JP2003046593A - Data transmitter, data communication system, and data transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data transmitter and data transmission method that can ensure a prescribed data rate, while reducing communication resources normally in use more than those of a conventional transmitter and method. SOLUTION: The data transmitter for transmitting object data at a first data rate in normal state transmits the object data, including those of retransmission request at a second data rate which is higher than that in the normal state, until a normal reception notice is received, after receiving a re- transmission request notice, so as to ensure the prescribed data rate. The data rate is increased by consuming more communication resources, such as a spread rate in the case of the CDMA communication, an occupied time slot number in the case of the TDMA communication and an occupied frequency bandwidth in the case of the FDMA communication than the ordinary state, but the period is limited to this period resulting in reducing the resource which is normally in use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission device, a data reception device, and a data communication method, and more particularly to a communication data rate guarantee technique.

[0002]

2. Description of the Related Art In the field of data communication, there is a great need for a communication technology capable of guaranteeing a predetermined communication data amount (hereinafter referred to as a data rate) per unit time viewed from a user. One application example of data communication that is required to guarantee a data rate is a real-time distribution / playback service of content information such as music and moving images.

If the content information is distributed from the server to a personal computer, a mobile information terminal or the like via a data communication line at a predetermined data rate, the personal computer, the mobile information terminal or the like receives the distribution of the content information. While
It is possible to reproduce the content in real time satisfactorily without interruption. In an actual data communication environment, data may be erroneously received or lost due to disturbance such as noise. Therefore, it is very common to retransmit data in which reception error and loss are detected between conventional data communication devices. To be done.

In order to guarantee a predetermined data rate even when the data is retransmitted, some conventional data communication apparatuses have a high data rate in which the data rate canceled by the retransmission is added in advance. Send communication data. In addition, other conventional data communication devices increase the error correction range on the receiving side by increasing the error correction information added to user data and transmitted, thereby suppressing the occurrence of retransmission and guaranteeing a predetermined data rate. To do. Alternatively, there is a conventional device that guarantees a predetermined data rate by combining both methods described above.

[0005]

However, in any of the above-described conventional data communication apparatuses, data is constantly transmitted at a high data rate in anticipation of the occurrence of retransmission or by adding a large amount of error correction information. Since it is transmitted, there is a problem that communication resource usage efficiency is low. Specifically, since each communication connection uses a wide band, it is not possible to expect an increase in the number of connections that can be accommodated in the entire communication system.

In view of the above problems, the present invention provides a data transmitting apparatus, a data receiving apparatus, and a data communication method capable of guaranteeing a predetermined data rate while suppressing the amount of communication resources constantly used as compared with the conventional one. With the goal.

[0007]

(1) In order to solve the above problems, a data transmitting apparatus of the present invention is a data transmitting apparatus for sequentially transmitting target data to a partner apparatus at a first data rate, and a retransmission request. Retransmission request notification receiving means for receiving a notification from the partner device, and transmission means for transmitting the target data at a second data rate higher than the first data rate when the retransmission request notification is received. Characterize. (2) Further, the data communication system of the present invention is a data transmission device for sequentially transmitting target data at a first data rate,
And a data communication system comprising a data receiving device for successively receiving the target data, wherein the data receiving device is a judgment means for judging whether or not the target data is correctly received, and a data receiving device for judging that the target data is not correctly received. In this case, the retransmission request notification transmitting means for transmitting a retransmission request notification to the data transmitting apparatus is provided, wherein the data transmitting apparatus receives the retransmission request notification from the data receiving apparatus, and the retransmission A target data transmitting means for transmitting target data at a second data rate higher than the first data rate when the request notification is received,
The data receiving device receives the target data transmitted at the second data rate. (3) Further, the data transmission method of the present invention is a data transmission method for transmitting target data to a partner device, and a first transmission step of transmitting the target data at a first data rate, and a retransmission request notification. It includes a retransmission request receiving step of receiving from the partner device, and a second transmitting step of transmitting target data at a second data rate higher than the first data rate when the retransmission request notification is received. And

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION 1. First Embodiment A data communication system according to a first embodiment is a data transmission device that sequentially transmits target data to a partner device and retransmits the target data in response to a retransmission request from the partner device; Is sequentially received, and the data receiving device has a function of detecting an error in the received data and requesting retransmission to the transmitting side.

The data communication system according to the present embodiment will be described in detail below with reference to the drawings. 1.1 Data Transmission Device The data transmission device according to the first embodiment sequentially transmits target data to a partner device at a first data rate, receives a retransmission request notification and a normal reception notification from the partner device, and retransmits the data. When the request notification is received, the target data indicated in the retransmission request notification is transmitted at a second data rate higher than the first data rate, and then the target data is transmitted until the normal reception notification is received. 2 Send to the other device at the data rate.

The data transmission device is, for example, a CD
It is assumed that the target data is transmitted and the retransmission request notification and the normal reception notification are received by wireless communication of MA (Code Division Multiple Access) system. 1.1.1 Configuration FIG. 1 shows a data transmission device 100 according to the first embodiment.
3 is a block diagram showing the functional configuration of FIG. Data transmitter 1
00 is a transmission data processing unit 110 and a CDMA processing unit 12
0, modem unit 130, wireless unit 140, antenna 160,
And a control unit 170.

The transmission data processing unit 110 includes a target data acquisition unit 111, a target data buffer 112, and a control information addition unit 113, the CDMA processing unit 120 includes an encoding unit 121 and a decoding unit 122, and a modem unit 130. Is
The wireless unit 140 includes a modulator 131 and a demodulator 132.
Includes a transmitter 141 and a receiver 142, and includes a controller 17
0 is a transmission range instruction unit 171, which has a transmission range table 172, a compression transmission instruction unit 173, and a response information identification unit 1.
Including 74.

