KR101075537B1 - An exciter and a quality monitering system for a base station - Google Patents

Abstract

The present invention relates to an exciter and a base station quality management system. Exciter according to the present invention comprises: signal input means for inputting a main ATSC service broadcast signal or an M / H service broadcast signal; Signal detecting means for detecting whether a signal input from the signal input means is a main ATSC service broadcast signal or an M / H service broadcast signal; Modulation means for performing modulation in a manner corresponding to a standard of each broadcast signal according to a detection result by the signal detection means; RF switching means for RF-converting and transmitting the signal modulated by the modulation means; And a signal analyzing means for receiving the input signal of the modulation means and the RF transmission signal as a feedback and comparing and analyzing the down-converted signal.

Description

An Exciter And A Quality Monitering System For A Base Station}

The present invention relates to an exciter and a base station quality management system, and more particularly, a feedback IF signal obtained by down-converting the baseband I / Q signal of the ATSC-MH exciter modulation unit and the RF transmission signal of the exciter. It compares and detects modulation signal quality, and it is about exciter and base station quality management system that can monitor remote control and exciter status and signal quality.

As shown in FIG. 1, the conventional ATSC exciter includes a signal input means 10 for inputting an ATSC broadcast signal, a modulation means 20, and an RF switching means 30, and the modulation means 20 is input. It is divided into a modulation module 21 which performs channel coding and modulation on a signal, and a DPD module 22 which performs a control on the modulation module 21 and performs a DPD process.

As shown in FIG. 2, the baseband I / Q signals generated by the conventional modulation module 21 are input to the DPD processor 23 of the DPD module 22 in synchronization with the system clock, and the DPD processor 23 is a module. Under the control of the control unit 25, the RF transmission signal receives the feedback IF signal inputted by the down-converting input and converts it into the DPD baseband I / Q signal, and the generated DPD baseband I / Q signal is synchronized with the system clock to the DAC. Passed and passed as IF signal.

The module controller 25 controls the DPD processor 23 and the RF switching means 30, and has a TPC / IP interface to transmit flag data on the exciter's system status to a remote location.

The conventional ATSC exciter 10 modulates the ATSC signal and transmits the RF signal by converting it into an RF signal. When hardware problems occur in each part of the exciter system, an alarm check function is performed and flag data is transmitted to a remote place by a TCP / IP interface. do..

For example, the alarm check performed in the existing ATSC exciter 10 is divided into a hardware alarm and a software alarm. In other words,

A. The hardware alarm has a part that checks the alarm in hardware in the main parts and modules of the exciter 10. Therefore, the flag (1 or 0) indicates whether an alarm has occurred. )

B. The software alarm checks the alarm in software and transmits the presence or absence of an alarm to the module control unit (FPGA) 25 as a flag.

C. The FPGA 26 or the CPU 27 of the module control unit 25 periodically checks the flag to check the alarm, and the existing alarm check determines the alarm based on whether the flag is 1 or 0.

The items checked for alarm in the conventional ATSC exciter 10 are as follows.

1) PLL unlock alarm: RF output does not go out when "PLL (key component which makes RF signal) unlock".

2) Power alarm: It informs the abnormal state of power input to each module or hardware.

3) Underflow / overflow alarm: An alarm about the status of the buffer used internally by software.

4) Input signal status alarm: It generates an alarm when an abnormal signal is input.

However, the following problems have arisen in the conventional exciter which has the above structure.

Although the quality of the base station or repeater in which the exciter 10 is used may ultimately be modulated and determined by the quality of the RF signal, the conventional exciter 10 may provide a simple hardware alarm check for each part of the system. Since it does not analyze the signal that is modulated and transmits the RF signal only, the system state of the base station or the repeater is separate and there is a problem that reliable monitoring of the transmitted signal quality becomes impossible.

An object of the present invention is to compare the modulation signal quality or RF signal quality by comparing the feedback IF signal obtained by down-converting the baseband I / Q signal of the exciter modulation unit operating in the ATSC-MH system and the exciter RF transmission signal. It is to implement an exciter and base station quality management system capable of detecting.

Another object of the present invention is to implement an exciter and base station quality control system capable of monitoring the exciter state and the signal quality generated by the exciter by remote control.

Exciter according to the present invention for achieving the above object is a signal input means for receiving a broadcast signal; Modulation means for performing modulation in a manner corresponding to a standard of a signal input from said signal input means; RF switching means for RF-converting and transmitting the signal modulated by the modulation means; And a signal analyzing means for comparing and analyzing the signal of the modulation means and the signal received feedback from the RF transmission signal.

