KR100638209B1 - Mobile Communication Terminal and its operating method - Google Patents

Abstract

The present invention relates to a mobile communication terminal that allows an optimum impedance matching by varying an impedance according to a radio wave environment when receiving an external signal through an antenna. The field strength (RSSI) and the signal-to-noise ratio (Ec / Io) are calculated, and a pulse signal corresponding to the maximum value of the field strength (RSSI) and the signal-to-noise ratio (Ec / Io) is output. According to the present invention, it is possible to greatly improve the call quality of the terminal by optimizing the input impedance of the received signal even in various propagation environments, thereby improving the reliability of the product, and configured to vary the input impedance using a filter and a capacitor. Therefore, there is an effect that the manufacturing process can be easily performed.

Antenna, Impedance, Matching Circuit, Capacitor, Mobile Communication Terminal

Description

 Mobile communication terminal and its control method             

1 is a diagram illustrating an antenna matching circuit of a mobile communication terminal receiving terminal according to the prior art;

2 is a block diagram schematically illustrating a receiving end of a mobile communication terminal according to the present invention;

3 is a diagram illustrating an antenna matching circuit of a mobile communication terminal receiving terminal according to the present invention;

4 is a flowchart illustrating a control method of a mobile communication terminal according to the present invention.

<Explanation of symbols on main parts of the drawings>

100: variable antenna matching unit 120: variable matching unit

121: variable capacitor 122: filter portion

200: MPU 210: PDM

300: memory

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication terminal, and more particularly, to a mobile communication terminal that enables an optimum impedance matching by varying an impedance according to a radio wave environment when receiving an external signal through an antenna.

1 is a diagram illustrating an antenna matching circuit of a receiver of a mobile communication terminal according to the prior art.

The mobile communication terminal according to the prior art includes an antenna (N) for receiving an external signal, an antenna matching unit (10) for matching an input impedance of a received signal, arithmetic processing for performing overall operations of the mobile communication terminal, and And a microprocessor unit (MPU) 20 that reads the signal output from the antenna matching unit 10 and converts the signal into an analog voice signal.

At this time, the antenna matching unit 10 is composed of a plurality of inductor or capacitor elements to match the input impedance of the signal received from the antenna (N) according to the impedance value determined by the inductor and the capacitor.

However, the mobile communication terminal according to the related art configured as described above has a problem of implementing an impedance matching circuit optimized only in a specific propagation environment because a plurality of elements constituting the antenna matching unit 10 have a specific fixed value. There is this.

In addition, the position of the terminal may be changed while performing a signal transmission / reception operation. In the case of a clamshell terminal, the folder is opened around the antenna N for transmitting and receiving radio signals such as the folder is opened toward the antenna. The radio wave environment is irregularly varied, and the level of the received signal is varied according to the variable radio wave environment.

Therefore, when the propagation environment optimized by the antenna matching unit 10 and the propagation environment of the signal received through the antenna N are different, the input impedance of the received signal is not matched normally, so that the received signal is the MPU. Not properly delivered to (20), thus causing a problem that the call quality of the mobile communication terminal is greatly reduced.

The present invention has been made to solve the above-mentioned problems of the prior art, and the input impedance of the received signal is varied according to the magnitude of the pulse signal output from the MPU so that an optimized impedance matching circuit can be implemented in various propagation environments. An object of the present invention is to provide a mobile communication terminal and a control method thereof.

The mobile communication terminal according to the present invention for solving the above problems is an antenna for transmitting and receiving a signal, a variable antenna matching unit for varying the input impedance of the signal received from the antenna and the electric field strength of the signal output from the variable antenna matching unit And a microprocessor unit (MPU) for calculating a signal intensity ratio (RSSI) and a signal-to-noise ratio (Ec / Io) and outputting a pulse signal corresponding to the highest value of the field strength (RSSI) and the signal-to-noise ratio (Ec / Io).

In addition, the control method of the mobile communication terminal according to the present invention comprises the first step of calculating and storing the initial field strength (RSSI) and the signal-to-noise ratio (Ec / Io) for the signal received from the antenna, the pulse signal for the received signal The second step of selecting the maximum value of the field strength (RSSI) and the signal-to-noise ratio (Ec / Io) calculated from the output signal by varying the and the maximum value of the field strength (RSSI) and signal-to-noise ratio (Ec / Io) And outputting a pulse signal corresponding to the third step.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a block diagram schematically illustrating a receiving end of a mobile communication terminal according to the present invention, and FIG. 3 is a diagram illustrating an antenna matching circuit of the receiving end of a mobile communication terminal according to the present invention.

