KR100606354B1 - Apparatus and method for remote optic transmission of base transceiver station in mobile communication system - Google Patents

Abstract

The present invention provides a remote optical transmission apparatus and a method of a base station in a mobile communication system, and amplifies the baseband signal to be transmitted to the CDMA frequency band, multiplexing the CDMA modem channel signal, the control signal and the loop back signal A base station; CDMA base station by comprising a remote repeater connected to the base station by an optical cable to demultiplex the CDMA modem channel signal, the control signal and the loop back signal multiplexed at the base station, and loop back the loop back control signal to the base station. In order to compensate for the time delay of the optical path, the cell shadow area can be eliminated, the range of propagation can be extended, and the base station lease cost can be reduced.

Description

Apparatus and method for remote optic transmission of base transceiver station in mobile communication system

1 is a block diagram of a general mobile communication system,

2 is a block diagram of a remote optical transmission device of a base station in a conventional mobile communication system,

3 is a flowchart illustrating a remote optical transmission method of a base station in a conventional mobile communication system,

4 is a block diagram of a remote optical transmission device of a base station in a mobile communication system according to the present invention,

FIG. 5 is a detailed block diagram of a multiplexer and neighboring blocks of a base station in FIG. 4.

FIG. 6 is a detailed block diagram of a demultiplexer and its neighboring blocks of a remote repeater in FIG. 4;

7 is a flowchart illustrating a remote optical transmission method of a base station in a mobile communication system according to the present invention,

FIG. 8 is a diagram illustrating an example of data configuration of a multiplexer and a demultiplexer in FIG. 4.

9 is a block diagram showing an example of configuring four remote repeaters to which the present invention is applied.

Explanation of symbols on the main parts of the drawings

100: base station 110: master CDMA modem channel signal processing unit

111 modem 120 master remote repeater control unit

121: CPU 130: multiplexer

140: parallel-to-serial conversion unit 150: all-optical conversion unit

200: first remote repeater 210: photoelectric conversion unit

220: serial-parallel conversion unit 230: demultiplexer

240: slave CDMA modem channel signal processing unit

241: RF converter 242: first power amplifier

243: second power amplifier 244: third power amplifier

245: first baseband filter 246: second baseband filter

247: third baseband filter 248: alpha antenna

249: beta antenna 250: gamma antenna

260: slave remote repeater control unit

300: second remote repeater 400: third remote repeater

500: fourth remote repeater 600: mobile station

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote optical transmission apparatus and a method of a base station in a mobile communication system, and more particularly, to compensate for a time delay of an optical line in a Code Division Multiple Access (CDMA) BTS (Base Transceiver Station). The present invention relates to a remote optical transmission apparatus and a method of a base station in a mobile communication system suitable for eliminating a shadow area of a cell, expanding coverage, and reducing a base station rental cost.

In general, a mobile communication system is a communication system that targets mobile devices such as people, cars, ships, trains, and airplanes, which includes key phone systems, mobile phones (mobile phones, vehicle phones), port phones, aircraft phones, and mobile phones. Trains, cruise ships, express buses), radio calling, radiotelephony, satellite mobile communication, amateur radio, and fishing service ships.

The mobile communication system includes an AMPS (Advanced Mobile Phone Service) system using an analog method, a Code Division Multiple Access (CDMA) system using a digital method, a Wideband Code Division Multiple Access (WCDMA), and a TDMA (Time). Division Multiple Access, Time Division Multiple Access (FDMA) system, Frequency Division Multiple Access (FDMA) system, Wireless Local Loop (WLL), CDMA2000-1x, IMT-2000 (International Mobile Telecommunication in the year 2000 , Global mobile communication (GSM) systems, and GSM (Global System for Mobile communication) systems.

1 is a block diagram of a general mobile communication system.

Where reference number 1 is a mobile switching center / visitor location register (MSC / VLR), 2 is a home location register (HLR), 3 is a public switched telephone network (PSTN) , 4 is a base station (Basic Station Controller / Base station Transceiver System, BSC / BTS), 5 is a terminal (Mobile Station, MS).

The MSC 1 thus performs an exchange function, serving as roads and intersections of all communication lines.

The HLR 2 is a database in which subscriber information is stored, and the VLR is a device that temporarily stores important subscriber information in order to prevent frequent HLR 2 inquiry.

