KR101547562B1 - Apparatus and method for controlling of service coverage in wireless communication system - Google Patents

Abstract

The present invention relates to an apparatus and method for adjusting a size of a service area in a wireless communication system, the method comprising the steps of: checking a signal strength of a terminal in a state in which a traffic call is established with the terminal; Comparing the current transmission power with a maximum transmission power when the current transmission power is less than the maximum transmission power and extending the service area by increasing the transmission power; There is an advantage that the quality can be improved.

Cellular system, transmit power, cell service area, signal-to-noise ratio (Ec / Io)

Description

TECHNICAL FIELD [0001] The present invention relates to a service area control apparatus and a method for controlling a service area in a 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 Fig.

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 method for controlling transmission power in a wireless communication system, and more particularly, to an apparatus and method for controlling transmission power according to a signal strength of a terminal in the wireless communication system.

The wireless communication system supports a service using a separate narrow band cell in an area that can not provide services such as a service area of a broadband network or a voice service area.

The narrow band cell may be matched with the broadband network to provide a mobile communication service such as a home radio apparatus and a mobile communication management apparatus (Core system). Therefore, the narrowband cell is installed in a region where the infrastructure of the macrocell is weak, by providing a small capacity output optimized for a small service area, not the same output as a base station of a macro cell of the broadband network. For example, the narrow band cell includes a Ubi cell.

The narrow band cell uses an adaptive RF function. That is, when the narrow band cell is installed in an area where the macro cell exists, the narrow band cell transmits to minimize the influence on the macro cell within a range capable of maintaining a call with a terminal included in the service area Minimize RF power.

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

As described above, in order to minimize the influence on the adjacent cells, the narrow band cell minimizes the RF power to be transmitted, thereby reducing the service area. That is, since the narrow band cell does not use the maximum RF power that can be transmitted to minimize the influence on adjacent cells, the service area that the narrow band cell can support is reduced.

If the narrow band cell does not use the maximum RF power, even if the terminal that is served in the narrow band cell moves to the edge of the service area and the signal strength weakens, the narrow band cell adaptively changes the transmission power Can not be increased. Therefore, there arises a problem that the communication state of the terminals located at the edge of the service area in the narrowband cell is deteriorated or the call is disconnected.

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

It is another object of the present invention 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 narrow band cell of a wireless communication system.

It is another object of the present invention to provide an apparatus and method for extending the service area by increasing the transmission power when the signal strength of the terminals is poor in the narrow band cell of the wireless communication system.

According to an aspect of the present invention, there is provided a method for adjusting a size of a service area in a wireless communication system, the method comprising: checking signal strength of a terminal in a state where a traffic call is established with the terminal; Comparing the current transmission power with a maximum transmission power if the signal strength is less than or equal to a reference value; and if the current transmission power is less than the maximum transmission power, expanding the service area by increasing the transmission power The method comprising the steps of:

According to a second aspect of the present invention, there is provided an apparatus for adjusting a size of a service area in a wireless communication system, the apparatus comprising: a signal strength checking unit for checking a signal strength of a terminal; An amplification control unit for controlling the power amplifier to increase the transmission power; and a power amplifier for expanding 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, there is provided a method for adjusting a size of a service area in a narrow band cellular system, the method comprising the steps of: Comparing a current transmit power with a maximum transmit power when the signal strength is less than or equal to a reference value; and if the current transmit power is less than the maximum transmit power, And a control unit.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

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

Hereinafter, a narrow band cell will be described as an example in a service area out of a broadband network or in a region where a service such as a shadow area can not be provided. If the maximum transmission power that can be supported by the narrowband cell is not used, the base station of the narrow band cell sequentially increases the transmission power according to the signal strength of the user terminal to the maximum transmission power, Will be described.

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

1, the base station includes a modem 101, a transmitter 103, a bandpass filter 105, a power amplifier 107 and an amplification controller 109, a signal strength checker 111).

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

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

The bandpass filter 105 suppresses a frequency band other than the frequency band set by the transmitting apparatus and outputs the signal provided from the transmitter 103.

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

The amplification control unit 109 controls the amplification rate of the power amplifier 107 according to the signal strength (e.g., signal-to-noise ratio (Ec / Io)) of the terminal provided from the signal strength check unit 111, Adjust the size. For example, when the signal strength of the terminal is poor, the amplification control unit 109 controls the power amplifier 107 to increase the power to extend the service area. At this time, the amplification control unit 109 controls the power of the power amplifier 107 to increase only to the maximum output of the power amplifier 107. Here, the amplification control unit 109 compares the signal strength of the terminal with a reference value to determine whether the power of the transmission amplifier 107 is increased.

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

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

Referring to FIG. 2, the BS sets up a traffic call with a mobile station in step 201.

