KR100318478B1 - wireless local loop system - Google Patents

Abstract

The present invention relates to a wireless subscriber network system that can change the FA using a switch switching method,

The receiver and transmitter are connected by an RF module control card (RFC); The receiver end unit (Rxfu) of the receiver receives a low noise amplifier (LNA), two band pass filters (BPF) for passing signals of a specific frequency band according to the received FA, and one of two band pass filters according to the received FA. And a first switch for selecting and connecting the output of the low noise amplifier to the input of the selected bandpass filter, and a second switch for connecting the output of the selected bandpass filter to the input of the frequency downconversion card.

The transmitter selects one of a frequency up-conversion card (UCC), a high output amplifier (HPA), two transmitting end units (Txfu) for outputting a signal according to a desired FA, and two transmitting end units according to the FA to select an output stage of the high output amplifier. And a third switch connecting the input terminal of the selected transmitting end unit and an output terminal of the selected transmitting end unit with the antenna.

Description

Wireless subscriber network system {wireless local loop system}

The present invention relates to a wireless subscriber network system, and more particularly, it is possible to change the FA by using a switch switching method, to efficiently manage cell management, and to minimize interference to adjacent cells. The present invention relates to a wireless subscriber network system that can be managed as one base station without separately managing a base station by FA.

Currently, in the case of a base station (RP: radio port) to which a wireless local area network (WLL) is applied, a frequency band of 30 MHz is allocated to a bandwidth of 10 MHz. Among the 30 MHz frequency bands, Korea Telecom has been assigned a frequency of 10 MHz 1FA (frequency assignment), while in Hanaro communication, a frequency of 20 MHz 2FA is allocated to prepare a service. In the wireless subscriber network system as described above, if one base station (RP) is fixed to a frequency band of 1FA, and if it is necessary to replace the base station (RP) of another frequency band (FA), it is inconvenient to replace all related modules. In the case of an area where cells overlap each other when operating with three sectors, it is difficult to overcome a call failure due to interference of adjacent cells.

1 is a block diagram showing a configuration of a transceiver used in a base station of a wireless subscriber network system according to the prior art.

Referring to FIG. 1, a receiver 10 and a transmitter 20 are connected through an RF module control card (RFC) 30. In this case, the receiver 10 includes a low noise amplifier (LNA) 11 for removing noise of a signal received through the antenna ANT, and a specific frequency band from a signal passed through the low noise amplifier 11. A receiver front end unit (Rxfu) consisting of a band pass filter (BPF) 12 which passes only a signal of (BPF) 13 and a frequency of a signal passing through the band pass filter 12 are lowered. The main is composed of a frequency down converter card (DCC) 14.

In addition, the transmitter 20 has a frequency upconverter card (UCC) 21 for increasing the frequency of a signal to be transmitted and a signal to be transmitted with a higher frequency in the frequency upconverter card 21. A high power amplifier (HPA) 22 for amplifying the signal, and a Txfu transmitter front end unit 23 for outputting the signal amplified by the high power amplifier 22 through an antenna ANT. It is composed.

In the wireless subscriber network system according to the related art having the above configuration, the receiver 10 and the transmitter 20 include an antenna Ant in the case of a receiving end unit (Rxfu: 13) and a transmitting end unit (Txfu: 23). It consists of 1FA. In this case, switching to another FA causes a new installation of the antenna of the pre-installed base station, which causes a problem that the base station is fixed when installed in the field.

In order to solve the above problems, a low noise amplifier (LNA: 11) and a band pass filter (BPF: 12) of the receiving end unit 13 and a transmitting end unit (i.e., RxFU, TxFU) can be manufactured to cover the 2FA. 23), but this method can solve the problem of FA switching, but all FA signals and other noise signals from other supporting stations are inputted through the antenna and interfere with the base station (RP). Problems arise that result in performance degradation.

In addition, when the cell overlaps when the base station (RP) is operated in a field of three sectors, interference with neighboring cells is caused by using the same frequency band. Is generated. In order to solve these phenomena, the operator has to manage the location and cell of the base station through many tests for the optimal cell design.

