JP2010219626A - Communication system, communication method, transmitter and receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the responsiveness of communication by eliminating the need of processing of transmitting and receiving the detected result of a bit error rate. <P>SOLUTION: In the communication system, in an on-vehicle device 11, an ECU 26 executes a noise measure to signals, and successively transmits a frame including the signals to which the noise measure is not executed and at least one frame including the signals to which the noise measure has been executed in ascending order of the degrees of the noise measure, via an antenna 22. In a portable device 12, a reception control section 43 successively receives the frames transmitted from the on-vehicle device 11 and stores them in a buffer memory 45, and a decoding section 51 selects the signals to be used in a transmission signal preparation section 53 on the basis of whether or not an error is generated in the signals included in the frames stored in the buffer memory 45. For instance, this invention is applicable to a passive entry system. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication system, a communication method, a transmission device, and a reception device, and particularly to a communication system, a communication method, a transmission device, and a reception device that can improve communication responsiveness.

  In recent years, for example, as a vehicle entry system, a so-called passive entry system (PES) that automatically locks and unlocks doors in a hands-free manner has been put into practical use and is expected to become more popular in the future. It is.

  In the passive entry system, for example, two-way wireless communication is performed between a portable device that can be carried by a user and an in-vehicle device, and the authenticity of the portable device based on electromagnetic waves (signals) received from the portable device by the in-vehicle device The operation of the locking mechanism of the vehicle door (unlocking operation and locking operation) is automatically realized by the control of the in-vehicle device, for example, by confirming the position and analyzing the position of the portable device.

  In the passive entry system, antennas connected to in-vehicle devices are arranged in vehicle door knobs, trunks, indoors, etc., and each antenna is LF wave (for example, 100 to 200 KHz) with respect to the portable device as necessary. In addition, the vehicle-mounted device and the portable device communicate with each other by receiving the signal transmitted from the portable device. In a passive entry system, for example, when a user operates a switch or the like provided on the outside of a vehicle door to unlock the door, the vehicle-mounted device and the portable device communicate with each other as a result of communication by the authorized user. When the locking operation is performed, the door is unlocked.

  In general, in a noisy wireless communication environment, a certain noise tolerance can be obtained by adding an error correction signal to a transmission frame. However, if the frame length becomes redundant by adding an error correction code, the reception processing time in the portable device becomes longer, and the current consumption of the portable device increases.

  In contrast, for example, Patent Document 1 discloses a technique for changing the redundancy of an error correction code in accordance with the bit error rate of a received frame. Thereby, in a communication environment with less noise, the redundancy of the frame length can be reduced, and an increase in current consumption of the portable device is suppressed.

JP-A-8-223624

  However, as described above, when the redundancy of the error correction code is changed according to the bit error rate, the process of transmitting / receiving the detection result of the bit error rate by the ACK (acknowledgement) function between the portable device and the vehicle-mounted device Is required. For this reason, a delay occurs in communication, and the responsiveness of the entire communication system may be reduced.

  The present invention has been made in view of such a situation, and is intended to improve communication responsiveness.

  In the communication system according to the first aspect of the present invention, noise countermeasures are taken by a noise countermeasure means for taking noise countermeasures on a signal, a frame including the signal without noise countermeasures, and the noise countermeasure means. Transmitting means for sequentially transmitting one or more frames including the signal in ascending order of noise countermeasures, receiving means for sequentially receiving the frames transmitted from the transmitting means, and receiving means received by the receiving means Selecting means for selecting a signal to be used in subsequent processing based on whether or not an error has occurred in the signal included in the frame;

  The communication method according to the first aspect of the present invention includes a frame that includes the signal that is subjected to noise countermeasures and is not subjected to noise countermeasures, and one or more frames that include the signal that has been subjected to noise countermeasures. Are sequentially transmitted in ascending order of noise countermeasures, the received frames are sequentially received, and based on whether or not an error has occurred in the signal included in the received frame, Selecting a signal to be used in the processing.

  In the first aspect of the present invention, a frame that includes a signal that has been subjected to noise countermeasures and that has not been subjected to noise countermeasures, and one or more frames that include a signal that has been subjected to noise countermeasures. Sequential transmission is performed in ascending order of noise countermeasures. Then, the transmitted frames are sequentially received, and a signal to be used in subsequent processing is selected based on whether or not an error has occurred in the signal included in the received frame.

