KR100293242B1 - Receiving System for WLL(Wireless Local Loop) RIU(Radio Interface Unit) and Receiving Power Control Method Thereof - Google Patents

Abstract

SUMMARY OF THE INVENTION An object of the present invention is to receive a signal from a wireless base station in a wideband code division multiple access wireless subscriber network subscriber station, and to maintain a stable signal conforming to the power of a signal transmitted from a base station and received to a subscriber telephone. In order to improve the quality of the entire communication service, thereby maximizing the number of subscriber terminals that can be managed by the base station, the wireless subscriber network radio access device receiving system and the reception power control that can minimize the cost of the communication service. To provide a way.

The configuration of the present invention calculates an amplification factor of a corresponding received signal according to the received amplification signal CTL, generates and outputs a digital control signal according thereto, and inputs an input channel error signal CHER and a frame error signal FRER. And a processor 50 for generating and outputting an output amplification control signal according to the received strength signal RSSI; A modem 60 which receives the digital control signal output from the processor 50 and generates and outputs an amplification control signal RX_CNTL converted into an analog signal; The signal received through the antenna ANT is received, modulated, and amplified according to the amplification control signal RX_CNTL output from the modem 60 to be converted into a baseband signal and output from the processor 50. The signal processing unit 70 amplifies and outputs the signal according to the output amplification control signal RXAGC.

Description

Receiving System for Wireless Local Loop (WLL) Radio Interface Unit (RIU) and Receiving Power Control Method Thereof}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless local loop (WLL) wireless access device receiving system and a receiving power control method. More particularly, the present invention relates to a wide code division multiple access (W-CDMA) scheme. Receiving a signal from a wireless base station in a subscriber network subscriber station, using a received signal strength signal (RSSI) and a frame error of a channel The present invention relates to a wireless subscriber network wireless access device receiving system and a receiving power control method for improving the quality of a generated baseband received signal by maintaining an amplification factor.

In general, the wireless subscriber network system is a system that replaces a predetermined interval between each subscriber's home and the public line switch in the existing public switched telephone network (PSTN) system by wireless instead of wired.

This technology was designed to reduce temporary equipment when making a phone call in a sparsely populated area, such as a farming and fishing village.It was originally designed at the US Bell Labs in the early 70's, but it was not easy to secure radio frequency. And the installation cost was too high to reach the commercialization stage.

However, with the rapid development of electronic communication technology in the mid-1990s, various manufacturers are introducing economical products to the market one after another, and communication operators are showing great interest in commercializing the wireless subscriber network.

The advantage of the wireless subscriber network is that the telephone network can be easily installed, the facility expansion cost is low, and the flexibility of the network design according to the increase of subscribers is good.

In addition, since the radio wave can be easily installed anywhere, there is a flexible network construction.

Products developed for wireless subscriber network include satellite system, fixed microwave system, cellular technology system and codeless technology system.

However, in the multiple access scheme applied to the wireless access network, frequency division multiple access (FDMA) is a multiple access scheme in which a plurality of stations divide a frequency band so that spectrum does not overlap each other in one repeater band and communicate with each other. Time Division Multiple Access (TDMA) method, which is a method in which multiple stations communicate with each other so that signals do not overlap with each other at the same carrier frequency in one repeater, and specific to each subscriber. Code division multiple access (CDMA), a multiple access method that assigns codes of the same carrier frequency, spreads the modulated waves of the same carrier frequency into codes, receives them on the same repeater, and identifies and connects the circuits on the receiving side. Code Division Multiple Access).

Current commercial products are mainly divided into the frequency division multiple access method and the time division multiple access method, but are being converted to the code division multiple access method with a much larger subscriber capacity than other access methods.

In addition, unlike the conventional narrowband code division multiple access wireless subscriber network, the wideband code division multiple access wireless subscriber network system employing the code division multiple access scheme employs only call, facsimile and data transmission. In addition, the development of the Integrated Services Data Network (ISDN) service and the packet (packet) network has the advantage of enabling the development is active.

