KR100699160B1 - Method for controlling a tuning of digital multimedia broadcasting receiver - Google Patents

Abstract

A tuning control method of a DMB receiver is disclosed. If it is determined that the channel change command from the UI task has been received, the tuner task generates a reset signal for resetting the baseband processor to remove information about a previous channel, and the channel change command is generated from the UI task. If it is determined that it has not been received, it is determined whether the synchronization status information changes by checking the synchronization status information at regular intervals, and counting the number of times the asynchronous state is maintained when it is determined that the synchronization status information is changed from the synchronous state to the asynchronous state. When the count of the counted asynchronous state is a predetermined number of times, the synchronous state information indicating that the asynchronous state is changed is transmitted to the UI task. According to the present invention, it is possible to ensure the reliability of the synchronization status information by resetting the baseband whenever the channel to be tuned is changed, and operate the system stably.

DMB, Tuning, UI Tasks, Tuner Tasks, Synchronous, Asynchronous

Description

Method for controlling a tuning of digital multimedia broadcasting receiver

1 is a flowchart illustrating a tuning control method of a general DMB receiver;

2 is a hardware block diagram of a DMB receiver to which the present invention is applied;

3 is a flowchart illustrating a tuning control method of a DMB receiver according to an embodiment of the present invention;

4 is a flowchart illustrating an operation of a tuner task according to whether synchronization state information is changed in FIG. 3.

Explanation of symbols on the main parts of the drawings

100: DMB receiver 110: tuner

120: baseband processing unit 200: UI task

300: Tuner Task

The present invention relates to a tuning control method for a digital multimedia broadcasting (DMB) receiver, and more particularly, to a method for controlling tuning of a DMB receiver in consideration of a change in synchronization state information according to electric field strength. .

DMB is a standard for mobile reception of multimedia. It is a next-generation broadcasting service that provides not only CD-quality high-quality audio service but also various data services, bidirectionality, and excellent mobile reception quality, compared to analog AM or FM broadcasting. . The DMB standard enables video broadcasting by transmitting MPEG-4 data to a data broadcasting standard within a digital audio broadcasting (DAB) standard.

1 is a flowchart illustrating a tuning control method of a general DMB receiver.

As shown in FIG. 1, when a channel selection signal is received from a user (S11), the UI task 10 transmits a channel change command to the tuner task 20 (S12).

If a channel change command is received from the UI task 10 while monitoring whether a channel change command is received (S21 and S22), the tuner task 20 tunes a channel corresponding to the received channel change command to a tuner (not shown). The frequency of the corresponding channel is set at step S23.

The tuner task 20 checks the synchronization status information indicating whether the broadcast signal is received according to the channel frequency setting (S24), and transmits the checked synchronization status information to the UI task 10 (S25).

The UI task 10 that has received the synchronization state information from the tuner task 20 determines that the broadcast signal exists in the corresponding channel when the received synchronization state information is information indicating the synchronization state, and processes the broadcast signal on the screen. On-Screen Display (OSD) for informing that the broadcast signal does not exist by determining that the broadcast signal does not exist in the corresponding channel when the synchronization state information received from the tuner task 20 is information indicating the asynchronous state. Process to display the message (S13).

On the other hand, if it is determined that the channel change command is not received from the UI task 10 as a result of the determination in step 22, the tuner task 20 compares the previous synchronization status information with the current synchronization status information and changes the synchronization status information. Only when there is a current state of synchronization information is transmitted to the UI task (10) (S26).

The UI task 10 having received the synchronization status information from the tuner task 20 performs an operation corresponding to the received synchronization status information (S14). That is, when information indicating that the broadcast signal received through the tuner is changed to the asynchronous state from the tuner task 20 is received, the UI task 10 displays an OSD message indicating that no broadcast signal exists. Process it for display.

On the other hand, if information indicating that the synchronous state is changed from the tuner task 20 is received while displaying an OSD message indicating that a broadcast signal does not exist, the UI task 10 processes the received broadcast signal on the screen. Process it for display.

As described above, according to the conventional method, the tuner task 20 may perform the UI task 10 when a channel change command is received from the UI task 10 or when there is a change in synchronization status information even when the channel change command is not received. The synchronization status information is transmitted to the user, and the UI task 10 performs an operation corresponding to the received synchronization status information.

However, since the synchronization state information changes from time to time depending on the strength of the received broadcast signal, the reception processing capability of the antenna and the tuner, the system performance of the DMB receiver is unstable according to the conventional method. For example, it is not a problem when the DMB receiver moves to an area where the received field strength is secured by a certain level. However, when the DMB receiver moves to an area where the received field strength is not secured, the reception frequency may be changed according to the broadcast reception state. The synchronous state frequently changes to synchronous or asynchronous. In this case, the UI task 10 needs to perform an operation according to the change of the synchronization state, which causes a problem that the system is unstable.

