WO2015166627A1

WO2015166627A1 - Transmission terminal apparatus, reception terminal apparatus, and communication system

Info

Publication number: WO2015166627A1
Application number: PCT/JP2015/001834
Authority: WO
Inventors: 友昭水田; 貴之佐々木
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2014-04-28
Filing date: 2015-03-30
Publication date: 2015-11-05
Also published as: JP6238036B2; JPWO2015166627A1

Abstract

A transmission terminal apparatus (1A) for use in a communication system, in which the transmission terminal apparatus (1A) and a reception terminal apparatus (2A) are connected to each other via a transport path and in which a plurality of transport rates can be selected and reception success/failure information of a training signal sent from the transmission terminal apparatus (1A) to the reception terminal apparatus (2A) is used to adaptively control the transport rate, comprises a control circuit that transmits a training signal at a higher transport rate than a previously set transport rate next time and determines and selects a transport rate on the basis of reception success/failure information from the reception terminal apparatus (2A).

Description

Transmission terminal device, reception terminal device, and communication system

The present invention relates to a transmission terminal device, a reception terminal device, and a communication system for a communication system that adaptively selects a transmission rate in accordance with the condition of a transmission path in a transmission method having multirate.

For example, the power line communication (hereinafter referred to as PLC (Power Line Communication)) method uses a spread spectrum method for low-speed PLC (10 kHz to 450 kHz) communication, and the primary modulation method is BPSK (Binary Phase Shift Keying) or QPSK (Quadrature). A plurality of modulation schemes such as Phase Shift Keying and QAM (Quadrature Amplitude Modulation) are used. The PLC method requires a transmission rate control method in which the noise level in the power line that is a communication path varies depending on the usage status of home appliances and follows the variation in the noise level. It was mainly developed by LAN (Local Area Network) method.

For example, in the IEEE 802.11 system, data frame transmission is performed by receiving a radio base station that has transmitted a data frame and an ACK frame that is an acknowledgment for the data transmission from the destination radio terminal apparatus or radio base station. In this case, “successful transmission”. On the other hand, data frame transmission is “transmission failure” when no ACK frame is received.

In the method according to the prior art, when there are a plurality of transmission rates R1, R2, and R3 (ascending order) and transmission is performed at the transmission rate R1, transmission is performed when a plurality of consecutive transmission failures occur. Transmission is performed at a transmission rate R2 lower than the rate R1. On the other hand, when transmission is performed at a transmission rate R2, when transmission is successful a plurality of times, transmission is performed at a transmission rate R1, which is faster than the transmission rate R2, thereby improving efficiency. As described above, in the conventional multi-rate control, the transmission rate is adaptively controlled according to the state of the transmission path based on the success / failure of transmission.

JP 2003-319007 A JP 2000-049663 A

However, when changing to a higher transmission rate, just because transmission was successful multiple times at the original transmission rate does not guarantee the error rate at the changed transmission rate. When the error rate of the high transmission rate to be changed is high, the retransmission rate becomes high, the traffic load is increased, and the efficiency may be lowered.

An object of the present invention is to solve the above-described problems and to provide a transmission terminal device, a reception terminal device, and a communication system including them that can perform adaptive control of a transmission rate efficiently with a small traffic load as compared with the prior art. It is to provide.

In the transmission terminal device according to the first aspect of the invention, the transmission terminal device and the reception terminal device are connected via a transmission path, a plurality of transmission rates can be selected, and training is transmitted from the transmission terminal device to the reception terminal device. A transmission terminal device for a communication system that adaptively controls a transmission rate using signal reception success / failure information, transmits a training signal at a transmission rate higher than a transmission rate set next time, and receives the training signal from the reception terminal device. And a control circuit that determines and selects a transmission rate based on the reception success / failure information.

In the transmission terminal device, the control circuit sets the data size of the training signal to the number of data that can be detected as a bit error rate to be guaranteed at least according to the transmission rate.

Further, in the transmission terminal device, the control circuit widens the transmission interval of the training signal when the reception success / failure information from the reception terminal device fails to receive a plurality of times in succession.