PSTN (3) refers to the entire telephone network used in homes.

Therefore, when making a call to the terminal 5 of the mobile communication subscriber from the ordinary home telephone, the home telephone signal is first connected to the PSTN 3 and then inputted to the switch 1 of the mobile communication operator using the telephone number.

The exchange 1 of the mobile communication provider inquires whether the subscriber is a valid subscriber and the location of the subscriber to the HLR 2 and transmits the information to the corresponding base station 4 to call the terminal 5.

The location of the BSC and VLR in terms of systems may vary depending on the equipment manufacturer. For example, the BSC may be in the same spatial location as the MSC or may be in the BTS, which is the base station 4. The base station 4 means that the BSC and the BTS are combined.

2 is a block diagram of a remote optical transmission device of a base station in a conventional mobile communication system.

As shown therein, the base station 10 amplifies the baseband signal and transmits it to the CDMA frequency band; It is composed of a remote repeater (Radio Frequency Unit, RFU) 20 is connected to the base station 10 and the optical cable (optic cable) to amplify and transmit the signal of the base station 10.

In the above, the base station 10 is connected to a communication line and performs a demodulation and demodulation, and the signal received from a source signal containing voice, video, and data connected to the modem 12 to 4FA (Frequency Allocation). A master CDMA modem channel signal processor (11) for processing a master CDMA modem channel signal having a 4FA splitter (13) for separating; A synthesizing unit 14 for synthesizing the signals separated by the 4FA separating unit 13 of the master CDMA modem channel signal processing unit 11; A directional coupler 15 for receiving and separating the output of the synthesis unit 14; A power amplifier 16 for receiving power from the directional coupler 15 and amplifying the power to radiate through the antenna 18; An electronic signal to optical signal converter 17 for receiving an output of the directional coupler 15 to convert an electrical signal into an optical signal.

The remote repeater 20 is an optical signal to electrical signal converter for converting an optical signal into an electrical signal by receiving a signal output from the all-optical converter 17 in the base station 10 through an optical cable 21; A power amplifier 22 which receives the output of the photoelectric converter 21 and amplifies the power; And a base pass filter (BPF) 23 that receives the output of the power amplifier 22 and performs baseband filtering to radiate through the antenna 24.

3 is a flowchart illustrating a remote optical transmission method of a base station in a conventional mobile communication system.

As shown therein, a step (ST11) of receiving communication data from the modem 12 and generating a plurality of FA signals modulated by a radio frequency (RF) signal by a carrier signal corresponding to each channel; Combining the generated plurality of FA signals into one, power amplifying and radiating the combined RF signal through the antenna 18, and converting the optical signal to the remote repeater 20 through an optical cable (ST12) (ST13) )Wow; Photoelectric conversion of the optical signal received from the remote repeater (20); Amplifying the photoelectrically converted electrical signal and radiating the amplified signal through the antenna 24 (ST15).

The operation of the prior art configured as described above will be described in detail with reference to the accompanying drawings.

First, the base station 10 amplifies the baseband signal and transmits it to the CDMA frequency band.

In the base station 10, the CDMA modem channel signal processing unit 11 is connected to a communication line to perform modulation and demodulation, and the modem 12 is connected to the modem 12 to receive a signal received from a source signal containing voice, video, and data. A 4FA separation unit 13 separating 4FA (Frequency Allocation) is provided to process the master CDMA modem channel signal.

At this time, the base station CDMA channel signal source, which is a source signal output from the modem 12, generates data for communicating with the terminal.

The 4FA separation unit 13 receives a plurality of FA signals (1FA, 2FA, 3FA, 4FA, ...) modulated by the high frequency (RF) signal by the carrier signal corresponding to the data of the CDMA modem 12 for each channel. Generate.

The synthesizer 14 synthesizes the signals separated by the 4FA separator 13 of the master CDMA modem channel signal processor 11. Thus, the combining unit 14 combines several analog signals and outputs one analog signal.

The directional coupler 16 receives the output of the combiner 14 and separates it. Thus, the directional coupler 16 separates one analog signal into two analog signals and outputs the same to the power amplifier 16 and the all-optical converter 17.

