JP2002359609A - Error correction rate variable systme - Google Patents

Abstract

PROBLEM TO BE SOLVED: To vary a correction rate for an error correction code by using a means entirely different from that of a conventional system. SOLUTION: A data processing section 9 monitors communication between communication devices at the data link layer level of the Open Systems Interconnection reference model to monitor an occurrence state of data re-transmission processing. A CPU section 10 revises the length of real data and the length of error correction purpose redundant data to be transmitted based on the result of monitor by the data processing section 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable error correction rate system, and more particularly, to a variable error correction rate system in a digital communication transceiver.

[0002]

2. Description of the Related Art In a wireless communication and a part of wired communication, when an error occurs in data on a transmission line or a communication line, it is necessary to correct the error between terminal devices facing each other. When performing error correction using the block coding method, it is necessary to attach redundant data for error correction to transmission data.

[0003]

However, if the length of the redundant data is increased, the strength against errors is increased.
There is a disadvantage that the actual data throughput is low.
For this reason, it is necessary to provide a means for securing the throughput, rather than uniquely lengthening the redundant data (rather than increasing the correction strength).

On the other hand, for example, Japanese Patent Application Laid-Open No. 1-158837 (hereinafter referred to as Prior Art Document 1) and Japanese Patent Application Laid-Open No. 1-15
No. 8838 (hereinafter referred to as Prior Art Document 2) discloses a technique for controlling the coding rate of an error correction code according to the state of channel congestion.
Japanese Patent Application Laid-Open No. 8-223624 (hereinafter referred to as Prior Art Document 4) and Japanese Patent Application Laid-Open No. 8-223624 (hereinafter referred to as Prior Art Document 4) disclose techniques for improving throughput by performing transmission without including an error correction code. −136218
Patent Publication (hereinafter referred to as Prior Art Document 5)
-285147 (hereinafter referred to as Prior Art Document 6)
Discloses a technique for detecting a data length and adding an optimal error correction code corresponding to each data length.

Therefore, an object of the present invention is to control the coding rate of an error correction code, that is, to vary the correction rate of an error correction code by using means completely different from the means disclosed in the above-mentioned prior art documents 1 to 6. An object of the present invention is to provide an error correction rate variable system.

[0006]

SUMMARY OF THE INVENTION To solve the above-mentioned problems, the present invention is a variable error correction rate system in a digital communication transmitting / receiving apparatus, the system comprising: Communication monitoring means for monitoring at the data link layer level of the basic reference model, and data length changing for changing the length of actual data to be transmitted and the length of redundant data for error correction according to the monitoring result of the communication monitoring means Means.

In the present invention, communication between devices is monitored at the data link layer level of the basic reference model of open system interconnection. Then, the length of the actual data and the length of the redundant data for error correction are changed according to the monitoring result. As a result, it is possible to increase the throughput of actual data within a range where the line quality is not deteriorated.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a preferred embodiment of a variable error correction rate system according to the present invention. An object of the variable error correction rate system according to the present invention is to change the length of real data and redundant data so as to increase the throughput of real data within a range where the line quality is not deteriorated. The change of the length is performed by a game apparatus (a slave transmission / reception apparatus 100 described later).
-2) is monitored by its own device (master-side transmitting / receiving device 100-1 described later), and is performed according to the monitoring result.

Referring to FIG. 1, a variable error correction rate system includes a master transmission / reception device 100-1, a slave transmission / reception device (other transmission / reception device) 100-2, and a relay device for transmitting and receiving data between the two devices. And a communication satellite 21 for performing the following. It should be noted that the master transceiver 100-
1 and the slave-side transmitting / receiving apparatus 100-2 have the same internal configuration. In the figure, as an example, the master side transmitting / receiving device 10
The configuration of 0-1 is displayed.

The master transmitting / receiving apparatus 100-1 includes a transmission data control unit 1, an error correction encoder 2, a modulator 3
, A transmitting antenna 4, a received data control unit 5, an error correction decoder 6, a demodulator 7, a receiving antenna 8,
A data processing unit 9, a CPU unit (central processing unit) 10,
Transmission timing generator 11 and reception timing generator 1
2 is included.

