JP4867275B2 - Receiver - Google Patents

Description

  The present invention relates to a receiving apparatus that receives a digital video signal as a radio signal.

  Recently, some reception apparatuses of this type generate a reception state signal indicating a reception state of a video signal as part of internal signal processing. An example of the reception status signal is a constellation signal. The constellation signal is a signal representing a plurality of constellations (points) mapped on the XY coordinates, and it is possible to visually determine whether or not the reception state is good according to the arrangement of the constellations. .

  Here, an example of a circuit configuration of a conventional receiving apparatus will be described with reference to FIG.

  Referring to FIG. 11, the receiving apparatus according to this conventional example includes a receiving unit 111, a demodulating unit 112, a decoder 113, an interface unit 114, and a D / A conversion unit 115.

  The reception unit 111 receives an RF signal (Radio Frequency), converts the received RF signal into an IF (Inter frequency) signal, and outputs the IF signal to the demodulation unit 112.

  The demodulation unit 112 converts the IF signal output from the reception unit 111 into a baseband signal, and performs a demodulation process and a decoding process on the converted baseband signal, thereby performing a transport stream signal (hereinafter referred to as “TS (Transport)”. Stream) signal ”is generated and output to the decoder 113. Further, the demodulation unit 112 generates a constellation signal as a reception state signal after demodulation processing, and outputs the constellation signal to the D / A conversion unit 115.

  The decoder 113 converts the TS signal output from the demodulation unit 112 into a digital video signal and audio signal, and outputs the video signal and audio signal to the interface unit 114. Note that the present invention is characterized by the processing of the video signal, and the processing of the audio signal can be performed using any known technique. Therefore, in the following, the processing of the audio signal performed by the receiving device in FIG. Description is omitted.

  The interface unit 114 outputs the digital video signal output from the decoder 113 to the main line, D / A converts the digital video signal to an analog format, and outputs the analog video signal to a general-purpose video monitor. As described above, in this type of receiving apparatus, in addition to outputting the video signal to the main line, outputting the video signal to the video monitor is usually performed in order to monitor the video signal.

The D / A converter 115 D / A converts the constellation signal output from the decoder 113 into an analog format and outputs the analog signal to a dedicated measuring instrument such as an oscilloscope. A technique for displaying a constellation signal with an oscilloscope is disclosed in Patent Document 1.
JP-A-2005-51755

  As described above, in the conventional receiving apparatus, the reception state signal is converted into an analog signal and output separately from the video signal, and the reception state signal is processed inside the demodulation unit 112. The data is converted into an analog signal.

  Therefore, in order to observe the reception state signal, it is necessary to use a dedicated measuring instrument such as an oscilloscope. Therefore, for example, when a video signal is relayed, it is necessary to grasp the transmission state. However, if a dedicated measuring device is not prepared at the relay point, the reception state signal cannot be observed.

  Therefore, an object of the present invention is to provide a receiving apparatus that can observe a reception state signal without preparing a dedicated measuring device.

In order to achieve the above object, the receiving apparatus of the present invention provides:
Receiving state signal generating means for generating a plurality of receiving state signals representing different receiving states of the received video signal,
Format conversion means for converting each of the plurality of reception status signals into a format that can be displayed on a video monitor;
Interface means for multiplexing the reception state signal converted by the format conversion means on the video signal and outputting the multiplexed signal to the video monitor.

  As described above, the present invention is configured to convert the reception state signal into a signal format that can be displayed on the video monitor. In general, a general-purpose video monitor is installed to monitor the video signal in an environment where the receiving device is used or an image signal is relayed to the receiving device. An effect is obtained that the reception status signal can be observed without preparing a device.

  In addition, since the reception state signal is multiplexed with the video signal, an effect is obtained that the general-purpose video monitor can simultaneously monitor the video signal and observe the reception state signal.