The present invention has been made to solve the above problems, the object of which is to easily change the FA by using a switch switching method as well as to operate the cell management more efficiently to reduce interference to the adjacent cells The present invention provides a wireless subscriber network system that can be minimized and can be easily solved by a single base station without having to separately manage a base station by FA in terms of an operator.

1 is a block diagram showing the structure of a transmitting and receiving unit of a wireless subscriber network system according to the prior art;

Figure 2 is a block diagram showing the configuration of the transmitting and receiving unit of the wireless subscriber network system according to an embodiment of the present invention

<Description of Symbols for Main Parts of Drawings>

110 receiver 111 receiver unit (Rxfu)

112: frequency down conversion card (DCC) 113: low noise amplifier (LNA)

114, 115: Band pass filter (BPF) 116, 117: Switch

120: transmitter 121: frequency up-conversion card (UCC)

122: high power amplifier (HPA) 123,124: transmitter end unit (Txfu)

125,126: switch 130: RF module control card (RFC)

According to a feature of the present invention for achieving the above object, a receiver and a transmitter capable of transmitting and receiving a frequency signal of a specific band is connected by an RF module control card (RFC), the frequency band of all FA (frequency assignment) In the wireless subscriber network system configured to use,

The receiver comprises a receiving end unit (Rxfu) and a frequency downconversion card (DCC) 112; The receiving end unit (Rxfu) is a low noise amplifier (LNA) for removing the noise of the signal received through the antenna (ANT), and 2 to pass a signal of a specific frequency band from the signal passed through the low noise amplifier according to the received FA A first bandpass filter (BPF) and a first switch for selecting one of two bandpass filters according to a received FA to connect an output of the low noise amplifier with an input of a selected bandpass filter, and a state of the first switch In accordance with the present invention, there is provided a wireless subscriber network system including a second switch for connecting an output terminal of a band pass filter selected in accordance with an input terminal of the frequency downconversion card.

At this time, according to an additional feature of the present invention, the transmitter is a frequency up-conversion card (UCC) for increasing the frequency of the signal to be transmitted, and a high output for amplifying the signal to be transmitted in the frequency up-conversion card Select one of two transmitting end units (Txfu) for outputting the amplifier (HPA), the signal amplified by the high output amplifier through the antenna (ANT) according to the desired FA, and two transmitting end units according to the FA to be transmitted Preferably, the third switch connects the output terminal of the high output amplifier with the input terminal of the selected transmission end unit, and the fourth switch connects the output terminal of the transmission end unit selected according to the state of the third switch with the antenna.

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

2 is a block diagram showing the structure of a transmitting and receiving unit of a wireless subscriber network system according to an embodiment of the present invention.

Referring to FIG. 2, reference numeral 110 denotes a receiver, 120 denotes a transmitter, and 130 denotes an RF module control card (RFC).

At this time, the receiver 110 is composed of a receiving end unit (Rxfu) 111 and a frequency downconversion card (DCC) 112, and the receiving end unit (Rxfu) 111 is a signal received through an antenna ANT. Low noise amplifier (LNA) 113 for removing the noise of the noise and two band pass filter (BPF) (114, 115) for passing only the signal of a specific frequency band of the signal passed through the low noise amplifier 113, A first switch 116 connected to an output terminal of the low noise amplifier (LNA) 113 to select one of two band pass filters (BPFs) 114 and 115 to provide an output signal of the low noise amplifier (LNA) 113; And a second switch 117 for outputting signals output from the two band pass filters (BPF) 114 and 115 to the frequency down conversion card (DCC) 112.