Further, in the transmission terminal device, the reception success / failure information from the reception terminal device includes reception quality, and the control circuit has a reception quality difference obtained by subtracting the previous reception quality from the reception quality is a predetermined threshold value. In this case, the transmission interval of the training signal is shortened.

Still further, in the transmission terminal device, the reception success / failure information from the reception terminal device includes reception quality, and the control circuit has a reception threshold value obtained by subtracting the previous reception quality from the reception quality at a predetermined threshold. When the value is equal to or greater than the value, the transmission rate of the training signal is increased by a transmission rate difference higher than the normal transmission rate difference.

In the transmitting terminal apparatus, the control circuit transmits a plurality of training signals to the receiving terminal apparatus, and determines a transmission rate based on statistical information on the plurality of reception success / failure information from the receiving terminal apparatus. It is characterized by selecting.

Further, in the transmission terminal device, the reception success / failure information from the reception terminal device includes reception quality, and the control circuit transmits a training signal including data of a plurality of different transmission rates to the reception terminal device. An error rate is estimated based on a plurality of reception qualities for data of a plurality of different transmission rates from the receiving terminal apparatus, and a transmission rate is judged and selected based on the estimated error rate.

In the receiving terminal device according to the second invention, the transmitting terminal device and the receiving terminal device are connected via a transmission path, a plurality of transmission rates can be selected, and training is sent from the transmitting terminal device to the receiving terminal device. A reception terminal device for a communication system that adaptively controls a transmission rate using signal reception success / failure information, wherein control is performed so as to transmit reception success / failure information in response to a training signal from the transmission terminal device. It is characterized by comprising a control circuit.

A communication system according to a third aspect of the invention includes the transmission terminal device and the reception terminal device.

According to the communication system including the transmission terminal device according to the present invention, the training signal is transmitted at a transmission rate higher than the transmission rate set next time, and the transmission rate is determined based on the reception success / failure information from the reception terminal device. select. Therefore, adaptive control of the transmission rate can be performed efficiently with a small traffic load as compared with the prior art.

FIG. 1 is a block diagram showing the configuration of the PLC communication system according to the first embodiment. FIG. 2 is a table showing an example of a required SNR table for the transmission rate in the PLC communication system of FIG. FIG. 3 is a diagram illustrating a packet format of a packet signal transmitted from the receiving terminal device of FIG. 1 toward the transmitting terminal device. FIG. 4 is a graph showing a characteristic example of FER (no retransmission) with respect to SNR using the transmission rate used in PLC communication according to Embodiment 1 as a parameter. FIG. 5 is a graph showing a characteristic example of a success rate with respect to an SNR using a transmission rate as a parameter when the spread spectrum method is used in the PLC communication according to the first embodiment. FIG. 6A is a timing chart illustrating an example of PLC communication according to Example 1-1. FIG. 6B is a timing chart illustrating an example of PLC communication according to the embodiment 1-2. FIG. 7 is a timing chart illustrating an example of PLC communication according to the embodiment 1-3. FIG. 8 is a flowchart illustrating the training signal control process performed by the transmission terminal apparatus according to Embodiment 1-4. FIG. 9 is a flowchart illustrating the training signal control process performed by the transmission terminal apparatus according to Embodiment 1-5. FIG. 10 is a timing chart illustrating transmission rate adaptive control processing using a plurality of training signals according to Embodiment 1-6. FIG. 11 is a timing chart illustrating transmission rate adaptive control processing using a training signal including a plurality of transmission rates according to Embodiment 1-7. FIG. 12 is a block diagram illustrating a configuration of a wireless communication system according to a modification.

Hereinafter, the PLC communication system according to the embodiment of the present invention will be described in detail with reference to the drawings. The PLC communication system according to the embodiment of the present invention can also be realized as a PLC communication method or program.

Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component arrangements, connection forms, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

Each figure is a schematic diagram and is not necessarily shown strictly. Moreover, in each figure, the same code | symbol is attached | subjected about the same structural member.