Specifically, the functions of the CDMA processing unit 120, the modem unit 130, and the radio unit 140 are realized by a programmable DSP (Digital Signal Processor), a signal amplifier, and the like. Further, the transmission data processing unit 11
0, and the control unit 170 is a CPU (Central Processing
Unit) and a memory, etc., and these functions are realized by the CPU executing a program stored in the memory.

FIG. 3 is a timing diagram showing the timing of communication performed between the data transmitting apparatus 100 and the partner apparatus. The data transmitting apparatus 100, in each channel multiplexed with the partner apparatus, 10 × 2 ^k bits (k) (k × 10) per channel for each time slot 302 formed by dividing the radio frame 301 repeated every 10 mS into 15 equal parts. = 1-6) is transmitted to the partner device.

Referring again to FIG. 1, the target data acquisition unit 11
1 obtains target data from a data source (not shown),
It is stored in the target data buffer 112. The control information adding unit 113 adds the control information corresponding to the instruction to the target data within the range of the target data buffer 112 according to the instruction from the control unit 170 for each time slot.
The target data is added by 13 to form target data, and the target data is output to the encoding unit 121 prior to the start of each time slot.

FIG. 4A is a format diagram showing the structure of the transmission data 310 output from the target data acquisition unit 111 to the encoding unit 121 for each time slot. In response to the instruction from the control unit 170, the control information adding unit 113 sets the order number 311 and the data range 3 in the target data 313.
12, the compression notice bit 314, and the CRC 315 are added to form the transmission data 310. Where sequence number 3
Reference numeral 11 is a serial number for identifying a time slot, data range 312 is a range of target data 313 in all target data, and compression notice bit 314 is notice information for giving notice to the partner device that the subsequent time slot is in the compressed communication mode. , And CRC 315 are additional information for error correction for each time slot.

The compressed communication mode is a mode in which communication is performed at a higher data rate than in the steady state, and a method of increasing the data rate will be described in the section of related components. Referring again to FIG. 1, the encoding unit 121
A transmission code representing the input transmission data is generated. The transmission code is configured by using 2 to 3 bits per 1 bit of the transmission data, and has an error correction capability for each bit of the transmission data according to the multiplication factor of the number of bits. As an example, a convolutional code is used. May be.

The encoding unit 121, when the compression notice bit processes the target data for which the compression communication mode is announced,
In accordance with an instruction given from the control unit 170 in the subsequent time slot, a process called puncturing which thins out a part of the bits constituting the generated transmission code is performed to reduce the error correction capability to some extent, but the target data. Increase the data rate of.

The encoding unit 121 has the above-mentioned generated puncture.
The charring transmission code is output to the modulation unit 131.
It The modulator 131 is a channel that represents the input transmission code.
The channel code used to transmit the transmission code.
It is generated according to The channel transmission code is data
For the channel between the transmitter 100 and the partner device
It is configured using a channel code that has been agreed in advance. Previous
For the channel code, 1 bit of the transmission code is 2 ^k(K = 2
~ 9) Represented in bits and correlated with the channel code of another channel
Is defined as no (orthogonal).

Due to the orthogonality of the channel code, the channel
Channel transmission code mixed with other channel transmission code
Then separated by correlating with the channel code
it can. That is, channel multiplexing is possible. Transmission code 1
Channel code length 2 ^kIs called the diffusion rate
Time depending on the channel number and desired data rate
It is changed for each slot.

Since the bit rate of the channel transmission code is constant in the whole wireless communication system, the data rate of transmission data is increased by decreasing the spreading rate. Modulator 1
When the compression notice bit processes the target data for which the compression notice mode has been noticed, 31 uses the channel code of half the length in accordance with the instruction given from the control unit 170 in the subsequent time slot to obtain the data. Double the rate.

Further, the modulating section 131 multiplies the generated channel transmission code by a spreading code sequence selected from a plurality of spreading code sequences having a small correlation with each other, thereby obtaining a signal from another data transmitting apparatus. A transmission signal that can be multiplexed with is generated and output to the transmission unit 141. Transmitter 14
1 amplifies the input transmission signal and transmits it from the antenna 160.

The selected spreading code sequence is notified to the partner device prior to the start of data communication by using a specific spreading code sequence shared by the entire wireless communication system. On the other hand, the receiving unit 142 amplifies the received signal received by the antenna 160 and outputs it to the demodulating unit 132. The demodulation unit 132 demodulates to a reception code by correlating the input reception signal with the spread code sequence used by the partner device to modulate the reception signal, and outputs the reception code to the decoding unit 122.

Decoding section 122 decodes the input received code to restore the received data and outputs it to control section 170.
The received data includes a resend request notification that is returned when the target device is erroneously received by the partner device or is detected as missing, and a normal response that is sent when the target data is correctly received. There is a reception notification, and these two are collectively called response information.

FIG. 4B is a format diagram showing the structure of the response information. The response classification 321 is flag information indicating whether the response information is a retransmission request notification or a normal reception notification, and the response number 322 is an order for identifying a time slot in which an error or a loss is detected in the retransmission request notification. In the normal reception notification, it is a sequence number for identifying a normally received time slot.

The control section 170 controls the overall operation of the data transmitting apparatus 100. In particular, the retransmission control is performed according to the content of the response information identified by the response information identification unit 174, and the encoding unit 121 and the modulation unit 131 are each punctured to instruct to change the spreading factor. As described above, the compressed communication mode is realized by using the puncturing, changing the spreading factor, or both. 1.1.2 Data Structure FIG. 5 shows an example of the target data stored in the target data buffer 112. Start offset column 401
Indicates the bit position for all the transmission data at the head of the transmission data currently stored in the target data column 402.

