KR20080054148A - Apparatus and method for controlling of service coverage in wireless communication system - Google Patents

Abstract

An apparatus and a method for controlling a service coverage in a wireless communication system are provided to increase transmission power and to extend the service coverage when the signal of a terminal providing a service is weak, thereby improving the speech quality of the terminal. A method for controlling the range of a service coverage in a wireless communication system comprises the following steps of: checking the signal intensity of a terminal in a state that a terminal is connected to a traffic call(207); comparing current transmission power with the maximum transmission power when the signal intensity of the terminal is smaller or equal to a reference value(209); and extending the service coverage by increasing the transmission power when the current transmission power is smaller than the maximum transmission power(215).

Description

Apparatus and method for controlling service area in wireless communication system {APPARATUS AND METHOD FOR CONTROLLING OF SERVICE COVERAGE IN WIRELESS COMMUNICATION SYSTEM}

1 is a block diagram of a base station in a wireless communication system according to the present invention;

2 is a diagram illustrating an operation procedure of a base station for controlling transmission power according to the present invention; and

3 is a diagram illustrating an operation procedure of a terminal for controlling transmission power according to the present invention.

The present invention relates to an apparatus and a method for controlling transmission power in a wireless communication system, and more particularly, to an apparatus and method for adjusting a size of a service area by controlling transmission power according to signal strength of a terminal in the wireless communication system.

The wireless communication system supports a service by using a separate narrow band cell in an area where a service, such as a service area of a broadband band network or a shade area, cannot be provided.

The narrowband cell is matched with the broadband network to provide a mobile communication service, such as a home radio device and a mobile communication management system (Core system). Therefore, the narrowband cell is not installed at the same level as the base station of the macro cell of the broadband network but provides a small capacity output optimized for a small service area, and is installed in an area where the infrastructure of the macro cell is weak. For example, the narrow band cell includes an ubi cell.

The narrowband cell uses an adaptive RF function. That is, when the narrowband cell is installed in the region where the macrocell is present, the narrowband cell transmits to minimize the effect on the macrocell within a range capable of maintaining a call with the terminal included in the service area. Minimize RF power.

In addition, even when the narrowband cells are adjacent to each other, the narrowband cell minimizes RF power transmitted to minimize the influence on the adjacent narrowband cell within a range capable of maintaining a call with a terminal included in a service area.

As described above, the narrowband cell reduces the service area by minimizing the RF power transmitted in order to minimize the influence on neighboring cells. That is, since the narrowband cell does not use the maximum RF power that can be transmitted in order to minimize the influence on neighboring cells, the service area that the narrowband cell can support is reduced.

When the narrowband cell does not use the maximum RF power, the narrowband cell adaptively transmits the outgoing power even when the terminal provided with the service in the narrowband cell moves to the edge of the service area and the signal strength is weakened. Can not increase. Accordingly, a problem arises in that a communication state of terminals located at an edge of the service area is degraded or a call is disconnected in the narrowband cell.

Accordingly, an object of the present invention is to provide an apparatus and method for adjusting transmission power according to signal strength of terminals in a wireless communication system.

Another object of the present invention is to provide an apparatus and method for adjusting the size of a service area by adjusting transmission power according to signal strength of terminals in a narrowband cell of a wireless communication system.

Another object of the present invention is to provide an apparatus and method for expanding a service area by increasing the transmission power when signal strength of terminals in a narrowband cell of a wireless communication system is poor.

According to a first aspect of the present invention for achieving the above object, a method for adjusting the size of a service area in a wireless communication system, the process of checking the signal strength of the terminal in the state of establishing a traffic call with the terminal, Comparing the current transmission power with the maximum transmission power when the signal strength is less than or equal to a reference value; and increasing the transmission power to expand the service area when the current transmission power is smaller than the maximum transmission power. It characterized in that it comprises a process.

According to a second aspect of the present invention, an apparatus for adjusting the size of a service area in a wireless communication system includes a signal strength checking unit for checking a signal strength of a terminal, and when the signal strength is less than or equal to a reference value, And an amplification control unit for controlling the power amplifier to increase the transmission power, and a power amplifier extending the service area by increasing the power of the signal under the control of the amplification control unit.

