KR100314214B1 - Apparatus for multi user signal modulation according to sector of base station in mobile communication system - Google Patents

Abstract

The present invention relates to a sector-by-sector multi-user modulation apparatus of a base station in a mobile communication system that modulates multiple users at the same time in a sector. When the area setting signal is generated to be stored and the received data is stored in the memory, the received data is stored in the corresponding area among the areas divided by the channel according to the area setting signal output from the microprocessor and the microprocessor generating the interrupt so that the data can be encoded The first dual port RAM storing the data, the encoder and the interleaver for encoding and interleaving the data output from the first dual port RAM according to the interrupt generated by the microprocessor, and the data output from the encoder and the interleaver for each channel. Dual Pole to store in RAM, a spreader that multiplies the data output from the second dual port RAM by a pseudo noise code, and a digital combiner that combines the multi-user signal output from the spreader, thereby using a single hardware. Can be modulated simultaneously

Description

Apparatus for multi user signal modulation according to sector of base station in mobile communication system}

The present invention relates to multi-user modulation in a mobile communication system [IMT-2000 system, digital cellular system (DCS), personal mobile communication system (PCS) using a code division multiple access (CDMA) method, In particular, the present invention relates to a sector-by-sector multi-user signal modulation apparatus of a base station in a mobile communication system that modulates multiple users at the same time.

More specifically, the base station in the mobile communication system to simplify the configuration of the overall base station apparatus by implementing the base station apparatus to divide each user signal by sector and to spread (modulate) it using a single hardware (modulator) Per sector of a multi-user signal modulation device.

In general, a mobile communication system employing a CDMA system includes a mobile terminal (called a mobile station) capable of making mobile calls and controlling and managing a base station and a base station performing wireless communication using a wireless interface method set in the IS-95. A control station, a mobile communication exchange connected to the control station for exchanging calls, and a mobile location exchange connected to the mobile communication exchange and manage subscriber information, and the like.

In such a general mobile communication system, when a call originates from a mobile terminal, the base station receives the call, passes it to a mobile communication exchange via a control station, and the mobile communication exchange switches so that the call can be connected to the other terminal. .

In such a general mobile communication system, a conventional base station device is composed of a baseband interface card assembly (BICA), a CDMA digital channel card assembly (CDCA), a self control and a routing card assembly (SRCA), and the like. A portion of the card assembly is shown in FIG. 1 attached.

Herein, reference numerals 11 to 20 denote first to tenth channel card units, and 30 denotes a combination of sectors of transmission I and Q channel signals obtained by the first to tenth channel card units 11 to 20 for each sector. Represents a digital combination.

The CDMA digital channel card assembly configured as described above modulates downlink data (direction of the base station from the control station) transmitted through the corresponding channel in each channel card unit 11 to 20, and each channel in the digital combination unit 30. The data modulated by the card units 11 to 20 are combined for each sector and output.

Here, one channel card unit is composed of twelve channel elements 41 to 52 and a microprocessor 53 for controlling each channel element 41 to 52, as shown in FIG.

One channel card unit configured as described above processes only the received signal corresponding to its own channel and sector at each channel element 41 to 52 for the input downlink data RX. Here, the twelve channel elements 41 to 52 are connected to each other in a cascade manner to transmit signals.

For example, channel element # 1 (41) processes the signal of an alpha sector of an arbitrary channel, channel element # 2 (42) processes the signal of a beta sector of an arbitrary channel, and channel element # 3 (43) It is assumed that a signal of a gamma sector of an arbitrary channel is processed, and channel element # 4 (44) processes a channel signal of an alpha sector of an arbitrary channel. In this case, the output of the channel element # 1 (41) is output through only the alpha sector of the three sectors and is transmitted to the channel element # 2 (42), and the channel element # 2 (42) is the channel element as the alpha sector. The signal obtained from # 1 (41) is output, and the signal processed by the self is output to the beta sector. The channel element # 3 43 then outputs a signal of the alpha sector output from the channel element # 2 42 to the alpha sector, and the signal of the beta sector output from the channel element # 2 42 to the beta sector. The sector signal is processed by the gamma sector. In addition, the channel element # 4 (44) outputs the alpha sector signal output from the channel element # 3 (43) and the alpha sector signal processed by the channel sector # 3 (43) to the alpha sector, and the channel element # 3 (43) to the beta sector. The beta sector signal obtained by is output as it is, and the gamma sector signal of the channel element # 3 43 is output as it is as a gamma sector.