In the objective data column 402, objective data acquired from the data source is recorded. Further, when the response information indicating the normal reception notification is received, the target data sent by the time slot indicated by the normal reception notification may be deleted. FIG. 6 shows an example of the transmission range information stored in the transmission range table 172. The sequence number column 411 shows the serial number for identifying the time slot, and the transmission range column 412 shows the range of the target data transmitted in the time slot indicated by the serial number.

The transmission range table 172 is referred to by the transmission range designating unit 171 to determine the transmission range in each time slot, and the determined transmission range is recorded. 1.1.3 Operation FIG. 7 is a flowchart showing the entire transmission process performed by the data transmission device 100, and particularly shows the retransmission process and the data rate change process executed under the control of the control unit 170 in detail. There is. The flowchart in the figure is
The transmission process has been described by using variables of untransmitted head, sequence number, compression notice bit, compression instruction flag, retransmission flag, and retransmission request number.

The target data to be transmitted is assumed to have been acquired from the data source by the target data acquisition unit 111 and recorded in the target data buffer 112 prior to the transmission, and detailed description of the acquisition of the target data will be given. Is omitted. The control unit 170 initializes the untransmitted head, the sequence number, the compression notice bit, and the retransmission flag to 0 (step S101).

The transmission range designating unit 171 executes a transmission target data selection process described later to select a range of target data to be transmitted in the next time slot (step S111). The transmission range table 17 stores the serial number for identifying the next time slot and the selected range.
2 is recorded (step S112). The untransmitted head is updated to point to the head of the target data that follows the selected range (step S113).

The control unit 170 temporarily sets the retransmission flag to 0 (step S121), and when the response information identification unit 174 identifies that the retransmission request notification has been received (step S122), sets the retransmission flag to 1 and The response number included in the resend request notification is recorded in the resend request number (step S123). The compression transmission instruction unit 173 records the value of the compression notice bit indicating the presence or absence of compression in the current time slot in the compression instruction flag (step S131),
A compression notice bit updating process, which will be described later, is executed to determine the presence / absence of compression in the next time slot (step S).
132). The control information addition unit 113 calculates a CRC for the sequence number, the data range, the target data of the selected range, and the updated compression notice bit (step S133), and the sequence number, the data range, and the selection. The transmission data including the target data in the range, the updated compression notice bit, and the calculated CRC is configured (step S134).

The encoding unit 121 encodes the transmission data thus constructed into a transmission code, and if the compression instruction flag is 1, further puncturing (step S14).
1). The modulator 131 modulates the encoded or punctured transmission code into a transmission signal with a spreading factor according to the compression instruction flag, and the transmission unit 141 transmits the modulated transmission signal (step S142). . Modulator 13
Specifically, when the compression instruction flag is 1, 1 is modulated with a spreading factor that is half the spreading factor used when the compression instruction flag is 0.

When all the target data has not been transmitted (step S151), the control section 170 sets the sequence number to 1
The number is increased and the process is repeated from step S111 (step S152). 1.1.3.1 Transmission Target Data Selection Process FIG. 8 is a flowchart showing details of the transmission target data selection process. The transmission target data selection process is called from step S111 in FIG. 7 and is executed by the transmission range instructing unit 171.

Here, the number of bits of target data transmitted in a steady state per time slot is represented by R ₀ , and the number of bits of target data transmitted when puncturing and spreading rate are reduced by half is represented by R _1. To do. If the compression notice bit is 0 (step S161), the target data at the bit positions from the untransmitted head to (untransmitted head + R ₀ -1) is selected (step S162). The selected target data is stored in the target data column 402 of the target data buffer 112 at bit positions from (untransmitted head-head offset) to (untransmitted head + R ₀ -1-head offset).

If the compression notice bit is 1, the retransmission flag is referred to, and if it is 0 (step S163), the target data in the bit position from the untransmitted head to (untransmitted head + R ₁ -1) is selected. Yes (step S164). If the retransmission flag is 1, the transmission range recorded corresponding to the retransmission request number is acquired from the transmission range table 172, and the acquired transmission range and the untransmitted head (from the untransmitted head +
The target data in the bit positions up to R ₁ -R ₀ -1) is selected (step S165). Target data buffer 11
The storage positions in 2 are the same as those described above. 1.1.3.2 Compression Notice Bit Update Process FIG. 9 is a flowchart showing details of the compression notice bit update process. The compression notice bit update process is called from step S132 of FIG. 7 and is executed by the compression transmission instruction unit 173.

If the retransmission flag is 1 (step S17)
1), the compression notice bit is set to 1 (step S172),
If the resend flag is 0, if the response information identifying unit 174 identifies that the normal reception notification has been received (step S173), the compression notice bit is set to 0, and otherwise the value of the compression notice bit is maintained. Yes (step S17
4). 1.2 Data Receiving Device The data receiving device according to the first embodiment sequentially receives the target data sent from the partner device at the first data rate or the second data rate, and checks the received data for errors and missing data. If it is determined that there is an error or missing, a retransmission request notification requesting retransmission of the received data is sent to the partner device, and if the retransmission target data is correctly received, a normal reception notification is sent to the partner device. To do.

This data receiving apparatus uses a CDMA (Code Di
By the vision multiple access) wireless communication, the reception of the target data and the transmission of the retransmission request notification and the normal reception notification are performed with the above-described data transmission device. 1.2.1 Configuration FIG. 2 shows a data receiving device 200 according to the first embodiment.
3 is a block diagram showing the functional configuration of FIG. Data receiving device 2
00 is an antenna 210, a radio unit 230, a modem unit 24.
0, CDMA processing unit 250, received data processing unit 260,
And a control unit 270.

The radio section 230 includes a reception section 231 and a transmission section 232, the modem section 240 includes a demodulation section 241 and a modulation section 242, and the CDMA processing section 250 includes a decoding section 2.
51 and an encoding unit 252, the reception data processing unit 26
0 is an error detector 261, a target data buffer 262,
And a target data output unit 263, and the control unit 270 includes a response information generation unit 271 and a retransmission request range register 272.

