JPH10327131A - System and device for decoding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compensate a loss in the continuity of sounds in the case of decoding and reproducing while eliminating the omission and error of transmission information caused by the degradation of communication quality by transmitting the encoded transmission information through a network, where the occurrence of temporary error is estimated, and performing error correction and temporary storage when recording that information. SOLUTION: A radio terminal 1 executes demodulating processing or the like to sound information received at an information reception part 13 through a radio channel and an antenna 11 and performs error correction through an error correction protocol terminal part 15 later. Further, a speaker 21 outputs the sound information, to which a decode part 19 performs decoding processing through a buffer part 17, as sounds. Besides, the buffer part 17 stores the sound information for 5 seconds and sends it to the decode part 19 continuously without interruption, and this sound information is decoded and reproduced by the decode part 19. Thus, even when hand-over is activated by the movement of radio terminal 1 and the radio signal is hit, the sound information is continuously decoded and reproduced without fail.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention secures the communication quality of encoded transmission information when end-to-end communication is performed via a network including a case where an error occurs temporarily. The present invention relates to a decoding method and a decoding method for decoding while performing decoding.

[0002]

2. Description of the Related Art In a conventional decoding method, a network including a case where an error occurs temporarily, for example, a mobile phone or a PHS (Personal Ha) using mobile communication technology.
The transmission information including the voice information of the call and the like transmitted from the NdyPhone System is decoded and reproduced without completely performing the error correction (see FIG. 8).

[0003] That is, when end-to-end communication is being performed between an encoding terminal that performs encoding at the time of transmission and a decoding terminal that receives and decodes, an error occurs in data on the network. However, the decoding unit on the receiving side decodes and reproduces the erroneous information as it is. For this reason, the occurrence of an error has caused the loss of sound (801) or the occurrence of the phenomenon of abnormal noise (802).

[0004]

As described above, as described above,
In the conventional decoding method and decoding apparatus, sound information sent from a network including a case where an error occurs temporarily, that is, information about sound such as music including sound is decoded without performing error correction. Had to be done.

[0005] Therefore, when an error occurs in the data in the network, the decoding unit on the receiving side decodes and reproduces the erroneous information with the erroneous information, and a phenomenon of sound loss (801) or generation of abnormal sound occurs ( 802), which leads to a decrease in service.

As a countermeasure for these, as shown in FIG.
By retransmitting the missing and erroneous parts of the sound information using the error correction technique and decoding the retransmitted sound information (901), it is possible to eliminate the missing and errors of the sound information due to radio quality deterioration. Conceivable. Thereby, the sameness of the sound information of the encoding terminal and the decoding terminal is guaranteed (902, 903).

However, when the above-described error correction technique is applied to a network including a case where an error occurs temporarily, when retransmission of sound information due to error correction occurs due to deterioration of the network quality, for example, the radio environment. ,
During the time (904, 905) required for retransmission, sound decoding and reproduction cannot be performed, so that sound continuity is lost and the service quality is reduced. In particular, unlike a telephone or the like that only needs to be able to communicate, when the sound is music, it becomes a very serious problem.

[0010] As shown in FIG. 10, when the data is accumulated by the buffer in the decoding device, the quality of the network, for example, the radio environment is continuously or intermittently degraded. ) Falls below the speed of decoding and reproducing the sound information (SD1), and when the stored sound information underflows, there is no sound information stored in the buffer, so that the sound information receiving unit receives the sound information and In this case, decoding is sequentially performed in real time, and continuity of sound is lost (1001), resulting in a decrease in service quality.

As shown in FIG. 11, since the storage capacity of the buffer has an upper limit, on the contrary, the receiving speed (SR2) of the sound information is changed to the decoding and reproducing speed (SD2) of the sound information.
, The sound information overflows and is accompanied by a loss (1101), resulting in a decrease in service quality.

[0010] The present invention has been made in view of the above problems, and has as its object to provide a decoding method and a decoding apparatus capable of eliminating transmission information loss and errors due to deterioration of communication quality.

[0011]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, encoded transmission information is transmitted through a network in which a temporary error is expected to occur. This is a decoding method for decoding transmission information, and the point is that error correction is performed when decoding the transmitted transmission information.

According to the first aspect of the present invention, by using an error correction technique, for example, by retransmitting when an error occurs, sound information is lost or erroneously, and "sound is lost" after decoding. Alternatively, the same sound information can be assured between the encoding terminal and the decoding terminal without "being different from the original sound".

According to a second aspect of the present invention, there is provided a decoding system for transmitting encoded transmission information through a network in which a temporary error is expected to occur and decoding the transmission information. In the decoding of the transmitted transmission information, error correction and temporary storage of the transmission information are performed.

According to the second aspect of the invention, in addition to the first aspect, continuity of transmission information is ensured.

Further, the network may include a wireless line, the transmission information may include sound information such as music, and the error correction may be a retransmission of an erroneous frame. good.

According to a sixth aspect of the present invention, there is provided a decoding apparatus for decoding transmission information which is transmitted through a network in which a temporary error is expected to occur and which is encoded on a transmission side. In decoding the transmission information, error correction means for performing error correction processing on transmission information in which an error has occurred, and transmission information obtained through the error correction means are temporarily stored and continuously stored. It is essential to have storage means for outputting.

