KR100926373B1 - Multi-band signal processing system and his signal processing method - Google Patents

Abstract

PURPOSE: A multiband signal processing system and a signal processing method thereof are provided to replace disabled DPD modules individually and easily. CONSTITUTION: A main control device(100) multiplexes one or more signals of frequency bands. An optical transmitter/receiver(210) converts an optical signal received through an optical cable into an electric signal. The second FPGA unit(220) performs the demultiplexing by converting the converted signal into a digital signal. A DSP unit divides the signal received through the second FPGA unit into I/Q signals. By using a frequency assignment channel filter, the DSP unit filters the divided I/Q signals of each channel.

Description

MULTI-BAND SIGNAL PROCESSING SYSTEM AND HIS SIGNAL PROCESSING METHOD}

According to the present invention, a digital predistortion is performed on optical signals of various frequencies received through one optical cable by attaching a plurality of signal processing system modules separated by signals having different frequency bands to a remote optical repeater in a detachable manner. A multiband signal processing system and a signal processing method are provided.

Optical repeaters, which are widely used in mobile communication systems, are used in terms of coverage expansion of base stations to expand mobile phone services in the region of the region where the signals of base stations are difficult to reach.

Currently, as mobile communication systems of various frequency bands such as CDMA (2G), W-CDMA (3G), WiBro, and 4G schemes to be used coexist, base stations of each mobile communication system are often installed in the same space.

In this case, if you use a heavy gauge that is manufactured differently for each system and each mobile communication service provider, it is not good for aesthetic appearance because a large number of repeaters are attached to the station area of subway, waiting room, and tunnel. There is an inefficient problem in installation cost, installation place, and the like.

In addition, as a plurality of repeaters are attached, the noise is high due to fan noise installed in each repeater, and a plurality of cables are installed in each repeater, whereby cables may be entangled. In addition, when a cable failure occurs, there is a problem that it is difficult to derive only a cable having a failure among many strands of cables.

In the conventional relay system, since a signal must be processed for each frequency, a plurality of repeaters corresponding to each frequency must be included, and thus, low power efficiency can be maintained in terms of network construction and operation.

Accordingly, a system capable of transmitting and receiving signals of various frequency bands through one optical cable instead of a plurality of repeaters and optical cables used for each signal processing, and receiving a signal in one repeater is required.

In order to solve the problems of the prior art, the present invention divides a signal received by one optical cable into a frequency band (by a service band of a telecommunication company) through a main controller, and separates the separated signal into a DPD module corresponding to each frequency. It is an object of the present invention to provide a multi-band signal processing system and a signal processing method for performing digital predistortion.

In the multi-band signal processing system and signal processing method of the present invention to achieve the above object, by separating the signal received through one optical cable by the service band (by frequency band) comprising a plurality of removable DPD module The signal processing system module unit may compensate for the distortion component of the signal.

The present invention relates to a multi-band signal processing system, comprising a main control device for multiplexing one or more signals of different frequency bands, mounted in a frame, and transmitting the received data, the data received from the main control device via an optical cable according to the frequency band Each may include at least one remote optical repeater for performing digital predistortion.

In the present invention, the main controller includes one or more transceivers for transmitting and receiving signals of different frequency bands, and an analog interface for converting analog signals received from the transceivers into digital signals. The apparatus may include a first FPGA unit for multiplexing the digital signal, and an optical transmitter / receiver for converting the multiplexed signal to all-optical transmission to a remote optical relay apparatus through one optical cable.

In the present invention, the signals of different frequency bands may include at least one signal selected from 2G, 3G, WiBro, and 4G.

In the present invention, the remote optical repeater includes an optical transceiver for converting an optical signal received through the optical cable into an electrical signal, demultiplexing by converting the signal converted by the optical transceiver to digital, each frequency A signal processing system module unit may include a second FPGA unit separated according to a band, and may receive a signal separated by the second FPGA unit, perform digital predistortion, and include at least one detachable DPD module.

In the present invention, the remote optical repeater may be connected in at least one or more forms selected from a cascade form and a branch form.

In the present invention, when the one or more remote optical relays are cascaded, when the service of the upper remote optical relay fails, it may bypass the lower remote optical relay or another remote optical relay.