Specifically, the radio section 230 and the modem section 24
0 and each function of the CDMA processing unit 250 are realized by a programmable DSP (Digital Signal Processor), a signal amplifier, and the like. In addition, the reception data processing unit 26
0, and the control unit 270 is a CPU (Central Processing
Unit) and a memory, etc., and these functions are realized by the CPU executing a program stored in the memory.

The receiving section 231 amplifies the received signal received by the antenna 210 and outputs it to the demodulating section 241. The demodulation unit 241 demodulates the input received signal into a channel transmission code by correlating with a spreading code sequence notified from the data transmitting apparatus 100 before starting data communication, and further, in advance, the data transmitting apparatus. Correlation with the channel code determined with 100 is demodulated into a reception code and output to the decoding unit 251.

The demodulation unit 241 demodulates the target data for which the compression notice bit gives notice of the compressed communication mode, by demodulating using the channel code of half the length in the subsequent time slot. The decoding unit 251 decodes the input reception code into reception data. This decoding process is a process of determining received data that is estimated to represent the received code with the highest probability based on the generation rule of the received code, and as an example, the Viterbi decoding method may be used.

When the compression notifying bit processes the target data for which the compression communication mode has been predicted, the decoding unit 251 determines that the generation rule includes a bit thinning process by puncturing in the subsequent time slot. Make a decision. The decoding unit 251 outputs the decoded reception data to the error detection unit 261.

The error detector 261 detects and corrects the received data by using the CRC included in the input received data. If no error is detected or the error can be corrected, the error detecting unit 261 includes the received data. The target data is recorded in the target data buffer 262 and the control unit 270 is notified of the sequence number included in the received data and the information indicating normal reception. On the other hand, when an error is detected and cannot be corrected, the control unit 270 is notified of the sequence number included in the received data and the information indicating the reception error.

When the error detection unit 261 notifies the control unit 270 of the sequence number and information indicating a reception error, the control unit 270 forms retransmission request notification data including the sequence number,
The data is transmitted to the data transmission device 100 via the encoding unit 252, the modulation unit 242, the transmission unit 232, and the antenna 210, and if there is no reception error in the retransmission request range register 272, it is received in that time slot. Record the range of target data that was previously recorded. On the other hand, when the sequence number and the information indicating the normal reception are notified from the error detection unit 261, the target data range recorded in the retransmission request range register 272 is changed to the target data range normally received in the time slot. Update to be excluded.

When all the target data ranges recorded in the retransmission request range register 272 are deleted by the update, the control unit 270 forms the normal reception notification data including the sequence number, and the encoding unit 252. , Modulator 24
2, the data is transmitted to the data transmitting apparatus 100 via the transmitting unit 232 and the antenna 210. Target data output unit 263
Outputs the received data recorded to a data use destination (not shown). 1.3 System Operation Example FIG. 10 shows a data transmission device 100 and a data reception device 2.
10 is a timing chart showing an operation example of the data communication system configured by 00.

In the figure, the horizontal axis represents the passage of time, the upper part of the transmission data transmitted from the data transmitting device 100, the middle part of the response information returned from the data receiving device 200, and the lower part of the record in the retransmission request range register. The target data range information is shown. The time scale shows the elapsed time in units of one time slot from the start of transmission of the target data, and the serial number of the time slot is shown between the scales.

In this example, it is assumed that the target data of 100 bits at a constant data rate and 200 bits of data in the compressed communication mode can be transmitted per time slot. Data transmitter 100 and data receiver 200
With respect to the above, the items already described individually will be omitted, and the interlocking relationship between both will be sequentially described for each time slot. (1) The data transmission device 100 uses the time slot T0.
(Hereinafter simply referred to as T0), transmission data including a sequence number 0 (hereinafter referred to as transmission data # 0) is transmitted at a normal data rate, and subsequently at T1, transmission data # 1 is transmitted at a normal data rate. To do.

As a result of the CRC check, the data receiving apparatus 200 recognizes at T1 that there is an uncorrectable reception error in the transmission data # 0, and sets the bit range 0 to 99 of the target data that should have been transmitted at T0. Record in the resend request range register. (2) The data receiving device 200 transmits a retransmission request notification to the data transmitting device 100 at T2 in response to the reception error of the transmission data # 0 recognized at T1. The data transmitting apparatus 100 notifies the reception of the resend request notification by T
It is recognized in the middle of 2, and the compression notice bit of the transmission data # 2 is transmitted as 1. (3) The data transmitting apparatus 100 applies the compressed communication mode after T3, and at T3, the 0th to 99th 100 bits transmitted by the transmission data # 0 that received the retransmission request are included in the transmission data # 2. 300 to 39 following the target data
The transmission data # 3 including the target data of 200 bits of 100th bit of No. 9 is transmitted. (4) As a result of the CRC check, the data receiving device 200 recognizes at T4 that the transmission data # 3 has been normally received, and the normally received range 0 to 99 is recorded in the retransmission request range register. Exclude from. As a result, the entire range recorded in the resend request range register is deleted, so that the normal reception notification is transmitted at T5. The data transmitting apparatus 100 recognizes that the normal reception notification has been received in the middle of T5, and transmits with the compression notice bit of the transmission data # 5 set to 0. (5) The data transmission device 100 performs transmission at the normal data rate after T6. 1.4 Summary As described above, the data transmission device 100 applies the compressed communication mode after receiving the retransmission request notification and until receiving the normal reception notification, and the target data requested to be retransmitted The target data for transmission is transmitted at a higher data rate than in the steady state. Since the change of the data rate is notified by the information transmitted in the immediately preceding time slot, the data receiving apparatus 200 can correctly follow the data rate changed by the data transmitting apparatus 100.

