KR20030077908A - Method and apparatus for controlling the power of mobile phone in a wireless telecommunication system - Google Patents

Abstract

PURPOSE: A method and an apparatus for controlling a power of an MS(Mobile Station) in a wireless communication system are provided to efficiently control a transmission power of the MS which is in a gating mode. CONSTITUTION: A measurer measures an SNR(Signal to Noise Ratio) from an MS which transmits data per predetermined interval according to a gating rate. A controller(821) compares the measured SNR with a predetermined threshold value, and generates power control information according to the compared result. A transmitter including signaling point mappers(802), channel adjusters(803), and multiplexers(804) repeatedly transmits generated power control information to the MS in a power control interval designated from the predetermined interval.

Description

Power control method and device for mobile terminal in wireless communication system {METHOD AND APPARATUS FOR CONTROLLING THE POWER OF MOBILE PHONE IN A WIRELESS TELECOMMUNICATION SYSTEM}

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for efficiently controlling the transmission power of a mobile terminal in an intermittent transmission mode (Gating Mode).

In general, wireless communication systems such as Code Division Multiple Access (CDMA) 2000, Wideband Code Division Multiple Access / Universal Mobile Telecommunications System (WCDMA / UMTS), General Packet Radio System (GPRS), and CDMA2000 1xEV-DO (Evolution Data Only) The third generation wireless communication system. Unlike the typical second generation wireless communication system which used only a voice service or a low speed data service, the third generation wireless communication system supports a high speed packet data service such as a video as well as a voice service. . The wireless communication system includes at least a base station controller (BSC), a base transceiver system (BTS), and a mobile station (MS). The base station controller is wired to the base station controller and the base station is connected to and communicates with the mobile terminal through a wireless channel.

In a wireless communication system that supports voice and data services through Code Division Multiple Access (CDMA), power control has an important effect on the performance of the system. Typically, the base station and the user terminal performs power control with each other. Such power control is typically performed through a dedicated power control channel (PCCH), which is a power control group (hereinafter referred to as "PCG") which is a time unit in which power control is performed. This is accomplished by transmitting and receiving a predetermined number of power control bits (hereinafter referred to as "PCB"). Typically, the length of 1 PCG is 1.25ms, so power control in units of 1 PCG is equivalent to power control in an 800 Hz period.

An example in which power control is performed through the power control bit described above is as follows. The terminal receives the power control bits from the base station through the power control channel. If the value of the received power control bit is '0', the transmission power of the terminal is increased by a preset amount (x dB) in the next PCG interval, and if it is '1', the transmission power of the terminal is increased in the next PCG interval (x). lower by dB). Here, the value of x can be adjusted. In the same way, the base station also adjusts the transmission power of the channel transmitted to the terminal through the power control bit received from the terminal.

In a typical wireless communication system, a base station forwards through a forward common power control channel (hereinafter referred to as "CPCCH" or "F-CPCCH") for reverse power control for a terminal receiving a high-speed packet data service. The reverse power control bit is transmitted to the mobile station, and the terminal receiving the reverse power control bit controls the transmit power according to the reverse power control bit value. Here, the reverse direction means transmission from the terminal to the base station, and the forward direction means transmission from the base station to the terminal.

In the above procedure, the base station measures the received power or signal-to-noise ratio (hereinafter referred to as "SNR") of the pilot channel received from the terminal and if the measured value is higher than a predetermined threshold, Generates a power control bit for a command to lower the transmit power to the other hand, while generating a power control bit for a command to increase the transmit power to the counterpart when the measured value is lower than a predetermined threshold.

1 shows a transmitter configuration of an F-CPCCH used in a conventional wireless communication system.

Referring to FIG. 1, reference numerals 102 to 104 denote blocks for I channel transmission, and reference numerals 112 to 114 denote blocks for Q channel transmission. Each of the power control bits for 12 users is transmitted through different offsets (TDMs) for each 1 PCG period through the I and Q channels. Thus, a total of 24 power control bits are transmitted on one F-CPCCH. Reference numerals 101 and 111 denote twelve power control bits for the I and Q channels, respectively. The power control bits 101, 111 are symbol mapped by the signal point mappers 102, 112 to a '+1' or '1' or '0' value and then multiplied by the power gain in the channel gain regulators 103, 113. The power gain value is controlled by the forward power control bit value received from each terminal. The power control symbols of all the power gain controlled users are multiplexed by I and Q channels in the multiplexers 104 and 114 and then transmitted on the F-CPCCH.

