JP2008219502A - Electric line conveyance communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an electric line conveyance communication system adaptive to various transmission paths and applications. <P>SOLUTION: The electronic line conveyance communication system is provided which superimposes communication data on an electric line 5 having a unique electric role by a carrier to perform communication, the electronic line conveyance communication system is characterized in that it is equipped with a plurality of modems 2, 4 which perform modulation/demodulation on different protocols A, B by carriers with different frequencies and S/N ratio measurement means 27, 47 for measuring S/N ratio of the respective carriers and that the frequencies of the respective carriers are changed to the directions where the S/N ratio of the respective carriers becomes better based on S/N ratio measurement results by the S/N ratio measurement means 27, 47. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrical line carrier communication system in which communication is performed by superimposing communication data on an electrical line having an inherent electrical role by a carrier.

  In conventional power line carrier communication equipment, in order to enable continuous communication without interruption, a method for automatically selecting the optimum transmission speed by changing the modulation speed according to the noise and attenuation of the power line that is the transmission path Etc. are adopted. (For example, see Patent Document 1)

JP 2001-237904 A (FIG. 1 and its description)

  Transmission characteristics (attenuation, noise, impedance, etc.) of the electrical line 5 such as power lines and general wiring have different frequency characteristics depending on the conditions such as line type, line length, branching, etc., and power equipment connected to the same wiring There is a fundamental problem that it is impossible to cope with one type of communication device (modem) that conforms to the transmission path characteristics of all the lines having these frequency characteristics. .

  The use of the high-speed / wide-frequency electric line carrier communication device is various, for example, high-speed Internet for access, VoIP (Voice over IP) telephone, distribution device control, low-speed / high-speed communication in the house. However, there is a fundamental problem that it is impossible to cope with all these application areas with a single communication device (modem).

  A conventional high-speed, wide frequency band electrical line carrier communication device is used to increase frequency utilization efficiency and realize high-speed communication in order to secure a sufficient band in terms of transmission characteristics such as high attenuation and noise fluctuation. In the example of an OFDM (Orthogonal Frequency Multiplexing) modem shown in FIG. 3A, for example, a communication line such as a power line and general wiring, an analog interface unit, an analog / digital conversion unit, a digital processor, It consists of a processor, etc., in the transmission unit, encoding, error correction code addition, interleaving, multiple modulation schemes, IFFT (Inverse FFT: inverse Fourier transform), GI (Guard Interval: guard interval) addition, on the receiving side, GI deletion, F In order to perform processing such as T (Fourier transform), deinterleaving, and decoding, it is necessary to configure a high-performance CPU, high-performance DSP (Digital Signal Processor), and large-capacity memory (ROM / RAM). It takes time for initial setting, synchronization processing, training processing for transmission speed optimization, etc., and it takes a predetermined time until communication is possible, so the startup time until communication is possible is increased, In addition, since the modulation method for determining the minimum communication speed is determined in advance according to the S / N, the selection of the modulation method with a predetermined minimum S / N or less, or communication that always ensures a wide band stably. There was a problem that there was a limit to adaptation to quality.

  On the other hand, an electrical line carrier communication device in a low speed / narrow frequency band can be realized with a simplified hardware configuration compared to an OFDM communication device such as FSK (Frequency Shift Keying), and modem communication starts. However, there is a problem that there is a limit in communication speed that only low speed can be realized, although there is an advantage that the start-up time is short and communication is possible with low S / N.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to obtain an electrical line carrier communication system that can cope with various transmission paths and applications.

  The electric line carrier communication system according to the present invention is an electric line carrier communication system in which communication data is superimposed on an electric line having a specific electric role by a carrier to perform communication on a different protocol depending on carriers of different frequencies. A plurality of modems for modulation / demodulation and S / N ratio measuring means for measuring the S / N ratio of each carrier, and the frequency of each carrier is determined based on the S / N ratio measurement result by the S / N ratio measuring means; The S / N ratio is changed in a direction that improves.

  The present invention relates to a plurality of modems that perform modulation / demodulation on different protocols with carriers of different frequencies in an electric line carrier communication system in which communication data is superimposed on an electric line having a specific electric role by a carrier to perform communication. S / N ratio measuring means for measuring the S / N ratio of the carrier is provided, and the frequency of each carrier is improved based on the S / N ratio measurement result by the S / N ratio measuring means. Since the direction is changed, there is an effect of obtaining an electrical line carrier communication system that can cope with various transmission paths and applications.

Embodiment 1 FIG.
Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS. 1, 2, 3A to 3D, 4A to 4C, and FIGS. 1. Configuration of the present embodiment 2. Functions of this embodiment The operation will be described in the order of this embodiment.

1 is a block diagram showing a configuration example of an electric line carrier hybrid communication device 1 having a plurality of protocols, and FIG. 2 is a configuration example (narrowband / low speed) of the electric line carrier hybrid communication device 1 having a plurality of protocols. However, FIG. 3A is a block diagram showing a protocol of a robust system that enables communication even at low S / N and an example of a configuration of an OFDM modulation / demodulation modem that realizes broadband, high S / N but high-speed communication FIG. 3B is a block diagram showing a modem (an example of a functional configuration of an OFDM modem for realizing broadband, high speed, and high frequency efficiency in the electrical line carrier hybrid communication apparatus 1), and FIG. Modem (OFDM modulation / demodulation model that achieves wideband, high speed, and high frequency efficiency in the electrical line carrier hybrid communication apparatus 1) 3C is a block diagram showing an example of protocol switching means, FIG. 3D is a diagram showing an example of the frame structure of a communication frame between external devices in a hybrid communication device, and FIG. 4A is a protocol A FIG. 4B is a flowchart illustrating the operation of a modem (high-speed) that implements the above (sequence example up to the start of communication of the OFDM modem shown in FIG. 3A), and FIG. 4B is the operation of the modem (high-speed) that implements protocol B (shown in FIG. 3B) FIG. 4C is a diagram illustrating an example of a startup sequence of protocol A and protocol B, and FIG. 5 is an example of frequency characteristics of attenuation of a power line or general wiring. FIG. 6 is a diagram showing an example of setting bands in the default of the occupied frequency band of the modems of the two protocols, FIG. Is a diagram illustrating an example of communication speed and communication quality requested by an application of an external device, FIG. 8 is a diagram illustrating an operation from power-on or reset to optimum bandwidth allocation, and FIG. It is a schematic block diagram at the time of connecting a plurality of target line carrying hybrid communication devices to an electric line.

  1. Configuration of this embodiment

  In FIG. 1, a communication circuit 1 and an electric line 5 having a specific electric role such as a power line of a power system, general wiring (building or home wiring, communication line, broadcasting line, etc.) are connected to a coupling circuit (coupling (Also referred to as a combiner or a coupling device) 8 is used for signal coupling, and communication data as an output of the communication device 1 is placed on the electrical line 5 via the coupling circuit 8 using a carrier (carrier wave). The communication data carried at 5 is input to the communication device 1 via the coupling circuit 8.

  The communication apparatus 1 includes a protocol A modem unit 2 that implements the protocol A, a protocol B modem unit 4 that implements the protocol B, and a protocol switching unit 3 that switches the protocol from the protocol A to the protocol B and switches from the protocol B to the protocol A. I have.

  As described above, the protocol A modem unit 2 for implementing the protocol A, the protocol B modem unit 4 for implementing the protocol B, and the protocol switching means 3 for switching the protocol from the protocol A to the protocol B or from the protocol B to the protocol A are provided. The communication device 1 that performs communication using the electric line 5 as a communication medium is referred to as an electric line carrier hybrid communication device in the first embodiment and each of the first and subsequent embodiments.

  Here, the protocol is defined including a physical layer and a MAC (Media Access Control) layer.

  The protocol A modem unit 2 for implementing the protocol A includes a coupling circuit 21 with an electrical line 5, a D / A (digital / analog) converter 22, an A / D (analog / digital) converter 23, a digital signal processor 24, a digital A CPU 25 for controlling the units and a memory 26 are provided.

  The digital signal processor 24 performs modulation / demodulation signal processing and communication control. The S / N ratio measuring means 27 for measuring the S / N (Signal to Noise) ratio of the carrier, and the S / N ratio measuring means 27 Adaptive modulation means 28 for changing the modulation method according to the N ratio measurement result and frequency changing means 29 for changing the used frequency are provided.

  Similarly, the protocol B modem unit 4 for implementing the protocol B includes a coupling circuit 41 with the electrical line 5, a D / A (digital / analog) converter 42, an A / D (analog / digital) converter 43, and a digital signal processor. 44, a CPU 45 for controlling the digital unit, and a memory 46.

