JP4670763B2 - Wireless system and program - Google Patents

Description

  The present invention is a system in which wireless transmission / reception is periodically or irregularly performed between 1: 1, 1: N, and M: N devices, and the power-on time required for communication is shortened as much as possible to consume. The present invention relates to a wireless system that reduces power.

  In recent years, security systems have been put into practical use in which an operation lock of an electronic device such as a mobile phone or a personal computer is wirelessly controlled in consideration of security.

  As one form of such a security system, in order to prevent the mobile phone from being stolen, a user of the mobile phone possesses an identification signal transmitter in the form of a card, and the mobile phone and the identification signal transmitter are previously connected. There is a mobile phone that can be used when a predetermined identification code is communicated with each other and the identification code is confirmed by both parties (see, for example, Patent Document 1).

  In Patent Document 1 of this wireless two-way communication system, a device (hereinafter referred to as an authentication device) mounted on the main body side such as an electronic device is periodically issued from a portable device (hereinafter referred to as a wireless key). It is described that the authentication ID is received and collated with the ID stored in the authentication device.

And it is described that an M-sequence signal is transmitted every second as a transmission signal. Although there is no particular description as a method for receiving the M-sequence signal, it is necessary to continue the reception operation for one second or more in order to receive the M-sequence signal without the preamble.
JP 2004-143806 A

  However, in the conventional configuration, in order to receive an M-sequence signal transmitted every second, it is necessary to perform a reception operation continuously for one second or more. In order to perform the receiving operation, it is necessary to turn on the power of the radio circuit, but this part consumes a large amount of power. In the case of a battery-powered device such as a mobile phone as in the conventional configuration, this has a problem of greatly affecting the battery life.

  On the other hand, in the above-described conventional configuration, it is described that an M-sequence signal is transmitted every second, but transmission is performed without continuously receiving for more than one second at the other party, that is, a radio device on the receiving side. A method is also conceivable in which the receiving side measures the timing on the receiving side, and the receiving side wireless unit is turned on at the timing at which the transmitting side will transmit the M-sequence signal.

  However, in that case, the point is how to know the timing of 1 second on the transmission side on the reception side. This is because if it is impossible to accurately know the timing of 1 second on the transmission side, it is necessary to increase the power-on time of the radio unit on the reception side in order to receive. In this regard, in the above-described conventional configuration, there is no description regarding how the receiving side knows the timing of the transmitting side.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a wireless system and a program for performing reliable communication while minimizing current consumption of the wireless device.

  The wireless device A includes a wireless device A and a wireless device B. The wireless device A wirelessly transmits a first identification signal at a predetermined cycle, and transmits at least one of the first identification signals, and then In the wireless system that wirelessly transmits the second identification signal at T1 that is an integer multiple cycle, the wireless device B receives the second identification signal transmitted by the wireless device A, thereby The transmission cycle interval T1 of the identification signal is measured by the internal clock of the wireless device B, and the time error ΔT is calculated from the value measured by the internal clock and the transmission cycle interval T1, and then the wireless device A transmits the time difference ΔT. In order to measure the timing of transmitting the second identification signal, the (T1 + ΔT) time is measured by the internal clock of the radio B, and the next reception of the second identification signal is started at the timing (T1 + ΔT) time. In the configuration to The time error ΔT calculated by the internal clock when receiving the second identification signal is added to the previous time error every time the second identification signal is received, and the result is used as the current time error. In this wireless system, the time error is measured by the internal clock this time, and reception of the next second identification signal is started at the timing when the measurement is completed.

  Further, since the relative error between the timepiece of the wireless device A and the timepiece of the wireless device B can be eliminated, the reception time of the signal including the first or second identification signal can be minimized and the current consumption can be reduced. It will greatly contribute to the reduction of

  According to the present invention, it is possible for the wireless device to reliably calculate the deviation of its internal clock with respect to the counterpart wireless device and accurately calculate the next reception timing. The power ON time can be suppressed to the minimum necessary, and the current consumption of the radio can be greatly reduced.

  For example, it is possible to achieve both the battery life of the wireless key and the convenience of misplacement and theft prevention.