  Further, since the configuration is such that a plurality of reception state signals are multiplexed on the video signal, an effect that the reception state can be observed from various angles with a general-purpose video monitor is also obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(First embodiment)
The circuit configuration of the receiving apparatus of this embodiment will be described with reference to FIG.

  Referring to FIG. 1, the receiving apparatus of this embodiment includes a receiving unit 1, a demodulating unit 2, a decoder 3, a control unit 4, a format converting unit 5, and an interface unit 6.

  The receiver 1 receives an RF signal that is a radio signal, converts the received RF signal into an IF signal, and outputs the IF signal to the demodulator 2.

  In addition, the receiving unit 1 graphs the reception levels of the selected channel and the adjacent channel adjacent thereto as shown in FIG. 2, and displays the reception levels of the selected channel and the adjacent channel on the video monitor. Each is measured, a reception level signal representing each measurement value is generated, and is output to the format conversion unit 5 as a reception state signal. In FIG. 2, the center indicates the reception level of the currently selected channel, and both sides indicate the reception levels of the adjacent channels. As a method of measuring the reception level of the adjacent channel, for example, a filter that allows only the signal of the selected channel to pass is prepared, and the signal remaining without passing through the filter is regarded as the signal of the adjacent channel and the reception level. There is a way to measure.

  The demodulation unit 2 converts the IF signal output from the reception unit 1 into a baseband signal, generates a TS signal by performing demodulation processing and decoding processing on the converted baseband signal, and outputs the TS signal to the decoder 3 .

  Further, the demodulator 2 is reflected by a directly arriving signal or building in order to display a delay profile, which is a correlation power distribution in the time direction in a multipath environment, on a video monitor as shown in FIG. For each baseband signal obtained from the signal, the correlation power value with the known code sequence is measured, and a delay profile signal representing the arrival time of each baseband signal and the measurement value of the correlation power value is generated as a reception state signal. Output to the format converter 5.

  Further, the demodulator 2 generates a constellation signal composed of I data and Q data in order to display a plurality of constellations (points) mapped on the XY coordinates on the video monitor as shown in FIG. And output to the format converter 5 as a reception state signal.

  In addition, the demodulator 2 has a margin representing a difference between the reception level measured by the receiver 1 and the reception level that is the reception limit, the bit rate of the TS signal, BER (Bit Error Rate), and MER (Modulation Error Rate). ) Etc., and the measured value is output to the control unit 4.

  The decoder 3 converts the TS signal output from the demodulator 2 into a digital video signal and audio signal and outputs the converted video signal and audio signal to the interface unit 6. Note that the present invention is characterized by the processing of the video signal, and the processing of the audio signal can be performed using any known technique. Therefore, in the following, the processing of the audio signal performed by the receiving apparatus in FIG. Description is omitted.

  In addition, the decoder 3 measures the video rate of the digital video signal and outputs the measured value to the control unit 4.

  The control unit 4 generates a character signal representing a measurement value or the like of a predetermined measurement item related to the reception state in order to display the reception state as characters on the video monitor as shown in FIG. 5 is output. In FIG. 5, “64QAM (Quadrature Amplitude Modulation)” indicates a modulation method, “5/6” indicates a coding rate, “756 ms” indicates an interlead delay time, and “FULL 1K 1/8” indicates a multiplexing method. ing. “ΜLEVEL” indicates the reception level of the selected channel measured by the receiving unit 1, and “TS”, “BER”, “MARGIN”, and “MER” are bit rates measured by the demodulating unit 2. , Margin, BER, and MER, and “VIDEO” indicates the video rate measured by the decoder 3. “RSERR” indicates that an error has occurred.

  Thus, the receiving unit 1, the demodulating unit 2, and the control unit 4 constitute a part of the reception state signal generating unit.

  The format converter 5 is an NTSC (National Television Standards Committee) format (for example, an NTSC video) that can display the reception status signals output from the receiver 1, the demodulator 2, and the controller 4 on a general-purpose video monitor. Composite signal) and output to the interface unit 6.