  The digital signal processor 44 performs modulation / demodulation signal processing and communication control, and the S / N ratio measurement means 47 for measuring the S / N ratio of the carrier and the S / N ratio measurement result by the S / N ratio measurement means 47 are shown in FIG. In response to this, an adaptive modulation means 48 for changing the modulation system and a frequency changing means 49 for changing the use frequency are provided.

  The protocol switching unit 3 has a function of switching between the protocol A modem unit 2 and the protocol B modem unit 4 according to the S / N ratio value measured by each S / N measurement unit and the instruction from the external interface unit 6.

  The external interface unit 6 is a data interface unit with an external device (not shown). The external interface unit 6 indicates an interface with a general external device such as an Ethernet (registered trademark) interface or a serial interface, and is connected to the protocol switching means 3 and the respective protocol modems 2 and 4 for transmission and reception with the external device. It has a function of transmitting and receiving data and control data to and from the modems 2 and 4 of each protocol via the protocol switching means 3.

FIG. 3C shows the internal configuration of the protocol switching means 3 described above.
In FIG. 3C, the protocol switching unit 3 includes a transmission / reception buffer 31 connected to the external interface 6, and a transmission / reception buffer remaining capacity / increase / decrease monitoring function unit 32 that monitors changes in overflow / remaining capacity / buffer increase / decrease in the transmission / reception buffer 31. The communication band monitoring unit 34 for monitoring the communication band of the protocol A modem 2 and the protocol B modem 4, the optimum frequency selecting unit 35 for selecting the optimum frequency of the protocol A modem 2 and the protocol B modem 4, and the optimum frequency selecting unit 35 are selected. The protocol switching instruction unit 33 is used to switch the communication frequency, communication speed, and communication time of the protocol A modem 2 and the protocol B modem according to the optimum frequency and the control information monitored by the communication band monitoring unit 34.

A plurality of electric line carrier hybrid communication devices 1 to 1n of the present invention are connected to the electric line 5 via coupling devices 8 to 8n, and FIG. 1 shows among the plurality of electric line carrier hybrid communication devices. Only one electric line carrier hybrid communication device 1 shows the internal configuration, and the other electric line carrier hybrid communication devices 1 to 1n have the same configuration and function as the electric line carrier hybrid communication device 1. (See Figure 9)
In addition, as illustrated in FIG. 9, when there are a plurality of electric line carrier hybrid communication devices, for example, one of them may be a master and the other may be a slave. : 1 or 1: N, and the essence of the present embodiment is not affected by the access method.

  2. Functions of this embodiment

  The electric line carrier hybrid communication apparatus 1 shown in FIG. 1 includes a protocol A modem unit 2 and a protocol B modem unit 4.

  The protocol A modem unit 2 in FIG. 1 implements, for example, a protocol (including hardware or software and both) for realizing high-speed (for example, a physical speed of several hundred Mbps) and broadband (for example, several tens of MHz) communication performance. The internal configuration of the digital signal processor 24 is, for example, the function of the digital unit of an OFDM (Orthogonal Frequency Division Multiplexing) modem 200 that realizes high-speed communication using a wideband, high frequency efficiency modulation / demodulation scheme as shown in FIG. It consists of a high-performance DSP (digital signal processor) and a high-speed CPU. This is an example, and other modulation schemes may be used. The method using the DSP is an example of implementation, and can be realized by mixing with a CPU or hardware.

  The protocol B modem unit 4 shown in FIG. 1 has a low-speed / low-frequency utilization efficiency, for example, but can easily realize a modulation / demodulation configuration, speeding up the synchronization pull-in time, and shortening the apparatus start-up time. A modem that implements the protocol. FIG. 2 shows a configuration example of the protocol B modem unit 4. FIG. 3B shows a configuration example of an FSK (Frequency Shift Keying) modem 300 as one of them. This is an example, and other modulation schemes may be used.

  FIG. 3A is an example of an OFDM modulation / demodulation modem that requires broadband, high frequency utilization efficiency, and high S / N, but realizes high-speed communication. In FIG. 3A, the transmission unit 210 of the OFDM modem 200 receives baseband data. As an input function to improve communication speed, error rate, frequency utilization efficiency, etc., interleaving 215 for randomizing the sequence of transmission data to prevent burst errors on the transmission path, FEC for performing data error correction (Forward Error Correction: Error Correction) 214, Modulation 213, IFFT (Inverse Fast Fourier Transform) 212 for converting data on the frequency axis to the time axis, GI (Guard Interval) addition 211 for multipath countermeasures, etc. It has the ability. For the modulation, for example, QAM (Quadrature Amplitude Modulation) modulation that performs modulation with amplitude / phase information with high frequency utilization efficiency is often used.

  On the other hand, the receiving unit 220 passes the A / D (analog / digital conversion) unit from the RF (wireless) unit, the GI deletion 221 added by the transmission unit, and the FFT (Fast) that converts the data on the time axis into the time axis. (Fourier Transform) 222, equalization 223 for channel correction, demodulation 224, deinterleaving 225 for converting interleaved data rearranged by interleaving into original data, and the like. In order to realize these functions, various types of digital signal processing are required, and a configuration such as a digital signal processor, a CPU, and a memory is required.

  In FIG. 1, the modem unit for realizing the protocol A and the protocol B is configured by a DSP (Digital Signal Processor) and a CPU, but the protocol B modem unit 4 may have another circuit configuration.

  Although FIG. 1 shows a configuration in which two modems of protocol A and protocol B are implemented, the modem may be configured by two or more modems.

  The external interface unit 6 in FIGS. 1 and 2 is a data interface unit with an external device. This indicates an interface with a general external device such as an Ethernet (registered trademark) interface or a serial interface, and is connected to the protocol switching means 3 and each protocol modem, and the protocol switching means transmits / receives data and control data to / from the external device. 3 has a function of transmitting / receiving to / from a modem of each protocol.

  FIG. 3A and FIG. 3B show examples of the protocol A modem 2 and the protocol B modem 4, but this is an example, and it is constituted by a modem realized by a plurality of protocols having means capable of changing the carrier frequency. May be.

FIG. 5 shows a conceptual diagram of the frequency characteristics of attenuation in a power supply line or general wiring as an example of transmission line characteristics.
The attenuation characteristic is not flat like a coaxial cable terminated with a constant termination resistance, but has a frequency-dependent variation and a deep notch. Such frequency characteristics vary depending on the observation place and dynamically change with time. Corresponding to such transmission characteristics, adapting to the optimal frequency characteristics, ensuring the maximum communication performance, and stably securing the bandwidth required by the external device to the modem that fits such a transmission path This is a problem on the transmission line.

FIG. 7 shows an example of communication quality required by the upper application.
For example, as an example of an application for transmission on a power line or general wiring targeted by the present invention, a power line or other general wiring connected to the power line is used as a communication line for wiring equipment control or general access system. VoIP communication and the like are given as typical examples of Internet and voice communication to be used.
For example, in the case of power distribution device control, a fast startup time is required, but the communication speed may be low. In the case of the Internet, a communication speed of several hundred kbps to several Mbps is required, but the activation time may be several minutes. In VoIP, the communication speed may be as low as several hundred kbps, but the delay time is limited.

  The protocol switching means 3 in FIG. 1 and FIG. 2 has the above-described (1) dynamically changing power line / general wiring transmission characteristics, that is, the communication speed of the transmission line, and (2) dynamically changing request from an external device. In order to adjust the application band and fluctuating traffic, the purpose is to control the optimum communication speed and the optimum frequency by adapting to the transmission line characteristic peculiar to the power line / general wiring.

  3. Operation of this embodiment

  <1> First, <operation for shortening start-up time by start-up sequence control after power-on> will be described.

  As shown in FIG. 4A, for example, the startup sequence until the start of communication includes power-on of the device (ST1), device initialization (CPU startup, DSP startup, memory initialization, communication program startup) (ST2A), frequency Search (ST3), synchronization acquisition at selected frequency (ST4A), training for each subcarrier (transmission power control, SINR (signal-to-interference noise power ratio) measurement bit loading (assignment of number of bits by selecting modulation scheme for each carrier) ) Value determination, etc.) (ST5), bit loading information exchange (ST6) between the communication devices, etc., the communication is started (ST7), so it takes time to start the communication.

  On the other hand, for example, in distribution system equipment control at the time of a power failure, a control time of about several hundred ms (milliseconds) to several s (seconds) may be required, and high-speed device activation is desired.

