JP4130665B2 - Transceiver and receiver system - Google Patents

Description

  The present invention is a transceiver for inducing an electric field based on information to be transmitted in an electric field transmission medium, detecting the induced electric field and transmitting / receiving information, and receiving an information by detecting the electric field induced in the electric field transmission medium. It is related with the receiving system which performs.

  Wearable computers are attracting attention due to the miniaturization and performance enhancement of portable terminals, and FIG. 4 shows an example in which such wearable computers are used while being worn by humans. As shown in the figure, the wearable computer 7 is mounted on a person's arm, shoulder, torso, etc. via a transceiver 9 to transmit / receive data to / from each other, and is further provided on the wall or floor so that it can be touched by the tip of a limb Communication is performed with a personal computer (PC) 8 provided outside through the transceivers 9a and 9b and the cables.

  Here, the transceiver 9 used for data communication between the wearable computer 7 and between the wearable computer 7 and the PC 8 uses a signal detection technique based on an electro-optic technique using a laser beam and an electro-optic crystal. Therefore, an electric field based on information to be transmitted is induced in a living body as an electric field transmission medium, and information is transmitted / received using the induced electric field.

The prior art document information related to this application includes the following.
JP 2001-352298 A

  The transceiver 9 has a method of removing noise by determining whether or not the received signal has a waveform amplitude equal to or larger than a predetermined threshold. That is, the transceiver 9 determines that the received signal has a waveform amplitude greater than or equal to the threshold value, and determines that the packet is a packet (data string). Remove the part.

  However, in the transceiver 9 used for the biometric communication described above, the amplitude of the received signal varies greatly due to the influence of the communication environment. As the communication environment, for example, a communication distance, a communication place, a height, and a contact area with an electrode (how to hold the transceiver 9, wearing through clothes, etc.) are conceivable.

  FIG. 5 is a diagram illustrating an example of a received signal. The received signal A shown in the figure includes a noise portion a1 having a relatively small waveform amplitude and a packet portion a2 having a relatively large waveform amplitude. Here, a predetermined large threshold D is used to extract the packet part a2. In this case, a small amplitude b less than the threshold value D that varies depending on the communication environment is regarded as noise and is deleted. On the other hand, a predetermined small threshold E is used in order to reliably extract the packet part a2. In this case, the noise c having a large amplitude equal to or greater than the threshold E is regarded as a packet and extracted.

  Thus, in the transceiver 9 used for biometric communication, it is difficult to uniquely determine an optimum threshold for removing noise. Even if a threshold value is set, there is a problem that communication errors frequently occur due to erroneous packet removal or erroneous noise extraction.

  The present invention has been made to solve the above-described object, and in a transceiver that induces an electric field based on information to be transmitted in an electric field transmission medium and detects the induced electric field to transmit and receive information, noise is suppressed. It is an object of the present invention to provide a transceiver that can be more accurately removed and can perform higher-quality communication.

  It is another object of the present invention to provide a receiving system capable of more accurately removing noise and performing higher-quality communication in a receiving system that receives information by detecting an electric field induced in an electric field transmission medium. .

  In order to achieve the above-mentioned object, the present invention as set forth in claim 1 is characterized in that an electric field based on information to be transmitted is induced in an electric field transmission medium, and the detected electric field is detected in a transceiver that transmits and receives information. Output means for receiving an electric field, converting it into a received signal containing the information and outputting it, and first potential comparing means for detecting the received signal having a potential higher than the ground potential and converting it to a first pulse wave A second potential comparing means for detecting the received signal having a potential higher than a first threshold set with a first potential difference with respect to the ground potential and converting the received signal into a second pulse wave; and the ground A third potential comparing means for detecting the received signal having a potential higher than a second threshold set with a second potential difference with respect to the potential and converting it to a third pulse wave; and the second pulse wave In And a first mask signal generating means for generating a first mask signal, a second mask signal generating means for generating a second mask signal based on the third pulse wave, and the first mask. Combining the signal and the second mask signal to generate a combined mask signal, and passing the first pulse wave in the gate period of the combined mask signal, thereby receiving the reception signal. And an information extracting means for extracting the information from the signal.