As described above, the base station performs power control in the reverse direction at 800 Hz by transmitting a power control bit of one bit for one PCG over the F-CPCCH.

2 shows an example of a reverse power control process over time.

Referring to FIG. 2, the base station receiving the pilot channel transmitted by the terminal during the PCG 2 period measures the SNR of the pilot channel, compares it with a predetermined threshold value, and generates a power control bit according to the comparison result. In the example of FIG. 2, it is assumed that the SNR of the pilot channel received from the UE during the PCG 2 period is higher than the threshold. Therefore, the base station generates a power control bit instructing the terminal to lower the power and transmits it through the F-CPDDH (during PCG 3 period). The terminal controls the pilot channel transmission power of the PCG 4 section by interpreting the power control bits received in the time interval allocated to the PCG 3 section (the third position in the example of FIG. 2). The above process is performed continuously during every PCG interval.

On the other hand, there is a gating mode in a conventional wireless communication system. Gating (intermittent transmission) mode is used to reduce interference for other users, such as when there is no data to be transmitted and received in the forward and reverse directions, such as 1/2 gating, 1/4 gating. In the 1/2 gating mode, the UE does not transmit a pilot channel for every PCG, but transmits a pilot channel once every 2 PCGs. In 1/2 gating mode, the base station transmits one bit of reverse power control bits every 2 PCG. That is, reverse power control of 400 Hz is performed. In the 1/4 gating mode, the UE does not transmit a pilot channel for every PCG, but transmits a pilot channel once every 4 PCGs. In 1/4 gating mode, the base station transmits one bit of reverse power control bits every 4 PCGs. That is, reverse power control of 200 Hz is performed.

3 illustrates a process of transmitting a reverse pilot channel and a forward power control bit in a half gating mode over time.

Referring to FIG. 3, in the 1/2 gating mode, the UE transmits a pilot once every 2 PCG in the reverse direction. In 1/2 gating mode, the base station transmits a reverse power control bit once every 2 PCG. That is, in the 1/2 gating mode, reverse power control is performed at 400 Hz.

4 illustrates a process of transmitting a reverse pilot channel and a forward power control bit in a quarter gating mode over time.

Referring to FIG. 4, in the 1/4 gating mode, the UE transmits a pilot once every 4 PCG in the reverse direction. In 1/4 gating mode, the base station transmits a reverse power control bit once every 4 PCG. That is, in the quarter gating mode, reverse power control is performed at 200 Hz.

As can be seen from the foregoing, in the gating mode of a conventional wireless communication system, the period during which power control is performed becomes relatively long. In this case, if the terminal incorrectly receives the power control bit from the base station, there is a problem that the original purpose of the gating mode of suppressing interference to other users cannot be properly achieved.

SUMMARY OF THE INVENTION An object of the present invention, which was devised to solve the above problems, is to provide a method and apparatus for performing efficient power control in a wireless communication system.

Another object of the present invention is to provide a power control method and apparatus for improving reception reliability of power control bits in a wireless communication system.

In order to achieve these objects, in a wireless communication system including a base station and a mobile terminal wirelessly connected to and communicated with the base station, the base station apparatus for controlling the transmission power of the mobile terminal is configured to transmit data at predetermined intervals according to an intermittent transmission rate. The received signal-to-noise ratio (SNR) from the mobile terminal for intermittent transmission is measured. The base station compares the measured signal-to-noise ratio with a preset threshold and generates power control information according to the comparison result. The base station repeatedly transmits the generated power control information to the mobile terminal in a power control section determined from the set section.

The mobile terminal receives the repeatedly transmitted power control information in the predetermined power control interval. Next, the mobile terminal combines the received power control information and controls the transmission power of data to be transmitted to the base station according to the combined power control information.

Preferably, when the intermittent transmission rate is N, the power control section is determined to be a section (1 / N).

Preferably, when the intermittent transmission rate is N, the power control section to which the received power control information is combined is determined in a section that is less than or equal to (1 / N) and more than two.

Preferably, the set interval is in a slot unit, and the power control information is a power control bit.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that those skilled in the art may better understand the detailed description of the invention that follows.

Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. Those skilled in the art should recognize that the disclosed concepts and specific embodiments of the invention may be readily used as a basis for modifying or designing other structures for achieving the same purposes of the present invention. Those skilled in the art should also recognize that structures equivalent to the invention do not depart from the spirit and scope of the broadest form of the invention.

1 is a diagram illustrating a transmitter configuration of an F-CPCCH used in a conventional wireless communication system.

2 is a view showing an example of a reverse power control process over time in a conventional wireless communication system.

3 is a diagram illustrating a process of transmitting a reverse pilot channel and a forward power control bit in a half gating mode over time;

4 is a diagram illustrating a process of transmitting a reverse pilot channel and a forward power control bit in a quarter gating mode over time;

5 is a flowchart illustrating a F-CPCCH transmitter procedure of a base station according to a preferred embodiment of the present invention.

FIG. 6 illustrates a process of transmitting a reverse pilot channel and a forward power control bit over time in a half gating mode according to a preferred embodiment of the present invention. FIG.

7 is a diagram illustrating a process of transmitting a reverse pilot channel and a forward power control bit over time in a quarter gating mode according to a preferred embodiment of the present invention.

8 is a diagram illustrating a transmitter configuration of an F-CPCCH of a base station according to an embodiment of the present invention.

9 is a diagram showing the configuration of a transmitter of the F-CPCCH receiver and the pilot channel of the terminal according to an embodiment of the present invention.

10 is a flowchart illustrating a power control bit generation process and a power control bit transmission method of an F-CPCCH transmitter of a base station according to an exemplary embodiment of the present invention.

FIG. 11 illustrates a process of transmitting a reverse pilot channel and a forward power control bit over time in a quarter gating mode according to another embodiment of the present invention. FIG.

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention will now be described with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention to be described below provides a method and apparatus for generating and transmitting a power control bit by a terminal in an F-CPCCH, and a method and apparatus for analyzing a power control bit value by a base station receiving the same. Actual power control is delayed by 1 PCG or 2 PCG due to the time it takes for the base station and the terminal to transmit the received power control bits in the forward and reverse power control processes to be described below, and the time required to interpret them. do. However, this delay time is taken as an example to help the understanding of the present invention and may have different values depending on the system characteristics and the propagation environment.

The present invention proposes a method for the base station to repeatedly transmit the power control bits by the inverse of the gating rate. In addition, the present invention proposes a method of combining the power control bits received at the receiver receiving the power control bits by the inverse of the gating rate.

5 is a flowchart illustrating an F-CPCCH transmitter procedure of a base station according to an exemplary embodiment of the present invention. In the F-CPCCH transmission method of the present invention according to this flow, when the intermittent transmission rate (gating rate) (Rate) in the gating mode is N, the base station 1 / N slot power control bits of the F-CPCCH over 1 / N slots It is characterized in that the transmission repeatedly N times.

Referring to FIG. 5, in step 501, a physical layer F-CPCCH transmitter of a base station receives a gating rate from an upper layer. In step 502, if the gating rate is '1', the power control bit transmitted on the F-CPCCH is not repeated. The gating rate of '1' means a mode in which no gating is performed, that is, a power control bit is transmitted at 800bps. In step 502, if the gating rate is not '1', that is, when the terminal to be controlled for power is in the gating mode, in step 504, the power control bit transmitted through the F-CPCCH to power control the corresponding terminal is transmitted. Repeated transmission of 1 / (gating rate) over 1 / (gating rate) slot.

6 illustrates a process of transmitting a reverse pilot channel and a forward power control bit in a half gating mode according to a preferred embodiment of the present invention over time.

Referring to FIG. 6, a base station receiving a pilot pilot channel (R-PICH: Reverse Pilot Channel) transmitted by a UE during the PCG2 period measures an SNR of the pilot channel and compares it with a predetermined threshold. Generate a power control bit. The base station repeatedly transmits the generated power control bit by 2, which is an inverse of the gating rate. That is, the base station generates and transmits power control bits having the same value during the PCG3 and PCG4 periods. The generated power control bit is transmitted through a forward common power control channel (F-CPCCH). The terminal combines the power control bits received during the PCG3 and PCG4 intervals, interprets the values, and controls the transmission power of the pilot channel during the PCG6 intervals. Such transmission power is controlled through a reverse power control sub-channel (R-PCSCH). The above process is continuous.

7 illustrates a process of transmitting a reverse pilot channel and a forward power control bit in a quarter gating mode according to a preferred embodiment of the present invention over time.