In the present invention, the DPD module includes a DSP unit for separating the signal received through the second FPGA unit into the I / Q signal, and filtering the separated I / Q signal by channel using a frequency allocation channel filter, the antenna RVS unit for low-noise amplifying the high-frequency signal received through the conversion to the intermediate frequency signal. And a DPD board for detaching and electrically connecting the DSP unit and the RVS unit to receive the I and Q signals and performing digital predistortion. The DPD board is attached to the DPD board to perform control and state monitoring. It may include an RCPU unit.

In addition, the present invention relates to a multi-band signal processing method comprising the steps of receiving a signal of a different frequency band received and converting the signal into a digital signal and multiplexing, mounting the multiplexed signal in a frame, and converts it into an optical signal And transmitting through the optical cable. The method may further include demultiplexing the received optical signal and transmitting the received optical signal to each DPD module corresponding to the corresponding frequency band, and performing digital predistortion in the DPD module and transmitting the same to the corresponding antenna. .

In the present invention, the DPD module includes separating the received digital signal into an I / Q signal, and filtering the separated I / Q signal for each channel through a frequency allocation channel filter, and filtering the filtered digital signal. Separating into I / Q signals. And digitally predistorting the I / Q signal and modulating the I / Q signal into an IF signal, and modulating and amplifying the modulated IF signal into an RF signal and transmitting the modulated IF signal to an antenna.

In the present invention, the frequency allocation channel filter may filter only a channel selected from the channels of the digital signal.

According to the present invention, by installing a plurality of detachable DPD modules in one remote optical relay, there is an effect that can be easily replaced individually in case of failure of the DPD module.

In addition, by mounting one or more DPD modules to one remote optical relay device, it is possible to prevent signal loss and noise caused by a cable connecting each module, and to reduce the size of the relay device.

In addition, a frequency allocation channel filter is provided in the DSP unit inside the DPD module to select and remove digital noise for each channel before amplifying the RF signal, thereby improving efficiency of the entire system.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings. In adding reference numerals to components of the following drawings, it is determined that the same components have the same reference numerals as much as possible even if displayed on different drawings, and it is determined that they may unnecessarily obscure the subject matter of the present invention. Detailed descriptions of well-known functions and configurations will be omitted.

1 is a block diagram showing a multi-band signal processing system according to an embodiment of the present invention, comprising a main control device 100 and a remote optical relay device 200, the main control device 100 is a base station and a dedicated circuit (RF cable) is connected.

In addition, although not shown in the drawing, one main controller 100 may be connected to a plurality of remote optical relays 200, and may be connected in a cascade form or a branch form.

If the remote optical relay 200 is cascaded, the remote optical relay 200 may be bypassed to a lower or another remote optical relay in case of service failure of the upper remote optical relay, thereby maintaining signal transmission.

The main controller 100 receives a CDMA (2G signal), a WCDMA (3G signal), a WiBro signal, and a 4G signal received through an RF cable, and multiplexes the signals into a frame to remotely repeat the optical relay device 200. To send.

The main control unit 100 includes a 2G transceiver 112 for receiving the CDMA signal, a 3G transceiver 114 for receiving a WCDMA signal, a WiBro transceiver 116 for receiving a WiBro signal, and 4G for receiving a 4G signal. An analog interface 120 for converting an analog signal received by the transceiver 118 into a digital signal, a first FPGA unit 130 for multiplexing the converted digital signal, and converting and receiving the received electrical signal into an optical signal It includes an optical transceiver 160.

The 2G transceiver 112 is a signal having a frequency range of 1840MHz or more and 1870MHz or less, and may receive, for example, 2G signals of K and L companies. The K company's 2G signal uses a frequency range of 1840 kHz to 1860 kHz, and the L company's 2G signal uses 1860 kHz to 1870 kHz. The present invention is not limited thereto, and a signal using a CDMA frequency band may be used. It can contain everything.

The 3G transceiver 114 may be a signal having a frequency range of 2160 MHz or more and 2170 MHz or less, for example, may receive a 3G signal of K company, but is not limited thereto. The 3G transceiver 114 may include all signals using the WCDMA frequency band.

The WiBro transceiver 116 is a signal having a frequency range of 2330 MHz or more and 2360 MHz or less. For example, the WiBro transceiver 116 may receive a WiBro signal of K company, but is not limited thereto and may include all signals using the WiBro frequency band.

The 4G transceiver 118 is a frequency band region currently under development, and receives a signal of a frequency band used in the future.