Exciter according to the present invention for achieving the above object, the signal input means for inputting the main ATSC service broadcast signal or M / H service broadcast signal; Signal detecting means for detecting whether a signal input from the signal input means is a main ATSC service broadcast signal or an M / H service broadcast signal; Modulation means for performing modulation in a manner corresponding to each broadcast signal according to a detection result by the signal detection means; RF switching means for RF-converting and transmitting the signal modulated by the modulation means; And a signal analyzing means for receiving the input signal of the modulation means and the RF transmission signal as a feedback and comparing and analyzing the down-converted signal.

The signal to be compared in the signal analyzing means may be a baseband I / Q signal input from the modulation means and an IF signal received from the feedback.

The exciter may be inputted with an ATSC signal and an ATSC-MH signal, and the ATSC mode and the ATSC-MH mode may be configured to perform modulation on the ATSC signal according to the received signal. It is characterized by performing a selection.

The signal analysis means is characterized by comparing and analyzing items including "Group delay", "Magnitude Response", "AM-AM", "PSD".

The base station quality management system according to the present invention for achieving the above object is an exciter; And remote control means for remotely controlling the exciter and monitoring the output signal quality of the exciter by accessing the signal analysis means at a remote location.

The remote control for the exciter is characterized in that it is made via a web (WEB).

The remote control means may monitor items including "Group delay", "Magnitude Response", "AM-AM", and "PSD" compared and analyzed by the signal analysis means.

According to the present invention, it is possible to select the modulation mode by analyzing the ATSC signal and the ATSC-MH signal by one exciter by itself, thereby enabling the service for the ATSC network and the ATSC-MH network.

In addition, the RF output signal of the exciter is received as a feedback and can be compared with the baseband I / Q signal of the modulation module, so that the quality and status of the input / output signal can be monitored and analyzed in remote locations in real time.

In addition, since the exciter of the present embodiment enables simultaneous services for the existing ATSC network and ATSC-MH network, it becomes possible to perform a dual function as a repeater as a base station.

In addition, remote monitoring of the base station or repeater is possible, so that efficient operation and management of the base station or repeater is possible.

1 is a schematic diagram illustrating a configuration of an exciter used in a conventional ATSC broadcasting system.
2 is a schematic diagram illustrating a DPD module of a general ATSC-MH exciter.
3A and 3B are schematic views illustrating the main configuration of the exciter of the embodiment of the present invention.
4 is a schematic diagram illustrating a configuration of an modulation module of an exciter according to an embodiment of the present invention.
5 is a schematic diagram illustrating a configuration of a DPD module of an exciter according to an embodiment of the present invention.
6 is a schematic diagram illustrating a modulation process for an ATSC signal performed in an exciter of an embodiment of the present invention.
7 is a schematic diagram illustrating a configuration of an ATSC-MH transmission system to which an exciter of an embodiment of the present invention is applied.

Hereinafter, the configuration of the preferred embodiment of the exciter and base station quality management system according to the present invention having the configuration as described above will be described in detail with reference to the accompanying drawings.

3A and 3B, the exciter 100 according to the embodiment of the present invention includes a signal input means 101 through which a broadcast signal is input and a modulation method in a manner corresponding to a standard of a signal input from the signal input means 101. And modulation means 103 for performing a DPD (Digital PreDistortion) process, RF switching means 130 for RF-converting and transmitting the signal modulated by the modulation means 103, and RF switching means 130 Feedback means 140 for down-converting the RF transmission signal by generating a feedback IF signal and a signal analyzing means 150 for comparing and analyzing the feedback input signal and a signal of the modulation means.

The signal input means 101 according to the embodiment of the present invention transmits a broadcast signal in which a main ATSC service packet and an M / H service packet of an ATSC-MH (Advanced Television System Committee-Mobile Handheld) system are mixed. Input to the signal detection means 102 as a standard.

The signal detecting means 102 of the present embodiment receives a broadcast signal in which a main ATSC service packet and a M / H service packet are mixed, and detects the PID of the input signal to determine whether the broadcast signal input is a main ATSC service packet. It detects whether or not the H service packet and inputs it to the modulation means (103).

Modulation means 103 of the present embodiment is a modulation module 110 that performs channel coding and modulation for the input signal, and controls the modulation module 110, using a baseband I / Q signal and a feedback IF signal By the DPD module 120 to perform the DPD process.

The modulation module 110 according to the present embodiment includes a channel coding unit 111 that performs channel coding corresponding to a main ATSC service packet or an M / H service packet, and a modulation unit 118 that performs modulation on the channel coded signal. Include.