  Thereby, for example, processing for transmitting and receiving the detection result of the bit error rate becomes unnecessary, and communication responsiveness can be improved.

  Further, it may further comprise error correction processing means for performing error correction processing on the signal in which an error has occurred, and the transmission means includes a frame including the signal not subjected to noise countermeasures, Continuously transmitting two frames, including a frame including the signal subjected to a measure against noise, and the selecting means has a predetermined error when an error occurs in the signal not subjected to noise countermeasure The signal on which a measure against noise is taken is selected, and the error correction processing means performs error correction processing on the signal selected by the selection means.

  Thereby, even in a wireless communication environment in which an error occurs in a signal of a frame for which noise countermeasures are not taken, communication can be performed reliably.

  The noise countermeasure applied to the signal transmitted from the transmission means is at least one of a method of adding an error correction code, a method of reducing the bit rate, and a method of extending the preamble length. Can be done in two ways.

  Thereby, communication can be reliably performed even in various wireless communication environments.

  The transmission device according to the second aspect of the present invention is a transmission device that transmits a signal, a noise countermeasure unit that performs noise countermeasures on the signal, a frame that includes the signal that is not subjected to noise countermeasures, Transmitting means for sequentially transmitting one or more frames including the signal subjected to noise countermeasures by the noise countermeasure means in ascending order of noise countermeasures;

  In the second aspect of the present invention, the signal includes a frame that includes a signal that has been subjected to noise countermeasures and that has not been subjected to noise countermeasures, and one or more signals that include a signal that has been subjected to noise countermeasures by noise countermeasure means. Frames are sequentially transmitted in ascending order of noise countermeasures.

  As a result, for example, processing for transmitting and receiving the detection result of the bit error rate becomes unnecessary, and responsiveness of communication with the receiving device that receives the transmitted signal can be improved.

  The receiving apparatus according to the third aspect of the present invention includes a frame including the signal not subjected to noise countermeasures and one or more frames including the signal subjected to noise countermeasures by the noise countermeasure means. A receiving device that communicates with a transmitting device that sequentially transmits in order from a small degree of countermeasure, the receiving device sequentially receiving the frames transmitted from the transmitting device, and the frame included in the frame received by the receiving device Selection means for selecting a signal to be used in subsequent processing based on whether or not an error has occurred in the signal.

  In the third aspect of the present invention, frames to be transmitted from the transmission device are sequentially received, and a signal used in subsequent processing is determined based on whether or not an error has occurred in the signal included in the frame. Selected.

  Thereby, for example, processing for transmitting and receiving the detection result of the bit error rate becomes unnecessary, and the responsiveness of communication with the transmitting apparatus that transmits the signal can be improved.

  According to the first, second, and third aspects of the present invention, communication responsiveness can be improved.

It is a block diagram which shows the structural example of one Embodiment of the passive entry system to which this invention is applied. It is a flowchart explaining the process which a vehicle equipment transmits a request signal. It is a flowchart explaining the process in which a portable device receives a request signal and responds.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration example of an embodiment of a passive entry system to which the present invention is applied. In the present specification, the system represents the entire apparatus constituted by a plurality of apparatuses.

  The passive entry system of FIG. 1 includes an in-vehicle device 11 mounted on a vehicle and a portable portable device 12 called FOB or the like possessed by a user of the vehicle.

  For example, when a user carrying the portable device 12 moves into an LF communication area, which is an area where communication is possible using radio waves in the LF (Low Frequency) band output from the in-vehicle device 11, the in-vehicle device 11 and the portable device Wireless communication with 12 is started. The portable device 12 receives a request signal that is transmitted from the in-vehicle device 11 and requests transmission of a vehicle ID (Identification) that identifies the vehicle, and receives an answer signal including the vehicle ID in response to the request by the request signal. Send. And the vehicle equipment 11 determines whether it is a valid user by collating vehicle ID contained in an answer signal.

  As shown in FIG. 1, the in-vehicle device 11 includes antennas 21 and 22, a reception control unit 23, a transmission control unit 24, a memory 25, and an ECU (Electronic Control Unit) 26.

