KR20030018987A - basestation transmission system - Google Patents

Abstract

PURPOSE: A base station transmission device is provided to integrate a hard hand-off circuit inside an individual block, and to generate a pilot signal for hard hand-off identical to an output of the base station, so that the arrangement of a pilot unit in an additional space is not necessary. CONSTITUTION: A channel board(1) allocates channels for call data signals inputted from mobile communication terminals, and performs digital signal processing for the data. A digital signal distribution board(2) allocates and outputs the digital data signals inputted from the channel board(1) to plural paths, and controls functions of a base station transmission device on the whole. A D/A(Digital-to-Analog) conversion board(3) converts plural digital signals respectively inputted from the plural paths into analog signals and then into RF(Radio Frequency) signals. A transmission amplifier(4) performs transmission power amplification for RF signals outputted from one of the plural paths of the D/A conversion board(3) and outputs the amplified signals. And a transmission filter module(6) performs channel and band filtering for the RF data signals outputted from the transmission amplifier(4), amplifies RF pilot signals directly inputted from the D/A conversion board(3) without passing a transmission path of the transmission amplifier(4), and performs band pass filtering, then delivers the signals to an external through an antenna(5).

Description

Base station transmission system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base station transmitter and, more particularly, to a base station transmitter that generates a hard handoff pilot signal identical to the base station output by integrating a hard handoff circuit in a separate block of the base station transmitter.

In general, a base station system processes a call by allocating a call channel to a mobile communication terminal in its sector. In this case, the mobile communication terminal frequently moves away from a base station to which a communication channel is allocated during a call and moves to a cell or another sector under the control of another base station. In this case, the neighboring base station is a new channel instead of the radio frequency channel in use. This function allows the call to be maintained by performing a handover or handoff function. However, the above-described base station uses the strength of the received signal and the carrier to interference ratio (C / I) and the like as parameters for determining the necessity of handoff of the mobile communication terminal.

For example, in the CDMA cellular system in which the handoff process is performed, the wireless channel being used and the newly allocated wireless channel are simultaneously occupied in order to prevent an instantaneous disconnection of the communication channel. When the signal of the newly allocated wireless channel becomes dominant, a method of completely switching over and recovering the previously used wireless channel is applied. This is called soft handoff. On the other hand, the conventional handoff method is called a hard handoff. The hard handoff method is a radio of an A cell without a time occupying a radio channel of an A cell and a B cell to be transferred simultaneously. The channel is recovered and occupies the radio channel of the B cell.

In this case, in order to enable frequency hard handoff between two base stations having different frequency allocations, a single frequency base station radiates a pilot signal corresponding to a multi-frequency to a multi-frequency base station. It is possible to hard-off the frequency from the terminal used to call to a single base station. Therefore, the conventional single frequency base station as described above is usually provided with a separate hard-off circuit for emitting a pilot signal.

Then, referring to FIG. 1, the base station transmitter 70 separately provided with the conventional hard-off circuit may be divided into a signal transmitter 71 and a hard handoff circuit unit 72. First, the signal transmitter A channel unit 73 assigns a channel to the mobile communication terminals (not shown) and digitally processes data transmitted from the mobile communication terminal to which the channel is assigned, and an input from the channel unit 73. Digital signal distribution board 74 for outputting the digital data signal to a specific transmission path (PATH) and overall control of the function of the base station transmitter 70, and the digital signal input from the digital signal distribution board 74 is analog A D / A conversion board 75 for converting a signal into a high frequency signal and then outputting the converted signal; a transmission amplifier 76 for amplifying and outputting a high frequency signal output from the D / A conversion board 75; Transmit Amplifier And a transmission filter module 78 for band-passing the high frequency signal output from the 76 to the outside through the antenna 77.

The hard handoff circuit unit 72 generates a pilot signal for generating a hard signal for a hard handoff of a mobile communication terminal entering the base station sector, and a pilot signal output from the pilot signal generator 79. A band pass filter 82 for band-pass filtering the pilot signal of the high frequency output from the transmit amplifier 80 and amplifying the signal to a predetermined level, and emitting it to the outside through the beacon antenna 81. It includes.