Referring to FIG. 7, the base station receiving the pilot channel transmitted by the terminal during the PCG1 period measures the SNR of the pilot channel, compares it with a predetermined threshold value, and generates a power control bit according to the comparison result. The base station repeatedly transmits the generated power control bit by 4, which is an inverse of the gating rate. The generated power control bits are transmitted on the F-CPCCH. That is, the base station transmits the power control bits of the same value during the PCG3, PCG4, PCG5 and PCG6 period. The terminal combines the power control bits received during the PCG3, PCG4, PCG5 and PCG6 intervals, interprets the values, and controls the transmission power of the pilot channel during the PCG9 intervals. This transmission power is controlled through the R-PCSCH. The above process is continuous.

The operation of controlling the transmission power of the mobile terminal in a wireless communication system including a base station and a mobile terminal wirelessly connected to and communicate with the base station according to the embodiment of the present invention are as follows.

First, the base station measures the received signal-to-noise ratio (SNR) from the mobile terminal which intermittently transmits data at predetermined intervals according to the intermittent transmission rate (gating rate). In order to measure the SNR, a reverse pilot channel (R-PICH) from the mobile station is used.

Secondly, the base station compares the measured signal-to-noise ratio with a preset threshold and generates power control information according to the comparison result. The generated power control information may be a power control bit (PC Bit).

Third, the base station repeatedly transmits the generated power control information to the mobile terminal in a power control section determined from the set section. The transmission of the generated power control information is performed through a forward common power control channel (F-CPCCH). When the intermittent transmission rate is N, the power control section is determined to be a section of (1 / N). The set interval is determined in units of slots. For example, assuming that the intermittent transmission rate is 1/2, the power control interval may be set to 2 (= 1 / (1/2)) (see FIG. 6). As another example, assuming that the intermittent transmission rate is 1/4, the power control interval may be determined as 4 (= 1 / (1/4)) (see FIG. 7).

Fourth, the mobile terminal receives and combines the repeatedly transmitted power control information in a power control section smaller than or equal to the power control section, and controls transmission power of data to be transmitted to the base station according to the combined power control information. . When the intermittent transmission rate is N, the power control section to which the power control information is combined is determined to be less than or equal to (1 / N) and two or more sections. For example, assuming that the intermittent transmission rate is 1/2, the power control interval to which the power control information is combined is set to 2 (= 1 / (1/2)) (see FIG. 6). As another example, assuming that the intermittent transmission rate is 1/4, the power control interval to which the power control information is combined may be determined as 4 (= 1 / (1/4)) (see FIG. 7). As another example, assuming that the intermittent transmission rate is 1/4, the power control interval to which the power control information is combined may be determined as 2 (<1 / (1/4)) (see FIG. 11).

8 shows a transmitter configuration of an F-CPCCH of a base station according to an embodiment of the present invention.

Referring to FIG. 8, reference numerals 802 to 804 denote blocks for I channel transmission, and reference numerals 812 to 814 denote blocks for Q channel transmission. Each of the power control bits for 12 users is transmitted over a time offset multiplexing (TDM) over a different offset for one PCG period on each of the I and Q channels. Thus, a total of 24 power control bits are transmitted on one F-CPCCH. Reference numerals 801 and 811 denote twelve power control bits for the I and Q channels, respectively. The controller 821 receives a gating rate as an input to control the power control bit values of the 801 and 811, so that the power control bit values are repeated by 1 / (gating rate). The power control bits 801, 811 are symbol mapped to a '+1' or '1' or '0' value by the signal point mappers 802,812 and then multiplied by the power gain in the channel gain regulators 803,813. The power gain value is controlled by the forward power control bit value received from each terminal. The power control symbols of all the power gain controlled users are multiplexed by I and Q channels in multiplexers 804 and 814 and then transmitted on the F-CPCCH.

9 illustrates a configuration of a transmitter of a F-CPCCH receiver and a pilot channel of a terminal according to an embodiment of the present invention.

Referring to FIG. 9, the controller 901 receives a gating rate as an input to control the operation of the combiner 902, but the combiner 902 receives the F-CPCCH by combining 1 / (gating rate). Do it. The power control bit interpreter 903 receives the output of the combiner 902 as an input and interprets the received power control bit value. Gain controller 904 controls the gain of reverse pilot channel transmitter 905 according to the value of power control bit interpreter 903.

