JP5477412B2 - Wireless terminal device - Google Patents

Description

  The present invention relates to a wireless terminal device and a transmission power control method used in a wireless communication system.

  In recent years, with the advancement of wireless communication technology, proposals and standardization of wireless communication methods that can obtain high communication speeds between a base station (BS) and a wireless terminal (MS: Mobile Station) have been made. ing.

  For example, in recent years, there is mobile WiMAX (Worldwide Interoperability for Microwave Access) (hereinafter referred to as WiMAX) which is being standardized as IEEE 802.16e. In WiMAX, OFDMA is adopted as a wireless communication system, and a communication speed can be increased by using a large number of subcarriers modulated at a high coding speed. For example, the modulation scheme includes 64QAM (Quadrature Amplitude Modulation). In WiMAX, a plurality of wireless terminals (MS) can share the same frequency band. For example, in WiMAX, both frequency division duplex (FDD) / time division duplex (TDD) are divided into areas called bursts.

  WiMAX employs such a multiplexing method. The BS simultaneously receives radio waves from a plurality of MSs and collectively performs demodulation processing. For this reason, in the BS, it is necessary that reception levels from each MS are arranged at a certain level. In the BS, transmission power control (TPC) is generally applied in order to make the reception level from the MS uniform. TPC is a control protocol for controlling transmission power between BS and MS. The MS adjusts the power appropriately based on this TPC. Here, when applying TPC in mobile communication, the MS may be located near the BS or may be located far away. In such an environment, in order for the power reaching the BS to be appropriate, the MS needs to be able to control the transmission power level finely and widely.

  For example, the MS has a plurality of variable gain amplifiers. The MS arranges the plurality of variable gain amplifiers in a plurality of stages. By doing so, the MS can take a wide control range of power and can obtain a wide output range.

   However, preparing an amplifier or attenuator having a continuous output variable mechanism is expensive. Therefore, when the MS has two variable gain amplifiers, one of the two variable gain amplifiers may be a simple variable mechanism capable of switching the gain in two stages. By doing in this way, the cost of components can be suppressed.

  For example, when a transmission amplifier incorporating a continuous variable amplifier with a maximum of 40 dB and an attenuator whose attenuation can be switched at 0 dB / −20 dB, a variable width of a maximum of 60 dB can be obtained.

JP 2001-358601 A

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

  A case will be described in which the MS has two variable gain amplifiers, and the gain switching step in one of the two variable gain amplifiers is large.

  In this case, a discontinuous point of transmission power tends to occur at a gain switching point in a variable gain amplifier having a large gain switching step.

  If the switching of the gains of the two variable gain amplifiers is both continuously variable, such a control is performed by fixing the gain of one variable gain amplifier and adjusting the gain of the other variable gain amplifier. Discontinuous points can be avoided.

  For example, a case where a transmission power that is -30 dB lower than the maximum gain is obtained is described. In this case, the amplifier side that switches the gain in two stages is set to 0 dB, and the amplifier side that can be continuously varied is set to decrease the −30 dB gain. The amplifier side that switches the gain in two stages is set to −20 dB, and the amplifier side that can be continuously varied is −10 dB. You can choose both settings to reduce the gain. However, there may be a case where the attenuation difference 20 dB between the continuously variable side and the two-stage gain switching side does not always match due to environmental factors such as individual differences of parts and temperature differences. In this case, a step occurs in the transmission power at the point where the gain distribution is switched.

  In order to suppress this transmission power level difference by a technique such as adjustment, it is necessary to add a circuit for calibration. This calibration circuit adjusts the power of the two operating points to be equal. However, adding such a calibration circuit is not preferable because an additional circuit and a control procedure must be mounted.

  The wireless terminal device and the transmission power control method provide a wireless terminal device and a transmission power control method that can reduce the influence of discontinuous transmission power in gain switching in transmission power control.

In order to solve the above problem, an embodiment of a wireless terminal device is:
In a wireless terminal device including a first gain adjustment unit capable of stepwise switching of a gain from a first gain to a second gain, and a second gain adjustment unit capable of finely adjusting the gain,
A first combined gain range obtained by gain adjustment of the second gain adjusting means when the first gain is set in the first gain adjusting means;
In the first gain adjusting means, when the second gain is set, the second gain adjusting means has a range that overlaps with the second combined gain range obtained by the gain adjustment of the second gain adjusting means,
A desired combined gain is within the overlapping range, and a gain difference between the desired combined gain and the end of the first combined gain range that is closer is the desired combined gain and the second combined gain. Judged based on the handover threshold, neighboring radio base station information, and the power level obtained by the scan performed on the radio base station when the gain difference between the ends of the combined gain range and the near end is larger. Control means for performing switching between the first gain and the second gain based on the transmission power range .

  According to the disclosed wireless terminal device, it is possible to reduce the influence of discontinuous transmission power in gain switching in transmission power control.

It is explanatory drawing which shows the radio | wireless communications system which concerns on one Example. It is explanatory drawing which shows an example of a frame format. It is a partial block diagram which shows the radio | wireless terminal apparatus which concerns on one Example. It is explanatory drawing which shows transmission power control. It is explanatory drawing which shows transmission power control. It is explanatory drawing which shows transmission power control. It is explanatory drawing which shows transmission power control. It is explanatory drawing which shows the transmission power control which concerns on one Example. It is explanatory drawing which shows the transmission power control which concerns on one Example. It is a flowchart which shows the transmission power control method which concerns on one Example. It is a flowchart which shows the transmission power control method which concerns on one Example. It is a partial block diagram which shows the radio | wireless terminal apparatus which concerns on one Example. It is explanatory drawing which shows the transmission power control which concerns on one Example. It is a partial block diagram which shows the radio | wireless terminal apparatus which concerns on one Example. It is explanatory drawing which shows the transmission power control which concerns on one Example. It is a partial block diagram which shows the radio | wireless terminal apparatus which concerns on one Example. It is a partial block diagram which shows the radio | wireless terminal apparatus which concerns on one Example.

Next, the best mode for carrying out the present invention will be described based on the following embodiments with reference to the drawings.
In all the drawings for explaining the embodiments, the same reference numerals are used for those having the same function, and repeated explanation is omitted.
(First embodiment)
A radio communication system according to the present embodiment will be described with reference to FIG.