According to the sixth aspect of the present invention, sound information is lost or erroneously determined by using an error correction technique to cause "loss of sound" or "sound different from original sound" after decoding. In this way, the sameness of sound information between the encoding terminal and the decoding terminal is guaranteed, and continuity of transmission information is ensured.
In addition, assurance of the sameness or continuity of the sound information is realized by appropriately controlling whether or not the transmission information stored in the storage unit is subjected to the decoding process, or by stopping the storage. Is done.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, taking a communication line including a radio line as an example of a network.

FIG. 1 is a block diagram showing the configuration of a wireless terminal 1 including a decoding device to which the decoding system of the present invention is applied. FIG. 1 shows only a main part of a receiving unit, a transmitting unit for transmitting transmission information via a wireless line, a control unit for performing various controls related to the operation of each unit, and an operating unit for performing various inputs during transmission and reception. , A display unit for displaying a transmission / reception state, an operation state, and the like, and a power supply unit for supplying power to each unit are omitted.

The radio terminal 1 shown in FIG. 1 receives sound information transmitted via a radio line by an information receiving unit 13 via an antenna 11 and performs demodulation processing and the like. PIAFS (PHS Intern
et Access Forum Standard)
Error correction is performed according to an error correction protocol such as that described above, and further, decoding processing is performed by the decoding unit 19 via the buffer unit 17, so that the received sound information is output as sound by the speaker 21.

The error correction protocol terminating unit 15 is adapted to transmit an error when an error occurs in a wireless section due to interference or the like when end-to-end sound information is transmitted via radio between an encoding terminal and a decoding terminal. An error correction protocol such as PIAFS is activated to correct an error due to the influence of the wireless environment. Thereby, the same sound information as the sound information transmitted by the encoding terminal provided on the transmitting side can be received by the decoding terminal on the receiving side.

Further, as shown in FIG.
Has a buffer (accumulation) capacity for the accumulation amount T1 (corresponding to 30 seconds), and simultaneously stores the sound information for the accumulation amount T2 (corresponding to 5 seconds) and decodes the accumulated sound information. The transmission to the unit 19 is started. In the decoding unit 19,
The decoding and reproduction of the sound information continuously and continuously transmitted from the buffer unit 17 is started. Thus, for example, even if a handover is activated due to the movement of the wireless terminal 1 and the wireless signal is momentarily interrupted during the time Th, the sound information is continuously decoded and reproduced regardless of the instantaneous interruption.

In the present embodiment, as shown in FIG. 3, the sound information is retransmitted by using an error correction technique (30).
1) It is possible to prevent the loss of sound information due to the deterioration of the quality of the network and the influence of the occurrence of errors. Thereby, the identity of the sound information between the encoding terminal and the decoding terminal can be guaranteed.

As for the continuity of decoding and reproduction of sound information generated by using the error correction technique, a buffer unit 18 having a storage capacity of the storage amount T1 is provided between the information receiving unit 13 and the decoding unit 19. Provided, the sound information is stored amount T
2 (0 ≦ T2 ≦ T1), the decoding is not performed (302), and the decoding / sound reproduction is started when the sound information is stored in the buffer unit 18 up to the storage amount T2. It is possible to do.

As shown in FIG. 4, in order to prevent the underflow of the buffer section 17 due to the deterioration of the radio environment, a reference value of the accumulation amount T3 (0 ≦ T3 ≦ T1) is set in advance and the buffer section 17 is set. When the storage amount of the sound information stored in the storage unit 17 falls below T3, the decoding unit 19 temporarily stops decoding and reproduction (401), and the storage amount of the sound information in the buffer unit 17 is T4 (0 ≦ 0). Decoding and reproduction are not performed (402) until the data is accumulated until T3 ≦ T4 ≦ T1). This makes it possible to compensate for the loss of sound continuity due to the buffer underflow, and to reduce quality degradation.

As shown in FIG. 5, in order to prevent overflow due to buffering, the accumulated amount T5 (0 ≦ T5 ≦
A reference value T1) is set in advance, and the buffer unit 1
When the storage amount of the sound information stored in the storage unit 7 exceeds T5, the decoding unit 19 requests the information reception unit 13 to temporarily stop the storage (501), and the buffer unit 17 When the storage amount of the sound information is different from the reference value T6 (0 ≦
The accumulation is not performed until the value is reduced to (T6 ≦ T5 ≦ T1) (502). As a result, loss of sound information due to a buffer overflow can be prevented.

FIG. 6 shows an example of another embodiment. In the present embodiment, a case is shown in which the transmission speed of the PIAFS continues to be 15 Kbps and is lower than the decoding reproduction speed of 20 Kbps due to intermittent handover / channel switching. In such a case, when the storage amount of the sound information stored in the buffer unit 17 falls below T3 (corresponding to one second), the decoding unit 19 temporarily stops decoding and reproduction (601). ), The storage amount of the sound information is T
Decoding and reproduction are resumed at the point of time when data is accumulated up to 4 (equivalent to 5 seconds) (602).