8 and 9, the operation performed by the apparatus for controlling the transmission power of the mobile terminal in a wireless communication system including a base station and a mobile terminal wirelessly connected to and communicated with the base station Looking at it as follows.

The base station includes a meter, a generator, and a transmitter. The measuring device (not shown in FIG. 8) measures a received signal-to-noise ratio (SNR) from the mobile terminal which intermittently transmits data at predetermined intervals according to the intermittent transmission rate. The generator compares the measured signal-to-noise ratio with a preset threshold and generates power control information according to the comparison result. This generator corresponds to controller 821 of FIG. The transmitter repeatedly transmits the generated power control information to the mobile terminal in a power control section determined from the set section. This transmitter corresponds to the remaining components in FIG. 8 except for the controller 821.

The mobile terminal includes a receiver, a combiner and a controller. The receiver (not shown in FIG. 9) receives the repeatedly transmitted power control information in a power control section that is less than or equal to the predetermined power control section. The combiner combines the received power control information at the mobile terminal. This coupler is a coupler at 902 in FIG. The controller controls the transmission power of data to be transmitted to the base station according to the combined power control information. This controller corresponds to the power control bit interpreter 903 and gain controller 904 of FIG.

10 is a flowchart illustrating a power control bit generation process and a power control bit transmission method of an F-CPCCH transmitter of a base station according to an exemplary embodiment of the present invention.

Referring to FIG. 10, the base station transmitter receives a gating rate from an upper layer (step 1002). In step 1003, it is determined whether the gating rate is '1'. If the gating rate is '1' in step 1003, the process proceeds to step 1004 to determine whether the SNR value of the reverse pilot channel received during the previous PCG period is greater than the threshold. If the SNR value of the reverse pilot channel received during the previous PCG period is greater than the threshold, it generates a power control bit '0'. On the other hand, if the SNR value of the reverse pilot channel received during the previous PCG period is not greater than the threshold, the power control bit '1' is generated. After transmitting the generated power control bit in step 1007, the transmitter returns to step 1001 to perform a time shift for one PCG period and then performs step 1002 again.

On the other hand, if the gating rate is not '1' in step 1003, it is determined whether the gating rate received in step 1002 is '1/2' in step 1010. If the gating rate is '1/2' in step 1010, the flow proceeds to step 1011 to determine whether the SNR value of the reverse pilot channel received during the previous PCG period is greater than the threshold. If the SNR value of the reverse pilot channel received during the previous PCG period is greater than the threshold, it generates a power control bit '0'. On the other hand, if the SNR value of the reverse pilot channel received during the previous PCG period is not greater than the threshold, the power control bit '1' is generated. In step 1014, the transmitter transmits the generated power control bit. After shifting for one PCG period in step 1015, and transmitting the power control bit once more in step 1016, the process returns to step 1001 and time shifts for one PCG period, and then performs step 1002 again.

On the other hand, if the gating rate is not '1/2' in step 1010, the flow proceeds to step 1020 to determine whether the SNR value of the reverse pilot channel received during the previous PCG interval is greater than the threshold. If the SNR value of the reverse pilot channel received during the previous PCG period is greater than the threshold, it generates a power control bit '0'. On the other hand, if the SNR value of the reverse pilot channel received during the previous PCG period is not greater than the threshold, the power control bit '1' is generated. In step 1023 to step 1029, the transmitter repeatedly transmits the generated power control bit four times. After that, the transmitter returns to step 1001 to perform a time shift for one PCG period and then performs step 1002 again.

11 illustrates a process of transmitting a reverse pilot channel and a forward power control bit in a quarter gating mode according to a preferred embodiment of the present invention over time.

Referring to FIG. 11, the base station receiving the pilot channel transmitted by the terminal during the PCG 1 period measures the SNR of the pilot channel, compares it with a predetermined threshold value, and generates a power control bit according to the comparison result. The base station repeatedly transmits the generated power control bit by 4, which is an inverse of the gating rate. That is, the same power control bit is transmitted during the PCG2, PCG3, PCG4, and PCG5 sections of FIG. The terminal combines the power control bits received during the PCG2 and PCG3 intervals, interprets the values, and controls the transmission power of the pilot channel during the PCG5 intervals. At this time, the terminal cannot use the power control bits received during the PCG4 and PCG5 period. This is because only power control bits received before one PCG may be used for power control for the PCG 5 section. The above process is continuous.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention provides an efficient reverse power control method for a terminal by a base station for a terminal receiving a high speed packet data service in a wireless communication system. As a result, the terminal can increase the reception reliability of the power control bit received from the base station. More accurate power control can be achieved through the reliable power control bit.