  A time division duplex (TDD) system is applied to the wireless communication system according to the present embodiment. In TDD, full-duplex communication is performed by switching between a downlink and an uplink at high speed. The uplink transmission signal and the downlink transmission signal can be transmitted in the same transmission band. For example, a transmission frame in the time division duplex scheme includes a downlink subframe in which a downlink signal is transmitted and an uplink subframe in which an uplink signal is transmitted. The downlink subframe and the uplink subframe include a plurality of OFDM symbols. The number of OFDM signal symbols included in the downlink subframe and the number of OFDM signal symbols included in the uplink subframe may be the same or different. A cyclic prefix (CP) is located between OFDM symbols. For example, a CP is arranged between symbols by adding a signal obtained by copying a signal of a predetermined length from the last part of the symbol as it is to the head of the symbol.

  Further, in the radio communication system according to the present embodiment, Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) is applied. Wireless communication systems having these requirements include WiMAX (Worldwide Interoperability for Microwave Access). Therefore, in this embodiment, WiMAX (Worldwide Interoperability for Microwave Access) will be described as an example. However, the RF unit includes a first gain adjustment unit capable of stepwise gain switching from the first gain to the second gain, and a second gain adjustment unit capable of fine adjustment of the gain. Any communication system having a wireless communication device can be applied to devices other than WiMAX.

The radio communication system according to the present embodiment includes a radio base station (BS) 100 (100 ₁ , 100 ₂ , 100 ₃ ). For example, the radio base station 100 is included in an access network. Although three radio base stations are illustrated in FIG. 1, there may be one, two, or four or more. The communication system according to the present embodiment includes wireless terminal devices 200 (200 ₁ , 200 ₂ , 200 ₃ ). The wireless terminal device 200 includes a PC capable of wireless communication, a mobile terminal, and an in-vehicle terminal mounted on a car.

  Further, the wireless communication system according to the present embodiment may include in-home equipment (CPE: Customer Premises Equipment).

  The wireless communication system according to the present embodiment includes an ASN-GW (access service network-gateway) 300. ASN-GW 300 connects a radio base station to a higher-level IP network. Further, the ASN-GW 300 controls handover between radio base stations. The ASN-GW 300 accommodates several radio base stations 200 and connects to a router of the core IP network.

  The wireless communication system according to the present embodiment includes a BRAS (Broadband Remote Access Server) 400. The BRAS 400 accesses the Internet from a broadband access line.

The wireless communication system according to the present embodiment includes a router 500. A router 500 relays data flowing on a network to another network. For example, the router 500 relays data flowing on MMD (Multimedia Domain) / IMS (IP Multimedia Subsystem) to the Internet. Then, the data is transmitted to another wireless terminal device ₄ connected to the Internet.

  The wireless communication system according to the present embodiment may include an HA (Home Agent) 700. The wireless communication system according to the present embodiment may include a SIP (Session Initiation Protocol) server 800.

  The radio base station 100 and the radio terminal device 200 perform radio communication by a time division duplex method. As shown in FIG. 2, a transmission frame in the time division duplex scheme is composed of a downlink subframe (DL Subframe) and an uplink subframe (UL Subframe), and includes a pair of downlink subframes and uplink subframes. One frame is configured. Further, the downlink subchannel includes a preamble, a frame control header (FCH), a DL-MAP, a UL-MAP, and a downlink burst (DL burst). For example, the frame control header may include the number of subchannels and DL-MAP coding information. The DL-MAP may include information on the position and size of the burst. The downlink burst may be divided (divided) into a plurality of regions. Further, the uplink subchannel includes a ranging region and an uplink burst (UL burst). The uplink burst may be divided (divided) into a plurality of regions.

The wireless terminal device 200 according to the present embodiment will be described with reference to FIG. 3. The wireless terminal device 200 according to the present embodiment includes a transmission RF unit 202. The transmission RF unit 202 transmits an uplink signal to the radio base station 100. For example, the transmission RF unit 202 converts D / A converted data into a radio frequency, performs transmission power control, and transmits.

  The wireless terminal device 200 according to the present embodiment includes a gain two-stage switching amplifier 204. The gain two-stage switching amplifier 204 switches the gain in two stages.

  The wireless terminal device 200 according to the present embodiment includes a gain continuous variable amplifier 206. The gain continuously variable amplifier 206 continuously changes the gain.

  The wireless terminal device 200 according to the present embodiment includes a D / A converter 208. The D / A converter 208 converts the baseband signal input by the UL signal generation unit 214 described later into an analog signal. Then, the D / A converter 208 inputs the baseband signal converted into the analog signal to the transmission RF unit 202.

  The wireless terminal device 200 according to the present embodiment includes a baseband processing unit 210. The baseband processing unit 210 performs processing related to the baseband signal.

  The wireless terminal device 200 according to the present embodiment includes a control unit 212. The control unit 212 performs switching control of the gain two-stage switching amplifier 204 and the gain continuously variable amplifier 206 described above.

  The wireless terminal device 200 according to the present embodiment includes a UL signal generation unit 214. The UL signal generation unit 214 generates an uplink signal. The UL signal generation unit 214 inputs the generated uplink signal to the D / A 208.

  The wireless terminal device 200 according to the present embodiment includes a receiving unit / reception processing unit 216. The reception unit / reception processing unit 216 performs processing related to the baseband signal input by the reception RF unit 218.

  The wireless terminal device 200 according to the present embodiment includes a reception RF unit 218. The reception RF unit 218 converts the downlink signal transmitted by the radio base station 100 into a baseband signal.

  When adjusting the transmission power, the wireless terminal device 200 according to the present embodiment performs control based on the change amount of the transmission power control instruction.

  The wireless terminal device 200 according to the present embodiment includes a gain two-stage switching amplifier 204 and a gain continuous variable amplifier 206. For this reason, the transmission power in radio terminal apparatus 200 is controlled as shown in FIG. FIG. 4 shows the relationship between the set gain and the transmission gain.

  As shown in FIG. 4, the final transmission gain is the sum of the gain by the gain continuously variable amplifier 206 that continuously changes the gain and the gain by the gain two-stage switching amplifier 204 that switches the gain in two stages. The gain variable range may not be covered only by adjustment by the continuous gain variable amplifier 206. For this reason, the gain in the gain two-stage switching amplifier 204 may be switched at a certain transmission gain. In this case, at the switching point, control is performed to lower the gain of the continuous gain variable amplifier 206 so as to cancel the gain change by the gain two-stage switching amplifier 204. For example, as shown in FIG. 4, at the operation switching point, the gain two-stage switching amplifier 204 switches the gain. For example, the gain two-stage switching amplifier 204 increases the gain by b. On the other hand, the gain continuously variable amplifier 206 decreases the gain by a in order to cancel the gain change b in the gain two-stage switching amplifier 204.