  1st invention is comprised with the radio | wireless machine A and the radio | wireless machine B, and the said radio | wireless machine A wirelessly transmitted the 1st identification signal with the predetermined period, and transmitted at least 1 or more of said 1st identification signals. Thereafter, in the wireless system that wirelessly transmits the second identification signal at T1 that is a period that is an integral multiple of the predetermined period, the wireless device B receives the second identification signal transmitted by the wireless device A. Thus, the transmission cycle interval T1 of the second identification signal is measured by the internal clock of the wireless device B, the time error ΔT is calculated from the value measured by the internal clock and the transmission cycle interval T1, and then In order to measure the timing at which the second identification signal is transmitted from the wireless device A, the (T1 + ΔT) time is measured by the internal clock of the wireless device B, and the next second time is measured at the timing of the (T1 + ΔT) time. Configuration that starts receiving the identification signal The time error ΔT calculated by the internal clock when receiving the second identification signal is added to the previous time error every time the second identification signal is received, and the result is the current time error. The current time error is measured by the internal clock, and reception of the next second identification signal is started at the timing when the measurement is completed.

  In addition, since the relative error between the timepiece of the wireless device A and the timepiece of the wireless device B can be eliminated, the reception time of the signal including the second identification signal can be minimized, greatly reducing current consumption. Will contribute.

2nd invention is comprised with the radio | wireless machine A and the radio | wireless machine B, and the said radio | wireless machine A wirelessly transmitted the 1st identification signal with the predetermined period, and transmitted at least 1 or more of the said 1st identification signal. Thereafter, in the wireless system that wirelessly transmits the second identification signal at T1 that is a period that is an integral multiple of the predetermined period, the wireless device B receives the second identification signal transmitted by the wireless device A. Thus, the transmission cycle interval T1 of the second identification signal is measured by the internal clock of the wireless device B, the time error ΔT is calculated from the value measured by the internal clock and the transmission cycle interval T1, and then In order to measure the timing at which the second identification signal is transmitted from the wireless device A, the (T1 + ΔT) time is measured by the internal clock of the wireless device B, and the next second time is measured at the timing of the (T1 + ΔT) time. Configuration that starts receiving the identification signal The wireless device A wirelessly transmits the first identification signal at the predetermined cycle, and the wireless device B receives the first identification signal transmitted at the predetermined cycle, the ΔT is set to a predetermined value. The value divided by the integer is regarded as the clock error of the radio device A and the radio device B per the predetermined period, and the timing at which the signal including the first identification signal is received by correcting the clock error. The time error ΔT calculated by the internal clock when receiving the second identification signal is added to the previous time error every time the second identification signal is received, and the result is obtained this time. A value obtained by dividing the current time error by a predetermined integer is regarded as the current time error of the wireless device A and the wireless device B per predetermined cycle, and the time error per predetermined cycle is With the internal clock Constant and, at the timing when the measurement is completed is obtained by the configuration starts receiving the next of said first identification signal.

  In addition, since the relative error between the timepiece of the wireless device A and the timepiece of the wireless device B can be eliminated, the reception time of the signal including the first identification signal can be minimized, greatly reducing current consumption. Will contribute.

  A third aspect of the invention is based on a point in time when the wireless device B detects a code for identifying the head of data in a preamble signal included in the second identification signal transmitted from the wireless device A. The time error ΔT is calculated.

  And since the error with the radio A is calculated based on the reception time of the signal for identifying the head of the data, the error can be calculated reliably, improving the communication accuracy and reducing the current consumption. It will greatly contribute to coexistence.

  According to a fourth aspect of the present invention, the wireless device B starts receiving the second identification signal when there is no error between the internal clock of the wireless device A and the internal clock of the wireless device B. The time until the detection of the code for identifying the head of the data is calculated in advance as an ideal value, and the data in the preamble signal from the timing at which reception of the ideal value and the second identification signal starts. The time until the detection of the code for identifying the head of the is compared, and the difference is set as the time error ΔT.

  Since the difference from the ideal value known in advance is calculated in order to calculate the error, the transmission timing of the wireless device A can be reliably measured, and the error can be calculated reliably. This greatly contributes to both improvement in communication accuracy and reduction in current consumption.

  According to a fifth aspect of the present invention, the wireless device B compares the ideal value A with the case where the second identification signal is received in a state where the error between the T1 measured by the wireless device A and its own internal clock is unknown. The wireless device A has the T1 measured by the wireless device A and the ideal value B to be compared when the second identification signal is received in a state where the error of its own internal clock is known. When the second identification signal is received in a state where the difference between the T1 and its own internal clock is not known, the head of the data in the preamble signal is identified from the timing when the reception of the second identification signal is started. The ideal time value A is compared with the time until the code for detecting the difference is set as the time error ΔT, and the error of T1 measured by the radio A and its own internal clock is known. When the second identification signal is received Includes comparing the ideal value B with the time from the start of receiving the second identification signal to the detection of the code for identifying the head of the data in the preamble signal, The error is ΔT.