  According to a second aspect of the present invention, in the first aspect of the invention, the first mask signal generation means expands each of the second pulse waves for a first time to obtain the first mask signal. And the second mask signal generating means generates the second mask signal by extending each of the third pulse waves by a second time, and the first time is the second time It is characterized by being larger than time.

  According to a third aspect of the present invention, in a receiving system for receiving information by detecting an electric field induced in an electric field transmission medium, an output for receiving the detected electric field, converting it to a received signal containing the information, and outputting it Means, a first potential comparison means for detecting the received signal having a potential higher than the ground potential and converting it to a first pulse wave, and a first potential set with a first potential difference with respect to the ground potential A second potential comparing means for detecting the received signal having a potential higher than a threshold and converting it to a second pulse wave; and a second threshold set with a second potential difference with respect to the ground potential. Third potential comparison means for detecting the received signal of potential and converting it to a third pulse wave, and first mask signal generation means for generating a first mask signal based on the second pulse wave And the third pal A second mask signal generating means for generating a second mask signal based on the wave; and a combined mask signal generation for generating a combined mask signal by combining the first mask signal and the second mask signal. And information extracting means for extracting the information from the received signal by passing the first pulse wave during the gate period of the combined mask signal.

  According to the present invention, in a transceiver that induces an electric field based on information to be transmitted in an electric field transmission medium and detects the induced electric field to transmit and receive information, noise is more accurately removed and communication with higher quality is performed. A transceiver capable of performing

  In addition, according to the present invention, in a receiving system for receiving information by detecting an electric field induced in an electric field transmission medium, a receiving system capable of more accurately removing noise and performing higher quality communication is provided. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a transceiver 1 according to an embodiment of the present invention. The transceiver 1 shown in FIG. 1 uses a signal detection technique based on an electro-optic technique using a laser beam and an electro-optic crystal, and induces an electric field based on information to be transmitted in a living body that is an electric field transmission medium. A transceiver that transmits and receives information using an induced electric field.

  More specifically, when the transceiver 1 receives transmission data from the computer 6 via the input / output (I / O) circuit 901, the transceiver 1 supplies the transmission data to the transmission / reception electrode 903 via the transmission unit 902. An electric field is induced in the electric field transmission medium via 903 and the insulating film 904, and this electric field is transmitted to other parts of the electric field transmission medium. In addition, the electric field induced and transmitted by the electric field transmission medium is detected by the transmission / reception electrode 903 via the insulating film 904, and this electric field is coupled to the electric field detection optical unit 905 and converted into an electric signal. This electric signal is subjected to signal processing such as amplification and noise removal by the signal processing circuit 906, and further waveform shaping by the waveform shaping circuit 907, and then the computer 6 via the input / output (I / O) circuit 901. Is output.

  Note that the signal processing circuit 906 of this embodiment uses two threshold values to remove noise from an analog electric signal and extract a packet (information, data string). Hereinafter, the signal processing circuit 906 will be described in more detail.

  FIG. 2 is a diagram specifically showing the configuration of the signal processing circuit 906. As illustrated, the signal processing circuit 906 includes a data comparator unit 101, an end side comparator unit 102, an end side mask generation unit 103, an axis side comparator unit 104, an axis side mask generation unit 105, and a mask synthesis unit. 106 and a packet extraction unit 107. The signal processing circuit 906 removes noise by processing the reception signal input from the electric field detection optical unit 905 by the above-described units 101 to 107, and only the data signal of the extracted packet is the waveform shaping circuit 907. It is a circuit that is output to.

  Here, the operation of the signal processing circuit 906 will be described using an example of an input waveform shown in FIG.

  FIG. 3A shows an example of the waveform of an analog signal (received signal) input from the electric field detection optical unit 905. It is assumed that the illustrated input waveform includes a noise portion a1 having a relatively small amplitude and a packet portion a2 having a relatively large amplitude. In this embodiment, in order to extract the packet part a2 with higher accuracy, two threshold values, the end threshold value S1 and the axial threshold value S2, are used.

  The end-side threshold value S1 is a threshold value set on the end side (side away from the analog ground G) with a predetermined potential difference with reference to the potential of the analog ground G. That is, the end-side threshold value S1 is a threshold value that is set based on the amplitude of a general packet and has a relatively large potential difference from the analog ground G. The axis-side threshold value S2 is a threshold value set on the side close to the analog ground G with a predetermined potential difference with respect to the potential of the analog ground G. That is, the shaft side threshold value S2 is a threshold value having a relatively small potential difference from the analog ground G used for noise discrimination.