As shown in FIGS. 3B, 6, and 7, when the input signal of the present embodiment is an ATSC receiver signal, the channel coding unit 111 inputs the random signal 112 and the RS. The encoder 113 and the convolutional encoder 116 are sequentially passed, and when the input signal is an ATSC-MH MUX output, the MHE packet (M / H Encapsulation Packet) data (ie, mobile data) among the output data is modified. The randomizer 112 forms a 207-byte packet via the unstructured RS encoder 115 and is input to the convolutional encoder 116. In the case of ATSC main packet data, the randomizer 112 and the systematic RS encoder ( 113 is input to the convolutional encoder 116 in the form of a 207-byte packet. The output signal of each convolutional encoder 116 is trellis encoded by the trellis encoder 117 and input to the modulation unit 118 by inserting the field sync byte, segment sync byte, and pilot signal (ATSC: S4-131r14-). A153-Part-2-RF-Transmission).

The modulation unit 118 according to the present embodiment generates a 16-bit baseband I / Q signal by pre-equalizing and VSB modulation the signal input by channel coding according to the clock signal provided from the DPD module 120 to generate a DPD module ( 120, the DPD module 120 receives the predistorted signal, generates an IF signal of 36 MHz, and inputs the RF signal to the RF switching unit 130.

The DPD module 120 according to the present embodiment is a DPD for performing DPD processing by using a module control unit 121 for controlling the modulation module 110 and a feedback signal which is converted into an IF signal by receiving an RF transmission signal. Block 125 and clock generator 128 for generating and distributing the clock used for modulation and DPD processing.

The module control unit 121 of the present embodiment receives the 16-bit baseband I / Q signal from the modulation unit 118 and inputs it to the DPD block 125 in synchronization with the system clock, and the modulation module 110 and the UPCU 131. , DCU, AMP 135 and the LCD and LED are controlled.

The DPD block 125 of the present embodiment performs digital pre-distortion on the baseband I / Q signal generated by the modulation unit 118 using the feedback IF signal, and generates the generated DPD baseband. The I / Q signal is transferred to the Digital to Analog Converter (DAC) in synchronization with the system clock and converted to an IF signal by the DAC.

The IF signal generated by the modulation means 103 of this embodiment is converted into an RF signal by the RF switching means and transmitted through the antenna.

RF switching means 130 of the present embodiment may be a configuration including a UPCU (131), AMP (135).

The signal analyzing unit 150 of the present embodiment includes a baseband I / Q signal input unit for receiving a baseband I / Q signal input from the modulation unit 118 to the module control unit 121, and an IF for receiving a feedback IF signal. And a signal input unit and analysis means for comparing and analyzing the baseband I / Q signal and the feedback IF signal.

Although the signal analysis means 150 of the present embodiment is implemented in the FPGA 122 constituting the module control unit of the DPD module, in another embodiment of the present invention, it may be implemented in a separate FPGA outside the FPGA 122. . In this case, the modulation unit 118 receives the baseband I / Q signal and the feedback IF signal from the ADC block 141 to compare and analyze the two signals.

The signal analyzing means 150 of the present embodiment performs signal analysis on items such as "Group delay", "Magnitude Response", "AM-AM", "PSD", and monitors the quality and state of the input / output signal in real time. Configured to do so.

"Group delay" in the signal analysis item of the present embodiment is to measure the relative time that the signal is delayed for each frequency, "Magnitude Response" is one of the frequency response characteristics of the signal means to measure the "Magnitude" response state of the signal "AM-AM" means a measurement item for determining the linear characteristics of the input and output. In addition, "PSD" (Power Spectrum Density) provides a graph to analyze the power and spectrum of a signal.

Looking at the configuration of the base station quality management system according to an embodiment of the present invention.

The base station quality management system of the present embodiment further comprises an exciter 100 and a remote control means 200 for performing remote control on the exciter.

The module controller 121 of the exciter 100 of this embodiment includes a TCP / IP interface, and the remote control means 200 remotely analyzes the analysis information analyzed by the signal analysis means 150 through the TCP / IP interface. It is configured to receive and control the real-time monitoring and exciter 100 function.

Remote control means 200 of the present embodiment can be connected to the exciter 100 via the web (WEB) regardless of the place via the TCP / IP interface, and check the status of hardware (that is, PLL unlock alarm, Power alarm, underflow / overflow alarm, input signal status alarm, etc.) and the system for monitoring the modulation state of the exciter 100 in real time by receiving the signal quality data analyzed by the signal analyzing means 150 through the TCP / IP interface. Remote control is possible.

When the exciter 100 of the present invention is used in a base station or repeater of an ATSC-MH network, the remote control means 200 makes it possible to remotely monitor and control the quality and state of the base station or repeater, respectively.