  The antennas 21 and 22 are configured to be able to transmit and receive radio waves in different frequency bands. For example, the antenna 21 receives radio waves in the UHF (Ultra High Frequency) band, and the antenna 22 is in the LF band. Is configured to transmit radio waves. The antenna 21 receives the radio wave transmitted from the portable device 12 and supplies a signal corresponding to the radio wave to the reception control unit 23, and the antenna 22 receives the radio wave corresponding to the signal supplied from the transmission control unit 24. Send.

  The reception control unit 23 demodulates the signal supplied from the antenna 21, for example, demodulates the answer signal described above, and supplies it to the ECU 26. The transmission control unit 24 modulates a signal supplied from the ECU 26 and supplies the modulated signal to the antenna 22 under the control of the ECU 26.

  The memory 25 is configured, for example, as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or the like, and appropriately stores necessary information in addition to the vehicle ID described above.

  The ECU 26 includes a CPU (Central Processing Unit), an input / output circuit, and the like. The ECU 26 is programmed to control the operation of the in-vehicle device 11. For example, the ECU 26 encodes a request signal to be transmitted to the portable device 12, supplies the encoded request signal to the transmission control unit 24, and periodically transmits the request signal via the antenna 22. Then, the ECU 26 waits for an answer signal to be transmitted from the portable device 12 in response to the request signal.

  Then, when transmitting one frame of a predetermined signal, the ECU 26 continuously transmits two frames for signals having the same content. First, the ECU 26 transmits a frame that includes a signal to be transmitted and has no error correction code for correcting an error occurring in the signal (hereinafter, referred to as a frame without an error correction code as appropriate). . Next, the ECU 26 generates an error correction code for correcting an error occurring in the signal to be transmitted, and adds the error correction code to the signal (hereinafter referred to as a frame with an error correction code as appropriate). ). That is, the ECU 26 continuously transmits a frame without an error correction code and a frame with an error correction code, and the frame length of the frame without an error correction code is shorter than that of a frame with an error correction code.

  Further, when the answer signal from the portable device 12 is supplied, the ECU 26 is a legitimate user by collating the vehicle ID stored in the memory 25 with the vehicle ID included in the answer signal. It is determined whether or not. When the ECU 26 determines that the user is a legitimate user, for example, the ECU 26 transmits a signal permitting unlocking of the door to a control unit of a locking mechanism (not shown).

  The portable device 12 includes antennas 41 and 42, a reception control unit 43, a transmission control unit 44, a buffer memory 45, a memory 46, and a control unit 47.

  The antenna 41 receives a radio wave in the LF band transmitted from the in-vehicle device 11 and supplies a signal corresponding to the radio wave to the reception control unit 43, and the antenna 42 corresponds to the signal supplied from the transmission control unit 44. To transmit UHF radio waves.

  The reception control unit 43 demodulates the signal supplied from the antenna 41 and supplies the demodulated signal to the buffer memory 45. The transmission control unit 44 modulates the signal supplied from the control unit 47 and supplies the modulated signal to the antenna 42 under the control of the control unit 47.

  The buffer memory 45 temporarily accumulates signals supplied from the reception control unit 43. The memory 46 appropriately stores necessary information in addition to the vehicle ID described above.

  The control unit 47 is a so-called microcomputer composed of a CPU, ROM (Read Only Memory), RAM (Random Access Memory), etc., and the CPU expands and executes a program stored in the ROM in the RAM. , Functions as a decoding unit 51, an error correction processing unit 52, and a transmission signal creation unit 53. Then, when one frame of the signal transmitted from the in-vehicle device 11 is accumulated in the buffer memory 45, the control unit 47 reads the one frame and performs processing based on the signal.

  The decoding unit 51 decodes the signal read from the buffer memory 45.

  As described above, the in-vehicle device 11 continuously transmits the frame without the error correction code and the frame with the error correction code, and the decoding unit 51 stores the frame without the error correction code in the buffer memory 45. First, a frame without an error correction code is decoded. Then, the decoding unit 51 supplies the decoded signal to the transmission signal creation unit 53 if the error is not included in the signal as a result of decoding the frame without the error correction code.

  On the other hand, if the decoding unit 51 decodes the frame without the error correction code and the signal includes an error, the decoding unit 51 waits until the frame with the error correction code to be transmitted is accumulated in the buffer memory 45. The frame with the error correction code is read from the buffer memory 45 and decoded. Then, the decoding unit 51 supplies a signal obtained as a result of decoding the frame with the error correction code to the error correction processing unit 52.

