KR19980074164A - Superimposed CDMA (Code Division Multiple Access) Communication Method and System - Google Patents

Abstract

The present invention provides a superposition that enables overlapping of the frequency bands of a narrowband system of a cellular or personal mobile communication service (PCS) and a wideband CDMA system for providing a mobile communication service to a digital code division multiple access (CDMA) system. CDMA communication method and system therefor.

A feature of the present invention is a narrowband radio by a CDMA type 800MHz cellular system having a narrow bandwidth of 1.23MHz and a PCS system of 1.7-2 GHz, including a radio base station, a mobile switching center and a controller, and a home location register. There is provided a system in which a communication service of a wideband CDMA radio base station having a bandwidth of 1.23 MHz or more is superimposed in a base station service area within the same frequency band as the above band.

Description

Superimposed CDMA (Code Division Multiple Access) Communication Method and System

The present invention provides a superposition that enables overlapping of the frequency bands of a narrowband system of a cellular or personal mobile communication service (PCS) and a wideband CDMA system for providing a mobile communication service to a digital code division multiple access (CDMA) system. CDMA communication method and system therefor.

CDMA technology allows multiple users to communicate simultaneously by assigning different codes to each user and using them to spread and transmit voice and data information to be delivered.

This CDMA technology is used in both cellular and PCS systems, and is considered as a technology that will lead the future mobile communication system because it can accommodate a large number of users and can easily transmit high-speed data.

1 is a block diagram of a typical cellular and PCS mobile communication system. Here, in the system connection and call connection method between the CDMA wireless base station 5 and 6 and the mobile terminal 7 and 8, the cellular system is a standard of the Telecommunications Industry Association / Electronic Industries Association (TIA / EIA). As defined in IS-95, PCS systems are defined in ANSI-J-STD-008 of the US Standards Bureau. However, these two systems differ only in the frequency band used, and the basic system configuration and call connection method are the same.

The radio base station 5 may provide several CDMA channels. The mobile terminal 7 selects an appropriate CDMA channel according to a procedure according to a predetermined standard, and uses the channel to register a message including its own telephone number and terminal serial number with the radio base station 5 and the mobile switch / controller 3. Through the home position register (4).

The home location register (4) checks the registered subscriber data base and performs authentication. If the authentication succeeds, the home location register (4) obtains the location information of the mobile terminal (7) and records it in the database.

After the CDMA channel selection and authentication, the mobile terminal 7 can receive a call from the landline 1 or other mobile terminal 8. For example, when making a call to the mobile terminal 8, the mobile exchanger 3 obtains the location information from the home location register 4 and transfers the call to the wireless base station 6, thereby transferring another call to the destination terminal 8 as the destination terminal. ) Can receive an incoming call.

2 is a block diagram of a mobile terminal used in a conventional narrowband CDMA system (collectively referred to as CDMA cellular system and PCS system).

As referred to herein, the mobile terminal checks the state of the antenna unit 31 for transmitting and receiving radio waves and the RF unit 32 for converting the signal received by the antenna unit and the signal to be transmitted to the antenna unit side. It includes a controlling terminal control unit 33, a terminal memory unit 34 connected to the terminal control unit, a CDMA modem 35 for digital code division multiple access, and a speaker / mic 36.

The mobile terminal receives radio waves of a desired band to the antenna unit 31 and limits the bandwidth of the 1.23 MHz bandwidth pre-allocated by the RF unit 32. Subsequently, the CDMA modem unit 35 separates the desired digital information from the radio signal limited to 1.23 MHz, converts it into an audio signal, and outputs it to the speaker side of the speaker / microphone 36 of the mobile terminal. On the contrary, the voice signal input by the microphone of the speaker / microphone 36 is transmitted to the counterpart mobile terminal through the RF unit 32 and the antenna unit 31 under the control of the terminal controller 33.

Operation control for various parts of the mobile terminal is performed by the terminal controller 33, and data necessary for the operation of the mobile terminal is stored and used in the terminal memory unit 34.

3 shows a frequency allocation table in a conventional CDMA cellular system and a PCS system. Here, the narrowband CDMA system can distinguish transmission data using a pseudo random number having a speed of 1.2288MHz, and the 3dB frequency bandwidth is 1.23MHz. In addition, narrowband CDMA frequencies with a frequency bandwidth of 1.23 MHz are allocated at intervals of 1.25 MHz.

