JPH09130313A - Multimedia wireless communication system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In wireless multimedia communication, only an image or only sound is transmitted and received finely when the reception state is bad due to the influence of a building or the like. SOLUTION: A changeover switch 10 which operates according to a reception state (R1 to R3) sent from a receiving side of sound and image data digitally converted by an A / D conversion unit 100.
1, the transmission medium is changed in the order of (image + sound) → image → sound, and coding corresponding to each is performed by the coding unit 102.
~ 104, and the reception side sequentially transfers the reception state to the transmission side, performs decoding according to the medium to be transmitted, and outputs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multimedia wireless communication system for transmitting and receiving voices and images from a transmitter side to a receiver side by using radio, and in particular, due to external factors such as topography and weather conditions. The present invention relates to a multimedia wireless communication system in which a transmission medium is switched between (image + sound), image, and sound in response to a communication state that actively changes or a receiving function on the receiver side.

[0002]

2. Description of the Related Art In the case of conventional wired multimedia communication, for example, in a videophone, since the media to be handled are voice and image, the transmitter side transmits an image signal whose information amount is compressed. Transmission data is created by coding and multiplexing both the audio signal and the audio signal, and is transmitted via a cable.The receiver side separates the transmitted transmission data into an image signal and an audio signal and decodes them. Communication is performed by expanding the data. In these communications, since the transmission state on the communication path does not change in a wired manner, the deterioration rate of information on the communication path is almost constant, and the same algorithm can be used for transmission and reception from the beginning to the end of the communication. It is possible. On the other hand, if this system is applied to wireless multimedia communication, the encoding and compression technology needs to be further compressed compared to the case of wired communication, but the media to be transmitted and received are images and audio, and these are There is no change in encoding, multiplexing and transmitting.

[0003]

However, unlike the case of wired communication, when the communication medium is wireless, the transmission state may be actively changed due to topographical obstacles such as buildings and meteorological obstacles such as rainfall. Can be considered. As a result, the transmission state may be poor from the beginning of communication, or if the terminal used for communication is a mobile terminal, the transmission state may deteriorate during communication. At that time, if the above-described wired multimedia communication algorithm of the prior art is directly applied to wireless communication, it may be impossible to receive voice or image in some cases. The present invention is made in view of the above-mentioned current situation,
When the receiver side monitors and grasps the reception status and transfers the reception status to the transmitter side one by one, when the reception of the image and voice is not good, the transmitter side (Image + Sound) → Image → Sound In addition to providing a multimedia wireless communication system that switches transmission media in order of transmission, the transmitter side (image + audio), depending on the receiving function of the receiver side,
The present invention provides a multimedia wireless communication system for switching and transmitting images, sounds and transmission media.

[0004]

In order to solve the above problems, first of all, a multimedia wireless communication system according to the present invention is a multimedia wireless communication system for transmitting and receiving voices and images from a transmitter side to a receiver side by radio. In a media wireless communication system, the receiver side has a function of constantly monitoring and grasping the reception state, a function of successively transferring the grasped reception state to the transmitter side, and a medium which is switched and transmitted by the transmission side. If the receiver is not in a good reception state, the transmitter side is provided with a function to switch the transmission medium in the order of (image + sound) → image → sound, and to send,
Depending on the reception status of the receiver, on the transmitter side, (image +
The feature is that the transmission medium is switched and transmitted in the order of (voice) → image → voice. In the above system, in order to cope with the actively changing transmission state, the receiving state detected by the receiver side is transferred to the transmitter side, and the medium to be transmitted is switched according to this, so Since the code amount can be increased in the order of (image + sound) → image → sound, clearer image or sound information can be obtained.

A multimedia wireless communication system according to a second aspect of the invention is a multimedia wireless communication system in which voice and images are transmitted and received from a transmitter side to a receiver side wirelessly. It has a function to receive information about the receiving function sent from the machine side, and a function to switch the transmission medium (image + sound), only image, only sound according to the receiving function of the receiver and send. The side consists of a receiver that receives (image + audio), a receiver that receives an image, and a receiver that receives audio. Each side has the function of transmitting its own receiving function to the receiver side, It is characterized in that the transmitter side switches (image + sound), image / sound and transmission medium according to the receiving function on the side of the device and sends. According to the above system, it is possible for one transmitting terminal to receive according to the medium even with receiving terminals having different media. The receiver side in the first and second inventions is a mobile terminal.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Invention> An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a transmitter side of a multimedia wireless communication system according to the present invention. The transmitter includes an A / D converter 100, a changeover switch 101, encoders 102 to 104, and a multiplexer 105.
Composed of FIG. 2 is a block diagram showing a configuration of a receiver of the multimedia wireless communication system according to the present invention. The receiver includes a reception state monitoring unit 200, a changeover switch 201, a separation unit 202, decoding units 203 to 205,
It is configured by the D / A conversion unit 206.