  When such control is performed, the gain reduction amount a in the continuous gain variable amplifier 206 is designed to be equal to the gain increase amount b in the gain two-stage switching amplifier 204. However, unless measures such as gain adjustment and gain temperature correction are taken, a = b is not necessarily achieved due to individual differences in the amplifier itself or differences in the characteristics of the two due to the environment.

  For example, as shown in FIG. 5, when a = b, the transmission gain is smooth with respect to the set gain. In other words, the transmission gain also increases monotonously as the set gain increases. However, as shown in FIG. 6, when a> b, the transmission gain temporarily decreases at the operation switching point, and a step is generated in the transmission gain. Also, as shown in FIG. 7, when a <b, the transmission gain temporarily increases at the operation switching point, and a step is generated in the transmission gain. Therefore, when a <b and a> b, the transmission gain becomes discontinuous with respect to the set gain at the operation switching point according to the difference between a and b.

  The gain switching operation in the gain two-stage switching amplifier 204 will be described with reference to FIG. In FIG. 8, the horizontal axis represents the gain in the gain two-stage switching amplifier 204, and the vertical axis represents the transmission gain. The transmission gain may be referred to as an output gain (total gain).

  FIG. 8 shows gain curves in two states when the gain in the gain two-stage switching amplifier 204 is high and low.

  The fact that the gain is switched in the gain two-stage switching amplifier 204 means that, at the operation switching point, the characteristic when the gain of the continuous gain variable amplifier 206 is high and the characteristic when the gain of the continuous gain variable amplifier 206 is low. Shown by being switched. The broken line in FIG. 8 shows a case where the gain in the gain two-stage switching amplifier 204 is switched to the higher one at the operation switching point. In this case, the characteristic indicating the transmission gain is switched from the characteristic when the gain of the continuous gain variable amplifier 206 is low to the characteristic when the gain of the continuous gain variable amplifier 206 is high.

  In FIG. 8, the “region that can be adjusted by both the gain two-stage switching amplifier and the continuously variable gain amplifier” is an area that can be selected regardless of whether the gain in the gain two-stage switching amplifier is low or high. In other words, when the first gain is set in the gain two-stage switching amplifier 204, a combined gain range (hereinafter referred to as a first combined gain range) obtained by gain adjustment by the continuous gain variable amplifier 206, and the gain When the second gain is set in the two-stage switching amplifier 204, this is an overlapping portion with a combined gain range (hereinafter referred to as a second combined gain range) obtained by gain adjustment by the continuous gain variable amplifier 206. . For example, the case where the gain in the continuously variable gain amplifier 206 can be adjusted from −40 dB to 0 dB and the gain in the gain two-stage switching amplifier 204 can be switched between −20 dB and 0 dB will be described. In this case, when the gain in the gain two-stage switching amplifier 204 is −20 dB, the total gain can be adjusted from −60 dB to −20 dB. When the gain in the gain two-stage switching amplifier 204 is 0 dB, the total gain can be adjusted from -40 dB to 0 dB. In this case, the “region that can be adjusted by both the gain two-stage switching amplifier and the continuously variable gain amplifier” is in the range of −40 dB to −20 dB.

  For example, a case will be described in which the operation switching point is set to the center of the “region that can be adjusted by both the gain two-stage switching amplifier and the gain continuously variable amplifier”, that is, −30 dB. In this case, in a situation where the gain adjustment is insufficient, the transmission gain becomes discontinuous with respect to the set gain every time the operation switching point is passed as a result of the transmission power control. For example, the transmission gain may decrease even when the set gain is set to increase the gain, or the transmission gain may increase even when the set gain is set to decrease the gain. is there. Here, in a situation where the gain adjustment is insufficient, the gain change b in the two-stage switching amplifier 204 and the gain change changed by the gain continuously variable amplifier 206 in order to cancel the gain change. The case where a is not equal is included. Such an operation is not preferable for the wireless terminal device 200.

  Therefore, when the transmission power is changed, the wireless terminal device 200 according to the present embodiment has a gain necessary to obtain the transmission power after the change is “a gain two-stage switching amplifier, a gain continuously variable amplifier, or the like. When it is included in the “region that can be adjusted by both”, the following processing is performed. When the change amount of the transmission power is very small, the wireless terminal device 200 sets the gain so that the desired transmission power is obtained by changing the gain in the continuous gain variable amplifier 206. In this case, radio terminal apparatus 200 does not perform gain switching in gain two-stage switching amplifier 204. In addition, when the change amount of the transmission power is large to some extent, the wireless terminal device 200 has a case where the gain in the gain two-stage switching amplifier 204 is the same as the gain necessary to obtain the transmission power after the change. The gain in the gain two-stage switching amplifier 204 is set so that the gain adjustment range can be widened.

  For example, FIG. 9 shows the transition of the operating point of the output gain when the change amount of the transmission power is small, in other words, when the transmission power is changed in small increments. In this case, a gain that achieves desired transmission power is set by changing the gain in the continuous gain variable amplifier 206 (1). When the gain cannot be dealt with by changing the gain in the continuous gain variable amplifier 206, the gain in the gain two-stage switching amplifier 204 is switched (2).

  Also, FIG. 9 shows the transition of the operating point of the output gain when the transmission power change amount is large to some extent. In this case, the gain in the gain two-stage switching amplifier 204 is switched before the gain change in the continuously variable gain amplifier 206 cannot be handled (3).

  A transmission power control method in the wireless terminal device 200 according to the present embodiment will be described.

  A transmission control method when the change amount of the transmission power is small, in other words, when the power change amount is less than the threshold will be described with reference to FIG.

The control unit 212 determines whether the gain (G ₂ ) is switched to the higher one (G _2high ) in the gain two-stage switching amplifier 204 (step S1002).

When the gain in the gain two-stage switching amplifier 204 is switched to the higher one (step S1002: YES), the control unit 212 indicates that the changed transmission power (P _new ) has a higher gain in the gain two-stage switching amplifier 204. When the gain is switched, the transmission power (P _Hmin ) obtained when the gain in the continuously variable gain amplifier 206 is set to the minimum value is determined (step S1004).

On the other hand, when the gain is switched to a lower one in the gain two-stage switching amplifier 204 (step S1002: NO), the control unit 212 determines that the changed transmission power (P _new ) Is switched to a lower value, it is determined whether or not it is less than the transmission power (P _Lmax ) obtained when the gain in the continuously variable gain amplifier 206 is set to the maximum value (step S1006).