  By calculating the clock error when the relative error is unknown and calculating the clock error when the relative error is known using separate arithmetic expressions, temporal synchronization correction can be reliably performed. This greatly contributes to both improvement in communication accuracy and reduction in current consumption.

  According to a sixth aspect of the present invention, the wireless device A transmits a plurality of the second identification signals having different preamble signal lengths to the wireless device B, and the wireless device B transmits the preamble of the second identification signal. A configuration having a plurality of ideal values for each signal length is adopted.

  For example, even when the preamble signal length differs between initial transmission and retransmission, error correction at the time of re-transmission / reception can be reliably performed, which greatly contributes to both improvement in communication accuracy and reduction in current consumption.

  The seventh invention is a program for causing a computer to realize at least a part of the wireless system of the first to sixth inventions. Since it is a program, at least a part of the present invention can be realized with simple hardware by cooperating hardware resources such as an electric / information device and a computer. In addition, the program can be distributed / updated and installed easily by recording on a recording medium or distributing the program using a communication line.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a block diagram of a radio system according to the first embodiment of the present invention.

  1 is a first antenna, 2 is a radio A, 3 is a first transmission / reception means, 4 is a first time control means, 5 is a first authentication means, 6 is a second antenna, 7 Is a radio B, 8 is a second transmission / reception means, 9 is a second time control means, and 10 is a second authentication means. Reference numeral 11 denotes a mobile phone connected to the wireless device.

  The wireless device A2 is, for example, a wireless key that is carried by the user of the mobile phone 11. The wireless device B7 restricts the use of the mobile phone 11 when the reception level of the radio wave from the wireless device A2 becomes weak. In FIG. 1, the mobile phone 11 and the wireless device B 7 are shown separately, but the wireless device B 7 is often built in the mobile phone 11.

  2 and 3 show a communication sequence between the wireless device A2 and the wireless device B7. FIG. 2 shows a communication sequence in search mode, and FIG. 3 shows a communication sequence in authentication mode.

  The search mode is a mode in which the wireless device A2 and the wireless device B7 confirm each other's existence and shift to the authentication mode.

  The authentication mode is a mode in which the wireless device A2 and the wireless device B7 regularly communicate with each other in time synchronization to confirm the existence of the other party. The presence of the other party is confirmed in the authentication mode, and the wireless device B7 does not restrict the use of the mobile phone 11 while receiving radio waves from the wireless device A2 at a predetermined reception level or higher.

  The search mode communication sequence will be described with reference to FIG.

The wireless device A2 periodically transmits a search signal 12. The time interval for transmitting the search signal 12 is, for example, every second. The search signal 12 includes a part of the ID indicating the wireless device A2.

  When receiving the search signal 12, the wireless device B7 transmits a search response 13 to the wireless device A2. When the wireless device A2 receives the search response 13, the wireless device A2 transmits an ID signal (1) 14 including all the IDs of the wireless device A2. The wireless device B7 compares the ID signal (1) 14 with the ID of the communication partner held inside the wireless device B7. If they match, the wireless device B7 generates an ID signal (2) 15 including the entire ID of the wireless device B7. Send.

  Then, when the wireless device A2 transmits the confirmation signal (1) 16 and the wireless device B7 receives the confirmation signal (1) 16, the wireless device A2 transmits the authentication signal (1) 17 created by using the second authentication means 10. Send to. When the wireless device A2 receives the authentication signal (1) 17, the first authentication means 5 creates the authentication signal (2) 18 and transmits it to the wireless device A7. The wireless device B7 receives the authentication signal (2) 18, and transmits a confirmation response signal (1) 19 to the wireless device A2 if authentication is established.

  When the wireless device A2 receives the confirmation response signal (1) 19, it determines that authentication with the wireless device B7 has been established. And it transfers to the authentication mode of FIG.

  In shifting to the authentication mode of FIG. 3, the wireless device A2 starts the timer T1 from the timing at which the authentication signal (2) 18 is transmitted. The wireless device B7 synchronizes with the wireless device A2 at the timing when the response signal 18 is received, and starts the timer T1 '.

  Next, a communication sequence in the authentication mode of FIG. 3 will be described.

