (Step 309).

  As described above, when the base station 100 and the mobile station 200 perform the transmission power control shown in FIG. 11, the closed loop transmission power control unit 102/202 performs communication because the DPCH transmission power is too low to receive the DPCH. It is possible to avoid an event that leads to interruption. Therefore, the base station 10, the mobile terminal device 20, and the wireless communication system having these according to the present embodiment can avoid communication disconnection at any timing when interference between the DPCH and another channel occurs.

3.1) Criteria using CPICH-RSCP (step 306)
In step 306 in FIG. 11, the common channel confirmation control unit 103 can estimate a DPCH receivable region in which the base station can receive the DPCH based on the common channel reception power CPICH-RSCP. Similarly, the common channel confirmation control unit 203 can estimate the DPCH receivable region in which the mobile station 200 can receive the DPCH based on the reception power CPICH-RSCP of the common channel.

  FIG. 12 is a diagram for explaining the estimation of the DPCH unreceivable area of the reception power at which the DPCH cannot be received based on the reception power of the common channel. The common channel confirmation control unit 103/203 can estimate the DPCH unreceivable area with, for example, wireless sensitivity. Further, the common channel confirmation control unit 103/203 may estimate the DPCH unreceivable region using the DPCH error rate obtained from the power ratio (energy ratio) between CPICH and DPCH. The DPCH receivable area can be estimated from such a DPCH unreceivable area.

3.2) TPC bit criterion based on CPICH-Ec / No (step 307)
In step 307 in FIG. 11, the common channel confirmation control unit 103 can estimate a DPCH receivable area in which the base station can receive the DPCH based on the reception quality CPICH-Ec / No of the common channel. Similarly, the common channel confirmation control unit 203 can estimate the DPCH receivable area in which the mobile station 200 can receive the DPCH based on the reception quality CPICH-Ec / No of the common channel.

  FIG. 13 is a diagram for explaining estimation of a DPCH unreceivable region of reception power at which DPCH cannot be received based on reception quality CPICH-Ec / No of the common channel. The common channel confirmation control unit 103/203 can estimate the DPCH unreceivable area by, for example, CPICH-Ec / No or CPICH-RSCP / RSSI. The DPCH receivable area can be estimated from such a DPCH unreceivable area. Moreover, the determination using such CPICH-Ec / No can use the DPCH reception characteristics (relationship between DPCH-RSCP and CPICH-Ec / No) determined in advance during development.

  As shown in FIG. 13, the common channel confirmation controller 103/203 determines that the SIR is higher than the SIR target value 105, the common channel reception power CPICH-RSCP is higher than a predetermined value, and the common channel reception quality CPICH. When -Ec / No is higher than a predetermined threshold, it is preferable to transmit a TPC bit that lowers the DPCH transmission power on the transmission side to the lowest value of the DPCH receivable area.

  According to the present embodiment, as shown in FIG. 13, not only DPCH-SIR and CPICH-RSCP but also DPSCH power control considering CPICH-Ec / No is performed, so closed loop transmission power A TPC bit that lowers the DPCH transmission power to the lowest value in the DPCH receivable area can be transmitted to the control unit 102/202. Further, when it is estimated that the DPCH reception area is below, it is possible to prevent a decrease in DPCH transmission power by preventing a transmission output reduction request and avoid a communication interruption event.

  In the present embodiment, the common channel that interferes with the received power and DPCH format is described as CPICH. However, the common channel confirmation control unit 103/203 also takes into account the timing arrangement of DPCH and other common channels. By determining whether or not to reduce the DPCH transmission power, a more appropriate determination can be made. Here, the other common channels are “P-SCH”, “S-SCH”, “P-CCPCH”, “S-CCPCH”, “AICH”, and “HS-SCCH” in FIG. “P-SCH” is a primary synchronization channel, “S-SCH” is a secondary synchronization channel, and “P-CCPCH” is a primary common control physical channel. ), “S-CCPCH” is a primary common control physical channel (Secondary Common Control Physical Channel), “AICH” is an acquisition indication channel (Acquisition Indication Channel), and “HS-SCCH” is a high-speed shared control channel (High). Speed-Shared Control Channel).

  In the embodiment of the present invention, the determination is made using CPICH-RSCP and CPICH-Ec / No. However, from the fluctuation amount of CPICH-Path Loss (base station broadcast power amount−own terminal's CPICH-RSCP). Similar determinations can be made. However, in the method using Path Loss, since it is estimated from the amount of variation, it is difficult to make a determination in a stationary state, and the usable environment is limited.

4). Additional Notes Part or all of the above-described embodiments may be described as the following additional notes, but are not limited thereto.