  FIG. 3B is an example of an FSK modem as an example of a modem that functions at a narrow bandwidth and a low communication speed. However, the transmission side has a transmission data memory 303 for storing data from the baseband unit, digital data '0', Frequency frequency generation 302 for converting “1” into frequency, transmission filter 301 for band limitation of the spectrum of the transmission waveform, the reception side performs reception filter 304 for band limitation, frequency detection 305, digital data conversion Functions such as a comparison judgment 306 for the purpose.

  When the FSK modem realizes a low speed of about several hundreds of kbps, the apparatus configuration includes a memory, a frequency generator, a PLL (Phase Locked Loop) for frequency synchronization, a transmission filter, a reception filter, and the like shown in FIG. 3A. Compared to a modem, it does not require a high-performance CPU and DSP, and can be configured with simple hardware and a startup sequence.

  In this case, for example, as shown in FIG. 4B, the startup sequence until communication is started includes turning on the device (ST1), initializing the device (CPU activation, memory initialization) (ST2B), and synchronous pull-in ( Since it is possible to start communication (ST7) upon completion of ST4B) and the like, the time from power-on to communication start is very short, and for example, it can be applied to distribution system equipment control at the time of power failure .

  FIG. 4C shows a time chart from the start of communication to the start of communication of the present communication apparatus incorporating the modems of protocol A and protocol B having different activation times from power-on to communication start. Protocol B has a short activation time and starts low-speed communication at the beginning.

  Next, when communication data of a certain band is received, the protocol A modem unit starts up, so that communication is performed using the band while adjusting the communication band so that the band is secured for the entire apparatus.

  Here, the internal configuration and operation of the protocol switching means 3 will be described with reference to FIG. 3C.

  The protocol switching means 3 includes a transmission / reception buffer 31 connected to the external interface 6, a transmission / reception buffer remaining capacity / increase / decrease monitoring function 32 for monitoring changes in overflow / remaining capacity / buffer increase / decrease in the transmission / reception buffer 31, and protocol A modem 2. And the communication band monitoring unit 34 for monitoring the communication band of the protocol B modem 4, the optimum frequency selection 35 for selecting the optimum frequency of the protocol A modem 2 and the protocol B modem 4, the optimum frequency selected by the optimum frequency selection 35, and the communication band According to the control information monitored by the monitor 34, a protocol switching instruction unit 33 that switches the communication frequency, communication speed, and communication time of the protocol A modem 2 and the protocol B modem is provided.

  In FIG. 3C, the communication band monitoring unit 34 always transmits the communication speed measured by the S / N measuring unit 27 or the bit error or communication rate measuring unit 47 of the protocol A modem unit 2 and the protocol B modem from the external device. Monitor whether the data speed is met.

  For example, in the case of the wiring device control, for the startup sequence from the time of the power failure of the power distribution device, the power distribution device control device serves as an external device via the external interface 6 of the electrical line carrier hybrid communication device 1 of the present embodiment. Shall be connected.

  At the time of recovery from a power failure, as described above, both the protocol A modem 2 and the protocol B modem unit 4 are controlled independently until the start of communication according to the startup sequence.

  The communication band monitoring unit 34 constantly monitors the communication speed measured by the S / N measuring unit 27 or the bit error or communication rate measuring unit 47 of the protocol A modem unit 2 and the protocol B modem for communication fluctuation on the transmission line side. On the other hand, as shown in FIG. 3D, for example, as shown in FIG. 3D, a method for determining a communication speed from frame type data in a communication frame received from an external device, or a transmission / reception buffer remaining capacity / increase / decrease monitoring unit 32 constantly monitors the remaining capacity of the transmission / reception buffer 31 and the increase / decrease in data. If “communication band of transmission path”> “communication speed of external device”, the communication band can be secured. It is determined whether the communication band can be secured by always comparing the two.

  Regarding the determination of the carrier frequency band, there are a case where a constant frequency is determined in advance by initial setting, and a case where optimum frequency selection described below is performed and the information is used as an initial setting value at the next start.

  As described with reference to FIG. 4C, the protocol B modem unit 4 that is first activated after the power is turned on and secures the band is monitored by the communication band monitoring unit 34 while monitoring the requested communication speed of the external device and the speed on the transmission line side. Start communication. Thereafter, when the protocol A modem unit 2 is started up and a wider band can be secured, transmission / reception of communication data is started.

  As a result, it is possible to effectively secure a bandwidth even when communication data having different communication speeds are communicated with a temporal difference as in distribution device control.

  <2> Next, <Securing the maximum bandwidth by selecting the optimum frequency> will be described with reference to FIG. 3C.

  The protocol switching unit 3 receives the S / N ratio values measured by the protocol A modem unit 2 and the protocol B modem unit 4 by the respective S / N measurement units, while communicating from an external device as described above. For example, as shown in FIG. 3D, the speed is determined by a method of determining the communication speed from the frame type data in the communication frame received from the external device, or the transmission / reception buffer remaining capacity / increase / decrease monitoring unit 32 always This is done by monitoring the remaining capacity and changes in data. If “communication band of transmission path”> “communication speed of external device”, the communication band can be secured. It is determined whether the communication band can be secured by always comparing the two.

  Here, if “transmission path communication band” <“communication speed of external device” occurs, the following factors are assumed.

(1) Due to fluctuations in transmission path characteristics (deterioration of S / N ratio due to increase in noise, decrease in impedance due to power equipment connected to the same transmission path, increase in transmission loss due to branching, influence of multipath, etc.) The communication speed of the external device due to the decrease in the communication band due to the deterioration of the S / N ratio on the transmission line side.
(2) Communication data from an external device is received by the application requesting a wider bandwidth (higher communication speed).
(3) The communication traffic of the external device has increased (such as an increase in the number of communication), and buffer overflow has occurred, making it impossible to secure a communication band.

  On the other hand, when the characteristics of the power line are taken into account, the factors of the transmission characteristic fluctuation as described in (1) are large. The present invention searches for a frequency band in which S / N can be secured, and assigns bands of protocols A and B to a frequency band estimated to obtain the lowest communication band.

  FIG. 8 shows a flowchart from the time of power-on or reset to the optimal bandwidth allocation.

  Each of the protocol A modem and the protocol B modem searches for the initially set frequency (ST81A) (ST81B) and performs frequency setting (ST82A) (ST82B). Each protocol A modem and protocol B modem starts synchronous control by this frequency (ST83A) (ST83B).

Next, each protocol A modem and protocol B modem measure the S / N ratio (ST84A) (ST84B).
ST84A and ST84B, which are S / N ratio measurement functions, are functions for measuring the S / N ratio (signal power to noise power ratio), and are obtained by an algorithm that subtracts noise power from received signal power.

  Next, in ST85A and ST85B, in each protocol A modem and protocol B modem, the number of bits per carrier and carrier frequency that are theoretically determined according to the S / N ratio and the modulation method of each protocol A modem and protocol B modem, etc. The communication speed is estimated by calculating the communication speed from

  Since the communication speed, that is, the number of bits allocated corresponding to each carrier, is determined according to the S / N ratio according to each modulation method in each protocol A modem and protocol B modem, in each protocol A modem and protocol B modem, When the S / N ratio information of each modem is compared with a threshold value set in advance, the S / N ratio is good, the required communication speed is satisfied, and the communication band required by the external device can be secured. The communication frequency is determined and communication is started (ST86A) (ST86B).

  In each protocol A modem and protocol B modem, if the S / N ratio is poor, it is possible to determine that the transmission path state is also poor and the required communication speed is not satisfied in the frequency band. When the required bandwidth is not satisfied, the S / N ratio information of each protocol A modem and protocol B modem is exchanged (ST87), and the frequency is sequentially moved by a certain arbitrary algorithm, thereby requesting the external device. The frequency band that can stably secure the maximum S / N ratio for a certain period of time is found while comparing with the band to be transmitted.

  In ST88, in each protocol A modem and protocol B modem, the communication speed can be calculated according to each modulation method from the obtained S / N ratio value. Therefore, the modem (protocol) that can secure the communication speed (bandwidth) is selected. The use efficiency can be increased.

  Furthermore, each protocol modem has a means for masking the carrier, and if it is necessary to assign the same frequency band to be used between the protocol modems, the lower priority modem masks its carrier. In addition, it has a function of preferentially allocating a carrier to a high-priority modem.

  FIG. 6 shows an example of the set bandwidth in the default of the occupied frequency band of the modems of two protocols A and B, for example.