  In the present embodiment, it is assumed that an analog signal having the waveform shown in FIG. 3A is input to the signal processing circuit 906. At this time, the data comparator unit 101 of the signal processing circuit 906 classifies the input analog signal into an H level and an L level with reference to the analog ground G. That is, the data comparator unit 101 compares the potential of the analog signal with the potential of the analog ground G, outputs an H level or L level signal, and generates a pulse wave (digital signal) as shown in FIG. Generate and output.

  Further, the end-side comparator unit 102 classifies the input analog signal into an H level and an L level based on the end-side threshold value S1. That is, the end-side comparator unit 102 compares the potential of the analog signal with the potential of the end-side threshold value S1, outputs an H-level or L-level signal, and outputs a pulse wave (digital) as shown in FIG. Signal) is generated and output.

  Then, the end mask generation unit 103 receives the pulse wave output from the end comparator 102. Then, the end-side mask generation unit 103 extends each pulse width (window) α of the input pulse wave in the time axis direction for a predetermined time Th. Then, the end mask generation unit 103 calculates the sum of each pulse wave with the extended pulse width, and generates and outputs an end mask window (gate period) as shown in FIG.

  The predetermined time Th is set to a sufficiently long time so as to make it less susceptible to (avoid) the influence of the amplitude variation of the packet part a2. For example, the predetermined time Th is 9.6 microseconds (μsec) or less, and is a value that can avoid the influence of amplitude fluctuation. By increasing the predetermined time Th, even if the packet signal b has a small amplitude that does not exceed the end-side threshold value S1, the packet level can be increased if the signal level exceeds the axial-side threshold value S2 and is within the predetermined time Th. Is determined.

  Further, the shaft side comparator unit 104 classifies the input analog signal into an H level and an L level with reference to the shaft side threshold value S2. That is, the shaft side comparator unit 104 compares the potential of the analog signal with the potential of the end side threshold value S2, outputs an H level or L level signal, and outputs a pulse wave (digital signal) as shown in FIG. ) Is generated and output.

  Then, the axial mask generation unit 105 receives the pulse wave output from the axial comparator unit 104. Then, the axis-side mask generating unit 105 extends each pulse width (window) β of the input pulse wave in the time axis direction for a predetermined time TL. Then, the axis-side mask generation unit 105 calculates the sum of each pulse wave with the extended pulse width, generates an axis-side mask window (gate period) as shown in FIG.

  The predetermined time TL is set to a relatively short time in order to prevent the noise signal c having a large amplitude exceeding the axial threshold S2 from being erroneously determined as a packet signal. For example, the predetermined time TL is 10 nanoseconds (nsec) or more and is a relatively short time.

  Then, the mask composition unit 106 outputs an end mask window (FIG. 3D) output from the end mask generation unit 103 and an axial mask window output from the axial mask generation unit 105 (FIG. 3F). And a composite mask window (gate period) as shown in FIG. 3G is generated and output.

  Then, the packet extraction unit 107 calculates the product of the pulse wave output from the data comparator 101 (FIG. 3B) and the combined mask window output from the mask combining unit 106 (FIG. 3G). The packet extraction unit 107 passes the pulse wave of the data comparator 101 during the gate period of the synthesis mask window, whereby the packet extraction unit 107 outputs the packet signal from which noise is removed as shown in FIG. Generate and output a signal.

  Therefore, according to the present embodiment, packets are extracted using two threshold values, so that an electric field based on information to be transmitted is induced in the electric field transmission medium, and the induced electric field is detected to transmit / receive information. Even if the transceiver 1 is used, noise can be more accurately removed and higher quality communication can be performed.

  In addition, a sufficient margin is secured by using two threshold values. Therefore, even a noise signal c having a large amplitude exceeding the axial threshold S2 is not regarded as a packet if the signal level does not reach the end threshold S1. Thereby, it is possible to appropriately remove only noise from the received electrical signal and extract only the packet with higher accuracy. That is, communication errors due to erroneous noise extraction can be suppressed.