In general, a broadband code division multiple access wireless subscriber network system, as shown in FIG. 1, receives a user's signal from a telephone 1 in each home and transmits the signal to a base station to a base station. 2), the radio base station (3) which is in charge of the connection and disconnection of the bearer (radio) with the radio access device (2), and the radio subscription that is responsible for link establishment of the call with the existing public circuit switched network (6) And a base station coordinator (4) for connecting a call link between the base station (5) and the base station (3) and the wireless subscriber network switch (5).

In the wireless subscriber network made as described above, the wireless access device 2 is installed indoors for each subscribing terminal as a wireless signal capable of transmitting a signal output from a telephone of each home to the wireless base station 3. And a transmission system (not shown) for converting and transmitting the signal, and a reception system (not shown) for receiving a radio signal transmitted from the radio base station 3 and inputting the signal.

Hereinafter, a wireless access device receiving system of a conventional broadband code division multiple access wireless subscriber network system will be described with reference to the accompanying drawings.

As shown in Fig. 2, the configuration of the radio access device receiving system of the conventional broadband code division multiple access wireless subscriber network system is

A processor (processor 10) for calculating an amplification factor of a corresponding received signal according to the received received amplification signal (CTL) and generating and outputting a digital control signal accordingly;

A modem (MODEM, 20) which receives the digital control signal output from the processor 10 and generates and outputs an amplification control signal RX_CNTL converted into an analog signal;

Receives and modulates the signal received through the antenna ANT, amplifies the signal according to the amplification control signal RX_CNTL output from the modem 20, and converts the signal into baseband signals RX_I and RX_Q to output the signal. It includes a processing unit 30.

The configuration of the signal processor 30,

A band pass filter 31 which receives a high frequency signal received through an antenna and passes only signals of a required frequency band,

A low noise amplifier 32 which receives a signal output from the band pass filter 31 and suppresses and amplifies noise;

A frequency mixer 33 for receiving a signal output from the low noise amplifier 32 and moving the signal to an intermediate frequency signal,

An intermediate frequency amplifier 34 receiving the signal output from the frequency mixer 33 and amplifying and outputting the signal according to the amplification control signal RX_CNTL output from the modem 20;

A demodulator 35 for receiving and demodulating the signal output from the intermediate frequency amplifier 34 to generate and output baseband signals RX_I and RX-Q;

And an output amplifier 36 formed of amplifiers 36A and 36B for receiving and amplifying each baseband signal output from the demodulator 35.

The operation of the radio access device receiving system of the conventional broadband code division multiple access type wireless subscriber network system made as described above is as follows.

The processor 10 is responsible for the overall control of the radio access device. In the receiving system, the amplification factor of the corresponding received signal is calculated according to the received amplification signal CTL, and the control signal is generated and output accordingly. Adjust the device of (20) to set the modem to meet the wireless connection standard.

In addition, the modem 20 functions as a general spreading function and converts the I signal RX_I and Q signal RX_Q, which are received and input as a baseband signal, into a signal that can be processed by the subscriber's telephone. The digital control signal output from the processor 10 is input to generate an amplification control signal RX_CNTL converted into an analog signal, and outputs the amplified control signal RX_CNTL to the signal processor 30.

The signal processor 30 receives and modulates a signal received through the antenna ANT, and amplifies the signal according to the amplification control signal RX_CNTL output from the modem 20 to baseband signals RX_I and RX_Q. By converting to and outputting to, and transmits the signal transmitted from the base station to the subscriber's phone.

Hereinafter, the operation of the signal processor 30 will be described in detail.

The band pass filter 31 of the signal processor 30 receives a high frequency signal received through an antenna, removes unnecessary noise components and transmit signal components, and passes only a received signal having a required frequency band.