  The interface unit 6 outputs the digital video signal output from the decoder 3 to the main line, multiplexes the NTSC reception state signal output from the format conversion unit 5 into the digital video signal, and multiplexes the multiplexed signal into the multiplexed signal. The included video signal is D / A converted from a digital format to an analog format, and the multiplexed signal is output to a general-purpose video monitor.

  Here, circuit configurations of the format conversion unit 5 and the interface unit 6 according to the present embodiment will be described with reference to FIG.

  Referring to FIG. 6, the format conversion unit 5 includes a storage unit 51, a display data setting unit 52, a read timing generation unit 53, and an NTSC conversion unit 54. The interface unit 6 includes a synchronization detection unit 61, a multiplexing unit 62, and a D / A conversion unit 63. Further, the storage unit 51 includes memories 511 to 514 and memory control units 515 to 518 provided corresponding to a total of four types of reception state signals, that is, a constellation signal, a delay profile signal, a reception level signal, and a character signal. It is configured.

  The memories 511 to 514 are a page memory, a frame memory, and the like that store data for one screen of the video monitor, and store corresponding reception status signals.

  The display data setting unit 52 displays the reception position signal on the screen when displaying the reception status signal on the video monitor for each of the four types of reception status signals including the constellation signal, the delay profile signal, the reception level signal, and the character signal. And data such as values are set.

  When the video signal output from the decoder 3 is displayed in a predetermined order on the screen of the video monitor, the synchronization detection unit 61 detects position information indicating the display position of the video signal on the current screen.

  Based on the position information detected by the synchronization detector 61, the read timing generator 53 generates a timing signal representing the timing for reading the reception status signal from the memory for each of the four types of reception status signals. This timing signal is individually output to the corresponding memory control unit among the memory control units 515 to 518, and is also output to the NTSC conversion unit 54 and the multiplexing unit 62.

  The memory control units 515 to 518 write the reception state signal to the corresponding memory based on the data set in the display data setting unit 52. Specifically, the memory control units 515 to 518 write the value at each display position on the screen when the reception state signal is displayed on the video monitor to the address on the memory corresponding to the display position.

  Further, the memory control units 515 to 518 read out the reception status signals stored in the corresponding memories in the order in which they are displayed on the screen at the timing when the timing signal is generated by the read timing generation unit 53, and Output.

  The NTSC converter 54 converts the reception status signal read from any of the memories 511 to 514 into an NTSC format signal that can be displayed on the video monitor at the timing when the timing signal is generated by the read timing generator 53. And output to the interface unit 6.

  The multiplexing unit 62 multiplexes the digital video signal output from the decoder 3 and the NTSC reception state signal output from the NTSC conversion unit 54 at the timing when the timing signal is generated by the read timing generation unit 53. The multiplexed signal is output to the D / A converter 63.

  The multiplexing format in the multiplexing unit 62 is set by a multiplexing setting signal input from the outside. For example, the multiplexing unit 62 performs multiplexing processing so that the video signal is set as the background as shown in FIG. 7 and the reception status signal is arranged in front of the video signal, but the reception status signal is made translucent as shown in FIG. Multiple processing can also be performed. The translucency can be realized using a known technique such as displaying the color of the reception state signal in a color obtained by blending the color of the original reception state signal and the color of the video signal in the background portion. Further, the multiplexing unit 62 can perform the multiplexing process so that only the reception state signal is displayed as shown in FIG.

  The D / A converter 63 D / A converts the digital video signal included in the multiplexed signal output from the multiplexing unit 62 into an analog format, and then outputs the multiplexed signal to the video monitor.

  Hereinafter, the operation of the receiving apparatus of this embodiment will be described.

  First, the reception unit 1 converts the received RF signal into an IF signal and outputs the IF signal to the demodulation unit 2. In addition, the reception unit 1 measures the reception levels of the selected channel and the adjacent channel, and outputs a reception level signal representing each measurement value to the format conversion unit 5 as a reception state signal. Further, the reception unit 1 outputs a measurement value of the reception level of the currently selected channel to the control unit 4.