FIG. 5 shows an example of attenuation frequency characteristics of a power supply line or general wiring as an example.
The attenuation characteristics are not flat but often have frequency-dependent fluctuations and deep notches. Such frequency characteristics vary depending on the observation place and dynamically change with time. Corresponding to such transmission characteristics, adapting to the optimal frequency characteristics, ensuring the maximum communication performance, and stably securing the bandwidth required by the external device to the modem that fits such a transmission path This embodiment, which is a problem, includes a modem that implements a plurality of protocols corresponding to a plurality of communication speeds and communication qualities, and realizes a function capable of selecting an optimum modem modulation method corresponding to a frequency characteristic. It solves the problem.

  <3> Next, <flow control as a communication speed control method> as an interface with the external apparatus side will be described with reference to FIG. 3C.

  In the protocol switching means 3, the operation to be solved by the present embodiment for the following items (2) and (3) as a factor when “communication bandwidth of the transmission path” <“communication speed of the external device” occurs. Will be described.

(2) Communication data from an external device is received by the application requesting a wider bandwidth (higher communication speed).
(3) The communication traffic of the external device has increased (such as an increase in the number of communication), and buffer overflow has occurred, making it impossible to secure a communication band.

  In the above two cases, a negotiation function such as limiting transmission data is required for the external device side.

  This operation will be described below.

  The size of the transmission / reception buffer 31 to be mounted is not less than the maximum frame size and is provided as a buffer for storing a plurality of frames. Even if a plurality of frames are sent simultaneously, they are stored in the transmission / reception buffer 31 so that the bandwidth can be secured on the transmission line side and transmission processing to the protocol A modem 2 or the protocol B modem 4 can be performed sequentially. Transmission processing is performed. However, the built-in memory capacity is limited, and when considering the delay in VoIP, etc., the maximum size is limited (generally several Mbytes), and many frames are sent simultaneously, If the transmission process is not in time, the accumulated frame capacity exceeds the transmission / reception buffer memory capacity, and a frame that cannot be stored cannot be processed.

  In such a case, a frame that comes later is not put into the buffer, and the buffer overflows, resulting in congestion that makes communication impossible.

In order to solve this problem, the present invention provides a sequence for requesting the transmission side device to stop transmission, and then requesting transmission to be resumed when a certain amount of free memory space is generated. In this way, the data traffic volume is controlled.
In order to perform such flow control, a dedicated command for performing flow control is prepared, and a frame is provided exclusively for flow control. For example, a transmission / reception frame includes information such as a dedicated address, a dedicated code, a communication interruption time, etc., which are arbitrarily determined at a destination address, and realizes flow control by interrupting transmission.

  The first embodiment is (1) In order to adapt to various applications (communication speed, operating frequency, start-up time, delay, etc.) to which an electric line carrier communication device such as a power line or general wiring is applied, 1 It is difficult to cope with a single protocol communication system (modem), and (2) one protocol communication system to adapt to transmission characteristics (access system, home, domestic, overseas, etc.) on various lines. In order to solve the problem that it is difficult to cope with (modem), in communication devices equipped with a plurality of protocols (including physical layer and MAC layer), transmission characteristics with various required applications and various frequency characteristics In addition, it is an object of the present invention to obtain an apparatus that can cope with various transmission paths and applications by having means adapted to be optimally adapted.

  In the first embodiment, as described above, the communication data is superimposed on the electric line such as the power line and the general wiring, and the data is assigned to the single or plural carriers on the frequency axis for communication. In a line carrier hybrid communication apparatus, a plurality of modems that handle modulation / demodulation on different protocols depending on carriers on different frequency axes, S / N ratio measuring means for measuring the S / N ratio of the carrier received at each modem, Means for changing the carrier frequency with which each modem communicates, means for measuring the optimum S / N ratio based on the S / N ratio measured at each modem section, and switching between a plurality of modem sections, and an external interface 1 is an electric line carrier hybrid communication device having a section. (Here, the protocol is defined including the physical layer and the MAC layer.)

  In other words, the first embodiment is an electric line carrier communication method in which communication data is superimposed on an electric line having a specific electric role by a carrier for communication, and modulation / demodulation is performed on different protocols by carriers of different frequencies. And a S / N ratio measuring means for measuring the S / N ratio of each carrier, and the frequency of each carrier is determined based on the S / N ratio measurement result by the S / N ratio measuring means. The S / N ratio is changed so as to be improved, and the modem having a lower frequency among the carriers is used as a modem for electrical control data.

  Further, in other words, the first embodiment has a plurality of modems having a plurality of protocols, and is optimal for transmission path characteristics (frequency characteristics) depending on communication conditions (startup conditions / frequency bands, etc.). By switching the protocol, a protocol that requires a fast start-up time and a protocol that requires a wide range of communication speeds can be run in parallel by frequency division to meet the start-up conditions and various communication conditions. Communication can be provided, and in particular, selection of optimum frequency characteristics, which is an important issue in power line carrier communication (PLC), can be realized.

Embodiment 2. FIG.
A second embodiment of the present invention will be described below with reference to FIGS. 1 and 10 to 14.
FIG. 10 is a diagram showing an example of reception level fluctuation according to the attenuation characteristic on the frequency axis of each carrier transmission path of a multi-carrier modem such as the OFDM multiplex system, and FIG. 11 is a graph according to the S / N ratio of the received signal. FIG. 12 is a diagram exemplifying a constellation (signal point arrangement) in a modulation scheme (BPSK, QPSK, 256QAM, etc.) assigned by the adaptive modulation means 28, and FIG. 12 is stored in the memory by the S / N measurement means 27. FIG. 13 is a diagram showing an example of a data structure of frequency and S / N ratio, FIG. 13 is a diagram showing an example of a flow chart until selecting an optimum frequency until communication start of a known part in the second embodiment, and FIG. 14 is an S / N ratio. It is a figure which shows the example of the optimal frequency selection system by referring data by a flowchart.

  In FIG. 1, the S / N ratio measuring means 27 measures the S / N ratio of the received signal, and the adaptive modulation means 28 of the digital signal processors 24 and 44 is measured by the S / N ratio measuring means 27. Based on the value, an optimum modulation scheme is assigned for each carrier so as to obtain the maximum throughput, and communication is performed, and a memory 26 for storing the S / N ratio measurement result corresponding to the frequency is provided.

  Next, the operation of the second embodiment will be described with reference to FIGS. 1 and 10 to 14.

  In FIG. 1, the S / N ratio measuring means 27 measures the S / N ratio of the received signal, and the adaptive modulation means 28 of the digital signal processors 24 and 44 is measured by the S / N ratio measuring means 27. Based on the value, each modem assigns an optimal modulation scheme for each carrier so that the maximum throughput can be obtained within the frequency band set by default, and the S / N ratio measurement result corresponding to the frequency is displayed. It has a function of storing in the memory 26 or the switching means 3, and the S / N ratio information of the memory can be secured by referring to the memory when each modem selects the optimum frequency. Since it becomes possible to perform frequency allocation after searching for the optimum frequency, a reliable communication band can be allocated at high speed.

  A frequency band 2 in FIG. 10 shows reception level fluctuations according to attenuation characteristics on the frequency axis of the transmission path of each carrier of a multicarrier modem such as the OFDM multiplexing system. A carrier in a frequency band with a large attenuation has a low reception level, and thus a low S / N ratio. The means for selecting an optimum modulation method corresponding to this S / N ratio is the adaptive modulation means 28 and 48 in FIG.

  As described above, if the S / N ratio can be measured, the communication speed can be theoretically calculated from the modulation speed. As an example, as shown in FIG. 12 showing the data structure of the frequency and S / N ratio stored in the memory by the S / N ratio measuring means 27, from the S / N ratio value in each preset frequency band, By selecting an S / N ratio that can ensure a higher communication speed, it is possible to select a good frequency band that can ensure a communication band.

  As an example, in FIG. 11, the S / N ratio measuring unit 27 includes a constellation in a modulation scheme (known BPSK, QPSK, 256QAM, etc.) in which the adaptive modulation unit 28 performs frequency allocation according to the S / N ratio of the received signal. (Signal point arrangement) is shown. The adaptive modulation means 28 and 44 determine the maximum value of the signal point distance according to the S / N ratio.

  BPSK (Binary Phase Shift Keying) is one of the modulation methods for converting a digital signal into an analog signal. As shown in the figure, information is expressed by a combination of a plurality of waves whose phases are shifted. 1 bit) information can be transmitted and received.

  QPSK (Quadrature Phase Shift Keying) (4 phase shift keying) is a modulation method for converting a digital signal into an analog signal, and as shown in the figure, information is expressed by a combination of a plurality of phases shifted in phase. It is possible to transmit / receive 4-value (2-bit) information at a time.

