KR100687259B1 - Mobile communication terminal having a picture quality reforming function and controlling method therefore - Google Patents

Abstract

A mobile communication terminal with a picture quality improvement function and a controlling method thereof are provided to predict a channel state by checking frequency of generation with the use of a transmission error, and to deliver a picture quality improvement request signal to the other party's terminal according to the predicted results, thereby improving the image quality of an image signal received from the other party's terminal. From an initial state(S1), an image is taken through a camera equipped in a terminal, and the taken image is transmitted to the other party to conduct a video call(S2). The frequency of generation of an error of the currently received transmission signal is checked, and channel state information is calculated according to results(S3). It is confirmed whether the current transmission channel state is inferior through the current channel state information(S4). If so, a channel predictive module requests a main controller to transmit an encoding parameter change H.245 message to the other party's terminal(S5). The main controller transmits the encoding parameter change H.245 message to the other party's terminal(S6). The other party's terminal receiving the message changes encoding parameters, and transmits a changed image signal to the responding terminal(S7).

Description

Mobile communication terminal having a picture quality reforming function and controlling method therefore}

1 is an explanatory diagram illustrating a mobile communication terminal equipped with a conventional video call function.

2 is an explanatory diagram illustrating a mobile communication terminal equipped with an image quality improving function of the present invention.

3 is an explanatory diagram illustrating a channel state prediction module of the present invention.

4 is a flowchart of the present invention.

<Detailed Description of Codes>

       1A-B: mobile communication terminal 2: base station system

       3A-B: Wireless Module Section 4A-B: Multiplexer Module

5A-B: Channel prediction module part 6A-B: Main control part

7A-B: Handset Phone 8A-B: Voice Codec Section

9A-B: Camera 10A-B: Video Codec Section

11A-B: Memory 12A-B: Display

13A-B: Key panel section 14: Transmission error measurement section

15: Channel status judgment section 16: Channel status update section

17A-B: Selective layer 18A-B: MUX

The present invention relates to a mobile communication terminal equipped with an image quality improvement function and a control method thereof. In particular, a channel state is predicted by checking an occurrence frequency using a transmission error, and then an image quality improvement request signal is sent to the other terminal according to the prediction result. The present invention relates to a mobile communication terminal having a quality improvement function for improving the quality of an image signal received from a counterpart terminal and a control method thereof.

In general, UMTS (Universal Mobile Telecommunication System) networks can transmit "third generation", broadband packet-based text, digitized voice or video, and multimedia data at high speeds of more than 2 Mbps, whether mobile or computer users are anywhere in the world. Provide consistent service. This UMTS network allows computer and telephone users to continue to access the Internet while traveling and have the same performance no matter where they are traveling. Users will use this UMTS service through a combination of terrestrial radio and satellite transmission technology. In addition, the third generation mobile communication system called IMT-2000, which is an example of the UMTS network as described above, has various communication services supported by fixed communication networks such as PSTN / ISDN / B-ISDN, for example, voice and A system that enables access by using a wireless link to an information service network including image data has also been developed and used. In addition, recently, dual-band terminals supporting WCDMA (3G) and CDMA (2G) [MM-MB (MULTI-MODE MULTI-BAND)] have also been developed and can be used with each other under 3G or 2G.

Then, referring to FIG. 1, the mobile communication terminal equipped with the conventional image function as described above is provided in the mobile communication terminal 70A-B, for example, using an AMR codec to make a handset phone 71A-B. A voice codec unit 72A-B for encoding and outputting a voice through a voice and performing the reverse process; The video codec unit 74A-B, which is provided in the mobile communication terminal 70A-B, encodes and outputs a video input through the camera 73A-B using, for example, the H.263 codec and performs the reverse process. B) and; Main control unit 75A-B including the voice codec unit 72A-B and the video codec unit 74A-B to control each module of the mobile communication terminal 70A-B through, for example, an H.245 message. Wow; A sequence number and a cyclic redundancy check are performed on the bitstreams of the H.245 message, the encoded voice, and the video inputted from the voice codec unit 72A-B, the video codec unit 74A-B, and the main control unit 75A-B. Add a CRC: Cyclic Redundancy Check (CRC) field to create an Adaptation Layer (76A-B) that checks for abnormality of data after transmission, and each data of the Selection Layer (76A-B) into a single bitstream. A multiplexer module 78A-B having an output MUX unit 77A-B and a single bitstream of the multiplexer module 78A-B are wirelessly processed and transmitted to the base station system 79 and vice versa. It includes a wireless module unit (80A-B) for executing.