When the transmission power after the change is switched to a higher gain in the gain two-stage switching amplifier 204, it is equal to or higher than the transmission power obtained when the gain in the continuous gain variable amplifier 206 is set to the minimum value (step S1004). : YES) and the changed transmission power is not less than the transmission power obtained when the gain in the continuously variable gain amplifier 206 is set to the maximum value when the gain is switched to the lower one in the gain two-stage switching amplifier 204. (Step S1006: NO), the control unit 212 sets the gain in the gain two-stage switching amplifier 204 to the higher one. Then, the control unit 212 switches the gain (G ₁ ) in the gain continuously variable amplifier 206 from the difference between the transmission power (P) after the change and the power (P _BB ) when the total gain is set to 0 dB, to change the gain in two steps. The gain in the amplifier 204 (the higher gain in the gain two-stage switching amplifier 204) ( _G2high ) is set to a gain (step S1008).

On the other hand, when the changed transmission power is switched to a higher gain in the gain two-stage switching amplifier 204, it is not equal to or higher than the transmission power obtained when the gain in the continuously variable gain amplifier 206 is set to the minimum value (step S1004: NO) and the transmission power after the change is less than the transmission power obtained when the gain in the continuously variable gain amplifier 206 is set to the maximum value when the gain is switched to the lower one in the gain two-stage switching amplifier 204. If present (step S1006: YES), the control unit 212 sets the gain in the gain two-stage switching amplifier 204 to the lower one. Then, the control unit 212 sets the gain (G ₁ ) in the continuous gain variable amplifier 206 to the gain two-stage switching amplifier 204 based on the difference between the transmission power after the change and the power (P _BB ) when the total gain is 0 dB. The gain is set by subtracting the gain (the lower gain in the gain two-stage switching amplifier 204) (G _2low ) (step S1010).

  A transmission control method when the amount of change in transmission power is large to some extent, in other words, when the amount of power change is equal to or greater than a threshold will be described with reference to FIG.

The control unit 212 obtains the changed transmission power (P _new ) when the gain in the continuously variable gain amplifier 206 is set to the maximum value when the gain is switched to the lower one in the gain two-stage switching amplifier 204. It is determined whether or not the transmission power (P _Lmax ) is _{equal to} or higher (step S1102).

When the transmission power after the change is less than the transmission power obtained when the gain in the gain continuously variable amplifier 206 is set to the maximum value (step S1102: NO), the control unit 212 changes the transmission power (P _new ) after the change. However, when the gain is switched to the higher one in the gain two-stage switching amplifier 204, it is determined whether the transmission power (P _Hmin ) obtained when the gain in the continuous gain variable amplifier 206 is set to the minimum value is less than (Step S1104).

When the transmission power after the change is switched to a higher gain in the gain two-stage switching amplifier 204, when the transmission power is equal to or higher than the transmission power obtained when the gain in the continuous gain variable amplifier 206 is set to the minimum value (step) S1104: NO), the control unit 212 sets the gain in the continuous gain variable amplifier 206 to the minimum value when the gain is switched to the higher one in the gain two-stage switching amplifier 204 from the changed transmission power (P _new ). When the value obtained by subtracting the transmission power (P _Hmin ) obtained in this case is switched to a lower gain in the gain two-stage switching amplifier 204, the gain in the continuous gain variable amplifier 206 is set to the maximum value. It is determined whether or not the transmission power (P _Lmax ) obtained is equal to or greater than the value obtained by subtracting the changed transmission power (P _new ) (step S1106). .

In step S1102, when the gain is switched to the lower one in the gain two-stage switching amplifier 204, the transmission power after the change is equal to or higher than the transmission power obtained when the gain in the continuously variable gain amplifier 206 is set to the maximum value. When it is determined that there is a gain (step S1102: YES) and when the gain is switched to the higher one in the gain two-stage switching amplifier 204 from the changed transmission power in step S1106, the gain in the continuous gain variable amplifier 206 is increased. The value obtained by subtracting the transmission power obtained in the case of the minimum value is obtained when the gain in the continuously variable gain amplifier 206 is set to the maximum value when the gain in the gain two-stage switching amplifier 204 is switched to the lower value. Is equal to or greater than the value obtained by subtracting the changed transmission power If it is determined (step S1106: YES), the control unit 212 sets a higher gain in the gain two-stage switching amplifier 204. Then, the control unit 212 determines the gain (G ₁ ) in the continuously variable gain amplifier 206 from the difference between the transmission power (P) after the change and the power (P _BB ) when the total gain is 0 dB. The gain obtained by subtracting the gain (G _2high ) in the switching amplifier 204 is set (step S1108).

On the other hand, in step S1104, when the changed transmission power is switched to a higher gain in the gain two-stage switching amplifier 204, the transmission power obtained when the gain in the continuously variable gain amplifier 206 is set to the minimum value. If it is determined that the gain is less than (step S1104: YES) and if the gain in the gain two-stage switching amplifier 204 is switched from the changed transmission power to the higher one in step S1106, the gain continuously variable amplifier 206 When the gain in the continuous gain variable amplifier 206 is set to the maximum value when the value obtained by subtracting the transmission power obtained when the gain is set to the minimum value is switched to the lower gain in the gain two-stage switching amplifier 204 Less than the value obtained by subtracting the changed transmission power from the transmission power obtained If it is determined that (Step S1106: NO), the control unit 212 sets the gain in the gain second stage switching amplifier 204 to the lower. Then, the control unit 212 determines the gain (G ₁ ) in the continuously variable gain amplifier 206 from the difference between the transmission power (P) after the change and the power (P _BB ) when the total gain is 0 dB. The gain _obtained by subtracting the gain (G _2low ) in the switching amplifier 204 is set (step S1110).

  As described above, in WiMAX, the downlink (DL) and the uplink (UL) are time division multiplexed. For this reason, in WiMAX, transmission is performed intermittently. Therefore, when it is assumed that a change in the transmission power occurs during the transmission stop period of the UL signal, the accuracy requirement in the transmission power control is low as compared with the wireless system in which the UL transmission is continuous. However, in WiMAX, when fine adjustment of power is performed at least in closed loop power control, it is important that power can be appropriately increased or decreased within the range of the fine adjustment. On the other hand, in the case of a power control instruction with a large change amount, the transmission gain decreases or increases at the operation switching point, in other words, the error is small with respect to the deviation of the change amount. For this reason, even if there is some discontinuity at the switching point due to the gain switching operation in the gain two-stage switching amplifier 204, it can be ignored.