3 is a block diagram illustrating an embodiment of the channel element.

As shown, the encoder and interleaver 61, the diffuser 62, and the digital adder 63 are formed.

The encoder and interleaver 61 is composed of a convolutional encoder and a block interleaver. In the convolutional encoder, an encoder using a characteristic in which finite past input data (constraints) affect the current data is used. It is an encoder with strong error correction capability, and the block interleaver functions to discrete data according to certain rules in order to prevent burst errors that are likely to appear on the radio path.

The signal encoded through the encoder and the interleaver 61 is spread in the spreader 62, wherein the spreading method spreads the input signal using a Walsh code orthogonal to each other for each channel, and pseudo There is a method of spreading using a noise code (PN code).

That is, the spreading method using a Walsh code spreads the band by multiplying an orthogonal Walsh code, and the spreading method using a pseudo noise code multiplies the Walsh code and multiplies the spread signal by a PN code. Spread the band.

The spread signal is transmitted to the digital adder 63, and the digital adder 63 digitally adds and outputs the sector signal processed in the corresponding channel element and the spread code received from the previous channel element.

Through such a series of processes, the digital combiner is cascaded to the channel element processing the same sector, and the digital combine value of the corresponding sector is output at the final stage.

On the other hand, there are 10 of these channel cards per base station, and the digitally combined signals outputted from the end of each channel card should be digitally combined again with the same sectors.

It is the digital combination unit 30 of FIG. 1 to perform this role, and FIG. 4 is a block diagram showing an embodiment of the digital combination unit.

As shown, the output signals of the ten channel cards (channel cards 0 to 9) are selectively transferred from the first to fifth serial adders 71 to 75 to the system clock sys_clk. Add synchronously and output.

That is, the first serial adder 71 adds and outputs the serial output signals of the channel card 0 and the channel card 1 in accordance with the system clock, and the second serial adder 72 outputs the serial output from the channel card 2 and the channel card 3. The third serial adder 73 adds and outputs the serial output signals of the channel card 4 and the channel card 5 in accordance with the system clock, and outputs the third serial adder 74 according to the system clock. In this case, the serial output signals of the channel cards 6 and 7 are added in accordance with the system clock, and the fifth serial adder 75 adds and outputs the serial output signals of the channel cards 8 and 9 according to the system clock. do.

Next, the sixth serial adder 76 adds and outputs signals output from the first and second serial adders 71 and 72, respectively, in synchronization with the system clock. A signal output from the third and fourth serial adders 73 and 74 is added and output in synchronization with the system clock, and a first deflip-flop 78 is configured to synchronize the system clock with the fifth serial adder. The output signal of 75 is latched and output.

The eighth serial adder 79 adds and outputs the output signals of the sixth and seventh serial adders 76 and 77 according to the system clock, and the second deflip-flop 80 supplies the system clock. In synchronization, the output signal of the first flip-flop 80 is latched.

In addition, the ninth serial adder 81 adds and outputs the signal output from the eighth serial adder 79 and the signal output from the second flip-flop 80.

The digital combination unit described above has described only the digital combination for the I channel. In order to digitally combine the Q channel signal, the digital combination unit combines the signals of the Q channel using the configuration as shown in FIG. That is, in practice, the digital combination unit is doubled in one embodiment as shown in FIG. 4 to digitally combine the signals of the I and Q channels.

However, in the conventional base station apparatus, the digital combining method primarily combines and outputs output signals of each channel element (12 channel elements) in the digital combiner in the channel element, and secondly, each channel card (10 channel cards). Since the output of the digital combination by the digital combination unit to output again, there is a problem that not only the digital combining process is complicated, but also its configuration.

Accordingly, the present invention has been proposed to solve various problems occurring in the base station apparatus of the conventional CDMA mobile communication system.

It is an object of the present invention to provide a sector-by-sector multi-user signal modulation apparatus of a base station in a mobile communication system that modulates multiple users simultaneously for each sector.

