KR100296404B1 - How to Display Receive Sensitivity Correction for Wireless Terminal - Google Patents

Abstract

The present invention relates to a receiving sensitivity correction display method of a wireless terminal.

In the conventional wireless terminal, even if the base station transmits the same wireless signal, the reception sensitivity is different for each wireless terminal of the same type due to the difference in the components of the RF module and the difference in the reference voltage which is the operation reference of the AD converter of the baseband controller chip. Since the value is displayed, there is a problem that the user has a doubt on the quality of the wireless terminal product, thereby lowering the reliability of the wireless terminal.

In the present invention, since the difference between the RF module component and the AD converter reference voltage of the baseband controller chip in the wireless terminal is corrected and displayed, the difference in the reception sensitivity of the wireless signal is improved, thereby improving the reliability of the wireless terminal. .

Description

Receiving sensitivity correction display method of wireless terminal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless terminal that performs wireless communication, in particular due to a difference in components of an RF (Radio Frequency) module and an AD converter (Analog to Digital Converter) reference voltage of a baseband controller chip in the wireless terminal. The present invention relates to a display method for correcting reception sensitivity of a wireless terminal for correcting a difference in reception sensitivity with respect to a wireless signal.

In general, a wireless terminal for performing wireless communication while moving is provided with an RF module, performs wireless communication through the corresponding RF module, and displays the wireless communication sensitivity to the user.

Looking at the radio terminal of the DECT (Digital Enhanced Cordless Telecommunication) system as an example in the existing radio terminal, the radio terminal is provided with an RF module as shown in FIG. That is, the RF module 10 of the wireless terminal includes a transmission and reception switch (SW), a low noise amplifier (LNA), a band pass filter (F1, F2), a SAW filter (F3), a Gaussian filter (F4), a mixer (MIX), A plurality of amplifiers (AMP1 to AMP4), intermediate frequency processing unit (IF, dual PLL (DP), attenuators (ATT1, 2), voltage controlled oscillator (VCO) and a voltage regulator (RG) is configured, the antenna ANT It performs a function of transmitting and receiving data wirelessly through), and outputs a RSSI (Radio Signal Strength Indicator) level indicating the strength of the radio signal received from the base station.

The RF module 10 as described above is connected to the baseband controller chip 20 as shown in FIG. 2 to adjust the RSSI level to the baseband controller chip 20 side through an RSSI output pin (indicated by a dotted line in the drawing). The baseband controller chip 20 converts the corresponding DC voltage applied from the RF module 10 into a digital value through an AD converter, and the wireless terminal displays the liquid crystal display using the converted digital value. The RSSI level is displayed on the device LCD to indicate the reception sensitivity of the radio signal.

However, in the conventional wireless terminal as described above, even if the base station transmits the same radio signal, the difference between the components of the RF module 10 and the reference voltages VREF and VBGP which are operating criteria of the AD converter of the baseband controller chip 20. Due to the difference of), since a different reception sensitivity value is displayed for each wireless terminal of the same model, there is a problem that the user has a doubt on the quality of the wireless terminal product, thereby lowering the reliability of the wireless terminal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and its object is to provide a reception sensitivity for a wireless signal generated due to a difference between a component of an RF module and a difference between an AD converter reference voltage of a baseband controller chip in a wireless terminal. The present invention provides a display method for correcting reception sensitivity of a wireless terminal for correcting and displaying a difference.

1 is a block diagram of an RF module of a conventional wireless terminal.

2 is a diagram illustrating a connection between an RF module and a baseband controller chip in a conventional wireless terminal.

3 is a reception sensitivity correction process of a wireless terminal according to the present invention.

4 is a device connection diagram for the AD converter correction in the present invention.

5 is a reception sensitivity characteristic diagram of a wireless terminal.

6 is a device connection diagram for setting a reference RSSI value in the present invention.

7 is a process diagram for setting a reference RSSI value for the sensitivity display correction of the received radio signal in the present invention.

8 is a reception sensitivity characteristic diagram of a radio terminal corrected.

Explanation of symbols on the main parts of the drawings

31, 42: personal computer 32: power supply

33: IIC / RS232 Converter WLT: Wireless Terminal

41: DECT test set

Features of the present invention for achieving the above object, a reference voltage correction process for correcting the AD converter reference voltage of the baseband controller chip by applying a reference voltage to the baseband controller chip; Setting a reference RSSI value for applying a radio signal having a reference RSSI value to the RF module to set a reference RSSI value for correcting an indication of the sensitivity of the received radio signal; And a sensitivity display process of correcting and displaying the sensitivity of the received radio signal based on the set reference RSSI value.

The reference voltage correction process may include entering the wireless terminal into an AD converter correction mode and recognizing and storing the reference voltage value for setting a low voltage warning in the wireless terminal.

