CN1595996A - Method for realtime display of signal intensity of analogue television signal receiving system - Google Patents

Abstract

The invention discloses a real-time display method for signal strength of an analog television signal receiving system. The method comprises the following steps: power on the system; perform system parameter initialization and self-inspection; enter the system main loop; in the main loop, call the signal strength determination program, output a bxSignalGain value; Press the "Display" button on the monitor to judge whether the image displayed in real time is an RF analog TV signal; if not, it will draw Video OSD; if it is, it will enter the program of drawing signal strength OSD; judge the input bxSignalGain value, and judge the corresponding input The value draws the signal strength icon of the corresponding level and displays it on the screen in real time. According to the real-time display of signal strength, users can know the signal strength of each analog TV signal channel, and effectively adjust the antenna to obtain the best audio and video quality. Adopting this method to control and adjust is simple, intuitive and precise.

Description

Real-time Display Method of Signal Strength in Analog TV Signal Receiving System

technical field

The invention relates to a measurement method for cable or aerial analog TV signal reception, in particular to a real-time display method for signal strength of an analog TV signal receiving system.

Background technique

The analog TV signal receiving system has the function of receiving analog TV signals. Analog TV signals come from a wide range of sources, including aerial analog TV broadcasting and cable TV, etc. Generally, the signal strength provided is a standard signal. In order to obtain better ratings for multiple analog TV signal channels The effect, the user often completes by adjusting the antenna. After the channel search is completed, the channel information is stored in a memory (such as EEPROM) as a channel list. After the machine is powered on, if the user wants to readjust or position the antenna, some analog TV signal channels may affect viewing because the signal strength is too low to be tuned out.

At present, when users adjust the antenna, they generally obtain a fuzzy judgment of signal strength by observing whether the image is the best effect, and it is impossible to obtain an objective and quantitative judgment standard.

Contents of the invention

The purpose of the present invention is to provide a real-time display method of signal strength of an analog TV signal receiving system, which can display the strength of analog TV signal on the screen in real time and quantitatively, so that the audience can adjust and obtain the best audio-visual effect.

The technical scheme that the present invention adopts for realizing the above object is:

A method for real-time display of signal strength of an analog television signal receiving system, said analog television signal receiving system comprising an antenna, a tuner, an SAW filter, an intermediate frequency processing chip, a baseband video processing chip, a display control chip, a microprocessor, a memory, OSD generator and display device, it is characterized in that described method comprises the steps:

a. Power on the system;

b. Perform system parameter initialization and self-test;

c. Enter the main loop of the system; in the main loop, call the signal strength determination program and output a bxSignalGain value;

d. After entering the signal strength determination program, first determine whether the line and field synchronization is locked, and then determine whether the color system is recognized, continue to detect whether it is currently in the state of channel search, and read out the values of the register and tuner;

e. Then enter the signal strength classification algorithm and output the bxSignalGain value;

f. Judging the real-time operation, judging whether the image displayed in real time is the radio frequency analog TV signal obtained from the tuner, if not, it will draw Video OSD, if it is, it will enter the program of drawing signal strength OSD;

g. Enter the OSD program for drawing signal strength, judge the input bxSignalGain value, and draw a graded signal strength icon corresponding to the input bxSignalGain value, which will be displayed on the screen in real time.

The TV signal strength level is obtained by processing 4 registers that indirectly indicate the received TV signal strength and 1 frequency band information. The 4 registers are VID_GAIN, TAGC_I_BS, TOP_SET_BS, NOISEME, and the frequency band information is TUNEBAND.

The invention has the advantages that the user can know the signal strength of each analog TV signal channel according to the real-time signal strength display, and accurately perform antenna adjustment or other operations to effectively obtain the best image quality. Control adjustments are simple, intuitive and precise.

Description of drawings

Fig. 1 is the composition block diagram of the analog television signal receiving system of the present invention, and this figure has shown the system composition that is used to receive and utilize the association of analog television signal;

Fig. 2 is the schematic diagram of OSD (on-screen display) among the present invention, and this figure has shown the analog TV signal strength display setting;

Fig. 3 is the main flowchart of the present invention;

Fig. 4 is the flow chart that the main process of the present invention relates to drawing signal strength OSD;

Fig. 5 is the flow chart that the main process of the present invention relates to the signal strength determination program;

Fig. 6 is a schematic diagram of an intermediate frequency processing chip module associated with the present invention;

Figure 7 illustrates the analog TV signal strength classification algorithm; among the figures: i represents the value of the VID_GAIN register, j represents the value of the TAGC_I_BS register, n represents the value of the NOISEME register, and 0x represents hexadecimal.