In step 203, the BS transmits a signal status request message to the MS to confirm the signal strength of the MS. Here, the BS periodically transmits the signal status request message.

Thereafter, the BS proceeds to step 205 and checks whether a signal status response message is received from the MS.

If the signal status response message is received, the BS proceeds to step 207 and checks the signal strength of the UE included in the signal status response message. Here, the signal strength of the terminal may include the strength of a signal received from the base station by the terminal.

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

If the signal strength is greater than the reference value (signal strength> reference value), the BS proceeds to step 211 and determines that the signal strength of the UE is good and maintains the transmission power. That is, the BS does not change the size of the service area by maintaining the transmission power.

Meanwhile, if the signal strength is less than or equal to the reference value (signal strength? Reference value), the BS proceeds to step 213 and compares the current transmission power with the maximum transmission power to determine whether the transmission power can be increased .

If the current transmission power is equal to the maximum transmission power, the base station determines that the transmission power can not be increased any more, and proceeds to step 211 to maintain the transmission power.

On the other hand, if the current transmission power has a small maximum transmission power, the base station proceeds to step 215 and increases the transmission power by a predetermined width (e.g., 1 dB) 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 ensures that the transmission power that has been increased by the constant width does not exceed the maximum transmission power.

Thereafter, the base station terminates the present algorithm.

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

Referring to FIG. 3, in step 301, the terminal sets up a traffic call to a base station.

The mobile station proceeds to step 303 and confirms 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 (e.g., signal-to-noise ratio (Ec / Io)) of the signal received from the base station.

After measuring the signal strength, the MS proceeds to step 307 and transmits a signal status response message including the signal strength information to the BS.

Thereafter, the terminal ends the algorithm.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

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 the quality of the call of the terminal can be improved by increasing the transmission power to expand the service area.

Claims (17)

A method for adjusting the size of a service area in a wireless communication system, Periodically transmitting a signal status request signal to a mobile station in a state in which a traffic call is established with the mobile station, Receiving a response signal for a signal status request signal from the terminal; Confirming a signal reception strength of the terminal included in the response signal; Comparing the current transmission power with a maximum transmission power when the signal reception strength is less than or equal to a reference value; And expanding the size of the service area by increasing the current transmission power if the current transmission power is smaller than the maximum transmission power, And if the signal reception strength is greater than the reference value, maintaining the current transmission power constant and not changing the size of the service area. delete The method according to claim 1, Wherein the signal reception strength comprises a signal-to-noise ratio (Ec / Io). The method according to claim 1, Wherein the current transmit power can be increased only up to the maximum transmit power. delete The method according to claim 1, If the current transmission power is greater than the maximum transmission power, maintaining the current transmission power constant and not changing the size of the service area. An apparatus for adjusting the size of a service area in a wireless communication system, A signal condition request signal is periodically transmitted to a terminal in a state where a traffic call is established with the terminal, a response signal for a signal status request signal is received from the terminal, and a signal reception strength of the terminal included in the response signal is checked A signal strength confirmation unit for, An amplification controller for controlling the power amplifier to increase a transmission power when the signal reception strength is less than or equal to a reference value; And a power amplifier for increasing the transmission power of the signal according to the control of the amplification control unit to expand the size of the service area, Wherein the amplification control unit controls the power amplifier to maintain the transmission power constant when the signal reception strength is greater than the reference value. 8. The method of claim 7, Wherein the signal reception strength comprises a signal-to-noise ratio (Ec / Io). 8. The method of claim 7, Wherein the amplification control unit comprises: Comparing the current transmission power being used to transmit a signal with a maximum transmission power if the signal reception strength is less than or equal to a reference value and increasing the current transmission power if the current transmission power is less than the maximum transmission power The power amplifier comprising: 8. The method of claim 7, Wherein the amplification control unit controls the power amplifier so that the transmission power can be increased only up to a maximum transmission power. delete A method for adjusting the size of a service area in a narrow band cellular system, Periodically transmitting a signal status request signal to a mobile station in a state in which a traffic call is established with the mobile station, Receiving a response signal for a signal status request signal from the terminal; Confirming a signal reception strength of the terminal included in the response signal; Comparing the current transmission power with a maximum transmission power when the signal reception strength is less than or equal to a reference value; And expanding the size of the service area by increasing the current transmission power if the current transmission power is smaller than the maximum transmission power, And if the signal reception strength is greater than the reference value, maintaining the current transmission power constant and not changing the size of the service area. delete 13. The method of claim 12, Wherein the signal reception strength comprises a signal-to-noise ratio (Ec / Io). 13. The method of claim 12, Wherein the current transmit power can be increased only up to the maximum transmit power. delete 13. The method of claim 12, If the current transmission power is greater than the maximum transmission power, maintaining the current transmission power constant and not changing the size of the service area.

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