The setting of the reference RSSI value may include: entering the wireless terminal into a wireless signal correction mode, inputting a wireless signal having a predetermined reference level to the RF module of the wireless terminal, and RF of the wireless terminal. The module applying a reference RSSI level corresponding to the radio signal having the reference level to a baseband controller chip, and an AD converter of the baseband controller chip corrects the reference RSSI level in the reference voltage correction process And digitally converting the received digital value as a reference RSSI value to the memory means.

On the other hand, the sensitivity display step, if a radio signal having an arbitrary RSSI level is input to the RF module of the wireless terminal, the RF module of the wireless terminal to apply the RSSI level corresponding to the wireless signal to the baseband controller chip And digitally converting the RSSI level applied by the baseband controller chip based on the reference voltage corrected in the reference voltage correction process and outputting the same to the CPU. And substituting the digital value applied to the predetermined equation based on the set reference RSSI value to calculate and display the sensitivity correction value of the received radio signal so as to be visually confirmed; The predetermined equation is "70- (Rank-RSSI_CAL) * A", wherein the Rank is a value obtained by digitally converting the RSSI level based on the corrected reference voltage, and the RSSI_CAL is the set reference RSSI value. A is an inverse of the slope of the characteristic sensitivity curve of the RF module.

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

In the present invention, by calibrating the AD converter reference voltage of the baseband controller chip and setting a reference RSSI value for calibrating the sensitivity display of the received radio signal, the difference between the components of the RF module and the AD converter reference voltage of the baseband controller chip. It was configured to correct and display the difference in the reception sensitivity caused by.

That is, in the present invention, as shown in Figure 3, by applying a reference voltage to the baseband controller chip to correct the AD converter reference voltage of the baseband controller chip, by applying a radio signal having a reference RSSI value to the RF module The reference RSSI value for correcting the sensitivity display of the received radio signal is set, and the sensitivity of the received radio signal is corrected and displayed based on a predetermined equation based on the reference RSSI value.

First, a process of calibrating the AD converter reference voltage of the baseband controller chip will be described.

When correcting the AD converter of the baseband controller chip, the baseband controller is connected by connecting the personal computer 31, the power supply 32, the IIC / RS232 converter 33, and the wireless terminal WLT as shown in FIG. Calibrate the chip's AD converter. The IIC / RS232 converter 33 operates by receiving 5.0 V of power from the power supply 32 to enable serial communication between the personal computer 31 and the wireless terminal WLT. The RS232 type serial information is converted into IIC type serial information and transferred to the personal computer 31, and the reference voltage 3.4V applied from the power supply 32 is transferred to the WLT. To the side. At this time, the voltage output from the power supply 32 is measured and adjusted using the multimeter 34. In addition, the personal computer 31 executes a predetermined program, issues a command to the wireless terminal WLT side through the IIC / RS232 converter 33, and enters the wireless terminal WLT into the AD converter correction mode. 32) transmits the reference voltage 3.4V for the low voltage warning setting applied through the IIC / RS232 converter 33 to the wireless terminal (WLT) side. At this time, the voltage output from the power supply 32 is measured and adjusted using the multimeter 34. In addition, the personal computer 31 executes a predetermined program, issues a command to the wireless terminal WLT side through the IIC / RS232 converter 33, and enters the wireless terminal WLT into the AD converter correction mode. 32) converts the reference voltage 3.4V for the low voltage warning setting applied through the IIC / RS232 converter 33 into a hexadecimal value to recognize the memory in the wireless terminal (WLT). The AD converter provided in the baseband controller chip of the wireless terminal WLT converts another analog value to digital based on the stored hexadecimal value.

Meanwhile, a process of setting a reference RSSI value for correcting a sensitivity display of a received radio signal will be described below.

5 is a diagram illustrating a reception sensitivity characteristic of a wireless terminal which is not corrected. The X axis (horizontal axis) represents the strength (dB) of the radio signal, and the Y axis (vertical axis) represents the digital value of the RSSI corresponding to the radio signal. The characteristic curves of the wireless terminals # 1 to # 4 have the same slope and only the starting point on the Y axis is different. Therefore, in order to correct the sensitivity display of the received radio signal in the wireless terminal, the slope of the reception sensitivity characteristic curve of the current RF module is calculated (when calculating the slope based on the measured data, the slope becomes about 1 / 0.37 = 2.7027). Each wireless terminal can be calibrated to have the same starting point on the Y axis, and the sensitivity display of the received radio signal is corrected by applying a reference RSSI level to the wireless terminal and moving the characteristic curve to be located at the same point on the Y axis. .

When setting the reference RSSI level for correcting the sensitivity indication of the received radio signal, the DECT test set 41, the wireless terminal WLT and the personal computer 42 are connected and corrected as shown in FIG. The DECT test set 41 applies a signal having a reference RSSI level to the wireless terminal WLT through a coaxial cable, and the personal computer 42 executes a predetermined program to apply a command to the wireless terminal WLT for wireless communication. Entering the terminal (WLT) into the wireless signal correction mode allows the wireless terminal (WLT) to store a digital value corresponding to the reference RSSI level applied from the DECT test set 41 in its own electrically erassble programmable ROM (EEPROM). .