  The wireless device A2 transmits a simple ID signal 20 that is a first identification signal when the timer T1 is an integer multiple of 4 seconds. The wireless device B7 receives at the timing of the simple ID signal 20 and measures the reception level.

  If the reception level is less than or equal to a predetermined value, the counter built in the second authentication means 10 constituting the wireless device B7 is incremented assuming that the distance from the wireless device A2 is more than the predetermined distance. When the counter reaches a predetermined count, a function restriction signal is output to the mobile phone 11.

  If the reception level is equal to or higher than a predetermined level, the counter is cleared. That is, when the reception level of the simple ID from the wireless device A2 every 4 seconds is continuously below the predetermined level and reaches the predetermined number of times, the use restriction signal is output.

  When the timer T1 reaches 32 seconds, the wireless device A2 transmits a confirmation signal (1) 21 that is a second identification signal. The wireless device B7 also starts reception when the timer T1 'elapses and receives the confirmation signal (1) 21. Then, the wireless device B7 creates and transmits an authentication signal (1) 22 created using the second authentication means 10.

  The wireless device A2 starts the timer T1 again at the timing when the confirmation signal (1) 21 is transmitted. When the authentication signal (1) 22 is received, it is determined that the authentication has been established and enters a dormant state.

When the wireless device A2 cannot receive the confirmation signal (1) 21, it transmits the confirmation signal (1) first retransmission 23 after T2 from the timing of transmitting the confirmation signal (1) 21, and the confirmation signal (1) retransmission 1 The timer T1 is started again at the timing of transmitting the 23rd time. If the authentication signal (1) 24 cannot be received, the confirmation signal (1) second retransmission 25 is transmitted after T3 from the timing of transmitting the confirmation signal (1) first retransmission 23, and the confirmation signal (1) second retransmission. The timer T1 is started again at the timing when 25 is transmitted. Then, the authentication signal (1) 26 is received.

  When the authentication signal (1) 26 cannot be received, the search signal 27 is transmitted after T4 from the timing of transmitting the confirmation signal (1) second retransmission 25, and the search mode is entered.

  On the other hand, the wireless device B7 measures the error between the internal clock of the wireless device A2 and the internal clock of the wireless device B7 at the timing when the confirmation signal (1) 21 is received. Then, the timer T1 'is started again.

  Thereafter, the sequence shown in FIG. 3 is repeated. At the next 32 seconds, the authentication signal (2) 18 shown in FIG. 2 is used instead of the exchange of the confirmation signal (1) 21 and the authentication signal (1) 22. Confirmation response signal (1) 19 is exchanged. In the next 32 seconds, the confirmation signal (1) 21 and the authentication signal (1) 22 are exchanged again.

  Here, a time error between the timer T1 of the wireless device A2 and the timer T1 'of the wireless device B7 will be considered. T1 measured by the wireless device A2 is measured based on the internal clock possessed by the wireless device A2, and T1 'measured by the wireless device B7 is measured based on the internal clock possessed by the wireless device B7.

  Here, T1 'measured by the wireless device B7 is essentially the same time as T1 measured by the wireless device A2, but the internal clocks of the wireless device A2 and the wireless device B7 have absolute accuracy. When the absolute accuracy of the timepiece is ± 100 ppm, the relative error between the timepieces of the wireless device A2 and the wireless device B7 is ± 200 ppm. Therefore, a relative error of ± 6.4 msec (assuming ΔT) occurs at 32 seconds.

  Therefore, when receiving the first confirmation signal (1) 21 that has shifted from the search mode to the authentication mode, the radio B7 has a value that is 6.4 milliseconds less than 32 seconds in consideration of the relative error ± 6.4 milliseconds. It is necessary to start reception when T1 ′ has elapsed.

  Therefore, the wireless device B7 starts the timer T1 ′ when the authentication signal (2) 18 is received and starts reception when the timer T1 ′ has elapsed, thereby reliably receiving the confirmation signal (1) 21. Will be able to.

  On the other hand, as described above, the wireless device B7 measures the error between the internal clock of the wireless device A2 and the internal clock of the wireless device B7 at the timing when the confirmation signal (1) 21 is received. Relative error ΔT with respect to the wireless device A2. When the wireless device B7 measures the relative error ΔT, the reception timing of the next 32 seconds is a time T1 ′ corrected by ΔT from the 32 seconds indicated by the timer T1 measured by the wireless device A2.

