KR950002438B1 - Channel serching method using last channel access in cordlessphone - Google Patents

Abstract

The method for using a LCA system to search an unused channel, checking an calling state of the basic channel to set a use channel, calling a handheld unit, if receiving a calling signal, to form a calling circuit upon a calling attempt, and setting the final calling channel as a basic channel upon returning to waiting mode. The wireless telephone circuit having a base unit and a portable unit, includes buffers (1,21), RF amplifiers (2,22), IF amplifiers and mixers (3,23), sound amplifiers (9,29), sending power amplifiers (7,27), microprocessors (6,26), a ring detector (10), a dialer (11), a keyboard (31), a hybrid (HYBRID), a microphone (MIC) and a speaker (SPK).

Description

Channel Search Method of Wireless Telephone Using LCA (Last Channel Access) Method

1 is a block diagram of a fixing device for a radiotelephone according to the present invention.

2 is a block diagram of a portable device of a wireless telephone according to the present invention.

3 is a channel search processing flow chart according to the present invention.

* Explanation of symbols for main parts of the drawings

1, 21: First and second transmission and reception buffer 2, 22: First and second high frequency amplifier

3, 23: 1st, 2nd intermediate amplifier and mixing section 4, 24: 1st, 2nd negative amplifier section

5, 25: first and second data detectors 6, 26: first and second microprocessors

7, 27: 1st, 2nd transmission power amplifier 8, 28: 1st, 2nd transmission modulator

9, 29: first and second signal amplifier 10: ring detector

11 dial portion 30 display portion

31: keyboard unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiotelephone of a common frequency method (called MCA), and more particularly to a method for searching for an unused channel using the LCA method.

In general, a radio telephone is a fixed device and a portable device, and a two-way call is possible by transmitting a voice signal and data to a high frequency signal, and a telephone handset is replaced by a portable device, and a signal between the handset and the fixed device is It is a system that is replaced by a high frequency signal for convenience.

However, as the demand for high-volume wireless telephones is so high, the use of wireless telephones in close range will cause interference from adjacent channels, which will interfere with calls. The method adopted to solve this problem is the MCA method.

In the first type (46/49 MHz) of the radiotelephone equipped with the MCA system currently used, 15 channels are mounted to select an unused channel and then configure a call circuit. When selecting the channel, the digital code type identification code must be embedded more than 20 bits. Therefore, when masking the microprocessor, 15 channels are searched from the set basic channel. Select an unused channel. Therefore, in the type 1 wireless telephone using the low frequency of 46 / 49MHz, the telephone circuit is composed, and a long delay of at least 2 ~ 3 seconds was inevitable. There was a problem.

Accordingly, the present invention can select the communication channel in the shortest time by first checking whether the last channel is in use by using the LCA method when constructing the communication circuit in the frequency common type wireless telephone to eliminate the above-mentioned problems. The purpose of the present invention is to provide a channel searching method of a wireless telephone.

In order to achieve the above object, the present invention provides a process for setting a use channel by checking whether a basic channel set when a call circuit is being used, and calling a mobile device when a call signal arrives after performing the process. And a process of configuring a circuit, and setting the last communication channel to a basic channel upon returning to the standby state when the call is completed.

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

1 is a block diagram of a fixed device of a radiotelephone according to the present invention, and FIG. 2 is a block diagram of a portable device, in which a part of configuration and operation (same RF configuration) are the same, and is transmitted and received through an antenna ANT. First and second transmission / reception buffers 1 and 21 for separating the high frequency signals to be used, first and second high frequency amplifiers 2 and 22 for amplifying the high frequency signals received therein, and the first and second high frequency amplification. Mixing the high frequency signal transmitted through the negative signal and the first local signal originating from the VCO in a mixer, generating the first intermediate frequency signal, passing only the intermediate frequency signal force in the intermediate frequency filter and restricting other forces to amplify the intermediate frequency. Amplified by the negative and input to the IF IC, the first and second intermediate frequency amplification and mixing section (3, 23) for generating the input signal as a second intermediate frequency signal inside the IC and the voice in the intermediate frequency signal Voice filter by detecting signal First and second voice amplifiers 4 and 24 which suppress noise and amplify them in the speaker amplifier, and a data detector that detects and amplifies a data signal from the intermediate frequency signal. And first and second data detectors 5 and 25 configured to detect whether carriers are present or not in each channel in the standby state, and also amplify a voice signal through a Tel-Line or a microphone, First and second signal amplifiers 9 and 29 for suppressing noise and outputting a voice signal through a compressor of an audio filter and a compander IC, and the transmitted audio signal and the microprocessor. The first and second transmission modulators 8 and 28 modulated transmission signals, in which the data signals transmitted from (6, 26) are transmitted to a modulator and the transmission frequency signals generated from the TX VCO are synthesized by the modulator. First and second transmission powers for amplifying and transmitting Amplifying units 7 and 27, first and second microprocessors 6 and 26 that control the wireless telephone, and ring detection unit 10 which detects ring signals human to the trunk line and gives status information to the microprocessor 6. And a dial unit 11 for performing dialing under the control of a microprocessor, a keyboard unit 31 for controlling the operation and function of the second microprocessor 26, and a high frequency signal. Antennas (A1, A2) for transmitting and receiving signals, hybrid (HYBRID) for signal transmission by separating transmission and reception of trunk lines, microphone (MIC) for converting voice signals to electrical signals, and converting electrical signals to voice signals Speaker (SPK) or the like.