  With regard to a signal point arrangement example of 64 QAM (64 Position Quadrature Amplitude Modulation), the upper 3 bits are assigned to Ich and the lower 3 bits are assigned to Qch, and Gray coding or the like is performed. These six modulation schemes having different multi-value numbers (64 values) are subjected to adaptive modulation in which each carrier is changed.

  Similarly, 256 QAM (256 Position Quadrature Amplitude Modulation) can transmit and receive 256-value information at a time.

  FIG. 13 shows a flowchart up to the selection of the optimum frequency until the start of communication in the conventional case where this method is not used. In order to check whether the requested communication speed is established after monitoring the communication speed for a certain period after searching for the optimum frequency in an arbitrary order, synchronizing and establishing the communication, request four steps from ST131 to ST134. It must be repeated many times until the communication speed is established, which takes time.

  FIG. 14 shows an optimum frequency selection method by referring to the S / N ratio data in this method. In FIG. 14, the requested communication speed may be established by executing four steps from step ST141 to ST144 only once. Compared with the method of FIG. 13, the frequency selection time is shortened and high-speed communication establishment is achieved. It becomes feasible.

  As described above, in the second embodiment, in the electrical line carrier hybrid communication apparatus of the first embodiment, the maximum frequency is set in the frequency band in which each modem is set based on the S / N ratio measurement value. By having an adaptive modulation means for allocating an optimum modulation method for each carrier so as to obtain a throughput, the measured S / N ratio value is stored in a memory, and each protocol modem refers to the memory table when selecting a frequency. It establishes communication optimally and at high speed.

  In other words, the second embodiment changes the frequency of each carrier in the direction of increasing the throughput in the electrical line carrier communication system of the first embodiment.

Embodiment 3 FIG.
The third embodiment of the present invention will be described below with reference to FIGS. 1, 15, and 16. FIG.
FIG. 15 relates to a method for switching a plurality of protocol modems shown in FIG. 1, and the protocol switching means 3 includes a memory 311 for setting switching conditions and a switching means setting means 312 so that parameters other than the S / N ratio can be obtained. FIG. 16 is a diagram illustrating an example of a configuration in which communication conditions are determined according to a plurality of protocol activation sequences according to (for example, a modem activation time until communication starts), and an optimum protocol is automatically selected. FIG. 16 illustrates the switching conditions in FIG. It is a figure which shows the example of the condition setting to the memory 311 to set.

  With respect to the method for switching a plurality of protocol modems shown in FIG. 1, as shown in FIG. 15, the protocol switching means 3 is provided with a memory 311 for setting switching conditions and a switching condition setting means 312, so that other than the S / N ratio. In accordance with the parameters, for example, there is provided means for automatically selecting an optimum protocol by determining a communication condition according to a request condition of the external device (modem activation time until the start of communication, activation sequence of a plurality of protocols).

  Next, the operation of the third embodiment will be described using FIG. 1, FIG. 15, and FIG.

  With respect to the method of switching a plurality of protocol modems shown in FIG. 1, the protocol switching means 3 includes a memory 311 for setting switching conditions and a switching means setting means 312 as shown in FIG. According to the parameters, for example, the communication protocol is determined according to the request condition of the external device (modem activation time until the start of communication, etc.) and the activation sequence of a plurality of protocols, and the optimum protocol is automatically selected.

  The memory 311 for setting the switching condition in FIG. 15 includes, for example, device start-up time, minimum S / N value necessary for modulation, information such as communication speed, delay, etc. that can realize each protocol, and after power-on and reset The startup sequence information from is stored. The switching means setting means 312 indicates a means for setting data in the memory from a CPU mounted on the protocol A, for example.

FIG. 16 shows an example of setting conditions in the memory 311 for setting switching conditions.
For each protocol modem, information such as device start-up time, minimum S / N value necessary for modulation, communication speed, and delay can be held.

  As described above, various controls are possible depending on the case in which the electric line carrier hybrid communication device 1 is used. This apparatus is assumed to be used under various conditions such as distribution device control on power lines, broadband processing such as Internet access, VoIP (Voice Over IP), and data communication between connected apparatuses. However, in the case of power distribution device control, high-speed activation of the apparatus after power activation, that is, after a power failure, is an essential condition. In such a case, an FSK modem that is an example of a protocol B modem as described in the first embodiment. In this case, since the hardware and firmware configuration can be simplified, the startup time is shortened compared to a high-performance CPU and DSP modem such as an OFDM modem as shown by the protocol A modem. If the start-up time is an issue as a required communication condition, the protocol B modem is preferentially connected in advance. As described above, by setting an activation sequence in the switching condition setting memory 31, communication that satisfies the required conditions can be made possible.

  In the third embodiment, as described above, in the electrical line carrier hybrid communication apparatus of the first embodiment, the optimum carrier is allocated so that each modem can obtain the maximum throughput based on the S / N ratio measurement value. In this case, a parameter other than the S / N ratio required by the host application (for example, modem startup time) and communication conditions corresponding to the performance that each protocol can realize are determined, and means for automatically selecting the optimum frequency band is provided. It can be applied to a plurality of protocol selections.

  In other words, the third embodiment selects one of the different protocols in accordance with the conditions required by the external device in the electrical line carrier communication system of the first or second embodiment. is there.

Embodiment 4 FIG.
A fourth embodiment of the present invention will be described below with reference to FIGS. 1, 17, and 18.
17 is a diagram illustrating an example of a configuration that enables processing of independently communicated data as one band according to the type of data to be communicated, and FIG. 18 illustrates frame division and frame reconstruction on the transmission side. It is a figure which shows the example of reception.

  The electrical line carrier hybrid communication apparatus 1 having a plurality of protocols shown in FIG. 1 stores, integrates and divides a plurality of bands of data frames transmitted between a plurality of protocol modems. As shown in FIG. 3, the data transmission unit has a data frame accumulation unit 321, a frame integration unit 322, and a frame division unit 323, and transmits data from a transmission device on the transmission side for the types of communication data transmitted / received independently among a plurality of protocols. The received data is accumulated, divided into bands that can be secured by each protocol modem, assigned a frame sequence number, etc., and transmitted to the receiving apparatus. On the receiving side, the data is rearranged from the frame sequence number and the like, the frame is reconstructed, and the data is received. With the above function, communication data handled by the hybrid can be processed as one band according to the type of data to be communicated, and the required band can be secured as a whole.

  Next, the operation of the fourth embodiment will be described with reference to FIG. 1, FIG. 17, and FIG.

  As described above, the electrical line carrier hybrid communication apparatus 1 having a plurality of protocols shown in FIG. 1 includes, in the protocol switching means 3, the data frame storage unit 321, the frame integration unit 322, the frame, as shown in FIG. For the data transmitted and received independently among a plurality of protocols, the transmission side stores the data transmitted from the transmission device, divides it into bands that can be secured by each protocol modem, and divides the frame sequence number And the like are transmitted to the receiving apparatus. On the receiving side, the data is rearranged from the frame sequence number and the like, the frame is reconstructed, and the data is received. With the above function, communication data handled by the multi-protocol can be processed as one band.

  FIG. 18 shows an example of receiving a data frame at the receiving device by dividing the data frame transmitted from the transmitting device on the transmitting side and reconstructing the frame on the receiving side. The transmission data is divided into protocol A and protocol B for each communication band secured according to the S / N state of the transmission path on the transmission side, and the divided data frame is transmitted on the reception side to the transmission device. By reconstructing the data, the required total traffic is transmitted.

FIG. 18 shows an example of securing the communication band as a whole by composing PHY / MAC frames of two types of protocol A modem and protocol B modem, for example, when configuring an Ethernet frame.
In FIG. 18A, one of the modems has a frame assembling / separating function, and a payload (A) and a payload (B) in which an optimum frequency band is secured by each protocol are combined into one ether frame. An example is shown.
FIG. 18B schematically shows a diagram in which transmission and reception bands are combined with two frequency bands to ensure a wide and stable band as a whole.

  With the above function, it is possible to process communication data handled for each multi-protocol modem as one band and to secure the requested band as a whole.

  More specifically, as illustrated in FIG. 18A, a data frame having a payload (A + B) obtained by combining a payload A corresponding to protocol A and a payload B corresponding to protocol B and an upper layer header is transmitted. The data frame having a payload A corresponding to protocol A, a transmission path header, and an upper layer header, and a data frame having a payload B corresponding to protocol B, a transmission path header, and an upper layer header. Each received data frame is sent to a transmission line, and the receiving side reconstructs each divided data frame received via the transmission line into a data frame having a payload (A + B) and an upper layer header. . As illustrated in FIG. 18B, transmission data (A + B Mbps) corresponding to protocol A and protocol B is transmitted on the transmission path as transmission data (A Mbps) and transmission data (B Mbps). On the receiving side, it is processed as received data (A + B Mbps).