The power amplifier 16 receives the output of the directional coupler 15 and amplifies the power to radiate through the antenna 18. This amplifies the power of the analog high frequency (RF) signal.

The all-optical converter 17 receives the output of the directional coupler 15 and converts the electrical signal into an optical signal. The converted optical signal is transmitted to the photoelectric conversion unit 21 of the remote repeater 20 through the optical cable.

The antenna 18 radiates high frequency (RF) signals to a wireless transmission line Air.

Meanwhile, the remote repeater 20 is connected to the base station 10 by an optical cable to amplify and transmit a signal of the base station 10.

In the remote repeater 20, the photoelectric converter 21 receives a signal output from the all-optical converter 17 in the base station 10 through an optical cable and converts the optical signal into an electrical signal.

The power amplifier 22 receives the output of the photoelectric converter 21 and amplifies the power. That is, the CDMA spreading waveform converted to the electric signal is amplified.

The baseband filter 23 receives the output of the power amplifier 22 and performs baseband filtering to radiate through the antenna 24. Therefore, the in-band (In_Band) CDMA spreading waveform amplified from the power amplifier 22, removes the out-band (Out_Band) noise and applied to the antenna 24 to communicate with the terminal Emits a high frequency signal.

This prior art operation will be described in more detail.

First, the master CDMA modem channel signal processor 11 of the base station 10 includes a plurality of FA signals (1FA) modulated at high frequency (RF) by the carrier signal corresponding to the communication data from the CDMA modem 12 of the base station for each channel. , 2FA, 3FA, 4FA, ...).

The generated FA signals are combined into one by the combining unit 14.

The combined RF signal is split into two by the directional coupler 15, one to the power amplifier 16 and the other to the all-optical converter 17.

The RF signal transmitted to the power amplifier 16 is amplified and radiated through the antenna 18 and communicates with the terminal.

The electrical analog CDMA spreading signal is transmitted to the all-optical converter 17 by the directional coupler 15.

The electrical signal thus transmitted is converted into an optical signal and transmitted to the remote repeater 20 through the optical cable.

The photoelectric conversion unit 21 of the remote repeater 20 converts the optical signal transmitted through the optical cable into an electrical signal.

After the CDMA modem channel high frequency (RF) signal is amplified by the power amplifier 22, baseband filtering is performed, and then radiated through the antenna 24 to communicate with the terminal of the region to which the base station 10 cannot. .

However, this conventional technology has the following problems.

First, since the signal transmitted to the optical cable is a high frequency analog signal, there is a problem that the cable loss (Cable Loss) is increased according to the temperature.

Second, since a plurality of analog high frequency (RF) signals (1FA, 2FA, 3FA, 4FA, ...) are transmitted through the optical cable, there was also a disadvantage of generating interference noise (Interference Noise).

Third, there is a problem in that the synthesis unit 14 cannot combine 1FA in sector A, 1FA in sector B, and 1FA in sector C.

Fourth, there is a disadvantage that it is not suitable to connect the repeater to the cascade (Cascade) and to perform long-distance transmission because it can not compensate due to the optical line time delay.

Accordingly, the present invention has been proposed to solve the above conventional problems, and an object of the present invention is to compensate for the time delay of the optical path in the CDMA base station to solve the shadow area of the cell and to expand the range of radio waves. The present invention provides a remote optical transmission apparatus and a method of a base station in a mobile communication system that can reduce the rental cost.

In order to achieve the above object, a remote optical transmission apparatus of a base station in a mobile communication system according to an embodiment of the present invention,

A base station for amplifying and transmitting the baseband signal to a CDMA frequency band and multiplexing and outputting a CDMA modem channel signal, a control signal, and a loop back signal; And a remote repeater connected to the base station by an optical cable to demultiplex the CDMA modem channel signal, the control signal and the loop back signal multiplexed at the base station, and loop back the loop back control signal to the base station. Features of the jacket.

Remote optical transmission method of the base station in the mobile communication system according to an embodiment of the present invention to achieve the above object,

A first step of multiplexing a base station CDMA modem channel signal source, digital I / Q baseband signals generated for each channel, and a remote repeater control signal and transmitting them to a remote repeater; And a second step of demultiplexing the multiplexed signal at the remote repeater after the first step so that the CDMA modem channel signal source radiates through the antenna for each sector and the remote repeater control signal controls the remote repeater and loops back to the base station. Performance is characterized by its technical construction.