Therefore, according to the present embodiment, even if variations or deviations occur in the gains of the two gain adjustment mechanisms, it is possible to reduce the influence due to the discontinuity of the control operation caused by the deviations.
(Second embodiment)
The radio communication system according to the present embodiment is the same as the radio communication system described with reference to FIG.

  In the wireless communication system according to the present embodiment, IEEE802.16e (hereinafter referred to as WiMAX) known as mobile WiMAX is adopted as a wireless communication protocol as described above. In the wireless communication system according to the present embodiment, the wireless terminal device 200 includes a WiMAX I / F card and a PC.

  A wireless terminal device 200 according to the present embodiment will be described with reference to FIG.

  The wireless terminal device 200 according to the present embodiment includes a transmission RF unit 202. The transmission RF unit 202 transmits an uplink signal to the radio base station 100. For example, the transmission RF unit 202 converts D / A converted data into a radio frequency, performs transmission power control, and transmits.

  The wireless terminal device 200 according to the present embodiment includes a gain two-stage switching amplifier 204. The gain two-stage switching amplifier 204 switches the gain in two stages.

  The wireless terminal device 200 according to the present embodiment includes a gain continuous variable amplifier 206. The gain continuously variable amplifier 206 continuously changes the gain.

  The wireless terminal device 200 according to the present embodiment includes a control unit 212. The control unit 212 performs switching control of the gain two-stage switching amplifier 204 and the gain continuously variable amplifier 206 described above.

  The wireless terminal device 200 according to the present embodiment includes a protocol processing unit 220. The protocol processing unit 220 processes a protocol defined in IEEE 802.16e known as mobile WiMAX.

  The wireless terminal device 200 according to the present embodiment includes a transmission power determination unit 222. The transmission power determination unit 222 determines transmission power. Then, the transmission power determination unit 222 inputs the determined transmission power to the gain distribution instruction unit 224. Further, the transmission power determination unit 222 determines a gain (gain) for obtaining the transmission power based on the determined transmission power. Then, the transmission power determination unit 222 may input the determined gain to the gain distribution instruction unit 224.

  The wireless terminal device 200 according to the present embodiment includes a gain distribution instruction unit 224. The gain distribution instructing unit 224 performs switching control of the gain two-stage switching amplifier 204 and the gain continuously variable amplifier 206 described above based on the gain input by the transmission power determining unit 222.

  In WiMAX, both closed-loop transmission power control and open-loop transmission power control can be selected as methods for controlling the transmission power of the wireless terminal device.

  A case where closed loop transmission power control is applied will be described. In this case, the radio base station 100 performs a process of relatively increasing the transmission power when the transmission power of a certain radio terminal device 200 deviates from an appropriate value. Alternatively, a control message including an instruction to reduce transmission power is transmitted to the wireless terminal device 200. The wireless terminal device 200 that has received the control message transmitted by the wireless base station 100 adjusts transmission power for transmission. Specifically, the transmission power determination unit 222 determines the transmission power based on the transmission power instruction included in the control message transmitted by the radio base station 100. Then, the transmission power determination unit 222 inputs the determined transmission power to the gain distribution instruction unit 224.

  The gain distribution determination unit 224 of the wireless terminal device 200 determines whether the difference from the previous transmission power is less than or equal to a certain threshold. When the difference from the previous transmission power is less than a certain threshold, the gain distribution determination unit 224 performs the transmission power control described with reference to FIG. On the other hand, the gain distribution determination unit 224 performs the transmission power control described with reference to FIG. 11 when the difference from the previous transmission power is a certain threshold or more.

  As a result, the gain distribution determination unit 224 determines the gain in the continuous gain variable amplifier 206 and the gain in the gain two-stage switching amplifier 204.

  As an example, a case where the threshold value of the change amount of transmission power is 3 dB will be described. In this case, when the transmission power change amount threshold is 2 dB, the transmission power control described with reference to FIG. 10 is performed. Further, when the change amount of the transmission power is 4 dB, the transmission power control described with reference to FIG. 11 is performed.

  A case where open loop transmission power control is applied will be described. In this case, the wireless terminal device 200 adaptively adjusts the transmission power according to a change in the strength of the radio wave from the wireless base station 100. For example, when the radio wave from the radio base station 100 decreases by 3 dB, it is assumed that the radio base station 100 does not reach an appropriate reception level unless the transmission power of the radio terminal device 200 is also increased by 3 dB. Therefore, in this case, the transmission power determination unit 222 of the wireless terminal device 200 determines to increase the transmission power by 3 dB. Then, the transmission power determination unit 222 inputs the determined transmission power to the gain distribution instruction unit 224.

  The gain distribution determination unit 224 of the wireless terminal device 200 determines whether the difference from the previous transmission power is less than or equal to a certain threshold. When the difference from the previous transmission power is less than a certain threshold, the gain distribution determination unit 224 performs the transmission power control described with reference to FIG. On the other hand, the gain distribution determination unit 224 performs the transmission power control described with reference to FIG. 11 when the difference from the previous transmission power is a certain threshold or more.

As a result, the gain distribution determination unit 224 determines the gain in the continuous gain variable amplifier 206 and the gain in the gain two-stage switching amplifier 204.
(Third embodiment)
The radio communication system according to the present embodiment is the same as the radio communication system described with reference to FIG.

  At the time of new connection with the radio base station 100, continuity with the power so far is not important. Accordingly, when determining the transmission power in the new connection, the distribution of the two variable gain portions to the power to be set is determined by the transmission power control method described with reference to FIG. By doing so, the wireless terminal device 200 can transmit a wide margin up to the operating point where the discontinuous operation occurs after connection with the wireless base station 100, and reduce the case of crossing the discontinuous operating point. Power control can be performed.

  In addition, when performing a new connection, the wireless terminal device 200 issues a connection request. When there is no response from the radio base station 100 to the connection request, the radio terminal device 200 retransmits the connection request. In this case, the wireless terminal device 200 may transmit with higher transmission power than the transmission power in the previous connection request. In such a case, the radio base station 100 does not know the transmission power applied to the connection request transmitted last time. For this reason, only the absolute value of the transmission power is important in the radio base station 100. That is, in this case, the relative value of the transmission power does not make sense. Also in this case, the wireless terminal device 200 determines the transmission power by the transmission power control method described with reference to FIG. FIG. 13 shows the operating point of this operation. The gain distribution instructing unit 224 selects an operating point with a wider adjustment range in the gain two-stage switching amplifier 204. Specifically, the gain distribution instructing unit 224 is within a region where the desired combined gain can be adjusted by both the gain two-stage switching amplifier 204 and the continuous gain variable amplifier 206, and the desired combined gain and the first combined gain The gain difference between the end of the gain range and the near end of the gain range is greater than the gain difference between the desired combined gain and the end of the second combined gain range of the near end. A first gain is set for the two-stage switching amplifier 204. In the opposite case, the gain distribution instruction unit 224 sets the second gain for the gain two-stage switching amplifier 204.