  The demodulation unit 2 converts the IF signal output from the reception unit 1 into a baseband signal, performs demodulation processing, and then performs decoding processing such as constellation determination processing and error correction decoding processing to convert the TS signal. Generate and output to the decoder 3. The demodulator 2 generates a constellation signal based on the constellation determination processing result, and outputs the constellation signal to the format converter 5 as a reception state signal. Further, the demodulator 2 measures a correlation power value with a known code sequence for each baseband signal, generates a delay profile signal based on the measured value, and outputs it to the format converter 5 as a reception state signal. In addition, the demodulator 2 measures the above-described margin, bit rate, BER, MER, and the like, and outputs the measured values to the controller 4.

  In the decoder 3, the TS signal output from the demodulator 2 is converted into a digital video signal and output to the interface unit 6. Further, the decoder 3 measures the video rate and outputs the measured value to the control unit 4.

  The control unit 4 generates a character signal based on the measurement value of each measurement item output from the reception unit 1, the demodulation unit 2, and the decoder 3, and outputs the character signal to the format conversion unit 5 as a reception state signal.

  In the format conversion unit 5, the memory control units 515 to 518 are used to display the reception status signals of the constellation signal, the delay profile signal, the reception level signal, and the character signal on the video monitor as shown in FIG. First, based on the data set in the display data setting unit 52, the value at each display position when the reception state signal is displayed is written to the addresses on the memories 511 to 514 corresponding to the display position. In addition, the memory control units 515 to 518 read out the reception state signals stored in the memories 511 to 514 in the order corresponding to the display positions on the screen at the timing when the timing signal is generated in the read timing generation unit 53. The NTSC converter 54 converts the reception state signals sequentially read from the memories 511 to 514 into NTSC format signals and outputs the signals to the interface unit 6.

  After that, the interface unit 6 outputs the digital video signal output from the decoder 3 to the main line. The multiplexing unit 62 multiplexes the reception state signal output from the format conversion unit 5 on the video signal, and the D / A conversion unit 63 performs D / A conversion of the video signal included in the multiplexed signal into an analog format. Then, the multiplexed signal is output to a general-purpose video monitor.

  Here, the operations of the format conversion unit 5 and the interface unit 6 will be described in more detail. In the following, a case where a constellation signal is processed among the reception status signals will be described as an example. However, other reception status signals can be multiplexed with video signals and output to the video monitor by the same processing. .

  First, a write operation to the memory 511 will be described.

  The constellation signal output from the demodulator 2 is composed of I data and Q data. For example, in FIG. 7 and FIG. 8, 64 constellations are obtained by taking 8 values for both I data and Q data, and regarding the values of I data and Q data as coordinate positions in the X-axis direction and Y-axis direction, respectively. Is displayed on the video monitor. In this case, the display data setting unit 52 determines the value at each display position in the display area of the constellation signal (left square portion in FIGS. 7 and 8) according to the values of I data and Q data. (For example, a value representing a display color) or the like is set. Further, a display area for the constellation signal is configured on the memory 511.

  Therefore, the memory control unit 515 uses the values of the I data and the Q data as addresses indicating the coordinate positions in the X axis direction and the Y axis direction in the display area of the constellation signal configured on the memory 511, and displays according to the addresses. The value set in the data setting unit 52 is written on the memory 511. For example, in the display area of the constellation signal configured on the memory 511, the memory control unit 515 displays a value representing “white” at the display position of the constellation and a color other than “white” at the other portions. Write the value to represent.

  Next, a read operation from the memory 511 will be described.

  When displaying the video signal on the video monitor, display one line from the left end of the top of the screen in the right direction, display it to the right end, return to the left end, and then display the line below it in order. One screen is displayed by displaying to the right end at the bottom.