In addition, the above-described problem occurs even when a problem occurs in the reception processing of the antenna and the tuner and the synchronization status information cannot be accurately identified. For example, the information on the channel being tuned previously may be reflected in the information on the channel currently being tuned, thereby causing a problem of not accurately grasp the current synchronization state.

Accordingly, the present invention has been made in an effort to provide a method for stably operating a system by controlling a tuning operation in consideration of a change in synchronization state information caused by a change in electric field strength accompanied by movement of a DMB receiver. have.

In order to solve the above technical problem, a tuning control method of a DMB receiver according to the present invention includes: determining whether a tuner task receives a channel change command from a UI task; If it is determined that the channel change command has been received, the tuner task generating a reset signal for resetting a baseband processor to remove information on a previous channel; And if it is determined that the channel change command has not been received, the tuner task checks the synchronization status information at regular intervals to determine whether to change the synchronization status information, but determines that the synchronization status information is changed from the synchronous state to the asynchronous state. And counting the number of times the asynchronous state persists, and if the counted asynchronous state is a preset number of at least three times, transmitting the sync state information to the UI task indicating that the asynchronous state changes to the asynchronous state. Is done.

The baseband processor may be configured to include an automatic frequency controller, an orthogonal frequency division multiplexer decoder, and a synchronization detector.

After the reset signal is generated, the tuner task further includes transmitting synchronization state information according to a detection result of the synchronization detector to the UI task.

The UI task may further include performing an operation corresponding to the synchronization status information received from the tuner task.

If it is determined that the counted number is less than the preset number, the counting factor of the asynchronous state counter is further increased by one.

On the other hand, if it is determined that the counted number exceeds the preset number, the synchronization status information is not transmitted to the UI task.

The predetermined number of times is characterized in that three times in a row.

On the other hand, if it is determined that the synchronization status information is changed from the non-synchronous state to the synchronous state as a result of determining whether the synchronization state information, further comprising the step of transmitting the synchronization state information to inform the UI task that the change to the synchronous state; do.

Hereinafter, with reference to the accompanying drawings will be described the present invention in more detail. However, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

2 is a hardware block diagram of a DMB receiver to which the present invention is applied.

As shown in FIG. 2, the DMB receiver 100 includes a tuner 110, a baseband processor 120, an audio and video decoder “A / V”, and an A / The V signal processor 140, the key panel unit 150, the memory 160, and the controller 170 are configured.

The tuner 110 tunes a broadcast signal corresponding to a set channel frequency among broadcast signals received through the antenna 105 and outputs it to the baseband processor 120. As shown in FIG. 2, the baseband processor 120 may be referred to as an automatic frequency controller (hereinafter referred to as "AFC") 122 or an orthogonal frequency division multiplex (OFDM). And a demodulator 124 and a synchronization detector 126.

In the above, the AFC 122 corrects and outputs the broadcast signal output from the tuner 110 using the frequency offset signal applied from the synchronization detector 126, and the OFDM demodulator 124 outputs the AFC 122. The frequency offset corrected signal is demodulated and output to the A / V decoder 130. The synchronization detector 126 detects a synchronization signal SYNC from the signal demodulated by the OFDM demodulator 124 and stores the detection result signal in a register (not shown). In addition, the synchronization detector 126 receives the demodulated signal by the OFDM demodulator 124, calculates a frequency offset, and provides the calculated frequency offset to the AFC 122.

The A / V decoder 130 decodes the A / V signal demodulated by the OFDM demodulator 124 and outputs the A / V signal to the A / V signal processor 140. The A / V signal decoded by the A / V decoder 130 is signaled by the A / V signal processor 140 and then output to the outside.

The key panel unit 150 includes a key operating unit 152 provided with a plurality of function keys and a light receiving unit 150 for receiving infrared signals transmitted from a remote controller, which is a remote controller, and controls a user key operation signal. It performs the role of applying to (170).

The memory 160 stores various control programs necessary to implement the functions of the DMB receiver 100, and the controller 170 controls the overall operation of the DMB receiver according to the control program stored in the memory 160.

Looking at the software configuration for controlling the tuning operation of the DMB receiver 100 configured as described above, the tuner task for controlling the tuner 110 and the baseband processing unit 120, and received through the key panel unit 150 And a user interface (“UI”) task for performing an operation according to a user key manipulation signal. The UI task is operated in response to a key manipulation signal from the user, and the tuner task is operated under the control of the UI task.

Hereinafter, a process of controlling the tuning operation of the DMB receiver 100 according to the UI task and the tuner task will be described in more detail with reference to FIGS. 3 and 4.

3 is a flowchart illustrating a tuning control method of a DMB receiver according to an exemplary embodiment of the present invention.