The CPU section 10 switches the transmission function to the transmission data control section 1 according to the switching condition from the data processing section 9, changes the transmission timing to the transmission timing generation section 11, and changes the reception timing to the reception data control section 5. The switching of the function and the change of the reception timing are notified to the reception timing generation unit 12.

Here, switching of the transmission function means switching between transmission of actual data and transmission of redundant data, and switching of the reception function means switching between reception of actual data and reception of redundant data. Say. Further, the change of the transmission timing refers to the separation between the actual data to be transmitted and the redundant data, that is, the change in the transmission correction rate. Change.

The transmission data control unit 1 adds correction mode information and test data to transmission data (actual data),
Edit to the desired data length and redundant data length.

Here, the correction mode information is, for example, information obtained by integrating the arrival rate indicating how much information has been correctly transferred to the game device.

The error correction encoder 2 performs processing necessary for error correction, and adds redundant data.

The transmission data and the like generated in this manner are transmitted to the modulator 3, the transmitting antenna 4, the communication satellite 21, the receiving antenna 8 of the slave transmitting / receiving device (other transmitting / receiving device) 100-2, and the demodulation. , And reaches the reception data control unit 5 via the error correction decoder 6.

Slave side transmission / reception device (other transmission / reception device)
The reception data control unit 5 of 100-2 detects the correction mode information and the test data, and notifies the CPU unit 10 of the detection. The error correction decoder 6 performs processing necessary for error correction based on the redundant data. Further, the reception data control unit 5 separates and edits desired actual data and redundant data.

Note that the same processing as described above is performed in the opposite direction, that is, from the slave transmitting / receiving apparatus (other transmitting / receiving apparatus) 100-2 to the master transmitting / receiving apparatus 100-1.

The data processing unit 9 monitors communication between the master and slave transmission / reception devices at the layer 2 level.
Monitors the status of retransmission processing. Then, the monitoring result is notified to the CPU unit 10.

The CPU section 10 of the master transceiver 100-1 determines whether to switch the correction mode based on the monitoring result.

FIG. 2 shows an example of a frame format of data transmitted between the master and slave transmission / reception devices. FIG. 7A shows a frame format at a certain point in time, following a predetermined length of correction mode information 41-1.
Real data 42-1 of length a, redundant data 43- of length b
1, ..., real data 42-n of length c (n is a positive integer),
This indicates that redundant data 43-n having a length d is transmitted in order.

On the other hand, FIG. 2B shows a state in which the lengths of the actual data and the redundant data are changed according to the monitoring result at the layer 2 level. That is, the total length of the actual data and the redundant data does not change, but the distribution of each data length is changed. For example, the actual data 4 in FIG.
2-2 has a longer data length than the actual data 42-1 in FIG. 6A, but the redundant data 43-2 in FIG.
Has a shorter data length than the redundant data 43-1 in FIG.

Next, the layer 2 will be described. OSI (Open System I) organized hierarchically as an international standard for protocols
basic reference model (interconnect: open system interconnection)
ce model) is known. FIG. 3 shows this OSI
3 is a configuration diagram of a basic reference model of FIG.

Referring to FIG. 1, the basic reference model of the OSI is composed of seven layers (layers). The lowermost layer 1 is a physical layer, the upper layer 2 is a data link layer, and the upper layer 3 is a network. The upper layer 4 is a transport layer, the upper layer 5 is a session layer, the upper layer 6 is a presentation layer, and the uppermost layer 7 is an application layer.

The physical layer defines the shape of the connector at the end of the cable used for connection, the number and type of pins, the standard of electric signals, and the like. The data link layer is where the bits (0 or 1) passed by the physical layer are separated as meaningful information units. The network layer is where a route is selected (routed). The transport layer is where the quality of the communication is guaranteed. The session layer is where communication is controlled to maintain order as a conversation. The presentation layer is where character sets and character codes are converted, and further, data structures are converted. The application layer is to provide a service that can actually use the application program of the computer.