 Meanwhile, referring to the operation of the conventional image function mobile communication terminal as described above, first, when the user of the terminal 70A inputs a telephone number through the key panel unit 81A, the main control unit 75A of the terminal 70A The signal is processed through the multiplexer module 78A and the wireless module unit 80A and transmitted to the base station system 79 to connect a normal call channel. At this time, when the counterpart terminal 70B accepts the call via the base station system unit 79, a voice call can be performed between the terminals 70A-B via the base station system 79.

After the process, the main control unit 75A-B of the terminal 70A-B additionally executes a multimedia session connection operation for the video call via the base station system unit 79. In this case, the main control unit ( The 75A-Bs are the types of the voice codec unit 72A-B, the video codec unit 74A-B and the selection layer unit 76A-B, which can be supported using the H.245 message, and the MUX unit 77A-B. After exchanging information such as levels, both terminals 70A-B can make the maximum supportable settings at the same time. That is, the terminals 70A-B must set the type and encoding method of the audio / video codec unit to be used for the video call, the multiplex for the transmission, and the like. In this case, when the multimedia session is set up through the above process, the terminal users execute a video call. In this case, the main control unit 75A-B of the terminal 70A-B is a handset phone 71A-B. The user's voice is input through the camera 73A-B, and the user's face is input to the voice codec unit 72A-B and the video codec unit 74A-B, respectively. Then, the voice codec unit 72A-B encodes a voice input through the handset phone 71A-B using an AMR codec, for example, and selects the layer 76A-B of the wireless module unit 78A-B. ) In addition, the video codec unit 74A-B simultaneously with the voice codec unit 72A-B also encodes a video inputted through the camera 73A-B using, for example, the H.263 codec and multiplexer module 78A-. It outputs to the selection layer part 76A-B of B). Therefore, the selection layer portion 76A-B of the multiplexer module 78A-B has a voice codec portion 72A-B, a video codec portion 74A-B and a video codec portion 74A-B according to a function control signal of the main control portion 75A-B. The bitstreams of the H.245 message, the encoded audio, and the video input from the main control unit 75A-B are processed by adding a sequence number and a cyclic redundancy check (CRC) field, and then the MUX unit 77A-B. ) Then, the MUX unit 77A-B makes each data of the selection layer unit 76A-B into one predetermined bitstream and outputs the data to the wireless module unit 80A-B. Accordingly, the radio module unit 80A-B wirelessly processes the bitstream input from the MUX unit 77A-B and transmits the signal to the counterpart terminal 70A-B via the base station system 79 through the currently set channel. Send it to.

Then, the terminals 70A-B process the input voice and image signals in the reverse process to the voice signal through the handset 71A-B and the image signal on the display 82A-B. Through). Therefore, the user of the terminals 70A-B executes a video call while watching the face of the other party displayed on the display 82A-B while listening to a voice signal through the handset phone 71A-B as described above. Will be done.

However, since the mobile communication terminal equipped with the above image function is a circuit switch based service of the PSTN, voice, video, and data calls must be made within 64 Kbps. Therefore, such conventional terminals currently use about 48Kbps of bandwidth among 64Kbps of video during most video calls. In order to improve the quality deterioration, the conventional terminals request the counterpart terminal to obtain a macroblock at the same position in the previous frame or to encode and transmit an intra frame through an H.245 VFU (video fast update) message. In some cases, this method cannot be used as a fundamental method of preventing image quality deterioration, and may make a user feel like a broken image, and may be repeatedly used as an intra frame under the same conditions in a poor channel condition. Encoding inefficiently uses transmission bands and does not reduce transmission errors.

In particular, the mobile communication terminal equipped with the above-described image function proceeds with a video call with the amount of image data and mux layer level determined in the multimedia session setup process. Continued video call with the setting is inefficient use of limited bandwidth, there is a problem that does not guarantee the best image quality to the user.