Referring to FIG. 3, when a channel selection signal is received from the user (S210), the UI task 200 transmits a channel change command to the tuner task 300 (S212).

The tuner task 300 monitors whether the channel change command is received from the UI task 200 in order to control the tuning operation of the tuner 110 (S310). If the channel change command is received from the UI task 200 while monitoring whether the channel change command is received (S320), the tuner task 300 tunes the channel corresponding to the channel change command to the tuner 110. A frequency is set (S322).

In addition, the tuner task 300 resets the AFC 122, the OFDM demodulator 124, and the synchronization detector 126, which constitute the baseband processor 120, to remove the information on the channel previously tuned. A signal is generated (S324). Accordingly, it is possible to solve the problem that the accumulated information affects the broadcast signal currently received and does not accurately grasp the synchronization state.

The tuner task 300 reads the synchronization status information from the specific register in which the synchronization detection result signal detected by the synchronization detector 126 is stored, and transmits the read synchronization status information to the UI task 200 (S326, S328). . The synchronization state information may be information indicating a synchronization state or information indicating an asynchronous state according to the synchronization detection result signal of the synchronization detector 126.

The UI task 200 which has received the synchronization status information from the tuner task 300 determines that the broadcast signal exists in the corresponding channel when the received synchronization status information indicates the synchronization status, and processes the broadcast signal to display the screen. And display the OSD message indicating that the broadcast signal does not exist by determining that the broadcast signal does not exist in the corresponding channel when the synchronous state information received from the tuner task 300 is information indicating the asynchronous state. Process (S214).

On the other hand, when it is determined in step 320 that the channel change command is not received from the UI task 200, the tuner task 300 checks the synchronization status information periodically (for example, at 0.2 second intervals) and synchronizes the synchronization status information. Is changed from the asynchronous state to the synchronous state or from the synchronous state to the asynchronous state, and when the asynchronous state continues a predetermined number of times (for example, three times in a row), the UI task 200 transmits the corresponding synchronous state information. (S330). More specifically, when it is determined that the synchronous state information is changed from the asynchronous state to the synchronous state without receiving the channel change command, the tuner task 300 informs the UI that the synchronous state information is changed from the asynchronous state to the synchronous state. Send to task 200.

On the contrary, if it is determined that the synchronous state information is converted from the synchronous state to the asynchronous state without receiving the channel change command, the tuner task 300 counts a period of time kept in the asynchronous state, and the counted number of times is continuous. In the third case, the UI task 200 transmits information indicating that the synchronous state information is changed from the synchronous state to the asynchronous state. As such, the reason for transmitting the asynchronous state to the U task 200 after being asynchronous for a predetermined number of times is to remove the cause of instability or malfunction of the system due to the rapid change in the electric field strength. The operation of the tuner task 300 according to whether the synchronization state information changes will be described in more detail below.

The UI task 200 which has received the synchronization state information from the tuner task 300 performs an operation corresponding to the received synchronization state information (S216). For example, when information indicating that the broadcast signal received through the tuner is changed to the asynchronous state from the tuner task 300 is received, the UI task 200 does not have a broadcast signal in the corresponding channel. Process to display an OSD message that informs you. On the contrary, if the information indicating that the synchronization signal is changed from the tuner task 300 is received while displaying the OSD message indicating that no broadcast signal exists, the UI task 200 processes the received broadcast signal and displays the screen. To be displayed.

4 is a flowchart illustrating the operation of the tuner task 300 according to whether the synchronization state information changes.

Referring to FIG. 4, the tuner task 300 reads the synchronization state information stored in a specific register and determines whether there is a change in the synchronization state information (S410). That is, the tuner task 300 may determine whether the synchronization state information is changed by comparing the previous synchronization state information with the current synchronization state information.

If it is determined in step 410 that there is a change in the synchronization state information, the tuner task 300 determines whether the change from the asynchronous state to the synchronization state (S420). If it is determined in step 420 that the synchronous state information is changed from the asynchronous state to the synchronous state, the tuner task 300 transmits the synchronous state information indicating the change from the asynchronous state to the synchronous state to the UI task 200 (S421). ). That is, when the synchronous state information is changed from the asynchronous state to the synchronous state, the synchronous state information is immediately transmitted to the UI task 200.

The tuner task 300 generates a reset signal for resetting the asynchronous state counter (S423). The tuner task 300 determines whether a predetermined time (for example, 0.2 seconds) has elapsed in order to periodically check the synchronization state information (S425). That is, the tuner task 300 performs an operation of checking the synchronization status information at 0.2 second intervals.