In the data communication system including the data transmitting apparatus 100 and the data receiving apparatus 200, the target data including the retransmitted target data is limited to the period from the detection of the reception error of the target data to the confirmation of the normal reception. Is transmitted at a higher data rate than in the steady state, it is possible to reduce the amount of communication resources that are used steadily, improve the use efficiency of communication resources more than before, and suppress the decrease in data rate due to retransmission. it can. 2. Second Embodiment A data communication system according to a second embodiment has a first
Similar to the data communication system in the embodiment, the target data including the retransmission target data is transmitted at a higher data rate than in the steady state, but the period for increasing the data rate is different from that in the steady state.

Hereinafter, description of the items equivalent to those of the first embodiment will be omitted, and different items will be described in detail. 2.1 Data Transmission Device The data transmission device 101 in the second embodiment has the same configuration as that of the data transmission device 100 described in the first embodiment, and details of the compression notice bit update process will be described. The same overall operation is performed except for the differences.

The data transmitting apparatus 101 determines the time of returning to the steady data rate as follows, without receiving the normal reception notification from the partner apparatus. 2.1.1 Compressed Notice Bit Update Process FIG. 11 is a flowchart showing details of the process called and executed in place of the compressed notice bit update process described in the first embodiment in the second embodiment. Is.

If the retransmission flag is 1 (step S18)
1), the compression notice bit is set to 1 (step S18)
2). On the other hand, if the retransmission flag is 0, the start time T _next of the _next time slot is calculated (step S183),
The start time T _org of the (third untransmitted head / an integer value obtained by rounding off R ₀ ) time slot since the start of transmission of the target data is calculated (step S184), and if T _next ≦ T _org (step S185), compression The notice bit is set to 0, and in other cases, the value of the compression notice bit is maintained (step S186).

Here, R ₀ is the number of bits of target data transmitted in a steady state per time slot, and T _org is the number of bits to be transmitted in the next time slot if no retransmission has been made since the start of transmission of target data. This is the start time of the time slot in which the target data to be transmitted was originally transmitted. The process, until the time when the target data is actually transmitted is equal to or earlier than the time originally transmitted,
It means that the compressed communication mode is continued. 2.2 Data Receiving Device The data receiving device 201 according to the second embodiment does not have the retransmission request range register 272, and does not perform the return of the normal reception notification and the process related to the return, and the first embodiment This is the same as the configuration and operation of the data receiving device 200 described in the form. 2.3 System Operation Example FIG. 12 is a timing chart showing an operation example of the data communication system according to the second embodiment. The notation of the timing chart is the same as that of FIG. 10 except that there is no retransmission request range register.

In this example, it is assumed that 100 bits of target data can be transmitted at a constant data rate and 150 bits of compressed data in a compressed communication mode per time slot. The operation of the data communication system will be sequentially described for each time slot. (1) The data transmitting apparatus 101 transmits the transmission data # 0 at the normal data rate at T0, and subsequently transmits the transmission data # 1 at the normal data rate at T1.

As a result of the CRC check, the data receiving apparatus 201 recognizes at T1 that there is an uncorrectable reception error in the transmission data # 0. (2) The data reception device 201 transmits a retransmission request notification to the data transmission device 101 at T2 in response to a reception error of the transmission data # 0 recognized at T1. The data transmitting apparatus 101 indicates that the retransmission request notification has been received.
It is recognized in the middle of 2, and the compression notice bit of the transmission data # 2 is transmitted as 1. (3) Since the data transmitting apparatus 101 applies the compressed communication mode after T3, the transmission data # 3 includes the transmission data # 0, which is the transmission data # 0, and has the numbers 0 to 99.
A total of 150 bits of target data including 0 bits and 50 bits of 300th to 349th subsequent to the target data included in the transmission data # 2 are included.

The data transmission device 101 uses the compression advance notice
Execute the update processing to compress the data included in transmission data # 3
Calculate the notice bit. At this time, the untransmitted head is 350
And T_nextIs calculated as the start time of T4, and T_orgIs
(Integer value rounding down 350/100) th time
It is calculated as the lot, that is, the start time of T3. In FIG.
This T_orgTo T₃₅₀Was shown. T₃₅₀<Start time of T4
Therefore, the compression notice bit of transmission data # 3 is maintained at 1.
Sent. (4) At T4, the data transmission device 101 continues to
Applying the reduced communication mode, the transmission data # 4 is 350-4.
Includes No. 99 150-bit target data. Sending day
Not transmitted when calculating the compression notice bit included in data # 4
500 at the beginning, T _nextIs the start time of T5, T_orgIs T5
Is calculated as the start time of. This T in FIG._orgTo T5
It was shown as 00. T₅₀₀= Start time of T5, so send data
The compression notice bit of data # 4 is set to 0 and is transmitted. (5) The data transmitting apparatus 101 uses the normal data record after T5.
Send it out automatically. 2.4 Summary As described above, the data transmission device 101 needs to retransmit.
Sent at the beginning of each time slot after receiving the solicitation.
If there is no resend of the target data to be sent,
Determine if it was sent in an earlier timeslot
However, if the target data is the original time slot or
Pressure until it is sent in the early timeslot
The destination data for which retransmission was requested by applying the reduced communication mode
Data and untransmitted target data
Send in tarate. To change the data rate,
Being foretold by the information sent in Imslot
Therefore, the data receiving device 201 is
It can follow the changed data rate correctly.