Based on the above structure, this invention is demonstrated with reference to FIGS.

3 is a flowchart of a channel search process according to the present invention.

First, a radiotelephone is a device for enabling two-way communication between a fixed device and a portable device shown in FIGS. 1 and 2 by transmitting a voice signal and data to a high frequency signal. In such wireless phones, since the MCA method must be embedded in the digital code by using MCA method to prevent radio interference from adjacent channels when using, it requires delay time to select channel by scanning in standby state. . This channel search delay can be reduced by shortening the channel search in the channel search processing method shown in FIG. 3 in the MCA wireless telephone, and this processing method will be described in detail below.

In the wireless standby state (1A), the first SCAM is used to analyze the state of all the channels and are detected by the microprocessor, and the carrier detection unit of the first and second data detection units 5 and 25 of the portable device and the fixed device is in SCAN. It is determined whether there is a carrier of each channel. If there is a carrier, the carrier detector transmits a "High" state. If there is no carrier, the carrier detector transmits a "Low" state to the first and second microprocessors. After recognizing the presence / absence status, the state of each channel is memorized in the next (2A) step, and if there is a CO line call ring signal in (3A), the initial channel is set in the CPU and the data is stored in the fixed PLL IC. Transmits (DATA) to control the TX VCO of the second transmission modulator 28 in the PLL to reduce the transmission frequency and to amplify the second transmission power amplification unit 27 to make a trunk line call. Transmitting the data to the ring to give a mobile device, it carries out a (1A) step if there is no trunk call ring signal.

If there is a CO line ring signal and performs step (4A) and transmits it, the mobile device is called by transmitting data (co-ring line + ID number) as in step (5A), and then the call is made in the mobile device in step (6A). Check if you try.

If the other party (caller) terminates the call without attempting to make a call in the mobile device, perform step (15A), and then, in step (16A), the transmission channel and the reception channel of the mobile device are stored in the CPU in step (16A). By setting the basic channel, step 12A is performed.

In addition, when the mobile device attempts to make a call in step 6A according to the call signal, the data of step 7A for connecting the call path is sent to the receiving unit of the fixed device, and the second microprocessor of the fixed device responds to the "call". If it is recognized in step (8A) that the call is connected to the call. During step (8A), if the call completion is continuously viewed in step (9A) and there is "call OFF" data in the portable device indicating that the call is completed, step (10A) is performed.

When returning to the standby state in step (10A), by performing the step (11A) of storing the last channel, which is the channel called by the microprocessor, as the default channel, the call in the mobile device as in step (12A) When the signal is generated due to the occurrence of the request or call line ring signal from the fixed device, the state of the basic channel set in step (11A) is determined in the receiving unit of the fixed device or the portable device in step (13A). The carrier detection unit of the data detectors 5 and 25 analyzes whether a carrier occurs in the set base channel, and if there is no carrier, performs step (17A) of transmitting data to the set base channel, and then continues with step (7A) again. It handles the call request, and if there is a carrier, performs step (14A) to determine the presence or absence of carriers of other channels and selects one channel (step 17A). Through to give treated according to the function of the flow.

By configuring according to the channel search processing flowchart of FIG. 3, the time for searching for a channel used in the next step except for a call flow in an initial (first call attempt) state can be shortened and used as a set default channel. The need to search for the last channel in the carrier comparator is as small as possible.

As described above, the present invention converts and sets the last used call channel into a reference channel in a wireless common frequency telephone (MCA method) to shorten the time for comparing and analyzing the state of all channels and configuring a call circuit. It is possible to connect the channel in the shortest time in order to prevent high frequency noise pollution in the space, and to improve the quality and functional reliability of the product which prevents the attenuation effect due to interference with other wireless devices.

Claims (1)

A method for searching a channel in a common frequency wireless telephone, comprising: a first step of setting a use channel by checking whether a basic channel set when configuring a communication circuit is in a call; and when a call signal arrives after performing the first step Wireless communication using the LCA method comprising a second process of configuring the call circuit shown in the call when the mobile device is called, and a third process of setting the last call channel as the default channel when returning to the standby mode when the call is completed. How to search channel on your phone.