On the other hand, if it is determined in step 420 that the synchronous state information is changed from the synchronous state to the asynchronous state, the tuner task 300 increases the counting coefficient of the asynchronous state counter by one (S422). In order to determine whether the asynchronous state is maintained three times in a row, the tuner task 300 waits for a predetermined time and checks the synchronization state information of the next cycle.

If it is determined in step 425 that the predetermined time has elapsed, the tuner task 300 returns to step 410 to read the synchronization state information stored in a specific register to determine whether the synchronization state information has changed. Repeat the operation.

On the other hand, if it is determined in step 420 that there is no change in the synchronization status information, the tuner task 300 determines whether the previous and current synchronization status is asynchronous (S430).

As a result of the determination in step 430, if there is no change in the synchronization state information and the previous and current synchronization state information is in the synchronous state, the tuner task 300 shifts to step 425 to check whether a predetermined time has elapsed.

Meanwhile, as a result of the determination in step 430, if there is no change in the synchronization state information and the current and current synchronization states are asynchronous, the tuner task 300 determines whether the asynchronous state continues three times in succession (S431).

If it is determined in step 431 that the asynchronous state continues three times in a row, the tuner task 300 transmits the synchronous state information indicating that the synchronous state information is changed from the synchronous state to the asynchronous state to the UI task 200 ( S433). The tuner task 300 increases the counting coefficient of the asynchronous state counter by 1 and then switches to step 425 (S435). This is because when the counting coefficient of the asynchronous state counter exceeds three consecutive times, the UI task 200 does not transmit the synchronous state information indicating that the current synchronous state is asynchronous.

On the other hand, if it is determined in step 431 that the asynchronous state does not last three consecutive times, the tuner task 300 determines whether it is less than three times (S432).

If it is determined in step 432 that the asynchronous state is less than three times, the tuner task 300 increases the counting coefficient of the asynchronous state counter by one (S434). Thereafter, the process returns to step 425 to check the synchronization status information of the next period.

On the other hand, if it is determined in step 432 that the asynchronous state exceeds three times, the tuner task 300 immediately switches to step 425. That is, when the asynchronous state exceeds three times, the synchronous state information is not transmitted to the UI task 200.

On the other hand, the terms used in the present invention (terminology) are terms defined in consideration of the functions in the present invention, which may vary according to the intention or practice of those skilled in the art and the definitions are used throughout the present invention. It should be based on the content.

In addition, the present invention has been described in detail through exemplary embodiments, but those skilled in the art to which the present invention pertains have various modifications within the scope of the present invention without departing from the scope of the present invention. I will understand what is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

As described above, according to the present invention, the reliability of the synchronization state information can be secured by resetting the baseband whenever the channel to be tuned is changed. That is, by resetting the baseband whenever the channel to be tuned is changed, the information on the current channel overlaps with the information of the previous channel accumulated in the baseband block, thereby preventing the reliability of the synchronization state information from being deteriorated.

In addition, according to the present invention, when the synchronous state information is changed from the synchronous state to the asynchronous state, the electric field strength is determined by changing the state of the system to be suitable for the asynchronous state only when the asynchronous state lasts for a predetermined period. Due to the change of the synchronization status information from time to time can be prevented from operating the system unstable.

Claims (8)

Determining, by the tuner task, whether to receive a channel change command from the UI task; If it is determined that the channel change command has been received, the tuner task generating a reset signal for resetting a baseband processor to remove information on a previous channel; And If it is determined that the channel change command has not been received, the tuner task checks the synchronization status information at regular intervals to determine whether to change the synchronization status information, but it is determined that the synchronization status information is changed from the synchronous state to the asynchronous state. And counting the number of times the asynchronous state is maintained at, and if the counted asynchronous state is a preset number of at least three times, transmitting the synchronization state information to the UI task indicating that the asynchronous state changes to the asynchronous state. Tuning control method of the DMB receiver. The method of claim 1, And said baseband processor comprises an automatic frequency controller, an orthogonal frequency division multiplexer decoder, and a synchronization detector. The method of claim 2, After generating the reset signal, And transmitting, by the tuner task, the synchronization status information according to the detection result of the synchronization detector to the UI task. The method according to claim 1 or 3, And performing, by the UI task, an operation corresponding to the synchronization state information received from the tuner task. The method of claim 1, And if the counting number is determined to be less than the preset number, increasing the counting coefficient of the asynchronous state counter by one. The method of claim 1, And if it is determined that the counted number exceeds the preset number, the tuning control method of the DMB receiver, wherein the synchronization status information is not transmitted to the UI task. The method according to claim 5 or 6, The preset number of times is three consecutive times, the predetermined period is 0.2 seconds tuning control method of the receiver. The method of claim 1, If it is determined that the synchronous state information is changed from the asynchronous state to the synchronous state, transmitting the synchronous state information indicating the change to the synchronous state to the UI task. Tuning control method of the DMB receiver characterized by.

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