Embodiments according to the present invention will be described below with reference to the drawings. In addition, in each following embodiment, the same code | symbol is attached | subjected about the same component.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a PLC communication system according to the present embodiment. 1, the PLC communication system according to the present embodiment is configured to include a transmission terminal device 1A, a reception terminal device 2A, and a power line 3 that connects them, and the transmission terminal device 1A, the reception terminal device 2A, Packet communication between the two. Here, the transmission terminal apparatus 1A includes a transmission rate control circuit 10A, a transmission frame generation circuit 11, a modulator 12, a PLC transmission circuit 13, a combiner 14, a PLC reception circuit 15, a demodulator 16, And a separation circuit 17. The reception terminal device 2A includes a transmission rate control circuit 20A, a transmission frame generation circuit 21, a modulator 22, a PLC transmission circuit 23, a combiner 24, a PLC reception circuit 25, a demodulator 26, and an SNR. And a measurement circuit 27.

In the transmission terminal device 1A, the reception signal received from the reception terminal device 2A is sent to the PLC reception circuit 15 via the coupler 14 for connecting the power line 3 to the transmission terminal device 1A and the reception terminal device 2A. In the PLC receiving circuit 15, the received signal is amplified and frequency-converted to an intermediate frequency or a baseband frequency. The frequency-converted signal is demodulated by the demodulator 16. The demodulated data signal is sent to the separation circuit 17, where it is separated into received data and a control signal for transmission rate switching control. The transmission rate control circuit 10A sends an ACK signal, which is an acknowledgment signal received from the receiving terminal device 2A, to the transmission frame generation circuit 11.

FIG. 2 is a table showing an example of the required SNR table 31 for the transmission rate in the communication system of FIG. As shown in FIG. 2, the transmission rate and the required SNR are determined for each transmission rate mode in the modulation scheme used. In the present embodiment, for example, as shown in the table 31 of FIG. 2, there are nine transmission rates R1 to R9. Here, the transmission speed increases as the transmission rate R1 is approached, while the transmission speed decreases as the transmission rate R9 is approached.

FIG. 3 is a diagram showing a packet format of a packet signal transmitted from the receiving terminal device 2A of FIG. 1 toward the transmitting terminal device 1A. As illustrated in FIG. 3, the transmission frame generation circuit 21 generates transmission frame (packet format information frame) including “information regarding reception quality” in transmission data (acknowledgment ACK), and sends the transmission frame to the modulator 22.

In the present embodiment, transmitting terminal apparatus 1A transmits a training signal to receiving terminal apparatus 2A at a transmission rate higher than the transmission rate set next time, and transmits data based on an ACK signal from receiving terminal apparatus 2A. The transmission rate is adaptively controlled. In particular, it is assumed that the relationship between the error rate and the SNR of each transmission rate is known in a transmission scheme in which a plurality of transmission rates can be selected based on the modulation degree and the coding rate. When the transmission rate is increased, the error rate that can be guaranteed is estimated based on the transmission success / failure information of the training signal using the test transmission rate, and the transmission rate that satisfies the target error rate is determined by determining the transmission rate. The rate can be selected reliably.

Here, the ACK signal is, for example, any of the following three types.
(1) An acknowledgment signal returned only when reception is successful in the receiving terminal device 2A (Example 1-1) (Note that if an ACK signal is received within a predetermined time after transmitting a training signal, “ "If reception is successful"
(2) ACK signal (embodiment 1-2) including a reception success / failure signal (including information on reception success or reception failure),
(3) An ACK signal (embodiments 1-2, 1-4, and 1-5) including a reception success / failure signal (including information on reception success and reception SNR).

In Example 1-3 described later, the ACK signal may be any as long as the transmission terminal device 1A can determine reception success or reception failure.

Also, in the transmission terminal device 1A, the transmission frame generation circuit 11 generates a transmission frame for a packet signal to be transmitted at the transmission rate by the transmission rate control circuit 10A based on the transmission data, and sends the transmission frame to the modulator 12. The transmitted transmission frame is modulated by a predetermined modulation method for PLC at a transmission rate by the transmission rate control circuit 10 A, and the modulated signal is sent to the PLC transmission circuit 13. The PLC transmission circuit 13 frequency-converts the modulated signal, further amplifies the power to generate a transmission signal, and the transmission signal is transmitted to the receiving terminal device 2A via the coupler 14 and the power line 3.