The low noise amplifier 32 receives the signal output from the band pass filter 31 to suppress the noise component as much as possible and amplifies and outputs only the signal component.

The frequency mixer 33 receives a signal output from the low noise amplifier 32 using a carrier frequency signal fc of a high frequency input, and extracts a signal of an intermediate frequency component from a signal of a high frequency component.

The intermediate frequency amplifier 34 receives the signal of the intermediate frequency component output from the frequency mixer 33 and amplifies and outputs the signal according to the amplification control signal RX_CNTL output from the modem 20.

The demodulator 35 receives and demodulates the signal output from the intermediate frequency amplifier 34 to generate and output baseband signals RX_I and RX-Q. In general, the baseband signal is a phase shift keying (PSK; Phase Shift Keying) Since it is modulated and received, it performs phase shift keying demodulation.

The output amplifier 36 receives the baseband signals RX_I and RX_Q output from the demodulator 35 and amplifies the baseband signals RX_I and RX_Q into signals having a predetermined magnitude.

By operating as described above, the signal is processed so that the subscriber's telephone can process the signal transmitted from the base station.

In general, in a wireless subscriber network, the size of a signal transmitted from a base station to each subscriber station, i.e., a signal received from a receiving system of a wireless access device, must be output with power specified in a standard to properly operate each communication state. Can be.

That is, the power of the signal transmitted from each base station and outputted to the subscriber station should be transmitted at a constant value according to the standard, so that a communication service can be made close to the theoretical number of subscriber stations managed by one base station.

By the way, even if the processor 10 outputs a control signal for amplifying the power according to the theoretical standard, and thus the amplification control signal RX_CNTL is output from the modem 20, the intermediate frequency of the signal processor 30 Each element including the amplifiers 36A and 36B of the amplifier 33 and the output amplifier 36 is an analog element, and thus each element is different depending on the environment such as the temperature or the state at the time of shipment from the product. Characteristics, and thus, the power of the signal output from the signal processor 30 and input to the subscriber's telephone is different from the theoretical value.

As a result, the signal quality of the subscriber decreases due to signal power degradation. Therefore, the subscriber station requires the base station to increase the transmission power in order to restore the communication service state. Accordingly, the base station increases the power of the transmitted signal. Let's do it.

However, when the power of the signal transmitted from each base station rises above a certain value, the service line of the subscriber station that can be managed by the base station is reduced, which requires the construction of additional base stations, the system operating cost There is a problem that rises.

Accordingly, an object of the present invention is to solve the problems of the prior art, and in receiving a signal from a wireless base station in a broadband code division multiple access wireless subscriber network subscriber station, it is transmitted from a base station to a subscriber telephone. By maintaining a stable signal in accordance with the standard to maintain the power of the signal received by the standard, thereby improving the quality of the overall communication service, thereby maximizing the number of subscriber terminals that can be managed by the base station, thereby minimizing the cost of the communication service The present invention provides a wireless subscriber network wireless access device receiving system and a receiving power control method.

1 is a block diagram applying a general wireless subscriber network system,

2 is a block diagram applying a wireless subscriber network radio access device receiving system according to the prior art;

3 is a block diagram of a system for receiving a wireless subscriber network wireless access device according to an embodiment of the present invention;

4A and 4B are flowcharts illustrating a method for controlling reception power of a wireless subscriber network wireless access device according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

50: processor 60: modem

70: signal processor 71: band pass filter

72: low noise amplifier 73: frequency mixer

74: intermediate frequency amplifier 75: demodulator

76: output amplifier

The configuration of the present invention for achieving the above object is made as follows.

In the receiving system of a wireless subscriber network wireless access device,

Calculate the amplification rate of the received signal according to the received amplification signal input, generate and output the digital control signal according to the input, and generate and output the output amplification control signal according to the input channel error signal, the frame error signal and the reception intensity signal Control means;

A signal converting means for generating and outputting an amplification control signal which receives the digital control signal output from the control means and converts it into an analog signal;

Receives and modulates the signal received through the antenna, amplifies it according to the amplification control signal output from the signal conversion means, converts it into a baseband signal, and amplifies it according to the output amplification control signal output from the control means. Characterized in that it comprises a signal processing means to.