4 is a flowchart illustrating a system access algorithm of a mobile terminal in a conventional narrowband CDMA system. It is based on the system's connection by IS-95 and J-STD-008. The IS-95 and J-STD-008 support narrowband CDMA and analog dual-mode terminals.

First, in a first step S1, the mobile terminal 7 selects a narrowband CDMA channel stored in the terminal memory unit 34 to obtain a narrowband CDMA system.

In the second step, if the strength of the pilot channel is examined by checking the strength of the pilot channel, it means that the mobile terminal 7 exists in the service area of the wireless base station 5, thereby acquiring and synchronizing the pilot channel. It is determined whether a system information message is received through a channel.

When the system connection is completed by receiving the system information message in the above step, the mobile terminal 7 enters the idle state for executing the third step S3. However, if the pilot channel acquisition and the synchronization channel message are not received within a predetermined time, the process returns to the first step S1 to perform narrowband CDMA channel selection.

In the third step (S3) of the system connection completion idle state, the call origination in the fourth step (S4), the incoming call in the fifth step (S5), and the registration and authentication in the sixth step (S6) can be arbitrarily executed. .

On the other hand, in the eighth step S8, when a narrowband CDMA channel list is received from the radio base station 5, a new narrowband CDMA channel is selected from the list by using a hash algorithm.

Subsequently, in the thirteenth step S13, if the narrowband CDMA channel selected again is different from the channel selected initially, the new channel is synchronized with the new channel, and the pilot channel acquisition and synchronization channel message are again performed.

The conventional narrowband CDMA scheme thus operated has a bandwidth of 1.23 MHz and a data rate of only 9.6 kbps or 1.4 kbps.

In order to transmit a large file or image data, it is necessary to have a transmission speed of about 2 Mbps. Therefore, it is necessary to widen the frequency band for use. Therefore, the development of a broadband system having a bandwidth of 5-20 MHz has been studied.

However, due to the limited frequency resources, operators providing services in narrowband CDMA systems will have to dismantle all existing narrowband CDMA systems in order to install future broadband CDMA systems, which will require enormous costs for service providers. On the subscriber side, there is a problem that a temporary interruption of service occurs.

SUMMARY OF THE INVENTION An object of the present invention is to enable overlapping of the frequency bands of a narrowband system of a cellular mobile communication or a personal mobile communication service (PCS) and a wideband CDMA system providing a mobile communication service in a digital code division multiple access (CDMA) system. An intermediate CDMA communication method and a system thereof are provided.

A feature of the present invention is a narrowband radio by a CDMA type 800MHz cellular system having a narrow bandwidth of 1.23MHz and a PCS system of 1.7-2 GHz, including a radio base station, a mobile telephone exchange and a controller, and a home location register. There is provided a method of superimposing and using a communication service of a broadband CDMA radio base station having a bandwidth of 1.23 MHz or more in a base station service area within the same frequency band as the band, and an overlapping mobile communication system for implementing the method.

1 is a block diagram of a conventional CDMA mobile communication system.

2 is a block diagram of a mobile communication terminal applied to a conventional system.

3 is a flowchart illustrating an operation process of a conventional mobile communication system.

4 is a graph of a frequency allocation state applied to a conventional mobile communication system.

5 is a block diagram of an overlapping CDMA mobile communication system according to the present invention.

6 is a block diagram of an overlapping mobile terminal applied to the system of the present invention.

7 is a flowchart illustrating the operation of the overlapping mobile communication system according to the present invention.

8 is a graph of a frequency allocation state applied to a mobile communication system of the present invention.

* Description of the symbols for the main parts of the drawings *

1, 71: landline phone 2, 72: public telephone network

3, 73: mobile switch / controller 4, 74: home position register

5, 6: wireless base station 7, 8: mobile terminal

31, 81: antenna unit 32, 85: terminal control unit

34, 86: terminal memory section 35: CDMA modem

36, 89: Speaker / microphone 75, 77: Narrow-band radio base station

76: broadband wireless base station 78: narrowband mobile terminal

79, 80: overlapping mobile terminal 82: broadband RF unit

83 switch unit 84 narrow-band RF unit

87: broadband modem 88: narrowband modem

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

5 is a block diagram of an overlapping CDMA mobile communication system according to the present invention. As referred to herein, the mobile switch / controller 73 having a home location register 74 is connected to the landline telephone 71 via a public telephone network 72, and also to the first and second narrowband radio base stations 75. 77 and broadband wireless base station 76 are also connected.