In the reception terminal device 2A, the reception signal received from the transmission terminal device 1A is sent to the PLC reception circuit 25 via the coupler 24 for using the same transmission path for transmission and reception. In the PLC receiving circuit 25, the received signal is amplified with low noise and frequency-converted to an intermediate frequency or a baseband frequency. The frequency-converted signal is sent to the demodulator 26 and the SNR measurement circuit 27. The frequency-converted signal is demodulated by the demodulator 26 and then sent to the transmission rate control circuit 20A and an external circuit as received data. On the other hand, the SNR measurement circuit 27 is a SNIR (value of a ratio of a received signal level to a noise level at the time of reception (including interference wave power and noise power level, and may not include interference wave power). Signal to Noise and Interference Ratio (hereinafter referred to as SNR (Signal-to-Noise Ratio)) (dB) is measured as reception quality and output to the transmission rate control circuit 20A. A method for measuring SNR is disclosed in, for example, Patent Document 2 and is well known.

The transmission rate control circuit 20A determines whether it is “successful reception” or “reception failure” based on the received data and the SNR, and determines one of the three types of ACK signals according to the embodiment. It is generated and output to the transmission frame generation circuit 21. As shown in FIG. 4, the transmission frame generation circuit 21 generates a transmission frame having a packet format including transmission data (ACK signal) and sends the transmission frame to the modulator 22. The transmitted transmission frame is modulated by a predetermined modulation method for PLC at a transmission rate by the transmission rate control circuit 10A, and the modulated signal is sent to the PLC transmission circuit 23. The PLC transmission circuit 23 frequency-converts the modulated signal, further amplifies the power to generate a transmission signal, and the transmission signal is transmitted to the transmission terminal device 1 </ b> A via the coupler 24 and the power line 3.

FIG. 4 is a graph showing a characteristic example of a frame error rate (FER (Frame Error Rate)) (no retransmission) with respect to an SNR using a transmission rate used in PLC communication according to the present embodiment as a parameter. In the communication system according to the present embodiment, a transmission rate higher than the next-set transmission rate is set and transmitted in the training signal, and when the training signal is successfully transmitted, data is transmitted at the next-set transmission rate. It is characterized by transmitting. As shown in FIG. 4, a high transmission rate R7 has a higher required SNR than a transmission rate R8 to be set and an error is likely to occur. Therefore, if a training signal is successfully transmitted at a high transmission rate R7, the number of packets can be reduced. A transmission rate that secures an error rate with a short number of data bits can be selected. For example, when there is a relationship between the frame error rate and the SNR as shown in FIG. 4, the frame error rate of the transmission rate R8 is 10 ^{−2 in} the transmission line state where the frame error rate (FER) is 0.8 at the transmission rate R7. It is. Therefore, if a training signal of 5 packets is transmitted at the transmission rate R7 and reception is successful even with the training signal of 1 packet, it can be said that the frame error rate of the transmission rate R8 is 10 ⁻² or less. If the error rate under the same condition is measured at the transmission rate R8, it is necessary to receive successfully 99 times or more out of 100 times.

In this embodiment, the bit error rate for which the data size of the training signal is to be guaranteed at least is changed to the number of detectable data according to the transmission rate. As a result, the efficiency of traffic can be improved by limiting redundant training signals to the minimum required size.

FIG. 5 is a graph showing a characteristic example of the success rate with respect to the SNR using the transmission rate as a parameter when the spread spectrum method is used in the PLC communication according to the present embodiment. As is apparent from FIG. 5, the higher the transmission rate, the higher the required SNR. At each transmission rate, the higher the SNR, the higher the success rate.

FIG. 6A is a timing chart illustrating an example of PLC communication according to Example 1-1. As shown in FIG. 6A, the transmitting terminal apparatus 1A transmits data at the current transmission rate R9, and sets a transmission rate R7 higher than the transmission rate R8 set next time as a training signal and transmits it. Then, when transmission of the training signal is successful based on the ACK signal from the receiving terminal device 2A, data is transmitted at the transmission rate R8 set next time. Therefore, the high transmission rate R7 has a higher required SNR than the transmission rate R8 to be set, and an error is likely to occur. The transmission rate that secures the error rate can be selected.