Accordingly, the present invention has been invented to solve the above-mentioned problems, and since the video terminal simultaneously controls the image transmission unit and the channel signal transmission unit according to the transmission channel state, the communication environment is optimized, and thus the mobile communication is provided with the image function. SUMMARY OF THE INVENTION An object of the present invention is to provide a mobile communication terminal and a control method thereof, each of which is provided with an image quality improvement function for optimizing the image quality of the terminal.

Still another object of the present invention is to improve the functionality of the mobile communication terminal by improving the functionality of the mobile communication terminal accordingly by correcting the transmission signal of the terminal with an appropriate parameter value corresponding to always grasping the surrounding communication conditions in the image function mobile communication terminal The present invention provides a provided mobile communication terminal and a control method thereof.

In order to achieve the above object, the present invention provides a video communication unit and a voice codec unit in a mobile communication terminal capable of video communication, which is provided in the mobile communication terminal and changes a radio channel signal and encoding parameter through a base station system. A wireless module unit for receiving and processing a message signal and vice versa, and a cyclic redundancy check (CRC) technique for transmitting a transmission error of a wireless channel signal (audio and image) input from the wireless module unit. And a multiplexer module for outputting to the lower stage, inserting a sequence number and a cyclic redundancy check (CRC) field into an upstream signal, and then outputting a single bitstream to output the signal detected by the multiplexer module. Count the errors, calculate the frequency of occurrence, predict the channel state, and code the wave according to the predicted channel state. And a channel prediction module unit for outputting a meter change request signal and a main control unit for generating a coded parameter change H.245 message signal according to the coded parameter change request signal of the channel prediction module unit and transmitting the generated signal to a counterpart terminal. Provides a mobile communication terminal.

Another feature of the present invention is a channel state information calculating step of checking an error occurrence frequency of a transmission signal currently received while a mobile communication terminal is executing a video call, and calculating channel state information according to the result; A channel state checking step of checking whether the current transmission channel state is bad through the current channel state information after the information calculating step and a channel prediction when the current transmission channel state is changed compared to the previous state as a result of checking during the channel state checking step. A request message generation step of requesting the module to transmit the encoding parameter change H.245 message to the other party's terminal, and after the request message generation step, the main control part of the terminal receives the encoding parameter change H.245 message including the image quality improvement information. Transmitting an image quality improvement request message to the terminal; A mobile communication terminal having a picture quality improvement function comprising a picture quality improvement execution step in which a counterpart terminal receiving an H.245 message having a coding parameter change after the pre-request message transmission step changes the coding parameters and transmits the changed picture signal to a terminal that responds. Provides a control method.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, the present invention is provided in the mobile communication terminals 1A-B to receive and process radio channel signals (audio and image) and coding parameter change H.245 message signals through the base station system 2. Cyclic Redundancy Check (CRC) for the transmission error of the radio module unit 3A-B executing the reverse process and the radio channel signal (audio and image) input from the radio module unit 3A-B. A multiplexer module (4A-B) which checks using a technique and outputs to a lower stage, inserts a sequence number and a cyclic redundancy check (CRC) field into an upstream signal, and then outputs a single bit stream. A channel prediction module unit 5A- that counts transmission errors detected by the multiplexer modules 4A-B, calculates a frequency of occurrence, predicts a channel state, and outputs a coding parameter change request signal according to the predicted channel state. B) and, In accordance with the coding parameter change request signal of the channel prediction module unit 5A-B, it generates a coding parameter change H.245 message signal and transmits it to the counterpart terminal. According to the main control unit 6A-B controlling through the 245 message and the function control signal of the main control unit 6A-B, the voice is encoded through the handset phone 7A-B using, for example, an AMR codec. A voice codec unit 8A-B for outputting and performing the reverse process and a function control signal of the main control unit 6A-B, for example, through a camera 9A-B using an H.263 codec. A video codec unit 10A-B for encoding and outputting an input video and vice versa, and processed by the mobile communication terminal 1A-B according to a storage control signal of the main control unit 6A-B. Connected to the memory unit 11A-B for storing various types of information and the main control unit 6A-B. A display (12A-B), a key panel unit (13) to enter the user's function setting signals to the main control unit 7 for displaying various information processed by the.