Another configuration of the present invention for achieving the above object is made as follows.

In the receiving power control method of a wireless subscriber network wireless access device receiving system,

Setting a reference strength signal and a channel coder error reference value by reading a signal transmitted from the base station;

Determining whether the call is in a connected state;

Comparing the channel coder error occurrence value and the reception strength signal with the reference value set above when the call connection state is not established, and adjusting the output amplification control value accordingly;

Setting a frame error reference value when in a call connection state;

And reading the frame error occurrence value and comparing the frame error reference value to adjust the output amplification control value accordingly.

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

As shown in FIG. 3, the configuration of a system for receiving a wireless subscriber network wireless access device according to an embodiment of the present invention is as follows.

In the receiving system of a wireless subscriber network wireless access device,

The amplification factor of the corresponding received signal is calculated according to the received received amplification signal CTL, and the digital control signal is generated and output according to the received channel amplification signal CTL. The received channel error signal CHER, the frame error signal FRER, and the received intensity signal A processor 50 generating and outputting an output amplification control signal according to RSSI);

A modem 60 which receives the digital control signal output from the processor 50 and generates and outputs an amplification control signal RX_CNTL converted into an analog signal;

The signal received through the antenna ANT is received, modulated, and amplified according to the amplification control signal RX_CNTL output from the modem 60 to be converted into a baseband signal and output from the processor 50. And a signal processing unit 70 for amplifying and outputting the output amplification control signal RXAGC.

The configuration of the signal processing unit 70,

A band pass filter 71 which receives a high frequency signal received through an antenna ANT and passes only a signal of a required frequency band;

A low noise amplifier 72 which receives the signal output from the band pass filter 71 and suppresses and amplifies noise;

A frequency mixer (73) for receiving a signal output from the low noise amplifier (72) and moving the signal to an intermediate frequency signal;

An intermediate frequency amplifier 74 which receives the signal output from the frequency mixer 73 and amplifies and outputs the signal according to the amplification control signal RX_CNTL output from the modem 20;

A demodulator 75 for receiving and demodulating the signal output from the intermediate frequency amplifier 74 to generate and output baseband signals RX_I and RX-Q;

And an output amplifier 76 formed of amplifiers 76A and 36B which receive respective baseband signals output from the demodulator 75 and amplify them according to the input output amplification control signal RXAGC. .

Operation of the embodiment of the present invention made as described above is as follows.

First, a general operation will be described. The processor 50 of the wireless subscriber network wireless access device is responsible for the overall control of the wireless access device. In the receiving system, a corresponding reception signal is received according to the received reception amplification signal (CTL). Calculate the amplification factor, and generate and output the digital control signal according to the output signal, and generate and output the output amplification control signal according to the input channel error signal CHER, the frame error signal FRER, and the reception strength signal RSSI.

The processor 50 adjusts the elements of the modem 60 to set the modem 60 to meet the wireless connection standard.

The modem 60 performs a general spreading function, converts an I signal RX_I and a Q signal RX_Q output from the signal processor 70 into a signal that can be processed by a telephone, and outputs the signal. The amplification control signal RX_CNTL generated by converting the digital control signal output from the digital signal 50 into an analog signal is generated and output to the signal processor 70.

The signal processor 70 receives and modulates a signal received through the antenna ANT, amplifies the signal according to the amplification control signal RX_CNTL output from the modem 60, and then performs a baseband I signal RX_I. And a Q signal RX_Q is generated and amplified according to the output amplification control signal RXAGC output from the processor 50.

Hereinafter, the above operation will be described in detail with reference to FIGS. 3, 4A, and 4B.