In addition, the D / A conversion board 75 includes a D / A converter 83 for converting a digital signal input from the digital signal distribution board 74 into an analog signal, as shown in FIG. A baseband modulator 84 for modulating the analog data signal output from the A converter 83 into the baseband, and a frequency mixer for converting the baseband data signal input from the baseband modulator 84 into a high frequency signal; A band pass filter 86 for band-filtering the high frequency data signal output from the frequency mixer 85 to a predetermined band, and a high frequency data signal output from the band pass filter 86 at a predetermined level. And an amplifier 87 for amplifying the signal and a variable attenuator 88 for variably attenuating the high frequency data signal output from the amplifier 87.

In addition, the digital signal distribution board 74 arranges and outputs a data control unit 89 for controlling a plurality of digital signals input from the channel unit 73 and digital signals output from the data control unit 89. It includes an alignment unit 90 to.

Next, referring to the operation of the base station transmitter provided with the conventional hard-off circuit as described above, the channel unit 73 of the signal transmitter 71 allocates a channel to the sectors or hand-off mobile communication terminals of the base station. Then, the data transmitted from each mobile communication terminal to which this channel is allocated are digitally processed and input to the data control unit 89 of the digital signal distribution board 74. Then, the data control unit 89 of the digital signal distribution board 74 controls the input and output of the digital signal of the plurality of mobile communication terminals to be input to the alignment unit 90 of the digital signal distribution board 74. . In addition, the alignment unit 90 of the digital signal distribution board 74 sorts the digital signals input from the data control unit 89 to the D / A conversion unit 83 of the D / A conversion board 75. Enter it. At this time, the D / A converter 83 converts the input digital signal into an analog signal and inputs it to the baseband modulator 84. The baseband modulator 84 converts the analog data signal input from the D / A converter 83 into a baseband signal and inputs the same to the frequency mixer 85. Then, the frequency mixer 85 filters the input analog baseband signal, for example, harmonics and spurious components, converts the harmonic and spurious components into high frequency signals, and inputs them to the bandpass filter 86. In the band pass filter 86, the high frequency data signal input from the frequency mixer 85 is band-filtered and amplified by the amplifier 87 and input to the variable attenuator 88. The variable attenuator 88 variably attenuates the input high frequency data signal by a predetermined amount of attenuation and inputs the same to the transmission amplifier 76. In this case, the transmission amplifier 76 amplifies the high frequency data signal input from the variable attenuator 88 of the D / A conversion board 75 and transmits it to the transmission filter module 78. Then, the transmission filter module 78 band-passes the high frequency signal output from the transmission amplifier 76 to the outside through the antenna 77.

Here, the hard handoff circuit unit 71 of the base station transmits a pilot signal to the outside for the hard handoff between the base station and the base station separately from the data transmission operation of the base station. In this case, the hard handoff circuit unit 71 The pilot signal generator 79 generates a pilot signal for hard handoff of the mobile communication terminal entering the base station sector and inputs the pilot signal to the transmission amplifier 80. The transmission amplifier 80 amplifies the pilot signal output from the pilot signal generator 79 to a predetermined level and then inputs it to the band pass filter 82. Then, the band pass filter 86 of the hard handoff circuit unit 72 band-passes the high frequency pilot signal output from the transmission amplifier 80 and emits it to the outside through the beacon antenna 81. Accordingly, if there is a mobile communication terminal moving into the cell of the base station, it receives a pilot signal transmitted through the beacon antenna 81 to hard hand off.

However, the base station transmitting apparatus provided with the conventional hard-off circuit as described above has to be equipped with a hard handoff circuit unit in a predetermined space separately from the transmitting apparatus of the base station. As a result, the space design of the base station transmitter is considerably degraded. Also, since the hard handoff circuit unit must be installed independently of the individual board of the base station transmitter, the utilization of the individual board of the base station transmitter is also reduced. There was a problem that considerably lowered.

Accordingly, the present invention has been invented to solve the above-mentioned general problems. By integrating the hard handoff circuit in the individual block of the base station transmitter, the hard handoff is generated by generating the same hard handoff pilot signal as the base station output. It is not necessary to provide a pilot unit in a separate space in order to provide a base station transmitter that improves the spatial design of the base station transmitter accordingly.

Another object of the present invention is to provide a base station transmitter that can implement a hard handoff circuit using individual blocks of the base station transmitter, thereby significantly reducing the manufacturing cost of the base station transmitter.