In the data communication system consisting of the data transmitting apparatus 101 and the data receiving apparatus 201, after the reception error of the target data is detected, the retransmission is performed only during the period until the transmission time of the target data catches up with the original transmission time. Since the target data including the target data is transmitted at a higher data rate than in the steady state, the amount of communication resources that are used steadily is reduced, and the use efficiency of communication resources is improved more than before, and the specified data rate is maintained. Can be guaranteed. (Other Modifications) Although the present invention has been described based on the above embodiment, the present invention is not limited to the above embodiment. The present invention also includes the following cases. (1) The present invention may be a method including the steps described in the embodiments. Further, these methods may be a computer program for implementing the method using a computer system, or may be a digital signal representing the program.

The present invention also provides a computer-readable recording medium in which the program or the digital signal is recorded, for example, flexible disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, D.
It may be a VD-RAM, a semiconductor memory, or the like. The present invention also provides a telecommunication line, a wireless or wired communication line,
Alternatively, it may be the computer program or the digital signal transmitted via a network typified by the Internet.

Further, the present invention is a computer system comprising a microprocessor and a memory, wherein the memory stores the program, and the microprocessor operates according to the program stored in the memory. The above method may be realized. Also, the program or the digital signal may be recorded in the recording medium and transferred, or transferred via the network or the like and implemented in another independent computer system. (2) The data transmission device of the present invention may be a wireless communication base station or a wireless communication mobile station in a wireless communication system of the CDMA system. (3) In the data transmitting apparatus of the present invention, when the data rate is doubled by applying the compressed communication mode, when the retransmission request notification is received, if the reception is not received, in the next time slot. The target data that was transmitted at a constant data rate and the target data that received the retransmission request are transmitted in the next time slot by applying the compressed communication mode, and then at the constant data rate again in the subsequent time slots. You may communicate.

According to this structure, switching between the compressed communication mode and the steady mode can be realized more easily than in the above-mentioned embodiment, and the data rate can be guaranteed. (4) In the data transmission device of the present invention, the configuration for increasing the data rate and the control method thereof are not limited to the puncturing and the reduction of the spreading factor exemplified in the above embodiments. For example, as another embodiment, when the used bandwidth is expanded and the data rate is increased by changing the modulation method, an FDMA (Frequency Divis) is used.
Ion Multiple Access) communication in which the number of used bands is increased to increase the data rate, and TDM
In the communication of the A (Time Division Multiple Access) system, the case where the number of used time slots is increased to increase the data rate is also included in the present invention. (5) Further, the example of the above embodiment does not limit the configuration for controlling retransmission itself and the control method thereof. For example, the present invention also includes the case of controlling the retransmission by confirming delivery by a so-called handshake method in which the success or failure of reception is returned for all time slots. (6) In addition, two data communication devices, each of which is a constituent of each of the data transmission device and the data reception device illustrated in the above embodiment, are parallel to each other,
The present invention also includes a case where information including all fields included in the transmission data and the response information exemplified in the above embodiment is transmitted and received, and the data rate control related to the retransmission in both directions is executed in parallel.

According to this configuration, full-duplex communication with a guaranteed data rate is realized.

[0061]

(1) The data transmitting apparatus of the present invention is the first
A data transmission device for sequentially transmitting target data to a partner device at a data rate, wherein a resend request notification receiving means for receiving a resend request notification from the partner device, and the first data when the resend request notification is received. And a transmission means for transmitting target data at a second data rate higher than the rate.

According to this structure, since the data transmitting device transmits the target data at a higher data rate than in the steady state only when the data is retransmitted, the amount of communication resources used constantly is reduced, It is possible to suppress the decrease in the data rate associated with retransmission while improving the use efficiency of communication resources as compared with the related art. (2) In the data transmission device according to (1), the retransmission request notification includes information instructing retransmission target data that the partner device desires to retransmit, and the transmission means includes the retransmission target data and other target data. And may be transmitted at the second data rate.

According to this structure, the same effect as the above (1) can be obtained. (3) In the data transmitting apparatus according to (2), the transmitting means transmits the retransmission target data and the purpose that is transmitted during the retransmission period of the retransmission target data if the retransmission request notification is not received. And the data may be transmitted at the second data rate.

According to this structure, in addition to the effect of (2), when the second data rate is more than twice the first data rate, the data rate when retransmission is not performed is guaranteed. You can (4) In the data transmission device according to (2), the transmission unit calculates the original time when the target data was started to be transmitted if the retransmission request notification was not received, and The target data whose transmission start time is later than the calculated original time may be transmitted at the second data rate.

According to this structure, in addition to the effect of (2), the data rate when retransmission is not performed can be guaranteed regardless of the ratio of the first data rate and the second data rate. . (5) The data transmission device of (2) further includes a normal reception notification receiving unit that receives a normal reception notification from the partner device, and the transmission unit receives the normal reception notification after receiving the retransmission request notification. The retransmission target data and other target data may be transmitted at the second data rate until the reception notification is received.

According to this structure, the same effect as the above (2) can be obtained. (6) The data transmitting device according to any one of (1) to (5) wirelessly communicates with a partner device using a code division multiplexing method, and the transmitting unit performs puncturing.
Alternatively, the target data may be transmitted at the second data rate by reducing the spreading factor or by performing both of them.

According to this structure, the same effect as any one of the above (1) to (5) can be obtained. (7) A data communication system of the present invention is a data communication system including a data transmitting device that sequentially transmits target data at a first data rate, and a data receiving device that sequentially receives the target data. Comprises a determination means for determining whether or not the target data has been correctly received, and a retransmission request notification transmission means for transmitting a retransmission request notification to the data transmission device when it is determined that the target data has not been correctly received, The data transmitting apparatus receives the retransmission request notification from the data receiving apparatus, and, when the retransmission request notification is received, receives the target data at a second data rate higher than the first data rate. Target data transmitting means for transmitting, and the data receiving device receives the target data transmitted at the second data rate. It is characterized in.