  Similarly, in the case of transmission with a sufficient interval from the previous transmission, it can be considered that the degree of fluctuation of the radio wave condition due to the environmental change over time is larger than the power gap of the discontinuous point. For this reason, it may be determined similarly in the procedure of FIG. The operating point of this operation is also the same as in FIG.

  In WiMAX, the connection with the radio base station 100 is started when the radio terminal apparatus 200 transmits a message called initial ranging to the radio base station 100. This message is implemented by transmitting a ranging code to a transmission position determined according to a certain procedure during a burst notified by the UL-MAP message for initial ranging transmission from the radio base station 100. When this transmission is performed, the radio terminal device 200 determines the appropriate transmission power to be transmitted from the radio field intensity from the radio base station 100 and the transmission power of the radio base station 100 that is accommodated and notified in the message broadcast by the radio base station 100. To decide. Further, when “Initial Ranging” is sent again without a response from the radio base station 100, the radio terminal device 200 retries with a power value slightly higher than the previous power. In these sequences, the radio base station 100 cannot recognize a relative difference from the previous transmission power. For this reason, the radio base station 100 cannot detect even if there is a change in transmission power across discontinuous points. For this reason, there is no problem even if the transmission power increases or decreases by the amount of discontinuity. It is preferable to perform power control so as not to cross discontinuous points as much as possible in communication with the radio base station 100 after that.

  Therefore, as illustrated in FIG. 14, the wireless terminal device 200 according to the present embodiment includes a switching suppression condition determination unit 226 in the wireless terminal device described with reference to FIG. 12. The switching inhibition condition determining unit 226 notifies the gain distribution determining unit 224 of a switching inhibition instruction when an operation that crosses the discontinuous points is not preferable.

  While connected to the radio base station 100, the switching suppression condition determination unit 226 receives a connection state notification from the protocol processing unit 220. Further, the switching inhibition condition determination unit 226 does not issue a inhibition instruction during Initial Ranging, and issues a inhibition instruction after the connection with the radio base station 100 is completed. The gain distribution instructing unit 224 performs the sequence described with reference to FIG. 10 according to whether the power control change amount is less than or equal to the threshold when the inhibition instruction is issued from the switching inhibition condition determination unit 226 and FIG. The sequence described with reference to is used properly. The gain distribution instruction unit 224 performs power control using the sequence described with reference to FIG. 11 when no inhibition instruction is issued.

  Further, the protocol control unit 220 determines an elapsed time from the previous transmission, and when the elapsed time exceeds a certain threshold, as a connection state notification, the switching suppression condition determination unit indicates that a sufficient time has elapsed since the previous transmission. 226 is notified. In response to this, the switching inhibition condition determination unit 226 stops the inhibition instruction to the gain distribution instruction unit 224.

The gain distribution instructing unit 224 controls the transmission power according to the sequence described with reference to FIG. 11 for the next transmission even when the radio base station 100 is connected. As a result, the gain distribution of each part can be set so that the power adjustment width until reaching the discontinuity after connection with the radio base station 100 is large.
(Embodiment 4)
The radio communication system according to the present embodiment is the same as the radio communication system described with reference to FIG.

  Even when connected to the same radio base station, the transmission power control procedure itself may change. In such cases, continuity of transmission power changes is generally not required. Therefore, at the time of switching the transmission power control procedure, the distribution of the two variable gain portions is determined by the procedure described with reference to FIG. As a result, a wide margin up to the operating point where the discontinuous operation is performed in the subsequent power control can be widened, and the case of crossing the discontinuous operating point can be minimized.

As mentioned above in WiMAX. Both closed loop transmission power control and open loop transmission power control are available. However, the latter is treated as an option on the protocol. A message for the radio base station 100 to give an instruction to switch these control procedures is defined. Therefore, the protocol processing unit 220 of the wireless terminal device 200 described with reference to FIG. 14 has the same configuration as that of the third embodiment described above, and notifies the switching suppression condition determination unit 226 of switching of the power control procedure. Then, the switching suppression condition determination unit 226 stops the suppression instruction to the gain distribution instruction unit 224 until the first transmission after the switching is completed. As a result, when the transmission power control procedure is switched, the transmission power is controlled by the sequence described with reference to FIG. 11 without using the procedure for avoiding the discontinuous point passing operation in the first transmission. The procedure for avoiding the discontinuous point passing operation is a procedure necessary when considering the accuracy of the difference from the power of the previous transmission. Here, the case where the transmission power control procedure is switched includes, for example, the case of shifting from closed loop transmission power control to open loop transmission power control. After switching the transmission power control procedure, the gain distribution instructing unit 224 sets the gain distribution so that the power adjustment width until reaching the discontinuous point is increased.
(Embodiment 5)
The radio communication system according to the present embodiment is the same as the radio communication system described with reference to FIG.

  The wireless communication system according to the present embodiment supports hand over (H / O). Further, in the radio communication system according to the present embodiment, the radio terminal device 200 does not start power control with the handover destination radio base station (hereinafter referred to as a new radio base station) from the initial connection procedure. Specifically, radio terminal apparatus 200 receives in advance parameters relating to power control, and determines in advance the power for transmission to the handover destination radio base station. And the radio | wireless terminal apparatus 200 which concerns on a present Example determines distribution of two variable gain parts with the procedure demonstrated with reference to FIG. 11 with respect to the instruction | indication power value which instruct | indicates the power determined in advance. Thereby, the radio | wireless terminal apparatus 200 can take the margin to the operating point used as a discontinuous operation | movement about the power control after a hand-over, and can suppress the case over a discontinuous operating point to the minimum.

  In WiMAX, information related to H / O candidate radio base stations is transmitted to radio terminal apparatus 100. This includes the value of transmission power for each radio base station. The information regarding the radio base station as an H / O candidate may be referred to as neighboring radio base station information. And before the H / O, the radio | wireless terminal apparatus 100 scans the transmission signal from a neighboring radio base station beforehand based on neighboring radio base station information. By doing in this way, the radio | wireless terminal apparatus 100 can investigate whether it can communicate with a neighboring radio base station with sufficient reception level. At this time, the radio terminal device 100 measures the received radio wave intensity from each radio base station. The received radio wave strength includes, for example, RSSI (receive signal strength indicator).