According to an aspect of the present invention, there is provided a channel board for allocating a channel to call data signals input from mobile communication terminals and digitally processing the data allocated to the channel, and digital data input from the channel board. A digital signal distribution board which allocates and outputs signals to a plurality of paths and controls overall functions of the base station transmitter, and converts a plurality of digital signals respectively inputted from a plurality of paths of the digital signal distribution board into analog signals. A D / A conversion board for converting and outputting a next high frequency signal, a transmission amplifier for amplifying and outputting a high frequency signal output from any one of a plurality of paths of the D / A conversion board, and outputting from the transmission amplifier; Channel and band filtering of the high frequency data signal, and not through the transmission path of the transmission amplifier. And to the D / A amplifies a high-frequency pilot signal directly inputted from the conversion board and pass filtering provides a base station transmission device consisting of these signals to the transmitting filter module for emitting to the outside through the antenna.

1 is an explanatory diagram illustrating a conventional base station transmitter.

2 is an explanatory diagram illustrating a D / A conversion board of a conventional base station transmitter.

3 is an explanatory diagram for explaining a base station transmitter according to the present invention;

4 is an explanatory diagram illustrating a digital signal distribution board of the present invention.

<Detailed Description of Codes>

1: Channel board 2: Digital signal distribution board

3: D / A conversion board 4: Transmission amplifier

5: antenna 6: transmit filter module

7: Data control unit 8: Data distribution unit

9: Sorter 10: D / A converter

11: baseband modulator 12: frequency mixer

13: bandpass filter 14: amplifier

15: Variable Attenuator 16: Channel Filter

17: amplifier 18: band filter

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

As shown in FIG. 3, the present invention provides a channel board (1) for allocating a channel to call data signals input from mobile communication terminals (not shown) and digitally processing the data to which the channel is assigned. A digital signal distribution board (2) for allocating and outputting a plurality of digital data signals inputted from (1) to, for example, first and second paths (PATH) and controlling overall functions of the base station transmitter; A D / A conversion board 3 for converting a plurality of digital signals respectively input from a plurality of paths of the board 2 into analog signals, and then converting and outputting them into a high frequency signal, and the D / A conversion board 3 In addition to channel and band filtering, a transmission amplifier 4 amplifies and outputs a transmission power of a high frequency signal output from any one of a plurality of paths, and a high frequency data signal output from the transmission amplifier 4. Transmitting filter for amplifying high frequency pilot signals directly input from the D / A conversion board 3 and then band-filtering them to the outside through the antenna 5 without passing through the transmission path of the new amplifier 4. Module 6.

The digital signal distribution board 2 is inputted from the data control unit 7 and the data control unit 7 for controlling a plurality of digital signals input from the channel board 1 as shown in FIG. Among the digital signals, a data divider 8 for distributing a pilot-allocated signal and a data signal to the first and second paths is input, and the data divider 8 is input along the first and second paths, respectively. And a sorting unit 9 for discriminating and aligning the output signals and outputting the signals through a plurality of paths.

In addition, the D / A conversion board 3 converts the digital signals input through the plurality of paths, for example, the first and second paths, of the digital signal distribution board 2 into analog signals, respectively, and converts them into a plurality of path signals. A baseband for outputting each of the D / A converter 10 and the analog data signals respectively inputted from the D / A converter 10 into the plurality of paths to the baseband and outputting the plurality of path signals, respectively. A modulator 11 and a frequency mixer 12 for converting baseband data signals respectively inputted from the baseband modulator 11 into a plurality of paths into high frequency signals and outputting the plurality of path signals respectively; A band pass filter 13 for band-pass filtering the high-frequency data signals respectively inputted from the plurality of paths into the set bands and outputting them as a plurality of path signals, respectively; and a plurality of paths from the band pass filter 13; To Accordingly, the amplifier 14 amplifies each of the high frequency data signals inputted to a predetermined level and outputs them as a plurality of path signals, and variably attenuates the high frequency data signals respectively inputted along the plurality of paths from the amplifier 14. The variable attenuator 15 outputs a plurality of path signals, respectively.

In addition, the transmission filter module 6 performs a channel filter 16 for channel filtering the high frequency signal output from the transmission amplifier 4 and the D / A conversion without passing through the transmission path of the transmission amplifier 4. An amplifier 17 for amplifying a high frequency signal directly input from the board 3, and a high frequency data signal and a high frequency pilot signal input from the channel filter 16 and the amplification unit 17, respectively, to filter these signals. And a band filter 18 which emits to the outside through the antenna 5, respectively.

Next, the operation and effects of the apparatus of the present invention as described above will be described.