The analog interface 120 is formed of an analog-to-digital converter (ADC) and a digital-to-analog converter (DCA) for converting an analog signal into a digital signal, and digitally converts the analog signal received by the transmission / reception unit 112, 114, 116, 118. It converts and transmits the signal to the first FPGA unit 130, converts the digital signal received from the first FPGA unit 130 into an analog signal, and transmits it to the transceivers 112, 114, 116, and 118 according to the frequency bands, respectively.

The first FPGA unit (Field Programmable Gate Array) 130 multiplexes (MUX) the digital signal received by the analog interface 120 and transmits the same to the optical transceiver 140.

The optical transceiver 140 converts the signal multiplexed by the first FPGA unit 130 from an electrical signal to an optical signal through an all-optical conversion, and transmits the signal to the remote optical relay 200 through one optical cable.

The remote optical relay 200 receives a signal received through an optical cable connected to the main controller 100.

The optical transmitter / receiver 210 converts an optical signal received through an optical cable into an electrical signal. In more detail, the optical transmitter / receiver 210 includes an optical pickup unit 212, a photodiode PD, 214a, and a laser diode LD, 214b.

The optical pickup unit 212 receives an optical signal from the main controller 100 or the upper remote optical relay, and the received optical signal is photoelectrically converted by a photodiode PD 324a to the second FPGA unit 220. Is sent. The electrical signal received from the second FPGA unit 220 is totally converted through a laser diode (LD) 324b and transmitted to the main controller 100 or the upper remote optical relay apparatus through the optical pickup unit 322. .

The second FPGA unit 220 demultiplexes the signal received by the optical transceiver 210, separates the signal for each frequency band, and transmits the signal to the signal processing system module 230.

The signal processing system module 230 performs digital predistortion through each of the DPD modules 232, 234, 236, and 238 formed for each received frequency band. Details of the DPD modules 232, 234, 236, and 238 may be referred to FIG. 2 below.

In the drawing, only four DPD modules, such as 2G, 3G, WiBro, and 4G, are set. However, the present invention is not limited thereto, and additional DPD modules may be mounted according to the development of communication services in the future.

Each signal subjected to digital predistortion by the signal processing system module 230 is transmitted to the corresponding antenna.

2 is a diagram illustrating a DPD system of a signal processing system module unit inside a remote optical repeater according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the DPD system constituting the signal processing system module 230 includes a DPD board 310, a DSP unit 320, an RVS unit 330, and an RCPU unit mounted on the DPD board 310. 340, which are all detachably mounted to the DPD board 310.

Each unit is electrically connected to each other, and receives an I signal and a Q signal to perform digital pre-distortion 312.

The digital predistortion I / Q signal is DA-converted, and the intermediate frequency (IF) of the converted I / Q signal is converted into a high frequency (RF) signal through an up converter (UPC, 314). The converted RF signal may be amplified by an amplifier (Power Amplifier, 316) and transmitted to the antenna.

The DSP unit 320 is mounted on the DPD board 310 in the form of a microprocessor chip. The DSP 320 filters an electric signal transmitted from the second FPGA unit for each channel using a frequency allocation channel filter, and filters the filtered digital signal using I and Q signals. Separate by signal.

Looking at the DSP unit 320 in more detail, the DSP unit 320 includes a third FPGA unit 322 and ADC 324 is made.

In the case of the forward path received from the second FPGA unit, the received electrical signal is a relay period connected by a sector selection block and a delay block in the third FPGA unit 322. By adjusting the delay time of the same), the selected one data is transferred to the DPD board 310 by 50MHz Base Band I / Q data conversion.

In the reverse path in which the forward path and the signal flow are in opposite directions, an RF signal received from an antenna is converted into an IF frequency by the RVS unit 330, and an input analog intermediate frequency (IF) signal is input. Is converted into a digital signal through the ADC 324. The converted digital signal is converted into a 12-bit digital signal by a sector selection block and a delay block in the third FPGA unit 322 and transferred to the second FPGA unit.

The third FPGA unit 322 may filter the digital signal for each channel and then split it into I / Q signals, or may separate the converted digital signal into I / Q signals and then filter for each channel.

The filtering method for each channel may be performed by a frequency allocation channel filter in the chip, and the in-band spurious characteristic of the W-CDMA band may be improved by the frequency allocation channel filter function.

The frequency allocation channel filter filters the signal of a channel selected to remove an increased noise flow as the analog signal is converted into a digital signal, thereby providing better emission mask characteristics than conventional digital linearization techniques. Can be formed to improve the performance of the system.