Hereinafter, an embodiment according to the present invention, a remote optical transmission apparatus of a base station and a method thereof in a mobile communication system will be described with reference to the accompanying drawings.

4 is a block diagram of a remote optical transmission device of a base station in a mobile communication system according to the present invention.

As shown therein, the base station 100 amplifies and transmits a baseband signal to a CDMA frequency band, and multiplexes and outputs a CDMA modem channel signal, a control signal, and a loop back signal; Remotely connected to the base station 100 by an optical cable to demultiplex the CDMA modem channel signal, the control signal, and the loop back signal multiplexed in the base station 100, and to loop back the loop back control signal to the base station 100. It is configured to include a repeater 200.

The remote repeater 200 is characterized in that to connect a plurality of remote repeaters with the base station 100 in a daisy chain (Daisy Chain).

In the above, the base station 100 includes a master CDMA modem channel signal processing unit 110 including a modem 111 and processing a master CDMA modem channel signal; A master remote repeater control unit 120 having a central processing unit (CPU) 121 and controlling a remote repeater; A multiplexer (130) for multiplexing the outputs of the master CDMA modem channel signal processor (110) and the master remote repeater controller (121); A parallel to serial converter 140 for converting the parallel signal output from the multiplexer 130 into a serial signal; It is further configured to include an all-optical conversion unit 150 for converting the electrical serial signal of the parallel-to-serial conversion unit 140 into an optical signal.

In the above, the master remote repeater control unit 120 checks the transmission / reception path by determining whether the data looped back from the remote repeater 200 is the same as the first data.

The master remote repeater control unit 120 measures the time of the signal looped back from the remote repeater 200 to compensate the time of each remote repeater (200 ~ 500) to the base station 100 and the respective remote It is characterized by matching the time synchronization of the repeaters (200 ~ 500).

The remote repeater 200 includes a photoelectric conversion unit 210 connected to an all-optical conversion unit 150 in the base station 100 by an optical cable to convert an input optical signal into an electrical signal; A serial to parallel converter 220 for converting the electric serial signal input from the photoelectric converter 210 into a parallel signal; A demultiplexer 230 which demultiplexes the parallel signal output from the serial-to-parallel converter 220; A slave CDMA modem channel signal processor 240 which performs CDMA modem channel signal processing on the signal output from the demultiplexer 230 and radiates it to antennas 248 to 250; It includes a CPU 261, and comprises a slave remote repeater control unit 260 for receiving a signal output from the demultiplexer 230 to control the remote repeater 200.

The slave CDMA modem channel signal processor 240 includes an RF converter 241 for converting a signal output from the demultiplexer 230 into an RF signal; A plurality of power amplifiers 242 to 244 for power amplifying the RF signal converted by the RF converter 241 for each sector; And a plurality of baseband filters 245 to 247 that perform baseband filtering on the signals amplified by the plurality of power amplifiers 242 to 244 to radiate them through the antennas 248 to 250. .

The slave remote repeater controller 260 controls the remote repeater 200 by using the remote repeater control signal output from the base station 100, and loops back a control signal to the base station 100 to transmit / receive a path. And check and time delay compensation.

7 is a flowchart illustrating a remote optical transmission method of a base station in a mobile communication system according to the present invention.

As shown in the figure, the base station CDMA modem channel signal source, digital I / Q (In-Phase / Quadrature Phase) baseband signals generated for each channel and the remote repeater control signals are multiplexed and transmitted to the remote repeater 200. First steps ST21 to ST24; After the first step, the multiplexed signal is demultiplexed in the remote repeater 200 so that the CDMA modem channel signal source radiates through the antenna for each sector, and the remote repeater control signal controls the remote repeater 200 and the base station 100 It includes a second step (ST25 ~ ST31) to loop back.

The first steps ST21 to ST24 include: multiplexing a base station CDMA modem channel signal source, digital I / Q baseband signals and a remote repeater control signal generated for each channel (ST21); Converting the multiplexed parallel signal into a serial signal (ST22); Converting the parallel-serial converted serial electric signal into an optical signal (ST23); And transmitting the all-optical converted optical signal to the remote repeater 200 through an optical cable (ST24).