The channel prediction module unit 5A-B includes a transmission error measuring unit 14 that counts the transmission error detected by the multiplexer module 4A-B and calculates and outputs the occurrence frequency as shown in FIG. 3. And a channel state determining unit for predicting a state of the currently received transmission channel, for example, whether the transmission channel is good or not according to the occurrence frequency result calculated by the transmission error measuring unit 14, and outputting a result signal. 15) and a channel state updater 16 for outputting a coded parameter change request signal to the main controllers 6A-B in accordance with the channel state signal calculated by the channel state determiner 15.

In addition, the multiplexer module 4A-B includes an H.245 message, an encoded voice, and the like input from the voice codec unit 8A-B, the video codec unit 10A-B, and the main control unit 6A-B. An adaptation layer (17A-B) for checking the abnormality of data after transmission by adding a sequence number and a cyclic redundancy check (CRC) field to the bitstream of the video, and the selection layer 17A-B. MUX unit 18A-B for outputting each data of &lt; RTI ID = 0.0 &gt;

Next, a control method applied to the present invention as described above will be described.

As shown in FIG. 4, the method of the present invention proceeds to the video call execution step S2 in the initial state S1, captures an image through a camera provided in the terminal, and transmits the image to the counterpart.

That is, when the power is applied to the mobile communication terminal 1A or 1B of the present invention, the main control unit 6A-B of the mobile communication terminal 1A or 1B proceeds to an initializing state from the internal memory unit 11A-B. Form the necessary information, execute the initialization process, and then go to standby.

At this time, the main control unit 6A-B of the terminal 1A or 1B recognizes when the user inputs a telephone number through the key panel unit 13A-B and presses a call button, and recognizes the telephone number input by the user. In addition to storing in the memory unit 11A-B, the system accesses the base station system 2 using the access channel through the wireless module unit 3A-B, and then transmits an outgoing signal to the corresponding telephone number. Then, the base station system 2 processes the outgoing signal transmitted from the terminal 1A or 1B and transmits an incoming signal to the counterpart terminal 1A or 1B to form a call.

At this time, when the counterpart terminal 1A or 1B accepts the call via the base station system 2, a voice call can be performed between the terminals 1A or 1B via the base station system 79.

Then, after the process, the main control units 6A-B of the terminal 1A or 1B additionally perform a multimedia session connection operation for the video call via the base station system 2, wherein the main control unit 6A -Bs are the types of voice codec unit 7A-B, video codec unit 10A-b and selection layer unit 17A-B that can be supported using H.245 messages, and levels of MUX unit 18A-B. After exchanging information, both terminals 1A or 1B simultaneously make the maximum supportable setting. That is, the terminals 1A or 1B need to set the type of audio / video codec unit to be used for a video call, an encoding method, a multiplex for transmission, and the like. In this case, when the multimedia session is set up through the above process, the terminal users execute a video call. In this case, the main controllers 6A-B of the terminal 1A or 1B are each handset phones 7A-B. The user's voice is input through the camera 9A-B, and the user's face is input to the voice codec unit 7A-B and the video codec unit 10A-B, respectively. Then, the voice codec unit 7A-B encodes the voice input through the handset phone 7A-B using an AMR codec, for example, and selects the layer 17A-B of the wireless module unit 3A-B. ) In addition, the video codec unit 10A-B simultaneously with the voice codec unit 7A-B also encodes a video inputted through the camera 9A-B using, for example, the H.263 codec and multiplexer module 4A-B. It outputs to the selection layer part 17A-B of B). Therefore, the selection layer portion 17A-B of the multiplexer module 4A-B has a voice codec portion 7A-B, a video codec portion 10A-B, and a function control signal of the main control portion 75A-B. The bitstreams of the H.245 message, the encoded audio, and the video input from the main control section 6A-B are processed by adding a sequence number and a Cyclic Redundancy Check (CRC) field, and then the MUX section 18A-B. ) Then, the MUX unit 18A-B makes each data of the selection layer unit 17A-B into one predetermined bitstream and outputs it to the wireless module unit 3A-B. Accordingly, the radio module unit 3A-B wirelessly processes the bitstream input from the MUX unit 18A-B and performs counterpart terminal 1A or 1B via the base station system 2 through the currently set channel. Send it to. Then, the terminals 1A-B process the input voice and image signals in the above and reverse steps, so that the voice signal is transmitted through the handset 7A-B and the image signal is displayed on the display 12A-B. Through). Therefore, the user of the terminals 1A-B executes a video call while watching the face of the other party displayed on the display 12A-B while listening to a voice signal through the handset phone 7A-B as described above. Will be done.