FIG. 6B is a timing chart illustrating an example of PLC communication according to the embodiment 1-2. In FIG. 6B, the transmitting terminal apparatus 1A transmits data at the transmission rate R9, and then transmits a training signal at the transmission rate R7. In response to this, the receiving terminal device 2A returns an ACK signal including reception success / failure information to the transmitting terminal device 1A. When the transmission terminal device 1A confirms “successful reception” by the ACK signal, the transmission terminal device 1A starts data transmission at the transmission rate R8 set next time.

FIG. 7 is a timing chart illustrating an example of PLC communication according to the embodiment 1-3. In FIG. 7, when data is transmitted at a transmission rate R10, a training signal is transmitted continuously at a transmission rate R8 and a plurality of times, and the reception terminal device 2A fails to receive it, the transmission interval of the training signal is set. spread. That is, the number of data transmissions is increased, and the training signal transmission interval is increased. That is, in order to monitor the transmission path state with the reception success / failure information included in the ACK signal, transmission is performed once in several times. However, if there is no fluctuation in the transmission path, it becomes a useless load. Need to be suppressed. It is possible to suppress the load by transmitting a training signal having a higher transmission rate and determining that the current transmission rate is optimal when a failure occurs a plurality of times.

FIG. 8 is a flowchart illustrating the training signal control process by the transmission terminal device 1A according to the embodiment 1-4.

In step S31 of FIG. 8, the transmission interval of the training signal is set to Ttr. In step S32, it is determined whether or not an ACK signal (successful reception) has been received. If YES, the process proceeds to step S33. If NO, Returns to step S32. Next, in step S33, it is determined whether or not the SNR difference obtained by subtracting the previous received SNR from the received SNR in the ACK signal is equal to or larger than a predetermined threshold value SNR _{th +} (for example, 3 dB). While the process proceeds to step S34, when the result is NO, the process returns to step S32. In step S34, the training signal transmission interval TTr is set to be shortened to Ttr-ΔTtr, and the process returns to step S32.

As described above, according to the embodiment 1-4, the receiving terminal apparatus 2A returns an ACK signal including information on the received SNR to the transmitting terminal apparatus 1A in response to the training signal. Here, when the SNR difference obtained by subtracting the previous reception SNR from the current reception SNR is equal to or greater than a predetermined threshold SNR _{th +} , the transmission interval of the training signal is shortened. As a result, the communication system can quickly follow fluctuations in the transmission path by adaptively controlling the transmission rate using a larger number of training signals.

FIG. 9 is a flowchart illustrating training signal control processing by the transmission terminal device 1A according to the embodiment 1-5.

In step S41 of FIG. 9, the transmission rate of the training signal is set to Rtr. In step S42, it is determined whether or not an ACK signal (successful reception) has been received. If YES, the process proceeds to step S43, while NO. If so, the process returns to step S42. In step S43, it is determined whether or not the SNR difference obtained by subtracting the previous received SNR from the received SNR in the ACK signal is greater than or equal to a predetermined threshold value SNR _{th +} (for example, 3 dB). If YES, step S44 is performed. On the other hand, if NO, the process proceeds to step S45. In step S44, the transmission rate Rtr of the training signal is set by increasing it by four steps (transmission rate difference), and the process returns to step S42. In step S45, the transmission rate Rtr of the training signal is set, for example, by two steps (transmission rate difference) as usual, and the process returns to step S42.

As described above, according to Embodiment 1-5, the receiving terminal apparatus 2A returns an ACK signal including information on the received SNR to the transmitting terminal apparatus 1A in response to the training signal. Here, when the SNR difference obtained by subtracting the previous received SNR from the current received SNR is equal to or greater than a predetermined threshold SNR _{th +} , the transmission rate of the training signal is increased. As a result, the communication system can quickly follow large fluctuations in the transmission path by adaptively controlling the transmission rate using a higher-speed training signal.

In the above embodiments 1-4 or 1-5, when the SNR difference obtained by subtracting the previous reception SNR from the current reception SNR is equal to or greater than the predetermined threshold SNR _{th +} , the transmission interval of the training signal is shortened. Or, increase the transmission rate of the training signal. The present invention is not limited to this, and when the SNR difference obtained by subtracting the previous reception SNR from the current reception SNR is equal to or greater than a predetermined threshold SNR _{th +} , the transmission interval of the training signal is shortened, and the training signal The transmission rate may be increased.