In the above-described second step ST25 to ST31, the second step ST25 to ST31 may be performed by photoelectric conversion of the signal transmitted after the first step, and then bypassing the signal to another remote repeater connected in a daisy chain.

The second step (ST25 ~ ST31), the step of serial-to-parallel conversion of the photoelectrically converted signal after the bypass (ST26) and; Demultiplexing the output parallel signal into a CDMA modem channel signal source and a remote repeater control signal (ST27); Transmitting the distributed CDMA modem channel signal source by sector to RF conversion, power amplifying the RF-converted 4FA signal, and radiating it through antennas 248 to 250 (ST28 to ST30); The distributed remote repeater control signal is further used to control the remote repeater and then loop back to the base station 100 (ST31).

The operation of the remote optical transmission apparatus and the method of the base station in the mobile communication system according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

First, the present invention is to compensate for the time delay of the optical path in the CDMA base station to eliminate the shadow area of the cell and to extend the range of propagation.

Thus, the present invention connects the base station 100 and the plurality of remote repeaters 200 to 500 in a daisy chain.

9 is a block diagram showing an example of configuring four remote repeaters to which the present invention is applied.

Wherein the first to fourth remote repeaters of 200 to 500 and 600 are mobile stations.

The configuration of the second to fourth remote repeaters 300 to 500 is the same as that of the first remote repeater 200, and the connection is daisy-chained.

On the other hand, the base station 100 amplifies and transmits the baseband signal to the CDMA frequency band, and multiplexes and outputs the CDMA modem channel signal, the control signal, and the loop back signal.

In the base station 100, the master CDMA modem channel signal processor 110 includes a modem 111 and processes a master CDMA modem channel signal.

The modem 111 in the master CDMA modem channel signal processing unit 110 generates a base station CDMA channel signal source to generate data for communication with the terminal.

The master remote repeater control unit 120 includes a central processing unit (CPU) 121 and controls a remote repeater.

The master remote repeater control unit 120 checks the transmission / reception path by determining whether the data looped back from the remote repeater 200 is the same as the data originally sent.

In addition, the master remote repeater control unit 120 compensates the time of each remote repeater (200 ~ 500) by measuring the time of the signal looped back from the remote repeater 200, the base station 100 and each remote repeater (200 ~ 500) Time synchronization).

The multiplexer 130 multiplexes the outputs of the master CDMA modem channel signal processor 110 and the master remote repeater controller 121.

FIG. 5 is a detailed block diagram of a multiplexer and neighboring blocks of a base station in FIG. 4.

Here, CTRL_DATA [0 ~ 7] Chipx1 input to the multiplexer 130 is a control signal received from the CPU 121 of the master remote repeater controller 120.

The Modem_chipx1 I_1FA_Alpha [16L], Modem_chipx1 Q_1FA_Alpha [16L], ..., Modem_chipx1 Q_1FA_Alpha [16L] signals are output from the modem 111 to radiate through the alpha antenna 248 of the alpha sector. As the alpha region I and Q signals of 4FA, a total of eight signals including I and Q signals are input to four FAs.

The Modem_chipx1 I_1FA_Beta [16L], Modem_chipx1 Q_1FA_Beta [16L], ..., Modem_chipx1 Q_1FA_Beta [16L] signals are outputted from the modem 111 to radiate through the beta sector beta antenna 249. As the beta region I and Q signals of 4FA, a total of eight signals including I and Q signals are input to four FAs.

The Modem_chipx1 I_1FA_Gamma [16L], Modem_chipx1 Q_1FA_Gamma [16L], ..., Modem_chipx1 Q_1FA_Gamma [16L] signals are output from the modem 111 to radiate through the gamma antenna 250 of the gamma sector. As the gamma region I and Q signals of 4FA, a total of eight signals including I and Q signals are input to four FAs.

The multiplexer then multiplexes 4FA / 3 sector I / Q data and control data.

The parallel-to-serial converter 140 converts the parallel signal output from the multiplexer 130 into a serial signal.

The all-optical conversion unit 150 converts the electrical serial signal of the parallel-to-serial conversion unit 140 into an optical signal.

Meanwhile, the remote repeater 200 is connected to the base station 100 by an optical cable to demultiplex the CDMA modem channel signal, the control signal, and the loop back signal multiplexed at the base station 100, and the loop back control signal to the base station 100. Loop back.