When the base station transmits a high frequency radio signal to the subscriber station, the subscriber station receives the signal through the antenna ANT, and the band pass filter 71 receives the received high frequency signal and receives only the signal of the required frequency band. Pass it through and extract only that signal.

The low noise amplifier 72 receives the signal output from the band pass filter 71 and amplifies and outputs a signal having a standard that can be signal processed internally by suppressing noise as much as possible.

The frequency mixer 73 receives a signal output from the low noise amplifier 72 and moves the signal to an intermediate frequency signal using a high frequency carrier signal fc.

The intermediate frequency amplifier 74 receives the signal of the intermediate frequency band output from the frequency mixer 73, amplifies and outputs the signal according to the amplification control signal RX_CNTL output from the modem 20.

The demodulator 75 receives and demodulates the signal output from the intermediate frequency amplifier 74, and generates and outputs an I signal RX_I and a Q signal RX-Q, which are baseband signals.

The output amplifier 76 receives the baseband signals RX_I and RX-Q output from the demodulator 75, and outputs the output amplifier control signal RXAGC that is output from the processor 50. Amplify according to the output.

By doing the above, the signal processing unit 70 converts the signal received through the antenna into a signal that can be processed by a telephone (not shown), and amplifies and outputs the signal.

By the way, the power of the signal output from the signal processing unit 70 should always be output according to a predetermined standard, the function of adjusting the magnitude of the output power is in charge of the intermediate frequency amplifier 74, the amplification control signal ( RX_CNTL) is adjusted by adjusting the modem 60 in the processor 50.

The processor 50 uses the amplified signal CTL received from the base station to adjust the value of the amplification control signal RX_CNTL.

By the way, when the size of the signal output from the signal processing unit 70 is out of the standard, a lot of errors occur in the modem or telephone processing the output signal, the signal quality is lowered, in the present invention to prevent such By separately controlling the amplification factor of the output amplifier 76 of the signal processor 70, the signal quality is improved.

Hereinafter, the amplification control operation of the output amplifier 76 will be described in detail with reference to FIGS. 3, 4A and b.

The processor 50 reads a signal transmitted from the base station (S10), receives a paging message (S20), and sets a channel coder error reference value and a received RSSI reference value (S30).

In operation S40, it is determined whether the call connection is in a call connection state. When the call connection state is not in the call connection state, the channel coder error occurrence value and the reception strength signal are compared with the reference value set above, and the output amplification control value is adjusted accordingly.

That is, the processor 50 reads the channel coder error occurrence value and compares the magnitude with the error reference value (S50), compares the received RSSI value with the reference RSSI value (S60), so that the channel coder error occurrence value is higher than the error reference value. If the received RSSI is small or larger than the reference RSSI, the channel coder error occurrence value at that time is set to the error reference value (S70), and the received RSSI at that time is set to the reference RSSI (S80), and then the output amplification control signal RXAGC. Decrease (S90).

When the channel coder error occurrence value is larger than the error reference value or the received RSSI is smaller than the reference RSSI, the channel coder error occurrence value at that time is set as an error reference value (S100), and the received RSSI at that time is referred to as the reference RSSI. After setting (S110), the output amplification control signal (RXAGC) is increased (S120).

If the channel coder error occurrence value is the same as the error reference value or the received RSSI is the same as the reference RSSI, the output amplification control signal RXAGC at that time is an appropriate value and is controlled without changing.

On the other hand, when it is determined that the call connection state in the step (S40), the processor 50 sets the frame error reference value (S130), and reads the frame error occurrence value and compares it with the frame error reference value and accordingly output amplification control Adjust the value.

That is, when the frame error occurrence value is smaller than the frame error reference value, the frame error occurrence value at that time is set to the frame error reference value (S150), and the output amplification control signal RXAGC is reduced (S160).

However, when the frame error occurrence value is larger than the frame error reference value, the frame error occurrence value at that time is set to the frame error reference value (S170), and the output amplification control signal RXAGC is increased (S180).