  Then, the wireless terminal device 100 uses the power when transmitting to the H / O destination wireless base station from the power when transmitting to the wireless base station before H / O (the transmission power of the new wireless base station). ) − (RSSI of new radio base station) − ((transmission power of current radio base station) − (RSSI of current radio base station)).

  As a result, when connecting to a new radio base station, the power level is adjusted to an appropriate level without any power adjustment.

  The wireless terminal device 200 according to the present embodiment is the same as the wireless terminal device described with reference to FIG.

The radio terminal device 100 transmits the control result to the new radio base station with the determined transmission power. In this case, the protocol processing unit 220 of the wireless terminal device 100 notifies the switching inhibition condition determination unit 226 of the occurrence of H / O. Then, the switching inhibition condition determination unit 226 stops the inhibition instruction to the gain distribution instruction unit 224 until the first transmission after H / O is completed. The gain distribution instructing unit 224 controls the transmission power according to the sequence described with reference to FIG. 11 even if the transmission power after H / O is substantially equal to the transmission power before H / O. In other words, the gain distribution instructing unit 224 does not use the procedure for avoiding the discontinuous point passing operation that is necessary when considering the accuracy of the difference from the power of the previous transmission in the first transmission. As a result, the gain distribution instructing unit 224 sets the gain distribution of each unit so that the power width until reaching the discontinuity point is large for the new radio base station.
(Embodiment 6)
The radio communication system according to the present embodiment is the same as the radio communication system described with reference to FIG.

  The wireless communication system according to the present embodiment supports H / O. In the radio communication system according to the present embodiment, the radio terminal device 200 receives or acquires parameters related to power control with a plurality of radio base stations as H / O destination candidates in advance, and then receives the H / O destination radio base station. Determine the station. In this case, the radio terminal device 200 determines in advance the initial transmission power when connecting to each H / O candidate radio base station. When the transmission power for the radio base station of the H / O destination is in the above-mentioned “region that can be adjusted by both the gain two-stage switching amplifier and the gain continuously variable amplifier”, the radio terminal apparatus 200 can receive other H / O destination candidates. The transmission power is determined based on the distribution of the initial transmission power when connected to the wireless base station. For example, the radio terminal device 200 sets the gain two-stage switching amplifier 204 to the “low” side as a region where either gain can be selected. The radio terminal device 200 is a radio base station capable of communicating with low transmission power even if the distance between the H / O destination and the determined radio base station is further moved away and higher transmission power is required. This is because there are cases where H / O can be performed. For example, the radio terminal apparatus 200 uses the gain two-stage switching amplifier 204 before the transmission power needs to be increased to a region where the necessary transmission power cannot be obtained unless the gain is set to the “high” side. H / O to a radio base station that can communicate with low transmission power. By doing in this way, the radio | wireless terminal apparatus 200 can H / O before exceeding the discontinuous point of transmission power control, and does not need to pass a discontinuous point as a result.

  As described above, when the H / O is performed, the radio terminal device 200 selects the gain of the gain two-stage switching amplifier 204 based on the transmission power required when connecting to another radio base station. . By doing in this way, the radio | wireless terminal apparatus 200 can suppress the case which straddles a discontinuous operation point to the minimum. FIG. 15 shows the operation in this case. The gain distribution instructing unit 224 is within a region where a desired combined gain can be adjusted by both the gain two-stage switching amplifier 204 and the continuous gain variable amplifier 206, and the desired combined gain and the end of the first combined gain range. Regardless of whether the gain difference between the near end and the gain difference between the desired composite gain and the near end of the second composite gain range is larger or smaller, the gain A first gain is set for the two-stage switching amplifier 204. For example, the first gain is the smaller gain in the gain two-stage switching amplifier.

  In WiMAX, the wireless terminal device can know an appropriate transmission power for transmission to the radio base station as an H / O candidate.

  As illustrated in FIG. 16, the wireless terminal device 200 according to the present embodiment includes the adjacent BS information management unit 228 in the wireless terminal device described with reference to FIG. 14. The adjacent BS information management unit 228 holds appropriate initial transmission power in each radio base station.

  When receiving the notification of H / O execution from the protocol processing unit 220, the switching suppression condition determination unit 226 checks the initial transmission power to the radio base stations that are candidates for each H / O. Further, the switching suppression condition determination unit 226 selects “low” as the gain of the gain two-stage switching amplifier 204 when it can be determined that communication is possible with sufficiently low transmission power even if H / O occurs again. An instruction is given to the gain distribution instruction unit 224. In response to this, the gain distribution instructing unit 224 sets “low” as the gain to the gain two-stage switching amplifier 204 and the gain continuously variable amplifier 206 regardless of the sequence described with reference to FIGS. Indicates a gain that provides a desired transmission power in the case of the gain when the gain two-stage switching amplifier 204 is set to the “low” side. As a condition for “determining that communication can be performed with sufficiently low transmission power even if H / O occurs again”, for example, for three or more other radio base stations, the initial transmission power for the radio base station is “gain 2”. The case is lower than the middle of the “adjustable range for both the step-switching amplifier and the continuously variable gain amplifier”. Further, the gain distribution instruction unit 224 is adjacent to the gain two-stage switching amplifier 204 in the period from the generation of the past H / O to the next H / O when the gain remains at the “low” side. The correlation of the initial transmission power to the radio base station may be learned to change the threshold dynamically.

  By performing such control, the radio terminal apparatus 200 simply performs the H / O destination radio base when there is a case in which the gain two-stage switching amplifier 204 remains “low” until the next H / O. It is possible to suppress the case where discontinuous transmission power control occurs due to the determination that the gain of the gain two-stage switching amplifier 204 is “high” only by the transmission power value to the station.

In the first to sixth embodiments described above, as a measure of “large (wide) power adjustment range”, the transmission power may be simply compared in decibels (dB), or a linear value expression of power For example, mW may be wider. In addition, a measure convenient for securing output characteristics may be introduced separately.
(Seventh embodiment)
The radio communication system according to the present embodiment is the same as the radio communication system described with reference to FIG.

  As shown in FIG. 17, the wireless terminal device 200 according to the present embodiment includes a host unit 250 and an I / F unit 260. Transmission power control is performed by software on the host 250 side. Specifically, it has a plurality of applications that realize the functions of the first to sixth embodiments described above, and performs power control.