In the remote repeater 200, the photoelectric conversion unit 210 is connected to the all-optical conversion unit 150 in the base station 100 by an optical cable to convert the input optical signal into an electrical signal.

The serial and parallel converter 220 converts the electric serial signal input from the photoelectric converter 210 into a parallel signal.

The demultiplexer 230 demultiplexes the parallel signal output from the serial-to-parallel converter 220.

FIG. 6 is a detailed block diagram of a demultiplexer and its neighboring blocks of the remote repeater of FIG. 4.

Thus, CTRL_DATA [0 ~ 7] _chipx1 output from the demultiplexer 230 is input to the CPU 261 of the slave remote repeater controller 260 to control the remote repeater and loop back to the base station 100. Control signal.

Modem_chipx16 I / Q_1,2,3,4FA_Alpha signals are output from the modem 111 of the base station 100, and the four signals are used to output the I and Q signals to be output through the alpha antenna 248 of the alpha sector. CDMA modem channel signal for alpha sector.

Modem_chipx16 I / Q_1,2,3,4FA_Beta signals are output from the modem 111 of the base station 100. The four signals are used to output the I and Q signals to be output through the beta sector 249 of the beta sector. CDMA modem channel signal for beta sector.

The Modem_chipx16 I / Q_1,2,3,4FA_Gamma signals are output from the modem 111 of the base station 100. The four signals are output of the I and Q signals to be output through the gamma antenna 248 of the gamma sector. CDMA modem channel signal for gamma sector.

In addition, the slave CDMA modem channel signal processor 240 performs CDMA modem channel signal processing on the signal output from the demultiplexer 230 and radiates it to the antennas 248 to 250.

In the slave CDMA modem channel signal processor 240, the RF converter 241 converts the signal output from the demultiplexer 230 into an RF signal.

In the slave CDMA modem channel signal processor 240, the first to third power amplifiers 242 to 244 power amplify the RF signal converted by the RF converter 241 for each alpha, beta, and gamma sector.

In the slave CDMA modem channel signal processor 240, the first to third baseband filters 245 to 247 perform baseband filtering on the power amplified signal for each alpha, beta, and gamma sector, respectively. Radiation is transmitted through the antennas 248 to 250 of the gamma sector.

The slave remote repeater controller 260 includes a CPU 261, and receives a signal output from the demultiplexer 230 to control the remote repeater 200.

In addition, the slave remote repeater control unit 260 controls the remote repeater 200 by using the remote repeater control signal output from the base station 100 and loops back the control signal to the base station 100 to check the transmission / reception path and compensate for the time delay. It works to make this possible.

Referring to the operation of the present invention in more detail as follows.

In the first step, the base station CDMA modem channel signal source, digital in-phase / quadrature phase (I / Q) baseband signals generated for each channel, and the remote repeater control signal are multiplexed and transmitted to the remote repeater 200.

To this end, first, the base station CDMA modem channel signal source, digital I / Q baseband signals generated for each channel, and the remote repeater control signal are multiplexed.

The multiplexed parallel signals are converted into serial signals.

In addition, the serial-to-serial converted electrical signals are converted into optical signals by all-optical conversion.

Then, the all-optical converted optical signal is transmitted to the remote repeater 200 through the optical cable.

Meanwhile, in the second step, the multiplexed signal is demultiplexed in the remote repeater 200, the CDMA modem channel signal source is radiated through the antenna for each sector, and the remote repeater control signal controls the remote repeater 200 and loops back to the base station 100. Let's do it.

It then photoelectrically converts the transmitted signal and bypasses it with other remote repeaters connected in a daisy chain.

After the bypass is performed, the photoelectrically converted signal is output in parallel and parallel conversion.

The output parallel signal is demultiplexed and distributed to the CDMA modem channel signal source and the remote repeater control signal.

The distributed CDMA modem channel signal source transmits by sector, RF-converts, amplifies the RF-converted 4FA signal, and radiates it through antennas 248 to 250.

The distributed remote repeater control signal is used to control the remote repeater and then loops back to the base station 100.

FIG. 8 is a diagram illustrating an example data configuration of the multiplexer and the demultiplexer in FIG. 4.