The mobile communication terminal according to the present invention includes an antenna (N) for transmitting and receiving a signal wirelessly from a base station, a transmitting end (not shown) for transmitting a signal to the outside through the antenna (N), and an input from the antenna (N). And a receiving end (not shown) for converting the signal to be readable.

In addition, it comprises a MPU (200, Micro Processor Unit) for converting the text, voice or video data to be transmitted to the base station through the transmitting end into a wireless signal, and reads the wireless signal input through the receiving end as data. do.

In this case, the receiving end is configured to include a variable antenna matching unit 100 to match the input impedance so that the external wireless signal input from the antenna (N) is transmitted to the MPU (200).

The variable antenna matching unit 100 changes the impedance according to the radio wave environment around the antenna N, which is changed by the position or state of the mobile communication terminal, thereby input impedance of the wireless reception signal received from the antenna N. Is optimally matched to be delivered to the MPU 200.

The variable antenna matching unit 100 is connected to the fixed matching unit 110 and the fixed matching unit 110 formed of a plurality of elements forming a predetermined impedance value in order to perform the function of the MPU (200) It includes a variable matching unit 120 to change the input impedance value in accordance with the signal input from).

The fixed matching unit 110 is composed of a plurality of inductors and capacitors having a specific value so that the impedance value is constant.

The variable matching unit 120 has a variable value due to a filter unit 122 for converting a pulse signal output from the MPU 200 into a DC voltage signal and a DC voltage signal output from the filter unit 122. It is configured to include a variable capacitor 121.

The filter unit 122 receives a pulse duration modulation (PDM) signal, which is a pulse signal generated from the MPU 200, rectifies the signal into a DC voltage signal, and applies the rectified signal to the variable capacitor 121. The filter unit 122 is preferably composed of an RC filter.

The MPU 200 calculates an electric field strength (RSSI) and a signal-to-noise ratio (Ec / Io) of a signal initially received through the antenna N, and varies the pulse width of the PDM 210 for a predetermined number of times. Output to the filter unit 122.

The filter unit 122 rectifies the variable pulse signal and converts it into a DC voltage, and the converted signal varies the capacitor value of the variable capacitor 121 to change the input impedance value of the variable antenna matching unit 100. Be sure to

The MPU 200 calculates and stores an electric field strength (RSSI) and a signal-to-noise ratio (Ec / Io) of a wireless signal received from the antenna N according to a variable input impedance value, and stores the pulse of the PDM 210. The electric field strength (RSSI) and the signal-to-noise ratio (Ec / Io) of the radio signal received by the MPU 200 are calculated and stored for a predetermined number of times of varying width.

In this case, the mobile communication terminal may further include a memory unit 300 for storing the electric field strength (RSSI) and the signal-to-noise ratio (Ec / Io) calculated from the MPU 200, respectively.

The MPU 200 selects the highest value of the stored field strength (RSSI) and the signal-to-noise ratio (Ec / Io), and corresponds to the maximum value of the field strength (RSSI) and the signal-to-noise ratio (Ec / Io). Set the pulse value of and output the pulse signal according to the set pulse value.
Here, the input impedance value of the variable antenna matching unit 100 is matched to the input impedance value corresponding to the set pulse value of the PDM 210.

Therefore, the capacitor value of the variable capacitor 121 is determined according to the pulse value finally output from the MPU 200, and the input impedance value of the variable antenna matching unit 100 is determined according to the determined capacitor value. In this case, the input impedance value determined at this time is formed to be an optimized value in the radio wave environment around the antenna (N).

Looking at the operation of the present invention configured as described above are as follows. 4 is a flowchart illustrating a control method of a mobile communication terminal according to the present invention.

Receives a radio signal through an antenna from a base station. When the received signal is applied to the MPU 200, the MPU 200 calculates an initial electric field strength (RSSI) and a signal-to-noise ratio (Ec / Io) of the received signal, and stores the calculated value (S1, S2). .

The MPU 200 varies the pulse width of the pulse signal generated therein and outputs the result to the antenna matching circuit, and the antenna matching circuit forms an input impedance value by varying the capacitor value according to the applied pulse signal (S3). .