Meanwhile, the exciter 100 according to the embodiment of the present invention may be configured to have an ATSC mode and an ATSC-MH mode so as to automatically set an appropriate modulation method by analyzing an ATSC receiver input signal and an ATSC-MH input signal.

In the case of an ATSC receiver input signal such as a repeater, as described above, the ATSC receiver may generate and transmit an RF signal by modulating by the modulation method for the ATSC signal of FIG. 6. In the case of the ATSC-MH signal, for example, the base station, the RF signal is generated and transmitted by modulating by the modulation method of the ATSC-MH transmission system post-processing unit of FIG.

The signal analyzing means 150 of the present invention uses the baseband I / Q signal and the feedback IF signal of the modulation unit 118 for both of these cases, such as "Group delay", "Magnitude Response", "AM-AM". Performs signal analysis on items such as "," PSD "to monitor and analyze the quality and status of input and output signals in real time.

On the other hand, ATSC mode or ATSC-MH mode can be set manually or automatically by analyzing signals.

In the case of automatic setting, 118 packets of the same PID consecutively detected from the broadcast stream in which the main ATSC service packet and the M / H service packet are mixed are detected as MHE packets, and the 118 MHE home packets are randomized and RS encoded. And 207-byte convolutionally coded 170 segment data formed by convolutional encoding (ie convolutional encoded MPH group format data; MPH Group Fomat after data interleaver, ATSC S4-131r14-A153-Part-2-RF-Transmission, Annex A). -2) extracts 276 data from the first data of the 53rd segment as signaling data, and extracts data from the first data of the 53th segment, and modulates the ATSC signal considering the ATSC broadcasting standard signal when the extracted data is valid. It is possible to.

On the other hand, valid signaling data is not extracted by the above method, or 118 consecutive PIDs input are de-formatted and convolutionally encoded with the same packet to extract data estimated as signaling data, and the validity of the data is determined. In this case, it is possible to perform modulation on the ATSC-MH signal by making the input signal an ATSC-MH signal (eg, a MUX output signal of the ATSC-MH transmission system).

The scope of the present invention is not limited to the above embodiments, but is determined by the matters described in the claims, and it is obvious that the present invention includes various modifications and adaptations made by those skilled in the art in the scope and equivalents of the claims.

100 ....... Exciter 101 ............. Signal input means
103 ....... Modulation means 110 ........ Modulation module
111 ....... Channel coding section 118 ............. Modulation section
120 ....... DPD module 121 ........ Module control part
122 .... FPGA 123 ........ CPU
130 ............ RF switching means 140 ............ Feedback means
150 ....... Signal analysis means 200 ........ Remote control means

Claims (8)

Signal input means for receiving a broadcast signal;
Modulation means for performing modulation in a manner corresponding to a standard of a signal input from said signal input means;
RF switching means for RF-converting and transmitting the signal modulated by the modulation means;
And an signal analyzing means for comparing and analyzing a signal of the modulation means and a signal received from the RF transmission signal.
Signal input means for inputting a main ATSC service broadcast signal or an M / H service broadcast signal;
Signal detecting means for detecting whether a signal input from the signal input means is a main ATSC service broadcast signal or an M / H service broadcast signal;
Modulation means for performing modulation in a manner corresponding to each broadcast signal according to a detection result by the signal detection means;
RF switching means for RF-converting and transmitting the signal modulated by the modulation means;
And an signal analyzing means for comparing and analyzing the down-converted signal by receiving the input signal of the modulation means and the RF transmission signal as a feedback.
The exciter according to claim 2, wherein the signal to be compared in the signal analyzing means is a baseband I / Q signal input from the modulation means and the feedback input IF signal.
The ATSC-MH of claim 2, wherein the exciter may receive an ATSC signal and an ATSC-MH signal, and perform an modulation on the ATSC signal and an ATSC-MH signal according to the received signal. Exciter characterized in that to perform any one of the modes.
The method according to any one of claims 1 to 4, wherein the signal analysis means,
Exciter characterized by comparing and analyzing items including "Group delay", "Magnitude Response", "AM-AM", "PSD".
An exciter according to any one of claims 1 to 4;
And remote control means for remotely controlling the exciter and monitoring the output signal quality of the exciter by accessing the signal analysis means at a remote location.
7. The base station quality management system according to claim 6, wherein the remote control of the exciter is performed through a web.
The method according to claim 6, wherein the remote control means,
The base station quality management system, characterized in that for monitoring the items including the "group delay", "Magnitude Response", "AM-AM", "PSD" compared and analyzed in the signal analysis means.

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