Detailed ways

Below in conjunction with the accompanying drawings and preferred embodiments, the specific implementation, composition and features provided according to the present invention are described in detail as follows:

Referring to Fig. 1, described analog TV signal receiving system comprises antenna 1, tuner 2, SAW filter 3, intermediate frequency processing chip 4, baseband video processing chip 5, display control chip 6, microprocessor 7, memory 8, OSD Generator 9 and display device 10 . Currently, in an analog TV signal receiving system, an OSD (on-screen display) is usually used as a main man-machine interface to provide functions of information transmission and control interface. The present invention can display different levels of signal strength in the OSD by drawing different icons.

The analog TV radio frequency signal is sent to the tuner 2 through the antenna 1. Antenna 1 includes various connection methods including aerial analog TV broadcasting and cable TV Cable, and can receive analog TV signals. The antenna 1 can be manually adjusted, and the signal is used to identify and tune various analog TV signal channels after being passed through the tuner 2 .

Under the control of the microprocessor 7, the tuner 2 converts the analog TV signal of a specific frequency to an intermediate frequency carrier, and after filtering through the SAW filter 3, it enters the intermediate frequency processing chip 4 for intermediate frequency processing; The intermediate frequency signal is converted to baseband video and enters the baseband video processing chip 5 for baseband processing; finally the signal is converted into RGB format and enters the display control chip 6, and the display control chip 6 controls the display 10 to finally form an image. In addition to other functions known in the art, microprocessor 7 provides control and implementation of various software programs/routines and communicates with various other components in accordance with aspects of the present invention.

In addition, the microprocessor 7 can also control the OSD generator 9 to generate and process OSD information/data. OSD information/data may be part of the received TV signal or generated internally. Such OSD information includes channel numbers, time, on-screen menus, teletext messages, and signal strength displays in the present invention. The microprocessor 7 also runs various necessary software to process/utilize various information.

Therefore, the microprocessor 7, the intermediate frequency processing chip 4, the baseband video processing chip 5 and the OSD generator 9 together form a module capable of realizing the present invention. This module can be completely independent, or form a different whole machine entity with other various modules. In this manner, the module may be incorporated into a TV, analog television signal receiving card or other component capable of receiving or utilizing analog television signals.

Referring to FIG. 2 , the screen display content of the display device includes channel information 11 , signal strength display 12 , audio format display 13 , screen menu display 14 and time display 15 . A typical on-screen OSD (On Screen Display) is described here. OSD (on-screen display), as the man-machine interface in the present invention, draws the required information on the screen.

The signal strength information is an on-screen message that is invoked by the user through a separate button on the remote control to invoke the signal strength information program, function or routine. After the call is made, certain icons will appear on the screen to represent signal strength information.

The specific implementation steps of the real-time display method for signal strength of the analog TV signal receiving system are described in detail below:

Referring to Figure 3, after the system is powered on, the program performs system parameter initialization and self-inspection, and enters the system main loop after completion. In the main loop, the program will call the signal strength determination program and output a bxSignalGain value. Then, the program will judge the user's operation, if the user presses the "Display" button on the remote control, the program will judge whether the currently displayed image is an RF analog TV signal obtained from the tuner, if not, it will draw Video OSD; If it is, it will enter the OSD program of drawing signal strength.

See Figure 4, after entering the OSD program for drawing signal strength, it will judge the input bxSignalGain value, if it is equal to 0, it will draw a 0-level signal strength icon; if it is equal to 1, it will draw a 1-level signal strength icon, and so on; The invention only exemplifies drawing 0-5 level signal strength icons corresponding to the input bxSignalGain value, and can draw 0-4, 0-6, 0-7 or several level signal strength icons during implementation.

Referring to Figure 5, after entering the signal strength determination program, first determine whether the line and field synchronization is locked, if not, bxSignalGain=0; if yes, then further determine whether the color system is recognized, if not recognized, bxSignalGain=0; if recognized, continue detection Whether it is in the state of searching for stations at present, if so, bxSignalGain=0; If not, read the value of register VID_GAIN, TAGC_I_BS, TOP_SET_BS, NOISEME and the value of tuner TUNEBAND among the present invention, enter signal strength classification algorithm. The final bxSignalGain value is output and displayed on the screen in real time.