On the other hand, the transmitter 120 is a frequency up-conversion card (UCC) 121 for increasing the frequency of the signal to be transmitted, and a high output for amplifying the signal to be transmitted in the frequency up-conversion card 121 An amplifier (HPA) 122 and two transmit end units (Txfu) 123, 124 for outputting the signal amplified by the high output amplifier 122 through an antenna ANT, and the high output amplifier (HPA) ( A third switch 125 connected to an output end of the high power amplifier (HPA) 122 to select one of two transmission end units (Txfu) 123 and 124 to provide an output signal of the high power amplifier (HPA) 122; A fourth switch 126 is included to allow a signal output from the Txfu) 123 and 124 to be output through the antenna ANT.

The FA conversion is easily solved by the configuration of FIG. 2 as described above. That is, when switching from the existing FA to another frequency band, the SPDT switch of the transmitter 120 and the receiver 110 is switched through the RF control module card 130, thereby enabling the switching to the FA for another band. In addition, in the cell design of the operator, the operator can solve the interference phenomenon of the overlapping of adjacent cells that may occur when operating in 1 sector by 3 sectors by using a different frequency band by FA switching.

In the present invention, for this purpose, the control signal for FA conversion is added to the RF control module card 130, it is possible to easily switch the desired FA by adding the switch for switching FA (116, 117, 125, 126). Using the present invention, it is possible to reduce the field test period over a long period of time in order to prevent the overlapping of adjacent cells.

In addition, in FIG. 2, the transmit / receive antenna that can use only 1FA frequency band is changed to an antenna that can use frequency band of all FAs. As a result, all FA signals can be transmitted and received through the antenna without attenuation, and the reception unit 111 and the transmission units 123 and 124 can be used for each FA.

In the present invention, when switching of the FA is required, the RF module control card 130 sends control signals to the receiver 110 and the transmitter 120 at the same time. First, in the case of the receiver 110, the connection state of the switches 116 and 117 located at the front and rear ends of the band pass filters 114 and 115 in the reception unit 111 is switched according to the FA, and in the case of the transmitter, the transmission units 123 and 124. By switching the connection state of the switches (125, 126) located in the front and rear of the same according to the FA as the receiver 110, it is possible to easily switch the FA of the sector required in one base station. This allows operators to minimize the shadow area of subscribers caused by overlapping adjacent cells that can occur in existing 1FA 3 sectors without having to perform long cell design tests.

Since the wireless subscriber network system of the present invention as described above enables the FA to be changed, overlapping occurs between adjacent cells due to the frequency band being determined in the base station having a 3-sector shape and the subscribers located in the call shadow area. It is effective to solve the call disturbance phenomenon.

In addition, in the wireless subscriber network (WLL) service, it is possible to easily use the FA of the base station having the shape of three sectors in a flexible manner, so that it is possible to easily solve the cell design problem of the operator.

Claims (2)

In a wireless subscriber network system, a receiver and a transmitter capable of transmitting and receiving a frequency signal of a specific band are connected by an RF module control card (RFC) and configured to use frequency bands of all frequency assignments. The receiver is composed of a receiving end unit (Rxfu) and a frequency downconversion card (DCC) 112, The receiving end unit (Rxfu) is a low noise amplifier (LNA) for removing the noise of the signal received through the antenna (ANT), and 2 to pass a signal of a specific frequency band from the signal passed through the low noise amplifier according to the received FA A first bandpass filter (BPF) and a first switch for selecting one of two bandpass filters according to a received FA to connect an output of the low noise amplifier with an input of a selected bandpass filter, and a state of the first switch And a second switch for connecting the output end of the band pass filter selected in accordance with the input signal of the frequency downconversion card. The method of claim 1, The transmitter includes a frequency upconversion card (UCC) for increasing the frequency of a signal to be transmitted, a high power amplifier (HPA) for amplifying a signal to be transmitted with a higher frequency in the frequency upconversion card, and an amplification in the high output amplifier. The output terminal of the high power amplifier is selected by selecting one of two transmission terminal units (Txfu) for outputting the signal through the antenna ANT according to the desired FA, and two transmission terminal units according to the FA to be transmitted. And a fourth switch for connecting an output terminal of the transmitting end unit selected according to the state of the third switch and a fourth switch for connecting the antenna to the antenna.