First, in order to grasp the transmission state at the start of communication, the transmitter side first detects the audio signal Aa and the image signal Va.
Is converted into a digital signal by the A / D converter 100. Next, the changeover switch 101 is connected to the encoding unit 102 to encode and compress the digital audio signal Ad and the digital image signal Vd. Then, the encoded audio data A and image data V are multiplexed by the multiplexing unit 105 and sent. The above process is the same as the case of wired. This transmission data A
On the receiver side receiving + V, the reception state monitoring unit 20 detects the reception state from the reception data whose quality depends on the reception state.
Monitor and grasp with 0. The reception state is monitored by, for example, level 1 when the level of the modulated wave signal propagated and received by radio is a sufficient value, while when the level of the signal level can be received to some extent and the value of the signal level is obtained to some extent, the level is monitored. A method of discriminating the signal level as 2 and the signal level which is difficult to receive as level 3 can be considered.

When the reception state is determined to be level 1 by the above method or the like, the reception state monitoring section 200 causes the reception side monitoring unit 200 to directly transmit the voice and the image because the reception side is good because the reception state is good. To the transmitter side of the level 1 mode R1
To transfer. On the transmitter side, in response to the level 1 mode R1, the image and sound are transmitted without changing the changeover switch 101 from the initial stage. The receiving side also sets the changeover switch 201 to level 1 reception in the level 1 reception state mode. Then, the received A + V is separated by the separation unit 202,
The decoding unit 203 corresponding to the encoding unit 102 expands and decodes the data. Decoded Ad and Vd are D / A
The conversion unit 206 converts the analog signals Aa and Va and outputs them.

When the reception state is level 2, the reception state is somewhat worse than that of level 1, and it is difficult to transmit and receive voice and images. Therefore, the reception side sends only the image to the transmission side of the partner station. The level 2 mode R2 is transferred to the transmitter side reception state monitoring unit 200 of the partner station so as to be transmitted. At the same time, on the reception side of the own station, the changeover switch 201 is changed over to the decoding unit (level 2) 204 which receives only the image. The transmitting side receives the level 2 mode R2 and receives the changeover switch 101.
To the image transmission mode. In the image transmission mode, all the code amount assigned to the audio data can be assigned to the image data. Therefore, the data compression at the time of encoding is switched to the encoding 2 by switching to the encoding unit 103.
The image data V encoded in this way is sent to the receiver as transmission data. On the receiver side, the decoding unit 204 corresponding to the data compression at the time of encoding on the transmitting side decodes Vd by decompressing the decoded data. The decoded Vd is converted into an analog signal Va by the D / A conversion unit 206 and output.

When the reception state is level 3, the reception state is worse than that of level 2, so the reception side transfers the level 3 mode R3 so that only the voice is transmitted to the transmission side of the partner station. At the same time, the changeover switch 201 on the receiving side of the own station
To level 3 for receiving voice. On the transmitting side, the changeover switch 101 is switched to a mode for receiving the level 3 mode R3 and transmitting voice. The voice transmission mode is
Similar to level 2, the coding amount allocated to the image data can be allocated to the audio data.
4 (encoding 3). Then, on the receiver side, after decoding the audio data Ad by the decoding unit (composite 3) 205 corresponding to the encoding compression of the encoding unit 104,
The D / A conversion unit 206 converts the analog signal Aa and outputs it.

Next, FIG. 3 shows a flowchart when the transceiver used is a portable terminal. Since the mobile terminal has a characteristic that the terminal moves, the mobile terminal may recover even if the reception state deteriorates. Therefore, step 3
At 00, first, voice and images are transmitted and received. If the reception state changes due to the movement of the terminal, step 302
If it is determined to be level 2 in step 1 and there is a request from the receiving side to change to level 2, the process proceeds to step 303 and only images are transmitted and received. If not, the image and sound are transmitted and received as they are. In step 305, when the communication state is restored and the request for changing to level 1 is made from the receiving side, the feedback is performed up to step 300, and the image and the sound are transmitted and received. Otherwise, step 30
If there is no request to change to level 3 in 6, only images are transmitted and received. In step 306, the level 3
If there is a request to change to, the process proceeds to step 307 and only voice is transmitted and received. If it is determined in step 309 that the degree of recovery from level 3 has recovered to level 2, feedback is given to step 303, and if it is determined in step 310 that level 1 has been recovered, feedback is given to step 300. To do. Steps 301, 304, and 308 determine the end of transmission / reception at levels 1, 2, and 3, respectively.

<Second Invention> Next, the transmitter side selects the transmission medium (image + audio) in accordance with the function of receiving the information regarding the reception function sent from the receiver side and the reception function of the receiver. ), It has a function to switch and send only images, only sounds, and the receiver side is a receiver that receives (image + sound),
It is composed of a receiver that receives images and a receiver that receives audio, and has the function of transmitting the reception function of its own station to the receiver side, depending on the reception function of the receiver side, on the transmitter side,
A multimedia wireless communication system will be described in which (image + sound), image, sound and transmission media are switched and sent.