Referring to Fig. 6, in the present invention, 4 register information and 1 frequency band information used to indirectly indicate the received TV signal strength are processed to finally obtain the TV signal strength level. These 4 registers are respectively VID_GAIN, TAGC_I_BS, TOP_SET_BS, NOISEME, frequency band information For TUNEBAND. The figure shows that the signal is received from the tuner 2, and sent to the SAW filter 3 after intermediate frequency conversion, and then enters the intermediate frequency front-end processing module 16 for demodulation processing after filtering, and the demodulated baseband signal is controlled by the VAGC module 17 for gain. Make it reach the standard setting value of 1V, and send it to the next step after being converted by the D/A module 18. That is to say, if the input baseband signal is less than the standard value of 1V, the VAGC module 17 will perform amplification processing. If it is greater than 1V, the VAGC module will 17 will perform attenuation processing, and the VAGC value is read by the register VID_GAIN. The larger the value, the larger the magnification factor, that is, the lower the signal strength. At the same time, the TAGC module 19 monitors the VAGC module 17. If the VAGC performs an attenuation action, the TAGC module 19 outputs the TAGC current to control the tuner to reduce the gain after the output control signal is converted by the D/A module 20, and the TAGC value is read by the register TAGC_I_BS. The higher the value, the less the amplification of the control tuner, i.e. the stronger the signal strength. The values of these two registers can indirectly reflect the strength of the TV signal. In addition, the TAGC start action point is set by the register TOP_SET_BS. In the baseband video processing chip 5, a register NOISEME is used to read out the strength of the baseband signal noise, which represents the signal signal-to-noise ratio, and the lower the signal-to-noise ratio, the greater the amount of noise in the signal.

The detailed meanings and value ranges of the above five parameters are shown in the table below: parameter significance range VID_GAIN Baseband signal automatic gain value 0x0～0x7FF TAGC_I_BS Tuner automatic gain current value 0x0～0x7FF top_SET_BS Tuner auto gain start point 0x0～0xF NOISE ME noise value 0x0～0x7F TUNEBAND Frequency band division 1(<143.25MHz)2(143.25～426.25MHz)3(>426.25MHz)

Under different TOP_SET_BS setting values and different TUNEBAND (frequency band) conditions, due to the frequency response characteristics of high frequency and intermediate frequency amplifiers, the values of registers TAGC_I_BS and VID_GAIN corresponding to different levels of signal strength will be different. In addition, considering different signal-to-noise ratio conditions, set the corresponding signal strength judgment parameter array to read out the values of TAGC_I_BS and VID_GAIN, search and judge in this array, and obtain the value of bxSignalGain.

The present invention exemplarily defines the above-mentioned signal strength grading standards, and several signal strength grading standards can be enumerated according to the concept of the present invention.

Referring to FIG. 7 , it shows an example of an analog signal strength level algorithm determination process example. For the sake of brief description, this process specifies the condition that the radio frequency domain is VHF_LOW (48.25-140.25 MHz), and TOP_SET is equal to 4. Under other conditions, the corresponding bxSignalGain value can also be found in the signal strength level array.

The invention provides a display method applied in an analog TV signal receiving system, which is used for displaying the intensity of the real-time signal of the analog TV. That is, a signal strength processing program/routine is used to detect and display the signal strength of the current receiving channel in real time, and the signal strength processing program/routine adopts a graphical user interface. Since the real-time signal strength is displayed at the same time as audio and video playback, this enables users to refer to its display for antenna adjustment or other operations to obtain the best image effect.

Claims (2)

1, a kind of anolog TV signals receiving system signal strength signal intensity real-time display method, described anolog TV signals receiving system comprises antenna, tuner, Surface Acoustic Wave Filter, intermediate frequency process chip, the base band video process chip, display control chip, microprocessor, memory, osd generator and display device is characterized in that described method comprises the steps:

A, system power on;

B, the initialization of carrying out system parameters and self check;

C, enter system's major cycle; In major cycle, call signal intensity decision procedure is exported a bxSignalGain value;

Behind d, the entering signal intensity decision procedure, judge at first whether the row field synchronization locks, and then judge whether the identification colors standard, continue to detect whether searching the platform state, the value of readout register and tuner at present;

E, entering signal strength grading algorithm then, output bxSignalGain value;

F, real-time operation is judged to judge whether the image that shows in real time is the radio frequency analog TV signal that obtains from tuner, if not, Video OSD will be drawn, if will enter drafting signal strength signal intensity OSD program;

G, enter and draw signal strength signal intensity OSD program, the bxSignalGain value of input is judged the bxSignalGain value drafting level signal intensity icon of corresponding input is shown on the screen in real time.

2, anolog TV signals receiving system signal strength signal intensity real-time display method according to claim 1, it is characterized in that register information and 1 band information of indication received television signal intensity draw through handling described TV signal intensity grade indirectly by 4,4 registers are respectively VID_GAIN, TAGC_I_BS, TOP_SET_BS, NOISEME, band information are TUNEBAND.

Images