Thus, in the multiplexer 130 of the base station 100, the 4FA / 3 sector digital baseband I / Q data, ATM control data, and each remote repeater looping (from the master CDMA modem channel signal processor 110 of the base station 100) Looping) data is synchronized with the Chipx48 clock, and multiplexed as shown in FIG. 4, and then the digital data transmitted in parallel from the serial-to-serial conversion unit 140 and serially converted to the all-optical conversion unit 150 is applied to the optical signal. The converted signal is transmitted to the remote repeater through the optical cable.

In addition, the demultiplexer 230 of the remote repeater 200 for 4FA / 3 sector digital baseband I / Q data, ATM control data and each remote repeater looping transmitted from the base station 100, which is a digital unit, via an optical cable. The data is synchronized to the Chipx48 clock to demultiplex as shown in FIG. 5, and 4FA digital baseband I / Q data is transmitted per sector to the up converter. Then, the RF converter 241 performs an up conversion to an RF spreading waveform and amplifies and radiates it through an antenna.

In addition, the ATM control operation will be described in more detail as follows.

It uses ATM protocol for communication between base station 100, which is a digital unit, and remote repeater 200, which is an RF unit, and downloads an operating system (OS) and application software in the remote repeater 200 to a remote repeater. Perform fault and condition management And when you add a remote repeater in a daisy chain, it increases the slot register (9 bit) of the ATM slot.

9 is a block diagram showing an example of configuring four remote repeaters to which the present invention is applied.

The loopback and time delay operations of the remote repeater will be described in detail with reference to FIG. 9.

First, the base station 100 and the remote repeaters 200 to 500 may be spaced up to 40 km apart, and send the data promised for the path check from the base station 100, and the remote repeaters 200 to 500 to the base station 100. Loop back.

The base station 100 may check the transmission / reception path by determining whether the looped data is the same as the data sent first.

In addition, the base station 100 measures the time of the signal looped back from each remote repeater (200 to 500), and compensates the time to each remote repeater (200 to 500) cascaded with the base station 100 Time synchronization of each of the remote repeaters 200 to 500 may be performed.

For example, if the propagation delay time of the forward wave (= propagation delay time of the reverse wave) is 244 m / chip, and the optical path delay is 5 microseconds / km (= 6.144 chip / km), The hardware delay of the remote repeater is as follows.

Hardware Delay of Remote Repeater

= Photoelectric conversion delay + receive link delay + demultiplexing delay + transmit link delay + all-optical conversion delay

= 4 microseconds + 77ns + 1 / chipx32 * 4 clocks + 44ns + 4 microseconds

= 10.072 chip

In addition, when the optical transmission path is 20km and the distance between the fourth remote repeater 500 and the mobile station 600 is 5km, the time delay between the base station 100 and the mobile station 600 is as follows.

Time delay between base station 100 and mobile station 600

= Propagation delay of forward propagation + 4x optical path delay + 4x remote repeater hardware delay

= 5000m / 244 + 4x10x6.144 + 4x10.072

= 512 chip

Accordingly, since the base station 100 calculates this and generates a time delay between the base station 100 and the mobile station 600 by 512 chips, this can be compensated for.

As such, the present invention is to compensate for the time delay of the optical path in the CDMA base station to eliminate the shadow area of the cell, to extend the range of radio waves and to reduce the base station rental cost.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, the remote optical transmission apparatus and method of the base station in the mobile communication system according to the present invention has the following effects.

First, it is possible to compensate the time of the remote optical transmission line to synchronize the time synchronization between the base station and the base stations, and each of the remote repeaters, the digital base station and the cascaded RF unit, so that the base station is cascaded into the base station. There is a scalable effect.

Second, since 4FA / 3 sector baseband I / Q data are multiplexed and transmitted and received to the remote base station, single mode optical communication is possible, thereby reducing the cost of all-optical and photoelectric conversion blocks and reducing the line rental cost. There is also an effect.

Third, the conventional integrated base station was used to rent a building to install a plurality of base stations. According to the present invention, a base station capable of performing optical transmission of a CDMA digital I / Q baseband signal remotely can centrally manage a plurality of digital units in one base station, and a remote repeater is an outdoor type separately. Since no base station is required, base station management can be facilitated and base station rental cost can be reduced.