  Therefore, the memory control unit 515 uses the timing signal generated by the read timing generation unit 53 based on the screen position information detected by the synchronization detection unit 61 to display the display position of the video signal as a constellation display. When it is detected that the area has been reached, the constellation signals stored in the memory 511 are read in the order in which they are displayed on the screen. The multiplexing unit 62 also uses the timing signal generated by the timing generation unit 53 to detect that the display position of the video signal has reached the multiplexing position where the constellation signal is multiplexed, and performs multiplexing processing.

  As described above, in the present embodiment, the reception state signal is converted to the NTSC signal format that can be displayed on the video monitor, so that it is received on a general-purpose video monitor without preparing a dedicated measuring instrument. A state signal can be observed.

  In addition, since the reception state signal is multiplexed with the video signal, it is possible to simultaneously monitor the video signal and observe the reception state signal with a general-purpose video monitor.

  In addition, since a plurality of reception state signals are multiplexed, the reception state can be observed from various angles using a general-purpose video monitor.

(Second Embodiment)
The receiving apparatus according to the first embodiment outputs a multiplexed signal as an analog signal on the assumption that a general-purpose video monitor serving as an output destination of a multiplexed signal obtained by multiplexing a reception state signal on a video signal has an analog input interface. It was.

  On the other hand, the receiving apparatus of this embodiment outputs a multiplexed signal as a digital signal on the assumption that a general-purpose video monitor as an output destination includes a digital input interface.

  The receiving device of this embodiment is different from the first embodiment shown in FIG. 1 only in that the format converter 5 and the interface unit 6 are changed to a format converter 7 and an interface unit 8, Other than that, the configuration is the same. Therefore, hereinafter, only the configuration of the format conversion unit 7 and the interface unit 8 will be described with reference to FIG.

  Referring to FIG. 10, the format conversion unit 7 is different from the format conversion unit 5 shown in FIG. 6 in that a digital video conversion unit 71 is provided instead of the NTSC conversion unit 54. The interface unit 8 is different from the interface unit 6 shown in FIG. 6 in that the D / A conversion unit 63 is deleted. Since the configuration other than the above is the same as that of the first embodiment, the same reference numerals are given and description thereof is omitted.

  In the present embodiment, the digital video conversion unit 71 converts the reception status signal read from any of the memories 511 to 514 into a digital signal that can be displayed on the video monitor, and outputs the signal to the interface unit 6. The multiplexing unit 62 multiplexes the digital format video signal output from the decoder 3 and the digital format reception state signal output from the digital video conversion unit 71, and uses the multiplexed signal in a digital format for general-purpose video. Output to the monitor. Therefore, the reception state signal can be observed even in a video monitor having a digital input interface.

  In the first and second embodiments, a total of four types of reception status signals, ie, a constellation signal, a delay profile signal, a reception level signal, and a character signal have been described as examples. However, the present invention is not limited to this. Of course, other reception status signals are applicable.

  In the first and second embodiments, the case where a total of four types of reception status signals, ie, a constellation signal, a delay profile signal, a reception level signal, and a character signal are displayed has been described as an example. The present invention is not limited to this, and it is possible to display only reception state signals arbitrarily selected from a total of four types of reception state signals. In such a configuration, it is only necessary that the read timing generation unit 53 generates a timing signal only when it is time to read the selected reception state signal from the memory.