  Even a packet signal b having a small amplitude that does not exceed the end-side threshold value S1 is regarded as a packet if the signal level exceeds the axis-side threshold value S2 and is within a predetermined time Th. Thereby, a packet can be extracted with higher accuracy from the received electrical signal. That is, communication errors due to removal of erroneous packets can be suppressed.

  In addition, by increasing the predetermined time Th in which the end-side mask generation unit 103 extends each pulse width, the amplitude variation of the packet portion is absorbed, and high-quality communication that is not easily affected by the communication environment such as amplitude variation is performed. be able to.

  Further, by shortening the predetermined time TL for extending each pulse width by the axis-side mask generation unit 105, it is possible to prevent extraction errors in portions corresponding to noise and perform high-quality communication.

While the embodiments of the present invention have been described above, various modifications and changes can be made to the embodiments of the present invention without departing from the spirit of the present invention. For example, in the present embodiment, the present invention has been described by taking the transceiver 1 as an example that induces an electric field based on information to be transmitted in the electric field transmission medium and detects the induced electric field to transmit and receive information. However, the present invention is not limited to this, and may be applied to a receiving system that receives an information by detecting an electric field induced in an electric field transmission medium.

It is a block diagram which shows schematic structure of the transceiver which concerns on embodiment of this invention. It is a block diagram which shows the structure of the signal processing circuit of the transceiver which concerns on embodiment of this invention. It is a waveform example which shows the effect | action of the signal processing circuit of the transceiver which concerns on embodiment of this invention. It is explanatory drawing which shows the example in the case of mounting | wearing and using a wearable computer for a person via a transceiver. It is a figure which shows an example of a received signal.

Explanation of symbols

1,9 Transceiver 6 Computer 7 Wearable computer 8 PC
DESCRIPTION OF SYMBOLS 101 Data comparator part 102 End side comparator part 103 End side mask generation part 104 Axis side comparator part 105 Axis side mask generation part 106 Mask composition part 107 Packet extraction part 901 I / O circuit 902 Transmission part 903 Transmission / reception electrode 904 Insulating film 905 Electric field Detection optical unit 906 signal processing circuit 907 waveform shaping circuit 910 receiving unit

Claims (3)

In a transceiver that induces an electric field based on information to be transmitted in an electric field transmission medium and transmits and receives information by detecting the induced electric field,
Output means for receiving the detected electric field, converting the received electric field into a reception signal including the information, and outputting the received signal;
First potential comparison means for detecting the received signal having a potential higher than the ground potential and converting it to a first pulse wave;
Second potential comparison means for detecting the received signal having a potential higher than a first threshold set with a first potential difference with respect to the ground potential, and converting the detected signal into a second pulse wave;
Third potential comparison means for detecting the received signal having a potential higher than a second threshold set with a second potential difference with respect to the ground potential, and converting the received signal into a third pulse wave;
First mask signal generating means for generating a first mask signal based on the second pulse wave;
Second mask signal generating means for generating a second mask signal based on the third pulse wave;
A combined mask signal generating means for combining the first mask signal and the second mask signal to generate a combined mask signal;
An information extraction means for extracting the information from the received signal by allowing the first pulse wave to pass during the gate period of the combined mask signal. The first mask signal generating means generates the first mask signal by extending each of the second pulse waves for a first time,
The second mask signal generating means generates the second mask signal by extending each of the third pulse waves for a second time.
The transceiver of claim 1, wherein the first time is greater than the second time. In a receiving system for receiving information by detecting an electric field induced in an electric field transmission medium,
Output means for receiving the detected electric field, converting the received electric field into a reception signal including the information, and outputting the received signal;
First potential comparison means for detecting the received signal having a potential higher than the ground potential and converting it to a first pulse wave;
Second potential comparison means for detecting the received signal having a potential higher than a first threshold set with a first potential difference with respect to the ground potential, and converting the detected signal into a second pulse wave;
Third potential comparison means for detecting the received signal having a potential higher than a second threshold set with a second potential difference with respect to the ground potential, and converting the received signal into a third pulse wave;
First mask signal generating means for generating a first mask signal based on the second pulse wave;
Second mask signal generating means for generating a second mask signal based on the third pulse wave;
A combined mask signal generating means for combining the first mask signal and the second mask signal to generate a combined mask signal;
An information extraction means for extracting the information from the received signal by allowing the first pulse wave to pass during the gate period of the synthesized mask signal.

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