In general, a packet defined by a higher-level protocol is handled as data of a lower-level protocol.

The layer 2 used for monitoring in the present invention is the data link layer of the OSI basic reference model.

In order to perform communication, at least (2
Layer 1 and 2 functions are needed (in the sense of performing point-to-point communication). Further, in order to perform 1: N (N is an integer of 2 or more) communication, a function of layer 3 or more is required as necessary.

As described above, according to the present invention, the communication between the master / slave transmitting / receiving apparatus is monitored at the layer 2 level to monitor the state of occurrence of retransmission processing. The length of the redundant data is changed to increase the throughput of the actual data within a range that does not lower the line quality.

[0030]

Next, an embodiment of the present invention will be described. FIG. 4 is a connection diagram between the user terminal and the transmitting / receiving device. As shown in the figure, the user terminal 51 is actually connected to the data processing units 9 of the master side transmission / reception device 100-1 and the slave side transmission / reception device 100-2. The transmission and reception of data are performed between the device and the device.

FIG. 5 is a connection diagram from the master user terminal to the slave user terminal. Referring to the figure, the master-side user terminal 51-1 and the master-side transmitting / receiving apparatus 100
-1 is connected to the data processing unit 9-1 via the transmission line 61,
The data processing section 9-1 and the communication satellite 21 are connected by a transmission line 62, and the communication satellite 21 and the slave transmitting / receiving device 10 are connected.
0-2 is connected to the data processor 9-2 via the transmission line 63, and the data processor 9-2 and the slave transceiver 10
The user terminal 51-2 is connected via a transmission line 64. The transmission paths 61 and 64 may be wired or wireless, and the transmission paths 62 and 63 are wireless. here,
For convenience, the transmission path 6 between the user terminal 51 and the data processing unit 9
1 and 64 are hereinafter referred to as “AA section”, and the data processing section 9
The transmission paths 62 and 63 between them are called "BB section".

In a word, the outline of layer 2 of the present invention is as follows:
That is, "the user data is converted into data suitable for the wireless section and transmitted and received." Hereinafter, the layer 2 will be described.

(1) The user terminal 51 or a user interface (not shown) is connected to the data processing section 9 as described above. The interface of this part is a general-purpose standard and has at least a layer 2 level. Anything above that level is allowed. As an example of a general-purpose standard, HDLC (High level Data Li) is used.
nk Control procedures), X.A.
25.

(2) The data processing section 9 performs termination and conversion of user data. Specifically, general-purpose communication is performed in the AA section, and converted communication is performed in the BB section. The terminating end in the AA section is to transmit and receive data according to a general-purpose communication protocol. After the termination (or performed) processing, the conversion is performed as follows.

The data processing unit 9-1 includes a user terminal 51-1.
Is converted into a data format to be transmitted in the BB section. The data processing unit 9-2 converts data received from the BB section into a data format to be transmitted to the user terminal 51-2.

In other words, in the AA section, HDLC or X.400 is used. 2
Assuming that packet communication such as 5 is performed, the data processing unit 9-1 terminates the data and converts the data into another type of packet communication for performing communication in the BB section.

The reason for terminating the data in the AA section is that errors occur more frequently in the wireless section than in the wired section, and a relatively long time is required for data transmission in the wireless section (particularly in the case of satellite communication). This is necessary. For this reason, it is more advantageous to handle communication so that communication delivery ends in the AA section.

On the other hand, another type of packet communication is performed in the BB section. Here, it has a function for performing packet communication. As an example of those functions, a header (hea)
der) addition, footer addition, FCS
(Frame Check Sequence) and other accompanying information.

(3) Communication in BB Section The BB section also has a protocol for performing communication. Particularly, in performing BB communication in a wireless section, a sequence number (sequence number) is required in order to guarantee a loss of transmission data.
ce number) is required. The sequence number may be, for example, a fixed (cyclic) number.