FIG. 7 shows an example of still another embodiment. In the present embodiment, the case where the transmission speed of PIAFS continues to be higher than the decoding / reproduction speed of 20 Kbps because the wireless environment is error-free and the transmission speed of PIAFS is 29.2 Kbps. In such a case, when the storage amount of the sound information stored in the buffer unit 17 exceeds T5 (corresponding to 29 seconds), the decoding unit 19 issues a flow control request to temporarily stop the storage. Is requested to the information receiving unit 13, and when the storage amount of the sound information is reduced to T6 (corresponding to 25 seconds) in the buffer unit 17, the flow control is released, and the storage in the buffer unit 17 is restarted. .

As described above, in each embodiment,
When end-to-end communication is performed between the encoding terminal on the transmitting side and the decoding terminal on the receiving side in a network including a communication line where a temporary error is expected to occur, any error correction protocol may be used. By performing the error correction and the buffering, “loss of sound” and “occurrence of abnormal sound” caused by decoding and reproduction can be prevented, and “continuity of sound” can be ensured.

In each of the above embodiments, the maximum transmission speed of the communication line is 29.2 Kbps, for example, 20
By transmitting at Kbps, time for accumulating in the buffer is gained.

Further, in each of the embodiments described above, a case where the present invention is applied to a network including a wireless line has been described as an example. However, the present invention is not limited to this and can be applied to any network.

[0032]

As described above, according to the present invention, when transmitting information in a network in which an error is expected to occur, error correction is performed when decoding transmission information.
It is possible to eliminate missing and errors in transmission information due to deterioration of communication quality. Further, by performing the buffering, it is possible to compensate for the loss of sound continuity during decoding and reproduction due to error correction. As a result, the present invention has effects such as improvement of service quality for the user.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a wireless device to which a decoding method according to the present invention is applied.

FIG. 2 is a sequence diagram for explaining a decoding method according to the present invention.

FIG. 3 is a sequence diagram illustrating a decoding method according to the present invention.

FIG. 4 is a sequence diagram for explaining a decoding method according to the present invention.

FIG. 5 is a sequence diagram for explaining a decoding method according to the present invention.

FIG. 6 is a sequence diagram for explaining a decoding method according to the present invention.

FIG. 7 is a sequence diagram for explaining a decoding method according to the present invention.

FIG. 8 is a sequence diagram for explaining a decoding method according to the present invention.

FIG. 9 is a sequence diagram for explaining an operation related to conventional decoding.

FIG. 10 is a sequence diagram for explaining an operation related to conventional decoding.

FIG. 11 is a sequence diagram for explaining an operation related to conventional decoding.

[Explanation of symbols]

 Reference Signs List 1 wireless terminal 11 antenna 13 information receiving unit 15 error correction protocol terminating unit 17 buffer unit 19 decoding unit 20 speaker

Claims (9)

[Claims] 1. A decoding method for transmitting encoded transmission information through a network in which a temporary error is expected to occur and decoding the transmission information, wherein the transmitted transmission information is A decoding method for performing error correction upon decoding of the data. 2. A decoding method for transmitting encoded transmission information via a network in which a temporary error is expected to occur, and decoding the transmission information, wherein the transmitted transmission information is A decoding method characterized by performing error correction and temporary storage of transmission information when decoding. 3. The decoding method according to claim 1, wherein the network includes a wireless line. 4. The decoding method according to claim 1, wherein the transmission information includes sound information. 5. The error correction according to claim 1, wherein when the transmission information is transmitted via a frame, when an error occurs in the frame, the error correction is performed by retransmitting the frame portion in which the error has occurred. Or the decoding method according to 2. 6. A decoding device for decoding transmission information transmitted through a network in which a temporary error is expected to occur and encoded on a transmission side, wherein the transmission information is decoded. In this case, there is provided an error correction means for performing error correction processing on transmission information in which an error has occurred, and a storage means for temporarily storing transmission information obtained through the error correction means and continuously outputting the transmission information. A decoding device characterized by the above-mentioned. 7. The storage unit stores the transmission information until the storage amount of transmission information stored in the storage capacity T1 of the storage unit reaches a predetermined storage amount T2 (0 ≦ T2 ≦ T1). 7. The decoding device according to claim 6, wherein the transmitted information is not subjected to a decoding process. 8. The storage means, when the storage amount of transmission information stored in the storage capacity T1 of the storage means falls below a predetermined storage amount T3 (0 ≦ T3 ≦ T1), The storage amount T4 in which the information storage amount is set in advance
7. The decoding device according to claim 6, wherein the stored transmission information is not subjected to the decoding process until (0 ≦ T3 ≦ T4 ≦ T1). 9. The storage unit, when the storage amount of transmission information stored in the storage capacity T1 of the storage unit exceeds a preset storage amount T5 (0 ≦ T5 ≦ T1), When the information storage amount is the storage amount T6 (0 ≦ T6 ≦ T
7. The decoding device according to claim 6, wherein the accumulation of the transmission information is stopped until the transmission information is reduced to (5 ≦ T1).