On the other hand, after the video call execution step (S2) proceeds to the channel state information calculation step (S3) to check the error occurrence frequency of the currently received transmission signal and calculates the channel state information according to the result. After the channel state information calculating step S3, the process proceeds to the channel state checking step S4 to check whether the current transmission channel state is bad through the current channel state information. If the current state of the transmission channel remains the same as before, the process returns to the video call execution step S2 and repeats the loop. However, if the current state of the transmission channel is changed as compared with the previous state as a result of checking during the channel state checking step (S4), the process proceeds to the request message generation step (S5), where the channel prediction module changes the encoding parameter to the main control unit. Request to send to the other terminal. After the request message generation step S5, the image quality improvement request message transmission step S6 is performed, and the main controller of the terminal transmits the encoding parameter change H.245 message including the image quality improvement information to the counterpart terminal.

In this case, when the transmission channel state is good, the video quality request message transmission step (S6) requires that a large amount of video data be allocated and transmitted. On the other hand, when the channel state is poor, the amount of video data is reduced and the remaining channel signals are further reduced. It further includes a variable transmission request step that requires a lot of allocation.

On the other hand, after the quality improvement request message transmission step (S6) to proceed to the image quality improvement execution step (S7) to the terminal receiving the encoding parameter change H.245 message to the terminal that changes the encoding parameters and responds to the changed image signal send.

Herein, in the step of improving image quality (S7), if the channel state signal included in the encoding parameter change H.245 message is good, a lot of video data is allocated and transmitted to the other party's terminal. The method further includes a variable transmission step of reducing a transmission amount and allocating more remaining channel signals to the counterpart terminal.

In other words, when the terminals 1A-B of the present invention make a video call as described above, a Cyclic Redundancy Check (CRC) technique is performed in the multiplexer module 4A-B of the terminals 1A-B. Check for transmission errors. At this time, the transmission error measuring unit 14 of the channel prediction module unit 5A-B measures the transmission error occurrence frequency checked by the multiplexer module 4A-B and determines the channel state data for the occurrence frequency. Output to the unit 15. The channel state determining unit 15 predicts the current channel state by referring to the data on the frequency of occurrence. For example, the channel state determining unit 15 determines whether the state of the current transmission channel is good or bad. Output to 16). Then, the channel state updating unit 16 requests the main control unit 6A-B to transmit the encoding parameter change H.245 message according to the channel state according to the input channel state signal. Then, the main controller 6A-B generates the H.245 encoding parameter change message according to the channel state by referring to the request of the channel state updater 16 and transmits the message to the counterpart terminal 1A-B. Then, the counterpart terminal 1A-B analyzes the encoding parameter change H.245 message including the image quality improvement information, and then encodes and transmits the transmitted signal by applying the changed encoding parameter.

That is, the terminals 1A-B use a video codec among all transmitted signals when the channel state is improved by using an H.245 encoding parameter change message, for example, an H.245 mode change and an H.245 Spatial Temporal Trade Off message. Allocate more data output from the unit 10A-B to improve the image quality. On the contrary, if the channel condition deteriorates, the amount of video data is reduced among the total transmission signals through the multiplexer module 4A-B and the remaining channel signals are reduced. By allocating and transmitting more, image quality is improved by reducing errors in transmission. In other words, depending on the terminal, the user requests H.245 Spatial Temporal Trade Off message to the other party to increase the frame rate rather than the image quality when there is a lot of motion so that the screen can be seen smoothly. You can increase the quality by allocating a large amount of data per frame.

Here, the reason for simultaneously controlling the data amount of the video codec unit 10A-B and the multiplexer module 4A-B is to prevent transmission delay in limited bandwidth because video call is an important factor in real time and QoS. . In addition, to prevent overload caused by the H.245 message transmission.

In the present invention, if the current channel state is the same as the previous channel state, the H.245 message is not transmitted.