According to this structure, the same effect as the above (1) can be obtained. (8) In the data communication system according to (7), the retransmission request notification transmitting unit includes, in the retransmission request notification, information instructing retransmission target data for which retransmission is desired, and transmits the information.
The target data transmitting means may transmit the retransmission target data and other target data at the second data rate.

According to this structure, the same effect as the above (2) can be obtained. (9) In the data communication system according to (8), the target data transmitting unit transmits the retransmission target data and the retransmission target data during the retransmission period of the retransmission target data if the retransmission request notification is not received. Target data may be transmitted at the second data rate.

According to this structure, the same effect as the above (3) can be obtained. (10) In the data communication system according to (8), the target data transmitting unit calculates the original time when the target data was started to be transmitted if the retransmission request notification was not received, and the retransmission purpose is determined. The data and the target data whose transmission start time is later than the calculated original time may be transmitted at the second data rate.

According to this structure, the same effect as the above (4) can be obtained. (11) In the data communication system according to (8), the data receiving device further includes a normal reception notification transmitting unit that transmits a normal reception notification when it is determined that the target data is correctly received, The transmitter is
Further, the normal reception notification receiving unit for receiving the normal reception notification from the data receiving apparatus is provided, and the transmission unit retransmits the data for a period from the reception of the retransmission request notification to the reception of the normal reception notification. The target data and the other target data may be transmitted at the second data rate.

According to this structure, the same effect as the above (5) can be obtained. (12) The data transmitting device according to any one of (7) to (11) wirelessly communicates with the data receiving device using a code division multiplexing method, and the transmitting unit performs puncturing or spreads. The target data may be transmitted at the second data rate by reducing the rate or both.

According to this structure, (7) to (1)
The same effect as each of 1) is obtained. (13) A data transmitting method of the present invention is a data transmitting method for transmitting target data to a partner device, the first transmitting step of transmitting the target data at a first data rate, and a retransmission request notification to the partner. A retransmission request receiving step of receiving from the device, and when the retransmission request notification is received,
A second transmitting step of transmitting target data at a second data rate higher than the first data rate.

According to this structure, the same effect as the above (1) can be obtained. (14) In the data transmission method according to (13), the retransmission request notification includes information instructing retransmission target data that the partner device desires to retransmit, and the second transmission step includes
The retransmission target data and other target data may be transmitted at the second data rate.

According to this structure, the same effect as the above (2) can be obtained. (15) In the data transmission method of (14), the second transmission step is performed during the retransmission period of the retransmission purpose data and the retransmission purpose data if the retransmission request notification is not received. Target data may be transmitted at the second data rate.

According to this structure, the same effect as the above (3) can be obtained. (16) In the data transmission method according to (14), the second transmission step calculates an original time when the target data was started to be transmitted if the notification of the retransmission request was not received, and the retransmission purpose is calculated. The data and the target data whose transmission start time is later than the calculated original time may be transmitted at the second data rate.

According to this structure, the same effect as the above (4) can be obtained. (17) The data transmission method of (14) further includes a normal reception notification receiving step of receiving a normal reception notification from the partner device, and the second transmission step includes: The retransmission target data and other target data may be transmitted at the second data rate until the normal reception notification is received.

According to this structure, the same effect as the above (5) can be obtained. (18) The data transmission method according to any one of (13) to (17) is used in a data transmission device that wirelessly communicates with a partner device using a code division multiplexing method, and the second transmission step is puncturing. The target data may be transmitted at the second data rate by performing the above or reducing the spreading factor, or both.

According to this structure, (13) to (1)
The same effect as each of 7) can be obtained.

[Brief description of drawings]

FIG. 1 is a data transmission device 10 according to a first embodiment.
It is a block diagram which shows the functional structure of 0.

FIG. 2 is a data receiving device 20 according to the first embodiment.
It is a block diagram which shows the functional structure of 0.

FIG. 3 is a timing configuration diagram showing the timing of communication performed between the data transmission device 100 and the partner device.

FIG. 4A is a format diagram showing a structure of transmission data. (B) is a format diagram showing the structure of the response information.

FIG. 5 shows an example of target data stored in a target data buffer 112.

FIG. 6 shows an example of transmission range information stored in a transmission range table 172.

FIG. 7 is a flowchart showing an overall transmission process performed by the data transmission device 100.

FIG. 8 is a flowchart showing details of a transmission target data selection process in the first embodiment.

FIG. 9 is a flowchart showing details of compression advance notice bit update processing in the first embodiment.

FIG. 10 is a timing chart showing an operation example of the data communication system according to the first exemplary embodiment.

FIG. 11 is a flowchart showing details of compression advance notice bit update processing according to the second embodiment.

FIG. 12 is a timing chart showing an operation example of the data communication system according to the second embodiment.

[Explanation of symbols]

100, 101 data transmission device 110 Transmission data processing unit 111 Purpose data acquisition unit 112 Target data buffer 113 control information addition unit 120 CDMA processing unit 121 encoder 122 Decoding unit 130 modem section 131 Modulator 132 demodulator 140 radio section 141 transmitter 142 Receiver 160 antenna 170 control unit 171 transmission range instruction unit 172 Transmission range table 173 Compressed transmission instruction unit 174 Response information identification section 200,201 Data receiving device 210 antenna 230 Radio 231 Receiver 232 Transmitter 240 modem section 241 Demodulator 242 Modulator 250 CDMA processing unit 251 Decoding unit 252 encoder 260 received data processing unit 261 Error detector 262 Target data buffer 263 Objective data output section 270 control unit 271 Response Information Generation Unit 272 Retransmission request range register 301 wireless frame 302 time slots 310 Transmission data 311 Sequence number 312 data range 313 Objective data 314 Compression notice bit 315 CRC 321 Response classification 322 Response number 401 Start offset column 402 Objective data column 411 Sequence number column 412 Transmission range column