Claims (18)

A method of controlling transmission power of a mobile terminal by a base station in a wireless communication system including a base station and a mobile terminal wirelessly connected to and communicated with the base station, Measuring a received signal-to-noise ratio (SNR) from the mobile terminal, which transmits data at predetermined intervals according to an intermittent transmission rate; Comparing the measured signal to noise ratio with a preset threshold and generating power control information according to the comparison result; And transmitting the generated power control information to the mobile terminal repeatedly in a power control section determined from the set section. The method as claimed in claim 1, wherein when the intermittent transmission rate is N, the power control section is determined to be a section of (1 / N). The method as claimed in claim 1 or 2, wherein the set interval is in a slot unit. The method as claimed in claim 1, wherein the power control information is a power control bit. A method of controlling transmission power of a mobile terminal in a wireless communication system including a base station and a mobile terminal wirelessly connected to and communicated with the base station, Measuring a received signal-to-noise ratio (SNR) from the mobile terminal for transmitting data at predetermined intervals according to the intermittent transmission rate in the base station; Comparing, by the base station, the measured signal-to-noise ratio with a preset threshold and generating power control information according to the comparison result; Transmitting, by the base station, the generated power control information to the mobile terminal repeatedly in a power control section determined from the set section; Receiving, by the mobile terminal, the power control information repeatedly transmitted in a power control period less than or equal to the predetermined power control period; Combining the received power control information at the mobile terminal and controlling transmission power of data to be transmitted to the base station according to the combined power control information. The method as claimed in claim 5, wherein when the intermittent transmission rate is N, the power control section is determined to be a section of (1 / N). 6. The method as claimed in claim 5, wherein when the intermittent transmission rate is N, the power control section to which the received power control information is combined is determined in a section less than or equal to (1 / N) and more than two. The method as claimed in claim 5, wherein the set interval is in a slot unit. The method as claimed in claim 5, wherein the power control information is a power control bit. A base station apparatus for controlling transmission power of a mobile terminal in a wireless communication system including a base station and a mobile terminal wirelessly connected to and communicated with the base station, A measuring unit for measuring a received signal-to-noise ratio (SNR) from the mobile terminal which transmits data at predetermined intervals according to an intermittent transmission rate; A generator for comparing the measured signal to noise ratio with a preset threshold and generating power control information according to the comparison result; And a transmitter for repeatedly transmitting the generated power control information to the mobile terminal in a power control section determined from the set section. The base station apparatus according to claim 10, wherein when the intermittent transmission rate is N, the power control section is determined to be a section of (1 / N). The base station apparatus according to claim 10 or 11, wherein the set interval is in a slot unit. The base station apparatus according to claim 10, wherein the power control information is a power control bit. An apparatus for controlling a transmission power of a mobile terminal in a wireless communication system including a base station and a mobile terminal wirelessly connected to and communicating with the base station: The base station; A measuring unit for measuring a received signal-to-noise ratio (SNR) from the mobile terminal which intermittently transmits data at predetermined intervals according to an intermittent transmission rate; A generator for comparing the measured signal-to-noise ratio with a preset threshold at the base station and generating power control information according to the comparison result; And a transmitter for transmitting the generated power control information in the base station repeatedly to the mobile terminal in a power control section determined from the set section. The mobile terminal is; A receiver for receiving the repeatedly transmitted power control information in the predetermined power control section; A combiner for combining the received power control information in the mobile terminal; And a controller for controlling transmission power of data to be transmitted to the base station according to the combined power control information. 15. The apparatus as claimed in claim 14, wherein when the intermittent transmission rate is N, the power control section is determined to be a section of (1 / N). 15. The apparatus as claimed in claim 14, wherein when the intermittent transmission rate is N, the power control section to which the received power control information is combined is determined in a section less than or equal to (1 / N) and more than two. 17. The apparatus as claimed in any one of claims 14 to 16, wherein the set interval is in a slot unit. The apparatus as claimed in claim 14, wherein the power control information is a power control bit.