FIG. 10 is a timing chart showing adaptive control processing of the transmission rate using a plurality of training signals according to Embodiment 1-6. In the above embodiments 1-1 to 1-5, the transmission rate is controlled based on one ACK signal for one training signal. However, the present invention is not limited to this, and the transmission rate may be controlled based on a plurality of ACK signals for a plurality of training signals as shown in FIG. At this time, statistical information (success rate) of reception success / failure may be calculated based on a plurality of ACK signals, and the transmission rate may be controlled based on the statistical information. For example, if the success rate is 60% to 79%, the transmission rate is increased by two stages, but if the success rate is 80% or more, adaptive control may be performed so that the transmission rate is increased by three or four stages. According to the present embodiment, the error rate can be more accurately guaranteed by selecting the rate based on the statistical information.

FIG. 11 is a timing chart showing transmission rate adaptive control processing using a training signal including a plurality of transmission rates according to Embodiment 1-7. In Embodiment 1-6, as shown in FIG. 11, the training signal may be composed of data of a plurality of transmission rates. For each transmission rate, the receiving terminal apparatus 2A measures the received SNR and returns it to the transmitting terminal apparatus 1A using ACK. The transmission rate control circuit 10A of the transmitting terminal apparatus 1A performs an error based on the received SNR for each transmission rate returned after the above measurement based on, for example, a BER (Bit Error Rate) or FER table for an SNR of a predetermined method. Estimate the rate. Then, for example, the transmission rate may be adaptively controlled so that the transmission rate with the minimum error rate is used as the optimum transmission rate in the next data transmission. Therefore, according to the present embodiment, by inserting data of a plurality of transmission rates into the training signal, the error rate of each transmission rate can be known, the estimation range of the received SNR can be narrowed, and the number of training signal transmissions can be reduced. It is possible to determine the optimum rate.

In Embodiment 1 above, Examples 1-1 to 1-6 have been described. However, the present invention is not limited to this, and Examples 1-1 to 1-6 may be combined with each other. .

(Modification 1)
FIG. 12 is a block diagram showing a configuration of a radio communication system according to this modification. The wireless communication system according to the modified example is compared with the PLC communication system of FIG.
(1) In place of the PLC transmission circuits 13 and 23, respectively, wireless transmission circuits 13A and 23A are provided,
(2) Instead of the

PLC receiving circuits

15 and 25, respectively,

wireless receiving circuits

15A and 25A are provided,
(3) In place of the

couplers

14 and 24, the

duplexers

14A and 24A are provided, respectively.
(4) In place of the power line 3,

antennas

18 and 28 are provided,
Instead of PLC communication, a packet signal is transmitted and received by wireless communication. The other effects are the same.

(Modification 2)
In addition, the transmission terminal apparatus etc. which concern on said embodiment or modification can also be expressed as follows.

That is, in the transmission terminal device according to the above-described embodiment or modification, the transmission terminal device and the reception terminal device are connected via a transmission path, and a plurality of transmission rates can be selected. A transmission terminal device for a communication system that adaptively controls a transmission rate by using reception success / failure information of a training signal to be transmitted to a reception terminal device, and transmits a training signal at a transmission rate higher than a transmission rate set next time. And a control circuit that determines and selects a transmission rate based on reception success / failure information from the receiving terminal device.

As a result, the transmission terminal apparatus can efficiently perform adaptive control of the transmission rate with less traffic load than in the prior art.

Further, in the transmission terminal device control method according to the above-described embodiment or modification, the transmission terminal device and the reception terminal device are connected via a transmission path, and a plurality of transmission rates can be selected. A transmission terminal apparatus control method for a communication system for adaptively controlling a transmission rate using reception success / failure information of a training signal sent from the apparatus to the reception terminal apparatus, wherein the control method includes a transmission rate set next time A transmission step of transmitting a training signal at a higher transmission rate, and a selection step of determining and selecting a transmission rate based on reception success / failure information from the receiving terminal device.

As a result, the same effects as those of the transmission terminal device can be obtained.

Further, the program according to the above-described embodiment or modification is a program for causing a computer to execute the control method of the transmission terminal device.