The received radio signal is applied to the MPU 200 via the antenna matching circuit, and the MPU 200 calculates and stores an electric field strength (RSSI) and a signal-to-noise ratio (Ec / Io) of the applied signal. In this case, the electric field strength (RSSI) and the signal-to-noise ratio (Ec / Io) have different values according to the input impedance value of the antenna matching circuit which varies according to the pulse signal. (S4)

Here, the MPU 200 changes the pulse width of the pulse signal again and outputs it to the antenna matching circuit, and then the electric field strength (RSSI) and the signal-to-noise ratio (Ec / Io) of the received radio signal according to the next variable pulse width. When the above-described process of calculating and storing is repeatedly performed for a predetermined number of times (S3 to S5), the respective electric field strengths (RSSI) and signal-to-noise ratios (Ec / Io) stored up to the point of time are compared (S6). , And select the highest value of the electric field strength (RSSI) and signal-to-noise ratio (Ec / Io) (S7). That is, the highest value of the electric field strength (RSSI) and the highest value of the signal-to-noise ratio (Ec / Io) are selected.

At this time, the process (S3 to S5) is preferably performed by repeating three to five times.

By detecting the pulse signal of the electric field strength (RSSI) and the signal-to-noise ratio (Ec / Io) corresponding to the selected highest value, the input impedance value of the antenna matching circuit at the time when the corresponding pulse signal is applied to the MPU (200) In operation S8, the input impedance value of the antenna matching circuit is matched according to the determined input impedance value.

At this time, the same pulse signal is applied to the antenna matching circuit according to the data such as the width and the period of the determined pulse signal.

Accordingly, when receiving a signal in a specific radio wave environment, it is possible to quickly calculate and vary the optimum input impedance so that the received signal is normally read through the MPU, thereby maintaining high call quality even in various radio wave environments.

As described above, the mobile communication terminal and the control method thereof according to the present invention have been described with reference to the illustrated drawings. However, the present invention is not limited by the embodiments and the drawings disclosed herein, and various modifications can be made through pulse signals output from the MPU. The technical idea of implementing an impedance matching circuit that can be optimized in a radio wave environment can be easily applied by those skilled in the art within a protected range.

The mobile communication terminal and the control method according to the present invention configured as described above by varying the input impedance through the pulse signal output from the MPU, thereby improving the call quality of the terminal by optimizing the input impedance of the received signal in various radio wave environments It can greatly improve the effect of improving the reliability of the product.

In addition, since it is configured to vary the input impedance using a filter and a capacitor, there is an effect that the manufacturing process can be easily performed.

Claims (8)

An antenna for transmitting and receiving a signal; A variable antenna matching unit configured to vary an input impedance of a signal received from the antenna; And The field strength (RSSI) and the signal-to-noise ratio (Ec / Io) of the signal output from the variable antenna matching unit are calculated, and a pulse signal corresponding to the maximum value of the field strength (RSSI) and the signal-to-noise ratio (Ec / Io) is obtained. And a microprocessor unit (MPU) outputting the mobile communication terminal. The method of claim 1, The variable antenna matching unit includes a fixed matching unit consisting of a plurality of elements having a specific value so that a predetermined magnitude of impedance value is formed; And And a variable matching unit connected to the fixed matching unit and provided with a variable capacitor configured to vary according to an applied signal, such that an input impedance value of a pulse signal input from the MPU is varied. Mobile communication terminal. The method of claim 1, The input impedance value is matched with an input impedance value for a pulse signal corresponding to the highest value of the field strength (RSSI) and signal to noise ratio (Ec / Io). The method of claim 1, And a memory unit for storing the field strength (RSSI) and the signal-to-noise ratio (Ec / Io) calculated from the MPU, respectively. The method of claim 1, The MPU calculates an initial electric field strength (RSSI) and a signal-to-noise ratio (Ec / Io) for a signal received from the antenna, varies the pulse width of a pulse signal for the received signal, and matches the variable antenna for a predetermined number of times. Mobile communication terminal, characterized in that to be applied to the negative. Calculating and storing an initial field strength (RSSI) and a signal-to-noise ratio (Ec / Io) for a signal received from an antenna; A second step of selecting a maximum value of the field strength (RSSI) and the signal-to-noise ratio (Ec / Io) calculated from the output signal by varying the pulse signal with respect to the received signal; And And outputting a pulse signal corresponding to the maximum value of the electric field strength (RSSI) and the signal-to-noise ratio (Ec / Io). The method of claim 6, The second step may include calculating an electric field strength (RSSI) and a signal-to-noise ratio (Ec / Io) from the output signal by varying the pulse signal; And And repeating the process for a predetermined number of times, selecting a maximum value of the stored field strength (RSSI) and the signal-to-noise ratio (Ec / Io), respectively. The method of claim 7, wherein The control method of the mobile communication terminal, characterized in that for repeating the process three to five times.

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