At this time, the processing procedure for radio signal correction is as shown in FIG. That is, in the state where the personal computer 42 executes a predetermined program to enter the radio terminal WLT into the radio signal correction mode (step ST71), the radio signal having the reference level of 70 dB by the DECT test set 41. Is transmitted to the RF module of the wireless terminal WLT (step ST72), the RF module of the wireless terminal WLT corresponds to the reference RSSI level corresponding to the radio signal having a reference level of 70 dB applied from the DECT test set 41. Is applied to the baseband controller chip, and the AD converter of the baseband controller chip digitally converts the reference RSSI level based on the voltage stored in the AD converter correction, and stores the corresponding digital value RSSI_CAL in its own EEPROM. (Step ST73) A reference RSSI value for correcting the sensitivity display of the received radio signal is set. Then, by adjusting the DECT test set 41 to input a radio signal having an arbitrary RSSI level to the RF module of the wireless terminal WLT (step ST74), the RF module of the wireless terminal WLT corresponds to the corresponding wireless signal. When the RSSI level is applied to the baseband controller chip, the baseband controller chip digitally converts the RSSI level based on the voltage stored at the time of AD converter correction, and outputs the corresponding digital value (Rank) to the CPU. The CPU corrects the wireless signal reception sensitivity according to the formula " dB = 70- (Rank-RSSI_CAL) * A " and displays it on the liquid crystal display of the wireless terminal WLT and on the screen of the personal computer 42. (Step ST75), the radio signal is corrected (step S76), where "RSSI_CAL" is a digital value of the reference RSSI level stored in step ST73, and "Rank" is a digital value corresponding to an arbitrary RSSI level. "A" is the RF module Reception sensitivity characteristic the inverse of the slope of the curve (in this case, corresponding to 0.37).

That is, even though the base station transmits the same radio signal, the conventional radio terminal is not shown in FIG. 5 due to the difference in the parts of the RF module and the difference in the reference voltage which is an operation reference of the AD converter of the baseband controller chip. The same RSSI level is received differently for each of the wireless terminals # 1 to # 4. In the present invention, as shown in FIG. 8, the hardware characteristic of the wireless terminal is changed by shifting the reference axis (Y-axis) without changing the characteristic curve. Instead, the reference axis (Y axis) is shifted programmatically to correct and display the sensitivity of the received radio signal. In FIG. 8, by shifting the characteristic curve of the wireless terminal # 3 of FIG. 5 to the Y-axis, the RSSI value of the wireless terminal # 3 is corrected and displayed by 'A' in the Y-axis direction. It shows that there is no difference in sensitivity of received radio signal from 4.

As described above, the present invention corrects and displays the difference in the reception sensitivity of the wireless signal generated due to the difference in the components of the RF module and the difference in the AD converter reference voltage of the baseband controller chip in the wireless terminal. Improved reliability

Claims (4)

A reference voltage correction process of correcting an AD converter reference voltage of the base band controller chip by applying a reference voltage to the base band controller chip; Setting a reference RSSI value for applying a radio signal having a reference RSSI value to the RF module to set a reference RSSI value for correcting an indication of the sensitivity of the received radio signal; And a sensitivity display process of correcting and displaying the sensitivity of the received wireless signal based on the set reference RSSI value. The method of claim 1, wherein the reference voltage correction process includes entering the wireless terminal into an AD converter correction mode and recognizing and storing the reference voltage value for setting a low voltage warning in the wireless terminal. Receiving sensitivity correction display method of the wireless terminal. The method of claim 1, wherein the setting of the reference RSSI value comprises: entering the wireless terminal into a wireless signal correction mode, inputting a wireless signal having a predetermined reference level into the RF module of the wireless terminal, and The RF module of the wireless terminal applying a reference RSSI level corresponding to the radio signal having the reference level to the baseband controller chip, and the AD converter of the baseband controller chip adjusts the reference RSSI level in the reference voltage correction process And digitally converting the digital value on the basis of the corrected reference voltage and storing the digital value as a reference RSSI value in the memory means. The baseband controller chip of claim 1, wherein the sensitivity display comprises: when a radio signal having an arbitrary RSSI level is input to an RF module of the radio terminal, the RF module of the radio terminal sets an RSSI level corresponding to the radio signal. Applying a digital signal to the baseband controller chip; and digitally converting the RSSI level applied by the baseband controller chip based on the reference voltage corrected in the reference voltage correction process and outputting the same to the CPU. Assigning a value to a predetermined equation based on the set reference RSSI value to calculate a sensitivity correction value of the received radio signal and to display it for visual confirmation; The predetermined equation is "70- (Rank-RSSI_CAL) *" A ", the Rank is a value obtained by digitally converting the RSSI level based on the corrected reference voltage, and the RSSI_CAL is the set reference RSSI value, A is a reception sensitivity correction display method of the wireless terminal, characterized in that the inverse of the slope of the sensitivity characteristic curve of the RF module.