The comprehensive or specific aspect according to the above embodiment may be realized by a recording medium such as a system, a method, an integrated circuit, a computer program, or a computer-readable CD-ROM. You may implement | achieve in arbitrary combinations of a circuit, a computer program, or a recording medium.

In addition, the embodiment can be realized by arbitrarily combining the components and functions in each embodiment without departing from the scope of the present invention, or a form obtained by subjecting each embodiment to various modifications conceived by those skilled in the art. Forms are also included in the present invention.

1A, 1B

Transmission terminal device

2A, 2B Reception terminal device 3

Power line

10A, 20A Transmission

rate control circuit

11, 21 Transmission

frame generation circuit

12, 22 Modulator 13, 23 PLC transmission circuit 13A, 23A

Wireless transmission circuit

14, 24

Combiner

14A,

24A Duplexer

15, 25

PLC receiving circuit

15A, 25A

Wireless receiving circuit

16, 26 Demodulator 17 Separating circuit 20m Internal memory 27 SNR measuring circuit

Claims

A transmission terminal device and a reception terminal device are connected via a transmission path, and a plurality of transmission rates can be selected, and adaptively using reception success / failure information of a training signal sent from the transmission terminal device to the reception terminal device A transmission terminal device for a communication system for controlling a transmission rate,
A transmission terminal apparatus comprising: a control circuit that transmits a training signal at a transmission rate higher than a transmission rate set next time, and determines and selects a transmission rate based on reception success / failure information from the reception terminal apparatus.
The transmission terminal apparatus according to claim 1, wherein the control circuit sets the data size of the training signal to the number of data that can be detected as a bit error rate to be guaranteed at least according to the transmission rate.
The transmission terminal device according to claim 1 or 2, wherein the control circuit widens the transmission interval of the training signal when the reception success / failure information from the reception terminal device is a reception failure continuously for a plurality of times.
The reception success / failure information from the receiving terminal device includes reception quality,
The control circuit shortens the transmission interval of the training signal when the reception quality difference obtained by subtracting the previous reception quality from the reception quality is a predetermined threshold value or more. The transmission terminal device according to any one of the above.
The reception success / failure information from the receiving terminal device includes reception quality,
When the reception quality difference obtained by subtracting the previous reception quality from the reception quality is equal to or greater than a predetermined threshold, the control circuit sets the transmission rate of the training signal to be higher than the transmission rate difference of the normal setting. The transmission terminal apparatus according to any one of claims 1 to 4, wherein the transmission terminal apparatus is increased by a difference.
The control circuit transmits a plurality of training signals to the receiving terminal apparatus, and determines and selects a transmission rate based on statistical information related to a plurality of reception success / failure information from the receiving terminal apparatus. The transmission terminal device according to any one of 5.
The reception success / failure information from the receiving terminal device includes reception quality,
The control circuit transmits a training signal including data of a plurality of transmission rates different from each other to the receiving terminal device, and generates an error based on a plurality of reception qualities for the data of a plurality of different transmission rates from the receiving terminal device. The transmission terminal apparatus according to any one of claims 1 to 6, wherein a transmission rate is estimated and a transmission rate is determined and selected based on the estimated error rate.
A transmission terminal device and a reception terminal device are connected via a transmission path, and a plurality of transmission rates can be selected, and adaptively using reception success / failure information of a training signal sent from the transmission terminal device to the reception terminal device A receiving terminal device for a communication system for controlling a transmission rate,
A receiving terminal apparatus comprising a control circuit that controls to transmit reception success / failure information in response to a training signal from the transmitting terminal apparatus.
A transmission terminal device according to any one of claims 1 to 7,
A communication system comprising the receiving terminal device according to claim 8.
A transmission terminal device and a reception terminal device are connected via a transmission path, and a plurality of transmission rates can be selected, and adaptively using reception success / failure information of a training signal sent from the transmission terminal device to the reception terminal device A control method of a transmission terminal apparatus for a communication system for controlling a transmission rate,
The control method is:
A transmission step of transmitting a training signal at a transmission rate higher than the transmission rate set next time;
And a selection step of determining and selecting a transmission rate based on reception success / failure information from the receiving terminal device.