According to a third aspect of the present invention, a method for adjusting the size of a service area in a narrow band cellular system includes: checking a signal strength of the terminal with a traffic call established with the terminal; When the signal strength is less than or equal to the reference value, comparing the current transmit power with the maximum transmit power; and when the current transmit power is less than the maximum transmit power, increasing the transmit power to expand the service area. Characterized in that it comprises a.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when 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.

Hereinafter, the present invention describes a technique for adjusting the size of a service area according to the signal strength of a terminal in a wireless communication system. In other words, a technique for controlling the size of the service area by adjusting the power transmitted according to the signal strength of the terminal in the wireless communication system will be described.

In the following description, an additional narrow band cell is described as an example in an area in which a service such as a service area of a broadband band network or a shadow area cannot be provided. In this case, when the maximum transmit power that can be supported by the narrowband cell is not used, the base station of the narrowband cell sequentially increases the transmit power to the maximum transmit power according to the signal strength of the terminal, thereby increasing the size of the service area. It describes a technique for extending the.

1 is a block diagram of a base station in a wireless communication system according to the present invention.

As shown in FIG. 1, the base station includes a modem 101, a transmitter 103, a band pass filter 105, a power amplifier 107, an amplification control unit 109, and a signal strength checking unit ( 111).

First, the modem 101 codes and modulates and transmits data to be transmitted according to a modulation level (Modulation and Coding Scheme (MCS) level).

The transmitter 103 up-converts the baseband signal provided from the modem 101 into a radio frequency (RF) signal and outputs the frequency.

The band pass filter 105 suppresses and outputs a signal provided from the transmitter 103 in a frequency band other than the frequency band set in the transmitter.

The power amplifier 107 amplifies the power of the signal provided from the band pass filter 105 under the control of the amplification controller 109 and transmits the power through the antenna.

The amplification control unit 109 controls the amplification rate of the power amplifier 107 according to the signal strength (eg, signal-to-noise ratio (Ec / Io)) of the terminal provided from the signal strength checking unit 111 to determine the service area. Adjust the size. For example, when the signal strength of the terminal is poor, the amplification controller 109 controls to increase the power of the power amplifier 107 to expand the service area. In this case, the amplification control unit 109 controls to increase the power of the power amplifier 107 only up to the maximum output of the power amplifier 107. Here, the amplification controller 109 compares the signal strength of the terminal with a reference value and determines whether the power of the transmission amplifier 107 is increased.

The signal strength checking unit 111 checks the signal strength information included in the signal received from the terminal and provides the signal strength information to the amplifying control unit 109. For example, the signal strength checking unit 111 transmits a signal status request message to the terminal to check the signal strength of the terminal. Thereafter, when the signal status response message is received from the terminal, the signal strength checking unit 111 checks the signal strength of the terminal included in the message and provides the signal strength to the amplifying control unit 109.

2 illustrates an operation procedure of a base station for controlling transmission power according to the present invention.

Referring to FIG. 2, first, the base station establishes a traffic call with the terminal in step 201.

In the state where the traffic call is established with the terminal, the base station proceeds to step 203 and transmits a signal status request message to confirm the signal strength of the terminal. Here, the base station periodically transmits the signal status request message.

In step 205, the base station determines whether a signal status response message is received from the terminal.

If the signal status response message is received, the base station proceeds to step 207 to check the signal strength of the terminal included in the signal status response message.

In step 209, the base station compares the signal strength of the terminal with a reference value. Here, the reference value may be changed according to the channel state and the amount of interference.

If the signal strength is greater than the reference value (signal strength> reference value), the base station determines in step 211 that the signal strength of the terminal is good and maintains the magnitude of the transmission power. That is, the base station does not change the size of the service area by maintaining the size of the transmission power.

On the other hand, if the signal strength is less than or equal to the reference value (signal strength ≤ reference value), the base station determines whether the transmission power can be increased by comparing the current transmission power with the maximum transmission power in step 213. .