In this case, the number of channels to be filtered may be manually specified by a user or automatically determined by a program of a frequency allocation channel filter.

In addition, when the existing filter is used by removing the noise for each channel in the third FPGA unit 322 before modulating the noise, which cannot be easily removed by the SAW filter or the general filter, existing in the RF stage into the RF signal. 3 to 4dBmc efficiency is improved.

The RVS unit 330 includes a down-converter (DNC) 332 and a low noise amplifier (LNA) 334, and the RF signal received by the antenna is low noise amplified.

The RF signal received by the low noise amplifier 334 is input to the DNC 332, and the DNC 332 may convert the input RF signal into an IF signal.

RCPU unit 340 is attached to the DPD board to configure the main control unit and the remote optical relay link (Link) to monitor the control and status necessary for the system and at the same time the wireless management system of the carriers (Rems) and the main control unit It may serve as a network management system (NMS), such as communication between and communication with the DPD board 310.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 is a block diagram showing a multi-band signal processing system according to an embodiment of the present invention.

2 is a view showing a signal processing system module unit inside a remote optical repeater according to an exemplary embodiment of the present invention.

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

100: main controller (MHU) 112, 212: 2G transceiver

114, 214: 3G transceiver 115, 216: WiBro transceiver

118, 218: 4G transceiver 120: analog interface

130: first FPGA unit 140, 210: optical transceiver

200: remote optical repeater (ROU) 212: OPU (optical pickup unit)

214a: PD (photodiode) 214b: LD (laser diode)

220: second FPGA unit 230: signal processing system module unit

232: 2G DPD Module 234: 3G DPD Module

236: WiBro DPD module 238: 4G DPD module

310: DPD board 312: digital predistortion

314: UPC (up-converter) 316: amplifier

320: DSP unit 322: third FPGA unit

324: ADC 330: RVS section

332: DNC (downconverter) 334: LNA (low noise amplifier)

340: RCPU unit

Claims (10)

A main control unit multiplexing one or more signals of different frequency bands and mounting the same in a frame and transmitting the same; And An optical transceiver for converting an optical signal received through an optical cable into an electrical signal; A second FPGA unit for converting the signal converted by the optical transceiver into digital, demultiplexing the signal, and separating the signal according to each frequency band; And A DSP unit for separating the signal received through the second FPGA unit into an I / Q signal and filtering the separated I / Q signal for each channel using a frequency allocation channel filter; An RVS unit for low noise amplifying the high frequency signal received through the antenna and converting the high frequency signal into an intermediate frequency signal; A DPD board to which the DSP unit and the RVS unit are detachably connected and electrically connected to each other, and receive the I and Q signals and perform digital predistortion; And a RCPU unit attached to the DPD board to control and monitor the state. Multi-band signal processing system comprising a. The method of claim 1, wherein the main controller, At least one transceiver which transmits and receives signals of different frequency bands, respectively; An analog interface for converting an analog signal received from a transmission / reception unit into a digital signal at all times; A first FPGA unit to multiplex the digital signal; And An optical transmission / reception unit for converting the multiplexed signal into an optical optical transmission unit through a single optical cable; Multi-band signal processing system comprising a. The signal of claim 1 or 2, wherein the signals of different frequency bands And at least one signal selected from 2G, 3G, WiBro, and 4G. delete delete The multi-band as claimed in claim 5, wherein when the one or more remote optical relays are connected in a cascade form, the service is bypassed to a lower remote optical relay or another remote optical relay in case of service failure of the upper remote optical relay. Signal processing system. delete Receiving the signals of different frequency bands, converting the received signals into digital signals, and multiplexing the signals; Mounting the multiplexed signal in a frame, converting the multiplexed signal into an optical signal, and transmitting the optical signal through an optical cable; Demultiplexing the received optical signal and transmitting the demultiplexed optical signals to respective DPD modules corresponding to a corresponding frequency band; Separating the digital signal received by the DPD module into an I / Q signal and filtering the separated I / Q signal for each channel through a frequency allocation channel filter; Separating the filtered digital signal into an I / Q signal; Correcting the digital predistortion of the I / Q signal and modulating the I / Q signal into an IF signal; And Modulating and amplifying the modulated IF signal into an RF signal and transmitting the modulated IF signal to a corresponding antenna; Multi-band signal processing method comprising a. delete 9. The method of claim 8, wherein the frequency assigned channel filter And filtering only a channel selected from the channels of the digital signal.

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