  As described above, the decoding unit 51 decodes the frame without the error correction code, and based on whether an error has occurred in the signal, the signal of the frame without the error correction code, the signal of the frame with the error correction code, Of these, the signal used by the transmission signal creation unit 53 is selected.

  The error correction processing unit 52 uses the error correction code included in the signal supplied from the decoding unit 51, that is, the signal obtained by decoding the frame with the error correction code, to correct the error included in the signal, The signal obtained as a result is supplied to the transmission signal creation unit 53.

  The transmission signal creation unit 53 creates a signal to be transmitted to the in-vehicle device 11 according to the signal supplied from the decoding unit 51 or the error correction processing unit 52 and supplies the signal to the transmission control unit 44. For example, when a request signal transmitted from the in-vehicle device 11 is supplied from the decoding unit 51 or the error correction processing unit 52, the transmission signal creating unit 53 reads the vehicle ID from the memory 46 and outputs an answer signal including the vehicle ID. The answer signal is generated, and the answer signal is encoded and supplied to the transmission control unit 44.

  In the portable device 12 configured as described above, if there is no error in the frame without the error correction code, processing based on the frame without the error correction code is performed, and if an error occurs in the frame without the error correction code. Then, processing based on a frame with an error correction code transmitted next is performed. That is, in the portable device 12, a frame without an error correction code and a frame with an error correction code are selectively used depending on an error that occurs according to the communication environment.

  Next, FIG. 2 is a flowchart for explaining processing in which the in-vehicle device 11 in FIG. 1 transmits a request signal.

  For example, the in-vehicle device 11 periodically outputs a request signal at a predetermined interval, and the processing is started when it is time to transmit the request signal. In step S11, the ECU 26 encodes the request signal to transmit the request signal. 24. The transmission control unit 24 modulates the request signal, transmits a frame without an error correction code via the antenna 42, and the process proceeds to step S12.

  In step S12, the ECU 26 generates an error correction code for correcting an error occurring in the request signal, adds the error correction code to the request signal, and the process proceeds to step S13.

  In step S <b> 13, the ECU 26 encodes the request signal to which the error correction code is added in step S <b> 12 and supplies the encoded request signal to the transmission control unit 24. The transmission control unit 24 modulates the request signal to which the error correction code is added, transmits the frame with the error correction code via the antenna 42, and the process ends.

  As described above, the in-vehicle device 11 sequentially transmits a frame without an error correction code and a frame with an error correction code. Here, the in-vehicle device 11 transmits the frame without the error correction code and the frame with the error correction code continuously (without providing a transmission interval), and between the frame without the error correction code and the frame with the error correction code. May be transmitted with a predetermined interval, for example, an interval of about 10 bits. When a frame without an error correction code and a frame with an error correction code are transmitted continuously, a preamble can be added only to the head of a frame without an error correction code.

  Next, FIG. 3 is a flowchart for explaining processing in which the portable device 12 of FIG. 1 receives and responds to a request signal.

  The portable device 12 is normally in a standby mode that waits for a signal transmitted from the in-vehicle device 11. When the portable device 12 enters the LF communication area of the in-vehicle device 11, the reception control unit 43 in step S21. Receives the frame without the error correction code transmitted in step S11 of FIG. The reception control unit 43 stores the received frame without error correction code in the buffer memory 45 in order from the first bit. When the reception control unit 43 stores one frame of frames without error correction code in the buffer memory 45, the process proceeds to step S22.

  In step S <b> 22, the decoding unit 51 of the control unit 47 reads and decodes the frame without the error correction code from the buffer memory 45.

  After the process of step S22, the process proceeds to step S23, and the decoding unit 51 determines whether or not an error is included in the request signal obtained as a result of decoding in step S22.

  For example, in the request signal transmitted from the in-vehicle device 11, a bit string (for example, vehicle ID) having a value determined at a predetermined fixed position is arranged, and the decoding unit 51 is arranged at the fixed position. If the bit string matches the bit string of the determined value, it is determined that the request signal contains no error. On the other hand, if the bit strings do not match, the decoding unit 51 determines that an error is included in the request signal. Also, CRC (Cyclic Redundancy Check) may be used as a method for determining whether or not an error is included in the request signal. For example, the in-vehicle device 11 transmits a request signal with a parity bit added, and the portable device 12 can determine whether or not the request signal contains an error based on the parity bit.