More specifically, the base station in the mobile communication system to simplify the configuration of the overall base station apparatus by implementing the base station apparatus to divide each user signal by sector and to spread (modulate) it using a single hardware (modulator) To provide a sector-by-sector multi-user signal modulator.

The present invention for achieving the above object,

By spreading (modulating) multiple users on a sector-by-sector basis with one piece of hardware, the traditional two-time digital combining process is reduced to one.

In addition, since hardware is allocated for each sector in a complicated process of digitally combining the same sectors in one channel card by cascading, the digital signal is simply digitally combined with only one adder after the spreader.

This simplifies the structure in terms of hardware and simplifies the overall base station device in terms of device size.

1 is a block diagram showing a system configuration of a portion of a base station apparatus in a conventional mobile communication system,

FIG. 2 is a block diagram showing an embodiment of one channel card unit of FIG. 1;

FIG. 3 is a block diagram illustrating an embodiment of one channel element of FIG.

4 is a block diagram showing an embodiment of the digital combination of FIG.

5 is a block diagram illustrating an embodiment of a multi-user signal modulation apparatus for each sector of a base station in a mobile communication system according to the present invention.

FIG. 6 is a block diagram illustrating an embodiment of a diffusion unit and a digital combination unit of FIG. 5.

<Explanation of symbols for the main parts of the drawings>

100 microprocessor

200, 400: first and second dual port RAM

300 encoder and interleaver

500 diffusion part

600: digital combination

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention according to the technical spirit as described above in detail.

5 is a block diagram illustrating an embodiment of a sector-specific multi-user signal modulation apparatus of a base station in a mobile communication system according to the present invention.

As shown, when the received data is delivered to the base station, the microprocessor generates an area setting signal to store the received data in areas divided by channels, and generates an interrupt to encode the received data when the received data is stored in the memory. 100; A first dual port RAM 200 for storing received data in a corresponding area among areas divided by channels according to an area setting signal output from the microprocessor 100; An encoder and an interleaver (300) for encoding and interleaving data output from the first dual port RAM (200) according to an interrupt generated by the microprocessor (100); A second dual port RAM 400 for storing data output from the encoder and the interleaver 300 in a corresponding region among regions divided by channels; A diffusion unit 500 multiplying and outputting data output from the second dual port RAM 400 by a pseudo noise code; The digital combiner 600 combines the multi-user signals output from the spreader 500.

Here, as shown in FIG. 6, the spreader 500 demultiplexes the multi-user signal output from the second dual port RAM 400 under the control of the microprocessor 100. ), A register unit 520 including a plurality of registers for temporarily storing the output signal of the demultiplexer 510 for each channel, and a plurality of parallel / serial units for serially converting each output signal of the register unit 520. A parallel / serial converter 540 comprising a converter, a PN code generator 560 for generating a PN code for despreading, a PN code output from the PN code generator 560, and a register unit 540. The multiplier 570 includes a plurality of multipliers that multiply the data output from the respective registers.

In addition, the digital combiner 600 includes an adder 610 for adding and outputting the outputs of the multipliers of the multiplier 570.

In the mobile communication system according to the present invention configured as described above, the multi-user modulation apparatus for each sector of the base station first determines in which region the received signal (signal transmitted from the control station in downlink) is stored in the microprocessor 100. The controller transmits a region setting signal to the first dual port RAM 200 in which storage regions are divided for each channel.

The first dual port RAM 200 stores the received channel signal in the corresponding area according to the area setting signal. That is, the received signal is stored in one channel area of the first dual port RAM 200 which is divided into channels for each channel, and the second received signal is stored in another channel area.

In this case, the microprocessor 100 generates an interrupt to the encoder and the interleaver 300 whenever the received signal is stored in an arbitrary area of the first dual port RAM 200 to transmit the received signal to the first dual port RAM 200. Notifies you that you saved it.

Then, each time the interrupt occurs, the encoder and the interleaver 300 receive the received signals stored in each area of the first dual port RAM 200 as time division, convolutionally encode and interleave the encoded signals, and encode the encoded received signals. The data is stored in a predetermined area of the second dual port RAM 400.