Continued front page    F-term (reference) 5K014 AA01 BA06 DA02 FA11 FA12                       HA01                 5K022 EE01 EE14 EE24                 5K034 AA01 CC02 CC05 DD02 EE03                       HH11 MM03 MM08                 5K067 AA13 BB04 BB21 CC10 GG01                       GG11 HH28

Claims (18)

[Claims] 1. A data transmission device for sequentially transmitting target data to a partner device at a first data rate, comprising: a resend request notification receiving means for receiving a resend request notification from the partner device; and the resend request notification received. In this case, the data transmitting apparatus further comprises a transmitting means for transmitting the target data at a second data rate higher than the first data rate. 2. The data transmitting apparatus, wherein the retransmission request notification includes information indicating retransmission target data that a partner apparatus desires to retransmit, and the transmitting unit includes the retransmission target data and other target data. The data transmitting apparatus according to claim 1, wherein the data transmitting apparatus transmits at the second data rate. 3. The data transmitting apparatus, wherein the transmitting means includes the retransmission target data, and the target data transmitted during the retransmission period of the retransmission target data if the retransmission request notification is not received. Is transmitted at the second data rate. 4. The data transmitting apparatus, wherein the transmitting means calculates an original time when the target data was started to be transmitted if the retransmission request notification was not received, and the retransmission target data and the 3. The data transmitting apparatus according to claim 2, wherein the target data whose transmission start time is later than the calculated original time is transmitted at the second data rate. 5. The data transmission device further comprises a normal reception notification receiving unit that receives a normal reception notification from the partner device, and the transmission unit receives the normal reception notification after the retransmission request notification is received. 3. The data transmitting apparatus according to claim 2, wherein the retransmission target data and the other target data are transmitted at the second data rate until the reception of the data. 6. The data transmission device wirelessly communicates with a counterpart device using a code division multiplexing method, and the transmission means performs puncturing, reduces a spreading factor, or both. Accordingly, the target data is transmitted at the second data rate, and the data transmitting apparatus according to any one of claims 1 to 5. 7. A data communication system comprising a data transmitting device for sequentially transmitting target data at a first data rate, and a data receiving device for successively receiving the target data, wherein the data receiving device comprises: The determining means for determining whether or not it is correctly received, and, if it is determined that it was not received correctly, comprises a retransmission request notification transmitting means for transmitting a retransmission request notification to the data transmitting device, the data transmitting device, Retransmission request notification receiving means for receiving a retransmission request notification from the data receiving device, and target data transmitting means for transmitting the target data at a second data rate higher than the first data rate when the retransmission request notification is received. And the data receiving device receives the target data transmitted at the second data rate. Over data communication system. 8. In the data communication system, the retransmission request notification transmitting means includes information instructing retransmission target data desired to be retransmitted in the retransmission request notification, and transmits the retransmission request notification. The data communication system according to claim 7, wherein target data and other target data are transmitted at the second data rate. 9. In the data communication system, the target data transmitting means transmits the retransmission target data and the purpose transmitted in the retransmission period of the retransmission target data if the retransmission request notification is not received. The data communication system according to claim 8, wherein the data is transmitted at the second data rate. 10. In the data communication system, the target data transmitting unit calculates the original time when the target data was started to be transmitted if the retransmission request notification was not received, 9. The data communication system according to claim 8, wherein the target data whose transmission start time is later than the calculated original time is transmitted at the second data rate. 11. In the data communication system, the data receiving device further includes: when it is determined that the target data is correctly received,
A normal reception notification transmitting means for transmitting a normal reception notification; the data transmitting apparatus further comprises a normal reception notification receiving means for receiving the normal reception notification from the data receiving apparatus; and the transmitting means for the retransmission request notification. 9. The data according to claim 8, wherein the retransmission target data and the other target data are transmitted at the second data rate during a period from the reception of the message to the reception of the normal reception notification. Communications system. 12. The data transmission device wirelessly communicates with the data reception device using a code division multiplexing method, and the transmission means performs puncturing, reduces a spreading factor, or both. 12. The data communication system according to claim 7, wherein the target data is transmitted at the second data rate by performing. 13. A data transmission method for transmitting target data to a partner device, comprising: a first transmitting step of transmitting the target data at a first data rate; and a retransmission request for receiving a retransmission request notification from the partner device. A data transmitting method comprising: a receiving step; and a second transmitting step of transmitting target data at a second data rate higher than the first data rate when the retransmission request notification is received. 14. The data transmission method according to claim 1, wherein the retransmission request notification includes information indicating retransmission target data that a partner apparatus desires to retransmit, and the second transmitting step includes the retransmission target data and other target data. The method of transmitting data according to claim 13, characterized in that is transmitted at the second data rate. 15. The data transmitting method, wherein in the second transmitting step, the retransmission target data and the purpose transmitted in the retransmission period of the retransmission target data if the retransmission request notification is not received. The data transmission method according to claim 14, wherein the data is transmitted at the second data rate. 16. In the data transmitting method, the second transmitting step calculates an original time when the target data was started to be transmitted if the retransmission request notification was not received, and 15. The data transmission method according to claim 14, wherein the target data whose transmission start time is later than the calculated original time is transmitted at the second data rate. 17. The data transmission method further includes a normal reception notification receiving step of receiving a normal reception notification from the partner device, and the second transmission step includes the normal reception notification after the retransmission request notification is received. The data transmission method according to claim 14, wherein the retransmission target data and other target data are transmitted at the second data rate until a reception notification is received. 18. The data transmission method is used in a data transmission device that wirelessly communicates with a partner device using a code division multiplexing method, and the second transmission step performs puncturing,
18. The data transmission method according to claim 13, wherein the target data is transmitted at the second data rate by reducing the spreading factor or by performing both of them.