In case of call signal processing of each digital data received from mobile communication terminals in the device of the present invention, the channel board 1 of the device of the present invention first allocates a channel to the mobile communication terminals (not shown) and assigns the channel. The digital data signals transmitted from the mobile communication terminal are input to the data control unit 7 of the digital signal distribution board 2. Then, the data control unit 7 of the digital signal distribution board 2 controls the input and output of the digital signal of the plurality of mobile communication terminals that are input, and then input to the data distribution unit 8 of the digital signal distribution board 2. Let's do it. Then, the data distribution unit 8 distributes a pilot-allocated signal and a data signal among the digital signals input from the data control unit 7 to a plurality of paths, that is, the first and second paths, respectively. When the signal input from the data control unit 7 is a call data signal, for example, the signal is output to the first path of the alignment unit 9. The sorting unit 9 classifies and sorts the call data signal input along the first path and then inputs the first data of the D / A converting unit 10 of the D / A converting board 3. In this case, the D / A converter 10 converts the digital signal input along the first path into an analog signal and inputs it into the first path of the baseband modulator 11. The baseband modulator 11 converts an analog data signal input from the first path of the D / A converter 10 into a baseband signal and inputs the same to the frequency mixer 12. Then, in the frequency mixer 12, the analog baseband signal input along the first path of the baseband modulator 11 is filtered, for example, the harmonic and the spurious component, and then converted into a high frequency signal to convert the bandpass filter 13 into a high frequency signal. Enter In the band pass filter 13, the high frequency data signal input along the first path of the frequency mixer 12 is band-filtered and amplified through the amplifier 14 and input to the variable attenuator 15. The variable attenuator 15 variably attenuates the high frequency data signal input along the first path of the amplifier 14 by a predetermined amount of attenuation and inputs it to the transmission amplifier 4.

In this case, the transmission amplifier 4 amplifies the transmission power of the high frequency data signal input along the first path of the variable attenuator 15 of the D / A conversion board 3 to transmit the channel board of the transmission filter module 6 ( Enter 1). The channel filter 16 performs channel filtering on the high frequency data signal input from the transmission amplifier 4 located on the first path line and inputs the same to the band pass filter 18 of the transmission filter module 6. Then, the band filter 18 of the transmission filter module 6 band-passes the high-frequency signal output from the channel filter 16 to the outside through the antenna 5 to perform a normal call function.

In this process, if a signal to which a pilot for hard handoff is allocated is input to the channel board 1, the channel board 1 allocates a pilot signal for hard handoff to a specific channel and assigns a digital signal. Input to the data control unit 7 of the distribution board (2). Then, the data control unit 7 of the digital signal distribution board 2 controls the input / output of the input pilot signal and then inputs it to the data distribution unit 8 of the digital signal distribution board 2. Then, the data distributor 8 selects a second path among the plurality of paths and outputs the pilot signal input from the data controller 7 to the second path of the alignment unit 9. In addition, the alignment unit 9 classifies and aligns the pilot signal input along the second path, and then inputs it to the second path of the D / A conversion unit 10 of the D / A conversion board 3. At this time, the D / A converter 10 converts the pilot signal input along the second path into an analog signal and inputs it into the second path of the baseband modulator 11. The baseband modulator 11 converts an analog pilot signal input from the second path of the D / A converter 10 into a baseband signal and inputs it to the frequency mixer 12. Then, the frequency mixer 12 filters the analog pilot signal input along the second path of the baseband modulator 11, for example, the harmonics and the spurious components, and converts the harmonic and spurious components into high frequency signals to the band pass filter 13. Enter it. In the band pass filter 13, the high frequency data signal input along the second path of the frequency mixer 12 is band-filtered and amplified through the amplifier 14 and input to the variable attenuator 15.

In this case, the variable attenuator 15 variably attenuates the high frequency data signal input along the second path of the amplifier 14 by a set amount of attenuation so that the amplifying unit of the transmission filter module 6 does not go directly through the transmission amplifier 4. 17).

The amplifying unit 17 amplifies power enough to transmit a high frequency pilot signal directly input from the variable attenuator 15 to the outside without passing through the transmission amplifier 4 along the second path, thereby transmitting a transmission filter module ( Input to the bandpass filter 18 of FIG. 6). Then, the band pass filter 18 of the transmission filter module 6 performs band pass filtering on the pilot signal output from the amplifier 17 to the outside through the antenna 5 to perform a normal hard handoff function.