The narrowband mobile terminal 78 is configured to be wirelessly connected to the first narrowband radio base station 75, and the first overlapping mobile terminal 79 is wirelessly connected to the broadband radio base station 76. The second narrowband mobile base station 77 is configured such that the second overlapping mobile terminal 80 is connected wirelessly.

Such a system of the present invention includes a landline telephone 71, a public telephone network 72, a mobile switchboard and a controller 73, and a home location register 74 having the same functions as a conventional system. In the area served by the narrowband radio base station 77, a broadband radio base station 76 of the same frequency band may be superimposed in another area.

In addition, those who use the mobile phone by receiving the service can receive the mobile communication service from the narrowband mobile terminal 78 or the first overlapping mobile terminal 79.

A user with the first nested mobile terminal 79 can receive wireless multimedia services within the service area of the broadband wireless base station 76.

6 is a block diagram of a CDMA overlapping mobile terminal according to the present invention. In this case, the RF signal received through the antenna unit 81 passes through the wideband RF unit 82 and the narrowband RF unit 84 through the switch unit 83, respectively, and then the broadband modem 87 and the narrowband modem. A voice transmission signal converted and output from each of the broadband modem 87 and the narrowband modem 88 to the radio base station through the switch unit 83 and the antenna unit 81. It is connected and configured to be transmitted.

The broadband modem 87 and the narrowband modem 88 are configured by connecting the terminal control unit 85 and the speaker / microphone 89, respectively. In addition, the terminal control unit 85 has a terminal memory unit 86 and is configured to control the switch unit 83, the wideband RF unit 82 and the narrowband RF unit 84 to control.

In the overlapping mobile terminal configured as described above, the signal received by the antenna unit 81 is divided into a wideband RF unit 82 and a narrowband RF unit 84 by the switch unit 83.

The dual broadband CDMA signal is transmitted to the speaker 89 through the broadband modem 87, and the signal transmitted to the narrowband modem 88 through the narrowband RF unit 84 is processed through the same process as that of the conventional mobile terminal. Output to the speaker of the speaker / microphone (89).

The terminal control unit 85 has a terminal memory unit 86 and controls the wideband RF unit 82 and the narrowband RF unit 84.

7 is a flowchart illustrating a CDMA frequency allocation and its access procedure in the overlapping mobile terminal system of the present invention.

In this case, first, when power is input to the overlapping terminal, the first step Sa determines a user preference system among the wideband system and the narrowband system.

If it is determined that the user preference system is a broadband system, it is determined whether a broadband system pilot channel is acquired in step Sb. If the acquisition of the pilot channel fails, the process proceeds to the third step Sc and determines whether to acquire a narrowband system pilot channel.

In the third step, if the acquisition of the narrowband system pilot channel fails, go back to the first step and execute again from the first step. If the acquisition of the narrowband system pilot channel is successful, execute the tenth step (Sj) to complete the narrowband system connection. Enter the IDLE STATE.

If the acquisition of the broadband system pilot channel is successful in the second step Sb, it is determined whether the synchronization channel message is received in the fourth step Sd. In this step, if no message is received, the process returns to the first step, and if there is a message, it is determined whether authentication is performed in the fifth step (Se).

If there is no authentication in the fifth step (Se) above, it returns to the first step as it is, and if there is authentication, the sixth step (Sf) is executed to complete the connection in the broadband system and enter the idle state.

Thereafter, in the seventh step Sg, the pilot signal is compared with its threshold value, and when the threshold value is less than the threshold value, the process returns to the first stage, and if the threshold signal is less than the threshold value, the sixth step Sf is repeated.

On the other hand, if the user preference system is a narrowband system as a result of the execution of the first step (Sa), it is determined whether to obtain a narrowband system pilot channel by executing the eighth step (Sh).

If no pilot channel is acquired in this step, a ninth step Si is performed to determine whether a broadband channel is acquired in the broadband system. As a result of the execution of the ninth step (Si), if there is no acquisition of the broadband system pilot channel, the process returns to the first step (Sa), and if there is an acquisition of the pilot channel, the determination step of receiving the synchronization channel message, which is the fourth step (Sd), is executed. .