It is a block diagram which shows the circuit structure of the receiver of the 1st Embodiment of this invention. It is a figure which shows an example of the display content at the time of displaying a reception level signal on a video monitor. It is a figure which shows an example of the display content at the time of displaying a delay profile signal on a video monitor. It is a figure which shows an example of the display content at the time of displaying a constellation signal on a video monitor. It is a figure which shows an example of the display content at the time of displaying a character signal on a video monitor. It is a block diagram which shows an example of the circuit structure of the format converter and interface part which concern on the 1st Embodiment of this invention. It is a figure which shows an example of the display content at the time of displaying the multiplexed signal which multiplexed the reception status signal on the video signal on a video monitor. It is a figure which shows the other example of the display content at the time of displaying the multiplexed signal which multiplexed the receiving condition signal on the video signal on a video monitor. It is a figure which shows the further another example of the display content at the time of displaying the multiplexed signal which multiplexed the reception status signal on the video signal on a video monitor. It is a block diagram which shows an example of the circuit structure of the format converter and interface part which concern on the 2nd Embodiment of this invention. It is a block diagram which shows an example of the circuit structure of the conventional receiver.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reception part 2 Demodulation part 3 Decoder 4 Control part 5 Format conversion part 6 Interface part 51 Memory | storage part 52 Display data setting part 53 Reading timing generation part 54 NTSC conversion part 61 Synchronization detection part 62 Multiplexing part 63 D / A conversion part 511- 514 Memory 515-518 Memory control unit

Claims (7)

Receiving state signal generating means for generating a plurality of receiving state signals representing different receiving states of the received video signal,
A plurality of memories each storing the plurality of reception status signals;
A plurality of memory control means provided corresponding to the plurality of memories, for writing a reception state signal to the corresponding memory and reading the reception state signal from the corresponding memory;
Conversion means for converting each of a plurality of reception status signals read from the plurality of memories into an NTSC format that can be displayed on the video monitor ;
Multiplexing means for multiplexing the reception state signal converted by the conversion means to the video signal and outputting the multiplexed signal to the video monitor ,
Synchronization detection means for detecting position information indicating a display position of the video signal on the current screen when displaying the video signal in a predetermined order on the screen of the video monitor;
Read timing generation means for generating, for each of the plurality of reception status signals, a timing signal indicating the timing for reading the reception status signal from the memory based on the position information detected by the synchronization detection means. And
Each of the plurality of memory control units reads out the reception status signals stored in the corresponding memory in the order in which they are displayed on the screen at the timing when the timing signal is generated by the read timing generation unit,
The conversion means converts the reception state signal read from any of the plurality of memories into the NTSC format that can be displayed on the video monitor at the timing when the timing signal is generated by the read timing generation means,
The multiplexing means outputs the reception status signal converted by the conversion means so that the reception status signal is arranged in front of the video signal at the timing when the timing signal is generated by the read timing generation means. A receiving device that multiplexes and outputs video signals . For each of the plurality of reception status signals, further comprising display data setting means in which data for displaying the reception status signal on the video monitor is set,
Wherein each of the memory controller, based on the set data to the display data setting unit writes the received status signal to the corresponding memory, the receiving device according to claim 1. The read timing generating means, only when it is time to read the receive status signal selected among the plurality of receiving state signal, generating said timing signal, the receiving apparatus according to claim 1 or 2. The receiving apparatus according to claim 1, wherein the multiplexing unit makes the reception state signal translucent and multiplexes the signal on the video signal. The reception status signal generation means includes
In order to graph the reception level of the selected channel and the adjacent channel adjacent thereto and display it on the video monitor, the reception level of the selected channel and the adjacent channel is measured, and the reception level representing each measured value comprising means for generating a signal as the reception state signal receiving apparatus according to any one of claims 1 4. The reception status signal generation means includes
In order to display a plurality of constellations mapped on XY coordinates on the video monitor, a constellation signal composed of I data and Q data is generated as the reception state signal, and in the time direction in a multipath environment. In order to display a delay profile that is a correlation power distribution on the video monitor, a correlation power value with a known code sequence is measured for each baseband signal obtained from the received video signal, and an arrival time of each baseband signal and a delay profile signal representing the measured value of the correlation power value includes means for generating as said reception state signal, the receiving apparatus according to any one of claims 1 to 5. The reception status signal generation means includes
A means for generating a character signal including a measurement value of a predetermined measurement item related to the reception state of the video signal as the reception state signal in order to display the reception state of the video signal as characters on the video monitor. The receiving device according to any one of 1 to 6 .