  In step S23, when the decoding unit 51 determines that the request signal does not include an error, the process proceeds to step S24. In this case, even if a frame with an error correction code transmitted following a frame without an error correction code is received by the reception control unit 43 and stored in the buffer memory 45, the decoding unit 51 does not have a frame with an error correction code. Is ignored.

  In step S24, the decoding unit 51 supplies the request signal decoded in step S22 to the transmission signal generating unit 53. The transmission signal creation unit 53 reads the vehicle ID from the memory 46 according to the request signal, creates an answer signal, encodes it, and supplies it to the transmission control unit 44.

  After the process of step S24, the process proceeds to step S25, and the transmission control unit 44 modulates the answer signal supplied from the transmission signal generation unit 53 in step S24, and transmits it to the in-vehicle device 11 via the antenna 42 for processing. Ends.

  On the other hand, when the decoding unit 51 determines in step S23 that the request signal includes an error, the process proceeds to step S26.

  In step S <b> 26, the reception control unit 43 receives the frame with the error correction code transmitted in step S <b> 13 in FIG. 2 and stores it in the buffer memory 45. When the reception control unit 43 stores one frame of the frame with the error correction code in the buffer memory 45, the process proceeds to step S27.

  In step S27, the decoding unit 51 reads and decodes the frame with the error correction code from the buffer memory 45, supplies the request signal obtained as a result to the correction processing unit 52, and the process proceeds to step S28.

  In step S28, the correction processing unit 52 performs error correction processing on the request signal supplied from the decoding unit 51 in step S27 using the error correction code added to the request signal, and the request obtained as a result A signal (correct request signal) is supplied to the transmission signal creation unit 53.

  After the process of step S28, the process proceeds to step S24, and the process described above is performed below. In this case, the transmission signal creation unit 53 creates an answer signal in accordance with the request signal from the correction processing unit 52.

  As described above, in the passive entry system including the in-vehicle device 11 and the portable device 12, the in-vehicle device 11 continuously transmits the frame without the error correction code and the frame with the error correction code, and the portable device 12 Since these frames are selectively used due to an error that occurs according to the wireless communication environment, communication responsiveness can be improved.

  That is, in a wireless communication environment in which no communication error occurs, the portable device 12 performs processing based on a frame without an error-correcting code having a short frame length that is transmitted first, so that it takes less time to receive a signal. In addition, the processing time can be shortened by eliminating the need for error correction processing, and the answer signal can be transmitted more quickly. Specifically, the portable device 12 can confirm that no error has occurred in the frame without the error correction code before the reception of the frame with the error correction code is completed. Based processing can be performed.

  In addition, since the portable device 12 performs the process based on the frame without the error correction code, for example, it is possible to suppress the consumption of the battery that drives the portable device 12 as compared with the case where the error correction process is performed. Thereby, the battery of the portable device 12 can have a long life.

  Further, in this passive entry system, for example, a process of transmitting / receiving a bit error rate detection result when starting communication is unnecessary, and therefore it is possible to avoid a decrease in responsiveness due to such a process.

  Furthermore, in a wireless communication environment in which a communication error occurs, the portable device 12 performs processing based on a frame with an error correction code. Therefore, even in such a communication environment, communication with the in-vehicle device 11 is reliably performed. Communication quality can be maintained.

  The in-vehicle device 11 may transmit two or more frames continuously, for example, three frames continuously, for example, a frame without an error correction code, a frame to which an error correction code with a small number of bits is added. , And frames to which an error correction code having a large number of bits is added may be continuously transmitted. As described above, the in-vehicle device 11 can sequentially transmit a plurality of frames in the order from the smallest noise countermeasure, and thereby can quickly respond in a wireless communication environment in which no communication error occurs. At the same time, in a wireless communication environment in which a communication error occurs, communication can be reliably performed with an error correction code having a large number of bits and high error correction capability.

  In the present embodiment, as a noise countermeasure, a method for transmitting a signal with an error correction code added has been described, but other than the method for adding an error correction code, for example, a method for reducing the bit rate, A method of extending the preamble length can be employed.