Fourth, the base station according to the present invention also has an advantage that is suitable for expanding the shadow base station and cell coverage.

Claims (12)

A base station for amplifying and transmitting the baseband signal to a CDMA frequency band and multiplexing and outputting a CDMA modem channel signal, a control signal, and a loop back signal; And a remote repeater connected to the base station by an optical cable to demultiplex the CDMA modem channel signal, the control signal and the loop back signal multiplexed at the base station, and loop back the loop back control signal to the base station. Remote optical transmission device of a base station in a mobile communication system. The method of claim 1, wherein the remote repeater, A remote optical transmission device of a base station in a mobile communication system, characterized in that daisy chaining a plurality of remote repeaters with the base station. The method of claim 1, wherein the base station, A master CDMA modem channel signal processor comprising a modem and processing a master CDMA modem channel signal; A master remote repeater control unit having a CPU and controlling a remote repeater; A multiplexer for multiplexing the outputs of the master CDMA modem channel signal processor and the master remote repeater controller; A parallel serial converter converting the parallel signal output from the multiplexer into a serial signal; And an all-optical converter configured to convert the electrical serial signal of the parallel-serial converter into an optical signal. The method of claim 3, wherein the master remote repeater control unit, The remote optical transmission apparatus of the base station in the mobile communication system, characterized in that for checking the transmission and reception path by determining whether the data looped back from the remote repeater is the same as the first data sent. The method of claim 3, wherein the master remote repeater control unit, Compensating the time of each remote repeater by measuring the time of the signal looped back from the remote repeater to synchronize the time synchronization between the base station and each of the remote repeater. The remote repeater according to any one of claims 1 to 5, wherein A photoelectric conversion unit connected to the all-optical conversion unit in the base station by an optical cable to convert an input optical signal into an electrical signal; A serial-to-parallel converter for converting the electric serial signal input from the photoelectric converter into a parallel signal; A demultiplexer for demultiplexing the parallel signal output from the serial-to-parallel converter; A slave CDMA modem channel signal processor for performing CDMA modem channel signal processing on the signal output from the demultiplexer and radiating the signal to the antenna; And a slave remote repeater controller configured to receive a signal output from the demultiplexer and control a remote repeater. The method of claim 6, wherein the slave CDMA modem channel signal processing unit, An RF converter converting the signal output from the demultiplexer into an RF signal; A plurality of power amplifiers for power amplifying the RF signal converted by the RF converter for each sector; And a plurality of baseband filters configured to perform baseband filtering on the signals amplified by the plurality of power amplifiers to radiate them through an antenna, respectively. The method of claim 6, wherein the slave remote repeater control unit, The base station in the mobile communication system is controlled to control the remote repeater using the remote repeater control signal output from the base station, and to loop back the control signal to the base station to check the transmission / reception path and compensate for the time delay. Remote optical transmission device. A first step of multiplexing a base station CDMA modem channel signal source, digital I / Q baseband signals generated for each channel, and a remote repeater control signal and transmitting them to a remote repeater; And a second step of demultiplexing the multiplexed signal at the remote repeater after the first step so that the CDMA modem channel signal source radiates through the antenna for each sector and the remote repeater control signal controls the remote repeater and loops back to the base station. Remote optical transmission method of a base station in a mobile communication system, characterized in that performed. The method of claim 9, wherein the first step, Multiplexing a base station CDMA modem channel signal source, digital I / Q baseband signals and a remote repeater control signal generated for each channel; Converting the multiplexed parallel signal into a serial signal; Optically converting the parallel-serial converted serial electrical signal into an optical signal; And transmitting the all-optical converted optical signal to a remote repeater through an optical cable. The method of claim 9 or 10, wherein the second step, And bypassing the signals transmitted after the first step by photoelectric conversion and bypassing them with other remote repeaters connected by daisy chains. The method of claim 11, wherein the second step, Outputting a parallel signal by performing parallel-to-parallel conversion on the photoelectrically converted signal after the bypass; Demultiplexing the output parallel signal into a CDMA modem channel signal source and a remote repeater control signal; Transmitting the distributed CDMA modem channel signal source by sector to RF conversion, amplifying the RF-converted 4FA signal and radiating it through an antenna; And using the distributed remote repeater control signal to loop back to the next base station used to control the remote repeater.

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