  As described above, in the fourth embodiment, in the electrical line carrier hybrid communication apparatus including the plurality of protocols of the first embodiment, accumulation, integration, and integration of data frames of a plurality of bands transmitted between modems of a plurality of protocols. In order to perform the division, a data frame accumulating unit, a frame integrating unit, and a frame dividing unit are provided, and the required bandwidth can be secured as a whole of a plurality of protocols.

  In addition, for data transmitted and received independently between a plurality of protocols, on the transmission side, the data transmitted from the transmission device is accumulated, divided into bands that can be secured by each protocol modem, and frame sequence numbers etc. are given, Send to the receiving device. On the receiving side, the data is rearranged from the frame sequence number and the like, the frame is reconstructed, and the data is received. With the above function, communication data handled by the multi-protocol can be processed as one band.

  In other words, the fourth embodiment is divided into frequency bands that can be secured by the respective modems on the communication data transmission side in the electrical line carrier communication system of the first or second embodiment, The communication data receiving side reconstructs the divided data obtained through the modems.

Embodiment 5. FIG.
A fifth embodiment of the present invention will be described below with reference to FIGS. 1, 19, and 20.
Note that FIG. 19 shows an example of a configuration that secures communication quality by selecting an optimal protocol from a plurality of protocol modems according to the traffic type of the higher-level application (for example, bandwidth, modem activation time, delay, etc.). FIG. 20 and FIG. 20 are diagrams illustrating the concept of an operation for selecting an optimum protocol among a plurality of protocol modems according to the traffic type (for example, bandwidth, modem activation time, delay, etc.) of the upper application.

  In the electrical line carrier hybrid communication apparatus 1 having a plurality of protocols shown in FIG. 1, the traffic type (for example, data communication such as the Internet, voice communication such as VoIP, application such as file transfer) (for example, the application) In order to select an optimal protocol among a plurality of protocol modems according to the bandwidth, modem startup time, delay, etc.) and to ensure communication quality, the protocol switching means 3 is used as shown in FIG. A frame application determination unit 331, an optimum protocol selection unit 332, a frame distribution unit 333, and a switching condition setting memory 311 are provided to enable communication under traffic conditions that are optimal for the application for each data frame.

For reference, the optimum traffic conditions in the case of data communication, voice communication, and control are exemplified below.
In the case of data communication (Internet (HTTP)) (feature: resendable, two-way communication)
Protocol: TCP / IP, maximum required bandwidth: several hundred kbps
For data communication (file transfer (FTP)) (features: resendable, one-way communication)
Protocol: UDP, Maximum required bandwidth: Several hundred kbps
For voice communication (VoIP) (feature: non-retransmittable, stable uninterrupted communication)
Protocol: RTP, Maximum required bandwidth: Several 64kbps, etc. For control (control command transmission / reception) (feature: shortest startup time)
Maximum required bandwidth: tens of kbps

  Next, the operation of the fifth embodiment will be described with reference to FIG. 1, FIG. 19, and FIG.

  As shown in FIG. 19, the electric line carrier hybrid communication apparatus 1 having a plurality of protocols (for example, protocols A and B) shown in FIG. 1 has a traffic type (for example, bandwidth, modem activation time, delay, etc.) of the upper application. ) To select an optimum protocol from a plurality of protocol modems, and in order to ensure the communication quality, the protocol switching means 3 sends the frame application from the data of the upper frame type, for example, the TOS field in the Ethernet packet. A frame application determination unit 331 that determines the type, an optimal protocol selection unit 332 that selects an optimal protocol that is suitable for the traffic type of the application among a plurality of protocols, from the communication conditions of each protocol stored in the switching condition setting memory 311; Each protocol To the frame distribution unit 333 for distributing frame provided makes it possible to perform communication at optimum traffic conditions in the application of each data frame.

The algorithm of the optimum protocol selection unit 332 in FIG. 19 is exemplified below.
(1) The type of the upper application is determined according to the information of each application as follows (a)
To determine (d).
(A) Start-up time constraint (b) Priority control by data type (c) Maximum required bandwidth (downlink)
(D) Maximum required bandwidth (upstream)
(2) The optimum protocol and the optimum band are selected from the transmission path condition of the modem itself of each protocol and the transmission condition of each data type transmitted by the modem.
For example,
(I) The data type is “control communication” and the startup time is the highest priority communication condition.
(1) If “Startup time” in (a) is a priority, this condition automatically
The protocol itself is selected.
(Ii) The data type is VoIP “voice communication” and the bandwidth is narrow.
When unstable transmission path conditions that cause communication interruption etc. are not allowed as communication quality
In this case, the S / N characteristics can be observed and a stable band can be secured for a certain time.
Judgment is made such as determining the col.

  FIG. 20 shows a conceptual diagram of the above-described operation in the present embodiment. That is, as illustrated in FIG. 20, for input control data (features are narrowband, high speed startup, low delay), VoIP voice data (features are narrowband, low delay), and communication data (features are wideband). The frame application determination unit 331 performs the frame application determination, the optimal protocol selection unit 332 performs the optimal protocol selection, and the frame distribution unit 333 distributes the frames for each protocol (data distribution). It is possible to perform communication under the traffic conditions optimal for the application for each frame.

  As described above, the fifth embodiment is different from the electric line carrier hybrid communication apparatus 1 having the plurality of protocols of the first embodiment in that the traffic type of the upper application (for example, bandwidth, modem activation time, delay, etc.) In order to select the optimal protocol among multiple protocol modems and ensure communication quality, a frame application determination unit, an optimal protocol selection unit, a frame distribution unit, and a switching condition setting memory are provided for each data frame. It is possible to perform communication under traffic conditions optimal for the application.

  In other words, in the fifth embodiment, in the electrical line carrier communication system of the first embodiment or the second embodiment, an optimum protocol is selected from a plurality of protocol modems according to the traffic type of the upper application. Is.

Embodiment 6 FIG.
A sixth embodiment of the present invention will be described below with reference to FIGS. 1, 19, 21, and 22.
FIG. 21 is a diagram illustrating the concept of carrier frequency allocation in the frequency hopping scheme, and FIG. 22 is a diagram illustrating an example of hopping patterns in the frequency hopping scheme.

  The electric line carrier hybrid communication apparatus 1 having a plurality of protocols shown in FIG. 1 may be a frequency hopping method as a protocol to be implemented.

  In the frequency hopping method, when a plurality of carriers are buried by noise on the transmission path and S / N cannot be secured and data cannot be received, the frequency with poor communication state is changed to a spare frequency all at once. If this means is provided in the electrical line carrier communication device, when the communication performance of any of the simultaneously output carriers deteriorates, communication can be performed by changing only that carrier to a spare carrier. it can.

  When the frequency hopping method is applied to the electrical line carrier hybrid communication device 1 having a plurality of protocols, the frequency hopping method needs to determine a hopping pattern that determines a carrier frequency allocation pattern. At the time of determination, based on the data in the switching condition setting memory 311 in FIG. 19, it has a function of adjusting and controlling a plurality of protocols, and the priority of the frequency band used by other protocols is high. In this case, it has a function of excluding the frequency from the hopping pattern.

  Next, the operation of the sixth embodiment will be described with reference to FIG. 1, FIG. 21, and FIG.

  In the electrical line carrier hybrid communication apparatus 1 shown in FIG. 1, when a known frequency hopping method is applied as a protocol to be implemented, it is necessary to determine a hopping pattern that determines a carrier frequency allocation pattern. .

  At this time, based on the data in the switching condition setting memory 311 in FIG. 19, a function for performing adjustment in consideration of the priority of other protocols based on the conditions of the switching condition setting memory 311 provided in the protocol switching means 3. And having a function of excluding the frequency from the hopping pattern when the priority of the frequency band used by another protocol is high.

  FIG. 21 shows a conceptual diagram of carrier frequency allocation in the frequency hopping scheme, in which the carrier frequencies are allocated in a discrete manner, such as frequency 1, frequency 2,.

  22 shows an example of a hopping pattern in the frequency hopping method, and as shown in FIG. 22, a method of assigning the frequency 1, frequency 2,... Frequency n in FIG. 21 in units of time t1, t2,. It is.