(Appendix 1)
A wireless communication device in a wireless communication system having a common channel and an individual channel provided for each wireless communication device,
A signal power to interference power ratio (hereinafter referred to as SIR) of a signal received from another wireless communication device through an individual channel is measured, and the measured SIR is compared with a preset SIR target value. Closed loop control means for controlling the transmission power of the other wireless communication device using a transmission power control signal so as to approach the SIR target value;
When the measured SIR is higher than the SIR target value, the presence / absence of interference between the dedicated channel and the common channel is confirmed, and when the interference occurs, the reception power of the common channel is equal to or higher than a predetermined value, and If the ratio of the reception power amount of the common channel to the total reception power amount including noise is equal to or less than a predetermined threshold, the transmission for reducing the transmission power of the other wireless communication device to the closed loop control means A common channel confirmation control means for suppressing transmission of a power control signal;
A wireless communication apparatus comprising:

(Appendix 2)
The common channel confirmation control means lowers the transmission power of the other radio communication device with respect to the closed loop control means when the reception power of the common channel is lower than a predetermined value when the interference occurs. The wireless communication apparatus according to appendix 1, wherein transmission of a transmission power control signal for suppressing the transmission is suppressed.

(Appendix 3)
If the ratio of the received power amount of the common channel to the total received power amount including the noise is larger than a predetermined threshold, the common channel confirmation control unit transmits the other radio communication device to the closed loop control unit. The wireless communication apparatus according to appendix 1 or 2, wherein transmission of a transmission power control signal for reducing power is executed.

(Appendix 4)
The common channel confirmation control means performs transmission of a transmission power control signal for reducing the transmission power of the other wireless communication device to the lowest value of the receivable area of the dedicated channel to the closed loop control means. The wireless communication apparatus according to appendix 3, wherein

(Appendix 5)
A base station of a wireless communication system, comprising the wireless communication device according to any one of appendices 1-4.

(Appendix 6)
A mobile station of a radio communication system comprising the radio communication device according to any one of appendixes 1-4.

(Appendix 7)
A wireless communication system comprising the base station according to attachment 5 and the mobile station according to attachment 6.

(Appendix 8)
A wireless communication device transmission power control method in a wireless communication system having a common channel and a dedicated channel provided for each wireless communication device,
A signal power to interference power ratio (hereinafter referred to as SIR) of a signal received from another wireless communication device through an individual channel is measured, and the measured SIR is compared with a preset SIR target value. A closed loop control step of controlling transmission power of the other wireless communication device using a transmission power control signal so as to approach the SIR target value;
When the measured SIR is higher than the SIR target value, the presence / absence of interference between the dedicated channel and the common channel is confirmed, and when the interference occurs, the reception power of the common channel is equal to or higher than a predetermined value, and If the ratio of the received power amount of the common channel to the total received power amount including noise is equal to or less than a predetermined threshold, transmission for reducing the transmission power of the other wireless communication device with respect to the closed loop control step A common channel confirmation control step for suppressing transmission of a power control signal;
A transmission power control method characterized by comprising:

(Appendix 9)
In the common channel confirmation control step, when the reception power of the common channel is lower than a predetermined value when the interference occurs, the transmission power of the other radio communication device is reduced with respect to the closed loop control step. The transmission power control method according to appendix 8, wherein transmission of a transmission power control signal for suppressing the transmission is suppressed.

(Appendix 10)
In the common channel confirmation control step, if the ratio of the reception power amount of the common channel to the total reception power amount including the noise is larger than a predetermined threshold value, the transmission of the other radio communication device with respect to the closed loop control step The transmission power control method according to appendix 8 or 9, wherein transmission of a transmission power control signal for reducing power is executed.

(Appendix 11)
The common channel confirmation control step performs transmission of a transmission power control signal for reducing the transmission power of the other wireless communication device to the lowest value of the receivable area of the dedicated channel with respect to the closed loop control step. The transmission power control method according to appendix 10, wherein the transmission power control method is performed.

(Appendix 12)
A program for realizing, in a program control processor, a transmission power control function of a wireless communication device in a wireless communication system having a common channel and an individual channel provided for each wireless communication device,
A signal power to interference power ratio (hereinafter referred to as SIR) of a signal received from another wireless communication device through an individual channel is measured, and the measured SIR is compared with a preset SIR target value. A closed loop control function for controlling the transmission power of the other wireless communication device using a transmission power control signal so as to approach the SIR target value;
When the measured SIR is higher than the SIR target value, the presence / absence of interference between the dedicated channel and the common channel is confirmed, and when the interference occurs, the reception power of the common channel is equal to or higher than a predetermined value, and If the ratio of the reception power amount of the common channel to the total reception power amount including noise is equal to or less than a predetermined threshold, transmission for reducing the transmission power of the other wireless communication device for the closed loop control function A common channel confirmation control function for suppressing transmission of a power control signal;
Is realized by the program control processor.