Here, the first path for transmitting the data signal is composed of a digital signal distribution board (2), a D / A conversion board (3), a transmission amplifier (4), a channel filter (16) and a band filter (18), The second path for pilot signal transmission includes a digital signal distribution board 2, a D / A conversion board 3, an amplifier 17, and a band filter 18.

Meanwhile, according to another embodiment of the present invention, the modulation characteristics of the current transmission output waveform may be measured between the transmission filter module 6 and the antenna 5 during normal operation of the base station. By using the result, the signal related to the base station transmit power is corrected, thereby improving the quality of the transmit output signal.

That is, according to the present invention, the pilot can be generated from the base station resources by allocating a channel for the pilot signal to the channel board 1 of the base station, and can perform the existing pilot beacon function with a signal almost identical to the base station signal. have. In addition, by implementing the existing pilot beacon function in a separate board of the base station transmitter, it is possible to directly and accurately perform the control and state management of the hard handoff function of the base station. In addition, since the transmission output signal of the base station can be measured during operation of the base station, it is possible to optimize the operating state of the base station.

As described above, the present invention integrates a hard handoff circuit into a separate block of a base station transmitter to generate a pilot signal for hard handoff that is identical to the output of the base station. Therefore, it is necessary to provide a separate pilot unit for hard handoff. Therefore, there is an advantage to improve the space design of the base station transmitter accordingly.

In addition, according to the present invention, it is possible to measure the modulation characteristics of the transmission output waveform of the base station itself, thereby improving the quality of a signal related to the transmission output of the base station.

Claims (6)

A channel board for allocating channels to call data signals inputted from mobile communication terminals and digitally processing the data allocated to these channels, and assigning and outputting the digital data signals inputted from the channel board to a plurality of paths A digital signal distribution board for controlling the overall function of the transmitter and a D / A conversion for converting a plurality of digital signals respectively inputted from a plurality of paths of the digital signal distribution board into analog signals and then converting them into high frequency signals. A transmission amplifier for amplifying and outputting a transmission power of a high frequency signal output from any one of a plurality of paths of the board, the D / A conversion board, and channel and band filtering the high frequency data signal output from the transmission amplifier; In addition, high frequency input directly from the D / A conversion board without passing through the transmission path of the transmission amplifier. And a transmission filter module for amplifying the wave pilot signals and then band filtering the signals to the outside through an antenna. The digital signal distribution board of claim 1, wherein the digital signal distribution board comprises: a data controller for controlling a plurality of digital signals inputted from the channel board; and a plurality of pilot signals and data signals allocated from the digital signals inputted from the data controller. And a data divider for distributing the signals through a plurality of paths and a sorting unit for dividing and aligning signals input along the plurality of paths from the data divider and outputting the signals through a plurality of paths. According to claim 1, wherein the D / A conversion board is a D / A conversion unit for converting each of the digital signals respectively inputted through a plurality of paths of the digital signal distribution board to an analog signal to output a plurality of path signals, respectively; A baseband modulator for modulating the analog data signals respectively input to the plurality of paths from the D / A converter into basebands and outputting the plurality of path signals respectively to the baseband modulators; A frequency mixer converts a data signal of a band into a high frequency signal and outputs a plurality of path signals, respectively, and band-filters the high frequency data signals inputted from the frequency mixer along a plurality of paths into a set band to a plurality of path signals. A band pass filter for outputting each of the band pass filters and a high frequency data signal respectively inputted from the band pass filter along a plurality of paths An amplifier for amplifying to a predetermined level and outputting each of the plurality of path signals, and a variable attenuator for variably attenuating the high frequency data signals input along the plurality of paths from the amplifier and outputting the plurality of path signals, respectively. Base station transmitter. The transmission filter module of claim 1, wherein the transmission filter module amplifies a channel filter for channel filtering the high frequency signal output from the transmission amplifier, and a high frequency signal input directly from the D / A conversion board without passing through the transmission path of the transmission amplifier. And a band pass filter for band-passing the high frequency data signals and the high frequency pilot signals respectively inputted from the channel filter and the amplification unit and emitting these signals to the outside through an antenna. The digital signal distribution board of claim 1, wherein the plurality of paths include: a first path via a digital signal distribution board, a D / A conversion board, a transmission amplifier, a channel filter, and a band filter; And a second path via the amplifier and the band pass filter. The apparatus of claim 5, wherein the first path is a path for data transmission and the second path is a path for pilot signal transmission.