  In FIG. 22, for example, when frequency 2 is preferentially used in another protocol, frequency 2 is excluded from the hopping pattern at time t2.

  In the sixth embodiment, as described above, when the frequency hopping scheme is applied to the electric line carrier hybrid communication apparatus having the plurality of protocols of the first embodiment, the frequency hopping scheme determines the pattern of the carrier frequency allocation. Although it is necessary to determine the hopping pattern, when determining this hopping pattern, there is a function for performing switching control and adjustment for switching a plurality of protocols based on the data in the switching condition setting memory 311 in FIG. When the priority of a frequency band used by another protocol is high, it has a function of excluding the frequency from the hopping pattern.

  In other words, in the sixth embodiment, in the electrical line carrier communication system of the first or second embodiment, the frequency of the carrier is assigned by the frequency hopping system.

Embodiment 7 FIG.
The seventh embodiment of the present invention will be described below with reference to FIGS. 1, 23, and 24. FIG.
In FIG. 23, a power frequency synchronization means 271 and a power frequency zero cross determination circuit 201 are provided in the S / N ratio measurement means and the electric line carrier hybrid communication device 1 to measure the S / N ratio. FIG. 24 is a diagram illustrating an example of a configuration in which averaging is performed at a period synchronized with the frequency and more accurate S / N ratio measurement is performed, and FIG. 24 is a diagram illustrating an example of a power supply frequency and a zero cross signal.

  The S / N ratio measuring means in the electrical line carrier hybrid communication apparatus 1 shown in FIG. 1 measures the S / N ratio of the received signal. At this time, the S / N ratio measurement is not determined by measuring only one frame of the transmission frame because noise and impedance fluctuations on the transmission line dynamically change in time. Process.

  Particularly in the case of power line conveyance, both power noise and impedance fluctuations are often generated at a power frequency cycle because they are affected by power distribution equipment connected to the power line.

  Therefore, in consideration of this, in FIG. 23, an output is provided for each zero cross point of the power supply voltage in the power supply frequency synchronization means 271 and the electric line carrier hybrid communication device 1 in the S / N ratio measurement means 27. A power supply frequency zero-cross determination circuit 201 to output, and using the zero-cross point detected by the power supply frequency zero-cross determination circuit 201, the S / N ratio measurement is performed a plurality of times in a period synchronized with the power supply period, and the average is performed. An object is to perform more accurate S / N ratio measurement.

  Next, the operation of the seventh embodiment will be described with reference to FIGS.

  In FIG. 23, the S / N ratio measuring means 27 has a function of averaging and determining a plurality of received frames in order to measure the S / N ratio. Further, a power frequency synchronization means 271 is provided in the S / N ratio measuring means 27 and a power frequency zero cross determination circuit 201 is provided in the electric line carrier hybrid communication apparatus 1, and the power frequency zero cross determination circuit 201 is as shown in FIG. The cell crossing point which is the voltage 0V point of the power cycle of 50 Hz or 60 Hz is determined, and an arbitrary signal is transmitted to the S / N ratio measuring means 27. The zero-cross determination circuit 201 can be arbitrarily designed, but can be easily configured by, for example, a photocoupler or a transistor.

  The power supply frequency synchronization unit 271 generates power supply cycle information based on the signal from the zero cross determination circuit 201. The S / N ratio measuring means 27 performs averaging in the period synchronized with the power supply period from the power supply period information, and averages and considers noise having periodicity so that accurate S / N with less fluctuation can be obtained. N ratio measurements can be made.

  FIG. 24 shows an example of the relationship between the power supply frequency of the seventh embodiment and the zero cross signal.

  In the seventh embodiment, as described above, in the electrical line carrier hybrid communication apparatus including the plurality of protocols of the first embodiment, the S / N ratio measurement unit measures the S / N ratio of the received signal. At this time, the S / N ratio measurement is not determined by measuring only one frame of the transmission frame, because noise and impedance fluctuations on the transmission line dynamically change in time. Process. Particularly in the case of power line conveyance, both power noise and impedance fluctuations are often generated at a power frequency cycle because they are affected by power distribution equipment connected to the power line. Therefore, taking this into account, the power frequency synchronization means 271 and the power line and general wiring carrier hybrid communication apparatus 1 are provided with the power frequency zero cross determination circuit 201 in the S / N ratio measurement means, and the S / N ratio measurement. Is averaged at a period synchronized with the power supply period, so that a more accurate S / N ratio measurement is performed.

  In other words, in the seventh embodiment, in the electric line carrier communication system of the first embodiment or the second embodiment, the S / N ratio measurement result averages the measured S / N ratios for a plurality of frames. Is obtained.

Embodiment 8 FIG.
The eighth embodiment of the present invention will be described below with reference to FIGS. 25, 26, 27, and 28. FIG.
25 is a diagram illustrating an example of a configuration in which the electrical line carrier hybrid communication device 1 is connected to the electrical line 5 via the signal coupling device 500, and FIG. 26 illustrates a case where the signal coupling device has a certain frequency characteristic. A signal coupling device that has a good characteristic and effective signal injection efficiency for the frequency band to be used can be obtained by synchronizing the operation of switching the modem by the protocol switching means 3 of the electrical line carrier hybrid communication device 1. FIG. 27 is a diagram illustrating a configuration having a signal coupling device changeover switch 100 for switching the injection device, FIG. 27 is a diagram illustrating an example of the attenuation characteristic (signal injection loss) of the signal injection device A, and FIG. It is a figure which shows an example of the attenuation | damping characteristic (signal injection loss).

  As shown in FIG. 25, the electric line carrier hybrid communication device 1 described in the first embodiment is inductively coupled to inject a communication signal into the electric line 5 that is energized so as to exhibit a unique function. It is connected to the electrical line 5 through a known signal coupling device 500 such as capacitive coupling.

  FIG. 25 shows a case in which a plurality of modems operating in a plurality of independent and different frequency bands in the electric line carrier hybrid communication apparatus 1 of the present invention are connected to the electric line 5 through one signal coupling device. It is a form to connect.

  FIG. 26 is an eighth embodiment of the present invention. In the case where the signal coupling device has a certain frequency characteristic, the signal coupling device that has a good characteristic for the frequency band to be used and can obtain an effective signal injection efficiency is shown in FIG. The protocol switching means 3 of the common line carrier hybrid communication device 1 includes a signal coupling device switching switch 100 for switching the signal injection device in synchronization with the operation of switching the modem.

  Next, the operation of the eighth embodiment will be described using FIG. 26, FIG. 27, and FIG.

  FIG. 26 shows an embodiment of the present invention. In the case where the signal coupling device has a certain frequency characteristic, the signal coupling device which has a good characteristic for the frequency band to be used and can obtain an effective signal injection efficiency is shown in FIG. The protocol switching means 3 of the line carrier hybrid communication device 1 has a signal coupling device changeover switch 100 for switching between signal coupling devices (also referred to as signal injection devices) A and B in synchronization with the operation of switching the modem.

  27 and 28 show the attenuation characteristics (signal injection loss) of the signal coupling device A and the signal coupling device B as an example. For example, in practice, the frequency characteristics differ greatly between the case of using a capacitor type signal injection device and the case of using an inductive type signal injection device. For example, in FIG. 27, it is assumed that the attenuation characteristics of the frequency f1 or lower and the frequency f2 or lower are poor and should not be used in order to obtain a certain communication performance. FIG. 28 shows that, for example, the injection loss is large in the frequency band of the frequency f1 or higher.

  In the above case, assuming that the signal injection characteristic at the operating frequency of the hybrid modem is not satisfied with only one signal coupling device, the protocol switching means 3 synchronizes with the operation of switching the modem, By using the signal coupling device changeover switch 100 for switching, it is possible to switch a plurality of signal injection devices having optimum characteristics for the frequency used by each protocol.

  In the eighth embodiment, it is assumed that a plurality of signal injection devices are installed in the electrical line 5 in advance.

  In the eighth embodiment, as described above, in the electric line carrier hybrid communication device having the plurality of protocols of the first embodiment, a signal coupling device having a certain frequency characteristic is connected to the power line and the general wiring carrier hybrid communication device. The signal switching device that has good characteristics and effective signal injection efficiency for the frequency band to be used is synchronized with the operation of switching the modem by the protocol switching means of the power line and general wiring carrier hybrid communication device 1. The signal coupling device switch 100 for switching the signal injection device is provided.

  In other words, in the electric line carrier communication system according to the first embodiment or the second embodiment, the eighth embodiment includes a plurality of signal coupling devices that inject the communication data into the electric line. It is selected corresponding to the modem.