When the frame error occurrence value is the same as the frame error reference value, the output amplification control signal RXAGC at that time is an appropriate value and is controlled as it is without changing.

As described above, the receiving system can maintain the power of the received signal even if the performance of each element of the signal processing unit 70 changes as the environment such as the ambient temperature changes, and the signal processing unit 70 Even though each device has slightly different performance from the factory, the output signal can be adjusted to a desired value.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, conversions, and modifications are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those who have knowledge.

Accordingly, the present invention operating as described above, in receiving a signal from a wireless base station in a wideband code division multiple access type wireless subscriber network subscriber station, the power of the signal transmitted from the base station to the subscriber telephone set according to the standard. By maintaining the correct stable signal, it is possible to minimize the cost of the communication service by improving the quality of the entire communication service, thereby maximizing the number of subscriber stations that can be managed by the base station.

Claims (5)

In the receiving system of a wireless subscriber network wireless access device, Calculate the amplification rate of the received signal according to the received amplification signal input, generate and output the digital control signal according to the input, and generate and output the output amplification control signal according to the input channel error signal, the frame error signal and the reception intensity signal Control means; A signal converting means for generating and outputting an amplification control signal which receives the digital control signal output from the control means and converts it into an analog signal; Receives and modulates the signal received through the antenna, amplifies it according to the amplification control signal output from the signal conversion means, converts it into a baseband signal, and amplifies it according to the output amplification control signal output from the control means. Wireless subscriber network radio access device receiving system comprising a signal processing means. The method of claim 1, wherein the signal processing means comprises: A band pass filter which receives a high frequency signal received through an antenna and passes only signals of a required frequency band, A low noise amplifier which receives a signal output from the band pass filter and suppresses and amplifies noise; A frequency mixer for receiving a signal output from the low noise amplifier and moving the signal to an intermediate frequency signal, An intermediate frequency amplifier receiving the signal output from the frequency mixer and amplifying and outputting the signal according to the amplification control signal output from the signal converting means; A demodulator configured to receive and demodulate a signal output from the intermediate frequency amplifier to generate and output a baseband signal; And an output amplifier configured to receive each baseband signal outputted from the demodulator and amplify according to the output amplification control signal inputted thereto. In the receiving power control method of a wireless subscriber network wireless access device receiving system, Setting a reference strength signal and a channel coder error reference value by reading a signal transmitted from the base station; Determining whether the call is in a connected state; Comparing the channel coder error occurrence value and the reception strength signal with the reference value set above when the call connection state is not established, and adjusting the output amplification control value accordingly; Setting a frame error reference value when in a call connection state; And reading the frame error occurrence value and comparing the frame error reference value to adjust an output amplification control value accordingly. The method of claim 3, wherein comparing the channel coder error occurrence value and the reception strength signal with the reference value set above and adjusting the output amplification control value accordingly If the channel coder error occurrence value is smaller than the error reference value or the received RSSI is larger than the reference RSSI, the channel coder error occurrence value at that time is set to the error reference value, the received RSSI at that time is set to the reference RSSI, and the output amplification control signal. Reduce (RXAGC), If the channel coder error occurrence value is larger than the error reference value or the received RSSI is smaller than the reference RSSI, the channel coder error occurrence value at that time is set to the error reference value, the received RSSI at that time is set to the reference RSSI, and an output amplification control signal. Receiving power control method of a wireless subscriber network wireless access device, characterized in that for increasing. The method of claim 3, wherein the reading of the frame error occurrence value and comparing the frame error reference value to adjust the output amplification control value accordingly include: If the frame error occurrence value is smaller than the frame error reference value, set the frame error occurrence value at that time as the frame error reference value, reduce the output amplification control signal, And if the frame error occurrence value is larger than the frame error reference value, setting the frame error occurrence value at that time as the frame error reference value and increasing the output amplification control signal.