That is, when an interrupt is first generated by the microprocessor 100, the encoder and the interleaver 300 read and encode a received signal stored in the first channel region of the first dual port RAM 200 to encode the second interrupt. When the received signal stored in the second channel area of the first dual port RAM 200 is read and encoded, the received signal stored in the first dual port RAM 200 is read by time division and encoded.

In addition, the second dual port RAM 400 stores the received signal encoded and output by the encoder and the interleaver 300 according to the region setting signal of the microprocessor 100 in an arbitrary region of the divided channel region.

That is, the second dual port RAM 400 stores the first received signal encoded and output by the encoder and the interleaver 300 according to the region setting signal of the microprocessor 100 in the first channel region of the divided channel region. The second received signal output from the encoder and the interleaver 300 is stored in the second channel region of the divided channel region.

The spreader 500 reads the received signals stored in each channel region of the second dual port RAM 400 in time division and spreads them.

That is, the spreader 500 reads the received signal stored in the first channel region among the received signals stored in each channel region of the second dual port RAM 400 and spreads the received signal in the second channel region. The stored received signal is read and spread.

6 is a configuration diagram illustrating an embodiment of the diffusion unit 500.

The demultiplexer 510 demultiplexes a received signal stored in one channel area output from the second dual port RAM 400 and separates the received signal into each channel signal (12 channels), and outputs the register unit 520. The channel signals are temporarily stored in the twelfth register 532.

The parallel / serial converter 540 is connected such that the first to twelfth parallel / serial converters 541 to 552 correspond to the first to twelfth registers 521 to 532 in one-to-one correspondence, respectively, and input the parallel data. Convert to serial data.

Each serial data converted as described above is transferred one to one to the first to twelfth multipliers 571 to 582 in the multiplier 570, and the multiplier 570 is respectively to the first to twelfth multipliers 571 to 582. The applied serial data (received data) and the PN code generated by the PN code generator 560 multiply and spread. This modulates the signals of several users at the same time.

On the other hand, the spread signal is applied to the digital combination unit 600, the digital combination unit 600, as shown in Figure 6, 12 sectors output from the multiplier 570 with only one adder 610 Each channel signal is added and output as a transmission signal TX1.

As described above, the present invention can modulate several user signals at the same time by using one piece of hardware for each sector, thereby providing an easy hardware implementation.

In addition, a simple digital combiner consisting of one adder can simultaneously combine several user signals corresponding to one sector, making it easy to digitally combine multi-user signals, and it is very simple in terms of hardware when compared to the configuration of existing digital combiners. The system is easy to implement, and the cost of the product can be reduced, which is an economic advantage.

Claims (4)

A base station apparatus of a mobile communication system, A microprocessor for generating an area setting signal to store the received data in areas divided for each channel when the received data is transmitted to the base station, and for generating an interrupt when the received data is stored in the memory; A first dual port RAM configured to store received data in a corresponding area among areas divided by channels according to an area setting signal output from the microprocessor; An encoder and an interleaver for encoding and interleaving data output from the first dual port RAM according to an interrupt generated by the microprocessor; A second dual port RAM configured to store data output from the encoder and the interleaver in a corresponding region among regions divided by channels; A spreader configured to multiply and spread the data output from the second dual port RAM with a pseudo noise code; And a digital combiner for combining the multi-user signals output from the spreader. The mobile communication apparatus of claim 1, wherein the encoder and the interleaver read and encode only a reception signal stored in one channel region among the reception signals stored in the first dual port RAM whenever an interrupt is input. Sector-based multi-user signal modulator of the base station in the system. The apparatus of claim 1, wherein the spreader comprises: a demultiplexer for demultiplexing a multi-user signal output from the second dual port RAM under a control of the microprocessor, and a plurality of temporarily storing output signals of the demultiplexer for each channel; A register unit comprising a plurality of registers, a parallel / serial conversion unit including a plurality of parallel / serial converters for converting each output signal in series, a PN code generator for generating a PN code for despreading, and the PN And a multiplier comprising a plurality of multipliers for multiplying a PN code output from a code generator and data output from respective registers in the register unit. The apparatus of claim 1, wherein the digital combiner comprises an adder configured to simultaneously add and output the outputs of the multipliers of the multipliers.