As described above, the present invention improves the image quality of the image signal received from the counterpart terminal by checking the occurrence frequency using the transmission error to predict the channel state, and then sending a picture quality improvement request signal to the counterpart terminal according to the prediction result. In addition, since the video terminal optimizes the communication environment by simultaneously controlling the image transmission unit and the channel signal transmission unit according to the transmission channel state, the image terminal has an advantage of optimizing the image quality of the mobile communication terminal equipped with the image function.

In addition, according to the present invention, since an image function mobile communication terminal always grasps a surrounding communication condition and corrects a transmission signal of the terminal with an appropriate parameter value corresponding thereto, there is also an effect of significantly improving the functionality of the mobile communication terminal.

Claims (7)

In a mobile communication terminal having a video codec unit and a voice codec unit, which enables a video call, A wireless module unit provided in the mobile communication terminal to receive and process a radio channel signal and a coded parameter change H.245 message signal through a base station system and perform the reverse process, and a wireless channel signal input from the wireless module unit ( Audio and video) errors are checked using the Cyclic Redundancy Check (CRC) technique, and then output to the lower stage, and the sequence number and the Cyclic Redundancy Check (CRC) field are inserted into the upstream signal. Then, the multiplexer module generates a single bit stream and outputs it, counts transmission errors detected by the multiplexer module, calculates a frequency of occurrence, predicts a channel state, and outputs a coded parameter change request signal according to the predicted channel state. The encoding parameter according to the channel prediction module unit and the encoding parameter change request signal of the channel prediction module unit Meter change H.245 A mobile communication terminal having a quality improvement function, characterized in that it comprises a main control unit for generating a signal signal and transmitting to the other terminal. The channel prediction module unit of claim 1, further comprising: a transmission error measuring unit for counting the transmission error detected by the multiplexer module and calculating a frequency of occurrence; and a current according to the occurrence frequency calculated by the transmission error measuring unit. A channel state determining unit for predicting a state of a received transmission channel and outputting a result signal, and a channel state updating unit outputting a coding parameter change request signal to a main controller according to the channel state signal calculated by the channel state determining unit. Mobile communication terminal equipped with a picture quality improvement function characterized in that. 2. The multiplexer module of claim 1, wherein the multiplexer module performs a sequence number and a cyclic redundancy check (CRC) on a bitstream of an H.245 message, an encoded voice, and a video inputted from the voice codec unit, the video codec unit, and the main control unit. Field) and a MUX unit for confirming whether there is an abnormality of data after transmission, and a MUX unit for outputting each data of the selected layer unit into a predetermined bit stream. terminal. A channel state information calculating step of checking an error occurrence frequency of a transmission signal currently received while the mobile communication terminal executes a video call, and calculating channel state information according to the result; and present channel state after the channel state information calculating step. A channel state checking step of checking whether the current transport channel state is bad through the information, and if the current transport channel state changes as compared to the previous state as a result of checking during the channel state checking step, the channel prediction module changes the encoding parameter to the main control part. A request message generation step for requesting the transmission of the H.245 message to the counterpart terminal; and an encoding parameter change in which the main control part of the terminal includes the picture quality improvement information after the request message generation step. Request message transmission step and the quality improvement request message transmission step Encoding parameter change H.245 The other terminal receiving the message changes the encoding parameter and the image quality improvement execution step of transmitting the changed image signal to the receiving terminal, characterized in that the mobile communication terminal having an image quality improvement function Control method. 5. The image quality improving function according to claim 4, further comprising a normal transmission step of returning to a video call execution step and repeating a loop if the current transmission channel state does not change as before. Control method of a mobile communication terminal. The method of claim 4, wherein the transmitting of the video quality request message requires the allocation of a large amount of video data when the transmission channel state is good, whereas the transmission of the video data is reduced when the channel state is poor. A control method of a mobile communication terminal with a quality improvement function, characterized in that it further comprises a variable transmission request step for requesting to transmit more allocated. 5. The method of claim 4, wherein in the step of improving image quality, when the channel state signal included in the encoding parameter change H.245 message is good, a lot of video data is allocated and transmitted to the counterpart terminal. And a variable transmission step of reducing the amount of data to be transmitted and allocating more remaining channel signals to the counterpart terminal.

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