  In addition, the I / F unit 260 performs transmission power control using a gain continuous variable amplifier and a gain two-stage switching amplifier. Specifically, transmission power control is performed as shown in the first to sixth embodiments described above. By doing in this way, the gain adjustment of a transmission part can be performed.

  According to the above-described embodiment, the generation of transmission power control across operating points where the transmission power changes discontinuously can be minimized, and the occurrence can be substantially avoided under normal operation. For this reason, in a simple transmission circuit configuration of two variable gain mechanisms, continuously variable and two-stage variable, there is no particular mechanism for eliminating potential power control discontinuities by calibration or the like. Can also achieve the target power control capability.

  In addition, since the transmission circuit of the wireless terminal device has a continuously variable gain adjusting unit and a gain adjusting unit capable of switching between high and low two-stage gains, the power value when connecting to the radio base station and the adjacent radio base station information By not using the discontinuous points of the transmission power change as much as possible, even in a circuit configuration that has a potential discontinuous operation factor, it is possible to avoid the power control discontinuous points.

Regarding the embodiment including the first to seventh examples, the following additional notes are disclosed.
(Appendix 1)
A wireless terminal device comprising: a first gain adjusting unit capable of stepwise switching of a gain from a first gain to a second gain; and a second gain adjusting unit capable of finely adjusting the gain. ,
In the first gain adjusting means, when the first gain is set, a combined gain range obtained by gain adjustment by the second gain adjusting means,
In the first gain adjustment means, when the second gain is set, the composite gain range obtained by gain adjustment by the second gain adjustment means has at least a portion that overlaps,
Transmission or reception is performed in the range where the combined gain is overlapped and the gain change width exceeds a predetermined width, or in the situation where the combined gain is overlapped and intermittent transmission or reception is performed. A wireless terminal apparatus comprising: control means for executing switching between the first gain and the second gain when belonging to a period that does not exist.
(Appendix 2)
In the wireless terminal device according to attachment 1,
The said control means is a radio | wireless terminal apparatus which switches to the direction from which the adjustment range of transmission power can be taken widely among the said 1st gain and the said 2nd gain.
(Appendix 3)
In a wireless terminal device including a first gain adjustment unit capable of stepwise switching of a gain from a first gain to a second gain, and a second gain adjustment unit capable of finely adjusting the gain,
A first combined gain range obtained by gain adjustment of the second gain adjusting means when the first gain is set in the first gain adjusting means;
In the first gain adjusting means, when the second gain is set, the second gain adjusting means has a range that overlaps with the second combined gain range obtained by the gain adjustment of the second gain adjusting means,
A desired combined gain is within the overlapping range, and a gain difference between the desired combined gain and the end of the first combined gain range that is closer is the desired combined gain and the second combined gain. A wireless terminal apparatus comprising: control means for setting the first gain to the first gain adjustment means when the gain difference between the ends of the combined gain range and the closer end is larger.
(Appendix 4)
A wireless terminal device comprising: a first gain adjusting unit capable of stepwise switching of a gain from a first gain to a second gain; and a second gain adjusting unit capable of finely adjusting the gain. ,
In the first gain adjusting means, when the first gain is set, a combined gain range obtained by gain adjustment by the second gain adjusting means,
In the first gain adjustment means, when the second gain is set, the composite gain range obtained by gain adjustment by the second gain adjustment means has at least a portion that overlaps,
Between the first gain and the second gain, based on a transmission power range determined based on a handover threshold, neighboring radio base station information, and a power level obtained by a scan performed on the radio base station. A wireless terminal device having control means for executing switching.
(Appendix 5)
In the wireless terminal device according to attachment 4,
The said control means is a radio | wireless terminal apparatus which performs switching between the said 1st gain and the said 2nd gain so that the said transmission power range can be covered widely.
(Appendix 6)
In the wireless terminal device according to attachment 4,
The said control means is a radio | wireless terminal apparatus which performs a switch to the one with a lower gain among the said 1st gain and a 2nd gain.
(Appendix 7)
Transmission power in a wireless terminal device including a first gain adjustment unit capable of stepwise switching of the gain from the first gain to the second gain, and a second gain adjustment unit capable of fine adjustment of the gain A control method,
In the first gain adjusting means, when the first gain is set, a combined gain range obtained by gain adjustment by the second gain adjusting means,
In the first gain adjustment means, when the second gain is set, the composite gain range obtained by gain adjustment by the second gain adjustment means has at least a portion that overlaps,
A period in which transmission or reception is not performed in a situation where the combined gain overlaps and the gain change width exceeds a predetermined width and the combined gain overlaps and intermittent transmission or reception is performed The gain difference between the desired combined gain and the end of the first combined gain range that is closer to the end of the first combined gain range is the closer of the desired combined gain and the end of the second combined gain range. The first gain and the second gain when the gain difference between the first and second ends is greater than or when the power level is acquired by scanning the handover threshold, the neighboring radio base station information, and the radio base station. A transmission power control method for performing switching between gains.

DESCRIPTION OF SYMBOLS 200 Radio | wireless terminal apparatus 202 Transmission RF part 204 Gain 2 step switching amplifier 206 Gain continuous switching amplifier 208 D / A converter 210 Baseband processing part 212 Control part 214 UL signal generation part 216 Reception part / reception processing part 218 Reception RF part 220 Protocol processing unit 222 Transmission power determination unit 224 Gain distribution instruction unit 226 Switching inhibition condition determination unit 228 Adjacent BS information management unit 260 I / F unit 270 Host unit

Claims (1)

In a wireless terminal device including a first gain adjustment unit capable of stepwise switching of a gain from a first gain to a second gain, and a second gain adjustment unit capable of finely adjusting the gain,
A first combined gain range obtained by gain adjustment of the second gain adjusting means when the first gain is set in the first gain adjusting means;
In the first gain adjusting means, when the second gain is set, the second gain adjusting means has a range that overlaps with the second combined gain range obtained by the gain adjustment of the second gain adjusting means,
A desired combined gain is within the overlapping range, and a gain difference between the desired combined gain and the end of the first combined gain range that is closer is the desired combined gain and the second combined gain. Judged based on the handover threshold, neighboring radio base station information, and the power level obtained by the scan performed on the radio base station when the gain difference between the ends of the combined gain range and the near end is larger. A radio terminal apparatus comprising: a control unit that performs switching between the first gain and the second gain based on the transmitted power range .

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