FIG. 6 is an explanatory diagram of the sequence number.
Referring to the figure, transmission packets (actual data) are numbered from 1 to n and transmitted in the order of transmission. That number is the sequence number.

Based on the sequence number, the data processing unit 9 on the receiving side confirms whether the data is received sequentially or not. If there is any missing data, the data conversion unit (for example, the CPU unit 10) on the transmission side is notified of the sequence number data (packet) that has not been delivered. Then, the CPU unit 10 switches the correction mode (ie, changes the length of the actual data and the length of the redundant data) based on the missing information, and notifies the transmission data control unit 1 of the missing sequence number. I do. Then
The transmission data control unit 1 notifies the other station of the transmission data by sending the unsuccessful sequence number to the transmission data transmitted from the own station apparatus.

(4) Management of delivery acknowledgment information Unreachable data (packets) are managed using the sequence numbers, and resends of unreachable data (packets) are performed.
In addition, the fact that retransmission has been performed is recorded to obtain statistical information per unit time. That is, the statistical information corresponds to the above-described correction mode information.

Taking this statistical information, if it is determined that the number of retransmissions per unit time is large, it is determined that the line quality is poor, and if the reverse is true, it is determined that the line quality is good. In addition, by accumulating this statistical information, time, day, month,
Predict how the line quality will change at the level of the year due to climate, season, etc. In addition, it is also used as a material for determining how much control is required by accumulating statistical information.
It is also possible for the device to automatically determine and change the correction strength. In addition, once you have this statistics,
When the apparatus is restarted at the time of maintenance or failure, it is also possible to set an appropriate correction strength using past information.

[0044]

According to the present invention, there is provided an error correction rate variable system in a digital communication transmitting / receiving apparatus, wherein the communication between the apparatuses is performed at a data link layer level of a basic reference model of an open system interconnection. In order to include a communication monitoring means to monitor in, and a data length changing means to change the length of the actual data to be transmitted and the length of redundant data for error correction according to the monitoring result in the communication monitoring means,
It is possible to control the coding rate of the error correction code, that is, to change the correction rate of the error correction code, by using means completely different from the means disclosed in the above-mentioned prior art documents 1 to 6.

In addition, it is possible to increase the throughput of actual data within a range where the line quality is not deteriorated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a preferred embodiment of an error correction rate variable system according to the present invention.

FIG. 2 is an example of a frame format of data transmitted between master / slave transmitting / receiving apparatuses.

FIG. 3 is a configuration diagram of a basic reference model of OSI.

FIG. 4 is a connection diagram between a user terminal and a transmitting / receiving device.

FIG. 5 is a connection diagram from a master user terminal to a slave user terminal.

FIG. 6 is an explanatory diagram of a sequence number.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transmission data control unit 2 error correction encoder 3 modulator 4 transmission antenna 5 reception data control unit 6 error correction decoder 7 demodulator 8 reception antenna 9 data processing unit 10 CPU unit 11 transmission timing generation unit 12 reception Timing generator 21 Communication satellite 51 User terminal 100-1 Master side transmission / reception apparatus 100-2 Slave side transmission / reception apparatus

Claims (3)

[Claims] 1. A variable error correction rate system in a digital communication transmitting / receiving apparatus, comprising: communication monitoring means for monitoring communication between the apparatuses at a data link layer level of a basic reference model of open system interconnection; An error correction rate variable system comprising: data length changing means for changing the length of actual data to be transmitted and the length of redundant data for error correction in accordance with the result of monitoring by the communication monitoring means. 2. The error correction rate variable system according to claim 1, wherein said communication monitoring means monitors an occurrence state of a data retransmission process. 3. A transmission packet is provided with a sequence number indicating a transmission order, and the communication monitoring means confirms whether or not reception is being performed sequentially based on the sequence number when receiving the packet. 3. The variable error correction rate system according to claim 1, wherein when the packet is missing, the missing information is notified to the data length changing unit.