  For example, in the method for reducing the bit rate, the in-vehicle device 11 transmits one frame at a bit rate lower than normal after transmitting one frame at the normal bit rate. In general, transmission at a low bit rate is more resistant to noise and less likely to generate errors than transmission at a high bit rate. Therefore, the portable device 12 is switched to a mode in which the reception control unit 43 receives a signal at a bit rate lower than normal when an error occurs due to reception of a frame transmitted at a normal bit rate, A signal at a bit rate lower than usual can be received.

  In the method of extending the preamble length, the in-vehicle device 11 transmits one frame with a preamble length longer than usual after transmitting one frame with a normal preamble length. In general, when the preamble length is longer, synchronization can be achieved at the time of reception than when the preamble length is shorter, and the signal can be reliably received. Therefore, when the portable device 12 fails to receive a frame transmitted with a normal preamble length, the portable device 12 can reliably receive a signal with a frame transmitted with a longer preamble length.

  In addition, as a noise countermeasure, methods other than these methods may be used, or these methods may be used in combination. Thus, by adopting various noise countermeasures, communication can be reliably performed even in various wireless communication environments.

  The portable device 12 may transmit an ID unique to the portable device 12 as an answer signal in response to the request signal from the in-vehicle device 11.

  In addition, the processes described with reference to the flowcharts described above do not necessarily have to be processed in time series in the order described in the flowcharts, but are performed in parallel or individually (for example, parallel processes or objects). Processing). Further, the program may be processed by a single CPU, or may be processed in a distributed manner by a plurality of CPUs.

  The embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  DESCRIPTION OF SYMBOLS 11 In-vehicle apparatus, 12 Portable machine, 21 and 22 antenna, 23 Reception control part, 24 Transmission control part, 25 Memory, 26 ECU, 41 and 42 Antenna, 43 Reception control part, 44 Transmission control part, 45 Buffer memory, 46 Memory , 47 control unit, 51 decoding unit, 52 error correction processing unit, 53 transmission signal creation unit

Claims (6)

Noise countermeasure means for taking noise countermeasures on signals,
Transmitting means for sequentially transmitting a frame including the signal not subjected to noise countermeasures and one or more frames including the signal subjected to noise countermeasures by the noise countermeasure means in ascending order of noise countermeasures; ,
Receiving means for sequentially receiving the frames transmitted from the transmitting means;
A communication system comprising: selection means for selecting a signal to be used in subsequent processing based on whether an error has occurred in the signal included in the frame received by the reception means. Error correction processing means for performing error correction processing on the signal in which an error has occurred, further comprising:
The transmission means continuously transmits two frames, a frame including the signal not subjected to noise countermeasures and a frame including the signal subjected to a predetermined degree of noise countermeasures,
The selection means, when an error has occurred in the signal that has not been subjected to noise countermeasures, to select the signal that has been subjected to a predetermined degree of noise countermeasures,
The communication system according to claim 1, wherein the error correction processing unit performs error correction processing on the signal selected by the selection unit. The noise countermeasure applied to the signal transmitted from the transmission means is at least one of a method of adding an error correction code, a method of reducing a bit rate, and a method of extending a preamble length The communication system according to claim 1 or 2. Take measures against noise on the signal,
A frame including the signal not subjected to noise countermeasures and one or more frames including the signal subjected to noise countermeasures are sequentially transmitted in ascending order of noise countermeasures;
Sequentially receiving the transmitted frames,
A communication method including a step of selecting a signal to be used in subsequent processing based on whether or not an error has occurred in the signal included in the received frame. In a transmission device that transmits a signal,
Noise countermeasure means for taking noise countermeasures on the signal;
Transmitting means for sequentially transmitting a frame including the signal not subjected to noise countermeasures and one or more frames including the signal subjected to noise countermeasures by the noise countermeasure means in ascending order of noise countermeasures; A transmission apparatus comprising: A transmission apparatus that sequentially transmits a frame including the signal not subjected to noise countermeasures and one or more frames including the signal subjected to noise countermeasures by the noise countermeasure unit in ascending order of noise countermeasures; In a receiving device for communication,
Receiving means for sequentially receiving the frames transmitted from the transmitting device;
A receiving apparatus comprising: selecting means for selecting a signal to be used in subsequent processing based on whether an error has occurred in the signal included in the frame received by the receiving means.

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