  1, 2, 3 </ b> A to 3 </ b> D, 4 </ b> A to 4 </ b> C, and FIGS. 5 to 28, the same reference numerals indicate the same or corresponding parts.

It is a figure shared with Embodiment 1- Embodiment 7 of this invention, and is a block diagram which shows the structural example of the electric line carrier hybrid communication apparatus 1 provided with a some protocol. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, The example of a structure of the electric line carrier hybrid communication apparatus 1 provided with a some protocol (It is a narrow system and a low speed, but a robust system which can communicate even with low S / N 1 is a block diagram illustrating an example of a configuration of an OFDM modem that realizes high-speed communication that requires a high-speed protocol and a wide bandwidth and high S / N. FIG. 1 is a diagram showing a first embodiment of the present invention and shows a modem (an example of a functional configuration of an OFDM modulation / demodulation modem that realizes wideband, high-speed, and high-frequency efficiency in the electrical line carrier hybrid communication device 1) in which the protocol A is implemented. It is a block diagram. FIG. 1 is a diagram illustrating a first embodiment of the present invention, and illustrates a modem (an example of a functional configuration of an OFDM modulation / demodulation modem that realizes wideband, high speed, and high frequency efficiency in the electrical line carrier hybrid communication apparatus 1) in which protocol B is implemented. It is a block diagram. It is a figure which shows Embodiment 1 of this invention, and is a block diagram which shows the example of a protocol switching means. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the example of the frame structure of the communication frame between external apparatuses in a hybrid communication apparatus. It is a figure which shows Embodiment 1 of this invention, and is a figure which illustrates the operation | movement (sequence example until the communication start of the OFDM modem shown to FIG. 3A) of the modem (high speed) which mounted the protocol A in a flowchart. It is a figure which shows Embodiment 1 of this invention, and is a figure which illustrates the operation | movement (sequence example until communication start of the FSK modem shown to FIG. 3B) of the modem (high speed) which mounted the protocol B in a flowchart. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the example of the starting sequence of the protocol A and the protocol B. FIG. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows an example of the frequency characteristic of attenuation of a power wire or a general wiring. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the example of the setting band by default of the occupation frequency band of the modem of two protocols. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows the example of the communication speed and communication quality which the application of an external apparatus requests | requires. It is a figure which shows Embodiment 1 of this invention, and is a figure which illustrates by a flowchart the operation | movement from the time of a power activation or reset to the optimal band allocation. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, and is a schematic block diagram at the time of connecting two or more electrical line carrier hybrid communication apparatuses to an electrical line. It is a figure which shows Embodiment 2 of this invention, and is a figure which shows the example of reception level fluctuation | variation according to the attenuation characteristic in the frequency axis of each carrier transmission line of a multicarrier modem like an OFDM multiplexing system. FIG. 7 is a diagram showing a second embodiment of the present invention, and shows an example of a constellation (signal point arrangement) in a modulation scheme (BPSK, QPSK, 256QAM, etc.) assigned by the adaptive modulation means 28 in accordance with the S / N ratio of a received signal. FIG. It is a figure which shows Embodiment 2 of this invention, and is a figure which shows the data structure example of the frequency and S / N ratio which are memorize | stored in a memory by the S / N measurement means 27. In Embodiment 2 of this invention, it is a figure which shows the example of a flowchart until the optimal frequency selection until the communication start of the conventional well-known part. It is a figure which shows Embodiment 2 of this invention, and is a figure which shows the example of the optimal frequency selection system by referring S / N ratio data with a flowchart. In the figure which shows Embodiment 3 of this invention, it is related with the system which switches the several protocol modem shown in FIG. 1, By providing the memory 311 which sets a switching condition, and the switching means setting means 312 in the protocol switching means 3, It is a figure which shows the example of the structure which determines communication conditions according to parameters other than S / N ratio (for example, modem starting time etc. until communication start) according to the starting sequence of a some protocol, and selects an optimal protocol automatically. It is a figure which shows Embodiment 3 of this invention, and is a figure which shows the example of the condition setting to the memory 311 which sets the switching condition in FIG. It is a figure shared by Embodiment 4 and Embodiment 5 of this invention, and is a figure which shows the example of a structure which makes it possible to process the data communicated independently as one band according to the data classification communicated is there. It is a figure which shows Embodiment 4 of this invention, and is a figure which shows the example of the reception by the frame division of the transmission side, and frame reconstruction. In the diagram showing the fifth embodiment of the present invention, the optimum protocol is selected from a plurality of protocol modems according to the traffic type (for example, bandwidth, modem activation time, delay, etc.) of the upper application, and the communication quality is improved. It is a figure which shows the example of the structure to ensure. In the figure which shows Embodiment 5 of this invention, the concept of the operation | movement which selects the optimal protocol in several protocol modems according to the traffic classification (for example, bandwidth, modem starting time, delay, etc.) of a high-order application is shown. It is a figure illustrated. It is a figure which shows Embodiment 6 of this invention, and is a figure which illustrates the concept of the carrier frequency allocation in a frequency hopping system. It is a figure which shows Embodiment 6 of this invention, and is a figure which shows the example of a hopping pattern in a frequency hopping system. In the figure which shows Embodiment 7 of this invention, the power frequency synchronization means 271 is provided in the S / N ratio measuring means, and the power frequency zero cross determination circuit 201 is provided in the electric line carrier hybrid communication apparatus 1, and S It is a figure which shows the example of a structure which averages / N ratio measurement with the period synchronized with the power supply period, and performs more exact S / N ratio measurement. It is a figure which shows Embodiment 7 of this invention, and is a figure which shows an example of a power supply frequency and a zero cross signal. It is a figure which shows Embodiment 8 of this invention, and is a figure which shows the example of a structure by which the electrical line conveyance hybrid communication apparatus 1 is connected to the electrical line 5 via the signal coupling device 500. FIG. 8 is a diagram showing an eighth embodiment of the present invention, and in the case where a signal coupling device has a certain frequency characteristic, the signal coupling device having a good characteristic and effective signal injection efficiency for the frequency band to be used is It is a figure which illustrates the structure which has the signal coupling | bonding apparatus switch 100 for the protocol switching means 3 of the carrier hybrid communication apparatus 1 for switching a signal injection apparatus synchronizing with the operation | movement which switches a modem. It is a figure which shows Embodiment 8 of this invention, and is a figure which shows an example of the attenuation | damping characteristic (signal injection loss) of the signal injection apparatus A. It is a figure which shows Embodiment 8 of this invention, and is a figure which shows an example of the attenuation characteristic (signal injection loss) of the signal injection apparatus B.

Explanation of symbols

1 Electric line carrier hybrid communication device,
2 Protocol A modem part,
3 Protocol switching means,
4 Protocol B modem section,
5 electrical lines,
8 signal coupling device,
27, 47 S / N ratio measuring means.

Claims (9)

  In an electrical line carrier communication system in which communication is performed by superimposing communication data on an electrical line having a specific electrical role and performing communication, a plurality of modems performing modulation / demodulation on different protocols using carriers of different frequencies, and S / S of each carrier S / N ratio measuring means for measuring the N ratio is provided, and the frequency of each carrier is changed in a direction that improves the S / N ratio of each carrier based on the S / N ratio measurement result by the S / N ratio measuring means. An electrical line carrier communication system.   2. The electric line carrier communication system according to claim 1, wherein said modem of a carrier having a low frequency among said carriers is used as a modem for electric control data.   The electric line carrier communication system according to claim 1 or 2, wherein the frequency of each carrier is changed in a direction in which the throughput is increased.   3. The electrical line carrier communication system according to claim 1, wherein any one of the different protocols is selected according to a condition required by an external device.   3. The electric line carrier communication system according to claim 1 or 2, wherein the communication data is divided into frequency bands that can be secured by each modem on the communication data transmission side, and is obtained through each modem on the communication data reception side. The electric line carrier communication system characterized by reconstructing the divided data.   3. The electric line carrier communication system according to claim 1, wherein an optimum protocol is selected from a plurality of protocol modems in accordance with a traffic type of a higher-level application. method.   3. The electric line carrier communication system according to claim 1, wherein the carrier frequency is assigned by a frequency hopping method.   The electrical line carrier communication system according to claim 1 or 2, wherein the S / N ratio measurement result is obtained by averaging measured S / N ratios for a plurality of frames. Carrier communication method.   The electrical line carrier communication system according to claim 1 or 2, wherein a plurality of signal coupling devices for injecting the communication data into the electrical line are selected corresponding to each modem. Electrical line communication system.

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