If the current transmission power and the maximum transmission power are the same, the base station determines that the transmission power can no longer be increased and proceeds to step 211 to maintain the magnitude of the transmission power.

On the other hand, if the current transmission power is the maximum transmission power is small, the base station proceeds to step 215 to increase the transmission power by a predetermined width (for example, 1dB) to improve the signal strength of the terminal. That is, the base station increases the transmission power by a certain amount to expand the service area. At this time, the base station does not exceed the maximum transmission power of the transmission power increased by a predetermined width.

The base station then terminates this algorithm.

3 illustrates an operation procedure of a terminal for controlling transmission power according to the present invention.

Referring to FIG. 3, first, the terminal establishes a traffic call with the base station in step 301.

In step 303, the terminal determines whether a signal status request message is received from the base station.

If the signal status request message is received, the terminal proceeds to step 305 and measures the strength (eg, signal-to-noise ratio (Ec / Io)) of the signal received from the base station.

After measuring the signal strength, the terminal proceeds to step 307 and transmits a signal status response message including the signal strength information to the base station.

Thereafter, the terminal terminates the present algorithm.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described. However, various modifications may be made 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 determined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, when the signal strength of the terminal providing the service in the wireless communication system is poor, there is an advantage that can improve the call quality of the terminal by increasing the transmission power to extend the service area.

Claims (17)

A method for adjusting the size of a service area in a wireless communication system, Checking the signal strength of the terminal with a traffic call set up with the terminal; When the signal strength is less than or equal to a reference value, comparing the current transmit power with the maximum transmit power; If the current transmit power is less than the maximum transmit power, increasing the transmit power to expand the service area. The method of claim 1, The process of checking the signal strength of the terminal, Transmitting a request signal for checking the signal strength of the terminal; If the response signal is received from the terminal, the method comprising the step of checking the signal strength included in the response signal. The method of claim 1, And the signal strength is a signal to noise ratio (Ec / Io). The method of claim 1, And wherein the transmit power is increased not to be greater than the maximum transmit power. The method of claim 1, And if the signal strength is greater than a reference value, maintaining the transmission power constant so as not to change the size of the service area. The method of claim 1, And if the current transmit power is equal to the maximum transmit power, maintaining the transmit power constant so as not to change the size of the service area. An apparatus for adjusting the size of a service area in a wireless communication system, A signal strength checking unit for checking the signal strength of the terminal; An amplifying controller for controlling a power amplifier to increase the transmission power when the signal strength is less than or equal to a reference value; And a power amplifier for expanding the service area by increasing power of a signal under the control of the amplification controller. The method of claim 7, wherein The signal strength check unit, And checking a signal-to-noise ratio (Ec / Io) included in the signal received from the terminal. The method of claim 7, wherein The amplification control unit, And control the power amplifier to increase the transmit power if the signal strength is less than or equal to a reference value and less than the current transmit power and the maximum transmit power. The method of claim 9, And the amplifying control unit controls the power amplifier such that the transmit power does not exceed the maximum transmit power. The method of claim 7, wherein The amplification control unit, And control the power amplifier to keep the transmit power constant when the signal strength is greater than a reference value. A method for adjusting the size of a service area in a narrow band cellular system, Checking the signal strength of the terminal with a traffic call set up with the terminal; When the signal strength is less than or equal to a reference value, comparing the current transmit power with the maximum transmit power; If the current transmit power is smaller than the maximum transmit power, increasing the transmit power to expand the service area. The method of claim 12, The process of checking the signal strength of the terminal, Transmitting a request signal for checking the signal strength of the terminal; If the response signal is received from the terminal, the method comprising the step of checking the signal strength included in the response signal. The method of claim 12, And the signal strength is a signal to noise ratio (Ec / Io). The method of claim 12, And wherein the transmit power is increased not to be greater than the maximum transmit power. The method of claim 12, And if the signal strength is greater than a reference value, maintaining the transmission power constant so as not to change the size of the service area. The method of claim 12, And if the current transmit power is equal to the maximum transmit power, maintaining the transmit power constant so as not to change the size of the service area.

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