(Appendix 13)
The common channel confirmation control function lowers the transmission power of the other radio communication device with respect to the closed loop control function when the reception power of the common channel is lower than a predetermined value when the interference occurs. 13. The program according to appendix 12, wherein transmission of a transmission power control signal for suppressing transmission is suppressed.

(Appendix 14)
If the ratio of the received power amount of the common channel to the total received power amount including the noise is larger than a predetermined threshold, the common channel confirmation control function transmits the other radio communication device to the closed loop control function. The program according to appendix 12 or 13, wherein transmission of a transmission power control signal for reducing power is executed.

(Appendix 15)
The common channel confirmation control function performs transmission of a transmission power control signal for reducing the transmission power of the other wireless communication device to the lowest value of the receivable area of the dedicated channel with respect to the closed loop control function. The program according to appendix 14, characterized in that:

  The present invention is applicable to a radio communication system having a closed loop transmission power control mechanism, its base station, and mobile station.

100 base station 101 radio unit 102 closed loop transmission power control unit 103 common channel confirmation control unit 104 common channel quality measurement unit 105 SIR target value 200 mobile station 201 radio unit 202 closed loop transmission power control unit 203 common channel confirmation control unit 204 common Channel quality measurement unit

Claims (9)

A wireless communication device in a wireless communication system having a common channel and an individual channel provided for each wireless communication device,
A signal power to interference power ratio (hereinafter referred to as SIR) of a signal received from another wireless communication device through an individual channel is measured, and the measured SIR is compared with a preset SIR target value. Closed loop control means for controlling the transmission power of the other wireless communication device using a transmission power control signal so as to approach the SIR target value;
When the measured SIR is higher than the SIR target value, the presence / absence of interference between the dedicated channel and the common channel is confirmed, and when the interference occurs, the reception power of the common channel is equal to or higher than a predetermined value, and If the ratio of the reception power amount of the common channel to the total reception power amount including noise is equal to or less than a predetermined threshold, the transmission for reducing the transmission power of the other wireless communication device to the closed loop control means A common channel confirmation control means for suppressing transmission of a power control signal;
A wireless communication apparatus comprising:   The common channel confirmation control means lowers the transmission power of the other radio communication device with respect to the closed loop control means when the reception power of the common channel is lower than a predetermined value when the interference occurs. The wireless communication apparatus according to claim 1, wherein transmission of a transmission power control signal for causing the transmission is suppressed.   If the ratio of the received power amount of the common channel to the total received power amount including the noise is larger than a predetermined threshold, the common channel confirmation control unit transmits the other radio communication device to the closed loop control unit. The wireless communication apparatus according to claim 1, wherein transmission of a transmission power control signal for reducing power is executed.   The common channel confirmation control means performs transmission of a transmission power control signal for reducing the transmission power of the other wireless communication device to the lowest value of the receivable area of the dedicated channel to the closed loop control means. The wireless communication apparatus according to claim 3, wherein:   A base station of a wireless communication system, comprising the wireless communication device according to claim 1.   A mobile station of a radio communication system comprising the radio communication device according to claim 1.   A wireless communication system comprising the base station according to claim 5 and the mobile station according to claim 6. A wireless communication device transmission power control method in a wireless communication system having a common channel and a dedicated channel provided for each wireless communication device,
A signal power to interference power ratio (hereinafter referred to as SIR) of a signal received from another wireless communication device through an individual channel is measured, and the measured SIR is compared with a preset SIR target value. A closed loop control step of controlling transmission power of the other wireless communication device using a transmission power control signal so as to approach the SIR target value;
When the measured SIR is higher than the SIR target value, the presence / absence of interference between the dedicated channel and the common channel is confirmed, and when the interference occurs, the reception power of the common channel is equal to or higher than a predetermined value, and If the ratio of the received power amount of the common channel to the total received power amount including noise is equal to or less than a predetermined threshold, transmission for reducing the transmission power of the other wireless communication device with respect to the closed loop control step A common channel confirmation control step for suppressing transmission of a power control signal;
A transmission power control method characterized by comprising: A program for realizing, in a program control processor, a transmission power control function of a wireless communication device in a wireless communication system having a common channel and an individual channel provided for each wireless communication device,
A signal power to interference power ratio (hereinafter referred to as SIR) of a signal received from another wireless communication device through an individual channel is measured, and the measured SIR is compared with a preset SIR target value. A closed loop control function for controlling the transmission power of the other wireless communication device using a transmission power control signal so as to approach the SIR target value;
When the measured SIR is higher than the SIR target value, the presence / absence of interference between the dedicated channel and the common channel is confirmed, and when the interference occurs, the reception power of the common channel is equal to or higher than a predetermined value, and If the ratio of the reception power amount of the common channel to the total reception power amount including noise is equal to or less than a predetermined threshold, transmission for reducing the transmission power of the other wireless communication device for the closed loop control function A common channel confirmation control function for suppressing transmission of a power control signal;
Is realized by the program control processor.

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