FIG. 4 shows a system configuration diagram schematically showing the configuration of the present invention. The transmitter 400 is the same terminal as in the above-mentioned embodiment. Different receivers A40 on the receiving side
1, the receiver B402, and the receiver C403 exist. FIG.
[Fig. 3] is a block diagram showing a configuration of the receiver A401. The receiver A is a terminal capable of receiving the sound 404 and the image 405. While the transmission data is input to the separation unit 500, the event F is output to the R1 generation unit 501.
The R1 generation unit 501 outputs the level 1 mode R1 to the transmitter 400 side regardless of the reception state while the event F is input. Then, the transmitted multiple signal A + V is separated by the separation unit 500, decoded by the above-mentioned decoding unit 203, converted into analog by the D / A conversion unit 206, and output.

FIG. 6 is a block diagram showing the configuration of the receiver B402. The receiver B is a terminal capable of receiving the image 406. Decoding unit (decoding 2 unit) 600
The event F is output to the R2 generation unit 601 while the transmission data is input to. As in the case of the receiver A, the R2 generation unit 601 outputs the level 2 mode R2 regardless of the reception state. The transmitted image signal V is decoded by the decoding unit 6
00 to decode, and the D / A conversion unit 206 performs analog conversion and outputs. FIG. 7 is a block diagram showing the configuration of the receiver C403. The receiver A is a terminal capable of receiving the voice 407. Decoding unit (decoding 3 units) 70
While the transmission data is input to 0, the event F is output to the R3 generation unit 701. This R3 generation unit 701 is level 3
By transmitting the mode to the transmitting side, an audio signal is transmitted and received.

[0015]

As described above, according to the present invention,
In wireless multimedia communication in which the reception status depends on the weather, terrain, etc., the media to be transmitted has a scalability function such that image + audio is the highest level, and (image + audio) → image → audio I'm changing
At the time of encoding, the code amount that can be assigned to the information of the transmission medium physically increases. Therefore, it is possible to obtain the effect that it is possible to obtain a finer image or audio information because the compression rate can be reduced in the compression at the time of encoding. Further, when considering a mobile terminal, the receiving state may be recovered as the mobile terminal moves. However, since the present invention has a function of shifting from a lower medium to an upper medium, an image or a sound and an image are displayed when the receiving state is restored. Can be transmitted and received again. In addition, since it is possible for one transmitting terminal to receive according to the media even with receiving terminals having different media, it is possible to obtain the effect that the convenience of the system is high.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a transmitter in a multimedia wireless communication system according to the present invention.

FIG. 2 is a schematic diagram showing a configuration of a receiver in the system of the present invention.

FIG. 3 is a flowchart showing processing when the receiver in the above system of the present invention is a mobile terminal.

FIG. 4 is a schematic diagram showing a configuration of a multimedia wireless communication system showing an embodiment of the second invention.

FIG. 5 is a receiver A in the system of the second invention.
It is the schematic which showed the structure of.

FIG. 6 is a receiver B in the system of the second invention.
It is the schematic which showed the structure of.

FIG. 7 is a receiver C in the system of the second invention.
It is the schematic which showed the structure of.

[Explanation of symbols]

 100 A / D conversion section 101 Changeover switch 102-104 Encoding section 105 Multiplexing section 200 Reception state monitoring section 201 Changeover switch 202 Separation section 203-205 Decoding section 206 D / A conversion section 400 Transmitter 401 Receiver A 402 Receiver B 403 Receiver C 404 Audio 405, 406 Image 407 Audio 500 Separation unit 501 R1 generation unit 600 Decoding unit (decoding 2 units) 601 R2 generation unit 700 Decoding unit 701 R3 generation unit Aa analog voice signal Va analog Image signal Ad Digital audio signal Vd Digital image signal A Encoded audio signal V Encoded image signal A + V Audio image multiplexed signal R1 Level 1 mode R2 Level 2 mode R3 Level 3 mode F R1 to R3 event that activates generator

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H04N 7/045 H04N 7/04 7/14

Claims (3)

[Claims] 1. From the transmitter side to the receiver side using radio,
In a multimedia wireless communication system that transmits and receives voice and images, the receiver side has the function of constantly monitoring and understanding the reception status,
The receiver has a function to successively transfer the grasped reception status to the transmitter side and a function to receive media sent by switching on the transmission side. The transmitter side can be used when the reception status of the receiver is not good. Is provided with a function of switching and transmitting the transmission media in the order of (image + sound) → image → sound. Depending on the reception status of the receiver,
A multimedia wireless communication system characterized in that the transmission medium is switched in order of (voice) → image → voice. 2. From the transmitter side to the receiver side using radio,
In a multimedia wireless communication system that transmits and receives voice and images, the transmitter side receives the information about the receiving function sent from the receiver side and the transmission medium (image + image) depending on the receiving function of the receiver. Voice), images only, and a function to switch and send only voice. The receiver side is composed of a receiver that receives (image + sound), a receiver that receives images, and a receiver that receives sound.
Each has its own function to send the receiving function to the receiver side, and depending on the receiving function of the receiver side, the transmitter side can switch (image + audio), image, sound and transmission medium and send. A multimedia wireless communication system characterized by. 3. The multimedia wireless communication system according to claim 1, wherein the receiver side is a mobile terminal.