When the narrowband system pilot channel is obtained as a result of executing the eighth step (Sh), the tenth step (Sj) is completed to complete the connection of the narrowband system and enter the idle mode.

Thereafter, the pilot signal is compared with its threshold in the eleventh step Sk, and if the threshold value is less than the threshold value, the process returns to the first stage, and if the threshold signal is less than the threshold value, the tenth step Sj is executed again.

8 is a frequency allocation graph in an overlapping CDMA system having two bandwidths according to the present invention. As referred to herein, narrowband CDMA systems are allocated narrowband CDMA frequencies with a bandwidth of 1.23 MHz at intervals of 1.23 MHz and at the same time wideband CDMA systems having a 4.9 MHz bandwidth are allocated at intervals of 4.92 MHz.

Accordingly, the service provider can simultaneously provide a conventional narrowband CDMA service and a wideband CDMA service in frequency, and the service user can receive the narrowband CDMA service and the broadband CDMA service in one terminal.

As described above, the integrated service scheme of the present invention enables a CDMA service provider to simultaneously provide an existing CDMA service and a broadband CDMA service in the same region at a given limited frequency, thereby providing a future broadband service. The burden of dismantling can be avoided, and the unique effect of being able to flexibly respond to the needs of both narrowband CDMA service users and wideband CDMA service users is shown.

Claims (3)

In a CDMA mobile communication service system including a cellular system and a PCS system, a narrowband movement is connected to a mobile telephone 71 via a public telephone network 72 and to a mobile switch / controller 73 having a home location register 74. Narrow-band radio base station 77 for connection between the broadband mobile base station 76 and the overlapping mobile terminal 80 for connection with the narrowband radio base station 75 and the overlapping mobile terminal 79 for connection with the terminal 78. Superimposed CDMA communication system configured to enable the integrated operation of a narrowband CDMA system and a wideband CDMA system by connecting the ()). The method of claim 1, The overlapping mobile terminal receives the RF signal received through the antenna unit 81 through the wideband RF unit 82 and the narrowband RF unit 84 through the switch unit 83, respectively, and then the broadband modem 87 and the narrowband. The voice transmission signal, which is connected to the modem 88 and is converted and output from each of the broadband modem 87 and the narrowband modem 88, is transmitted through the switch unit 83 and the antenna unit 81. The terminal controller 85 and the speaker / microphone 89 are connected to the broadband modem 87 and the narrowband modem 88, respectively, and the terminal controller 85 is connected to the terminal memory unit 86. And a switch unit (83), a wideband RF unit (82), and a narrowband RF unit (84) connected to each other so as to control the superimposed CDMA communication system. A CDMA mobile communication service method comprising a cellular system and a PCS system, the method comprising: determining a user preference system among a broadband system and a narrowband system (Sa); and if the determination result of the user preference system is a broadband system, a broadband system pilot channel Determining whether to acquire (Sb), if there is no pilot channel acquisition step of determining whether to obtain a narrowband system pilot channel (Sc), and if there is no narrowband system pilot channel acquisition in the step (Sc) the first step Re-executing from (Sa), when the narrowband system pilot panel is obtained, completing the narrowband system connection and entering the idle state (Sj); and when the wideband system pilot channel is obtained in the step (Sb), a synchronization channel Determining whether or not the message is received (Sd), and if there is no message received in the step (Sd) and returns to the first step (Sa) and the message Determining whether or not authentication (Se) if there is a reception, and if no authentication in the above step (Se), and returns to the first step as it is, if there is authentication step of completing the connection in the broadband system (Sf), If the pilot signal is compared with the threshold value or less than the threshold value, the process returns to the first first step. If the pilot signal is less than or equal to the threshold value, it is determined whether to re-execute step Sf. In a narrowband system, determining whether a narrowband pilot channel is acquired (Sh), and if there is no pilot channel obtained in the step (Sh), it is determined whether the broadband system acquires a pilot channel. Returning to the first step (Sa), if the pilot channel is obtained, performing the step (Sd) (Si), and performing the step (Sh) when the narrow band When the stem pilot channel is acquired, the step (Sj) of completing the connection of the narrowband system and entering the dormant mode, and then compares the pilot signal with its threshold value, returns to the first step if it is below the threshold, and if it is not below the threshold, And determining (Sk) whether to re-execute.