  In the example of FIG. 3, a value obtained by subtracting ΔT from 32 seconds is the reception timing of the next 32 seconds, which is T1 ′ to be measured by the wireless device B7. Here, since the simple ID 20 is transmitted every 4 seconds, correction of the reception timing of the simple ID 20 subtracts ΔT × n / 8 from the value of the timer T1 '. n is the nth reception timing of the simple ID 20. The time error ΔT with respect to the timer T1 of the wireless device A2 is measured at the next 32 second reception timing and added to the previous ΔT. The above-described correction is performed using ΔT as a result of the addition. Thereafter, this correction process is repeated.

  Here, details of this correction processing will be described.

  FIG. 4 shows a message format of the confirmation signal (1) 21 and the authentication signal (2) 18. As shown in FIG. 4, the confirmation signal (1) 21 and the authentication signal (2) 18 are generated from a bit synchronization signal for synchronizing each bit constituting the code and a frame synchronization signal for identifying the head of data. It consists of a preamble signal and a data part.

  Here, since the frame synchronization signal is for identifying the head of the data, the radio B7 on the side receiving the request signal 21 receives the frame synchronization signal, thereby confirming the signal (1) 21. And the timing of the wireless device A2 on the transmission side of the authentication signal (2) 18 can be identified.

  Next, FIG. 5 shows an operation when the wireless device B 7 receives the request signal 21 and the response signal 18. FIG. 7 shows an operation flowchart of the wireless device B7 at this time. In FIG. 5, since the vertical axis represents time, the confirmation signal (1) 21 and the authentication signal (2) 18 transmitted from the wireless device A2 to the wireless device B7 are written with diagonal lines.

  In FIG. 5, the wireless device A2 transmits a simple ID signal 20 at a timer T1 / 8 × n, that is, every 4 seconds. Then, when the timing of 32 seconds, that is, the time of timer T1 / 8 × 8 = T1 has elapsed, “transmission preparation” of confirmation signal (1) 21 and authentication signal (2) 18 is started. “Transmission preparation” is an operation of turning on the power of the wireless transmission unit or adjusting the transmission frequency.

  When the “transmission preparation” is completed, the wireless device A2 transmits a confirmation signal (1) 21 and an authentication signal (2) 18 to the wireless device B7. Here, the time required for “preparation for transmission” is Th. This Th may be the time itself required for “transmission preparation”, or may be measured in advance on the wireless device A2 side, and “transmission preparation” may be completed during this Th.

  After Th elapses, the wireless device A2 starts transmitting the confirmation signal (1) 21 and the authentication signal (2) 18 in the format of FIG.

  On the other hand, the wireless device B7 checks whether the time of the timer T1 '/ 8xn has elapsed (S1 in FIG. 7), and if it has elapsed, checks the number of times n (S2 in FIG. 7). Here, when n ≠ 8, the wireless device B7 determines that the reception timing of the simple ID signal 20 is reached, and increments the number of times n (S3 in FIG. 7), and the next 4-second timer (timer T1 ′ / 8). Is started (S4 in FIG. 7), and the simple ID signal 20 is received (S5 in FIG. 7).

  Next, timer T1 '/ 8x8 = T1', that is, when 32 seconds have elapsed, n = 1 is set (S6 in FIG. 7). At this time, the wireless device B7 starts measuring Ta (S7 in FIG. 7). Here, Ta indicates the time from when the reception preparation is started until the reception of the frame synchronization signal included in the confirmation signal (1) 21 and the authentication signal (2) 18 is completed.

  In addition, the wireless device B7 also starts measuring Tg in order to start “reception preparation” (S7 in FIG. 7). Here, “reception preparation” is an operation of turning on the power of the wireless reception unit or adjusting the reception frequency. When the “preparation for reception” is completed, the wireless device B7 starts receiving the confirmation signal (1) 21 and the authentication signal (2) 18.

  Here, Tg is the time required for “reception preparation”. This Tg may be the time required for “preparation for reception” or may be measured in advance on the side of the wireless device B7, and “preparation for reception” may be completed during this Tg.

  After Tg has elapsed (S9 in FIG. 7), the wireless device B7 starts receiving the confirmation signal (1) 21 and the authentication signal (2) 18.

Since the frame synchronization signal is for identifying the head of the data as described above, the wireless device B7 receives the frame synchronization signal (S10 in FIG. 7) and stops the timer for measuring Ta (see FIG. 7 (S12) and thereafter, the data portion is recognized and received, and the completion of data reception is awaited (S13 in FIG. 7).

  Here, in an ideal state where there is no error between the internal clocks of the wireless device A2 and the wireless device B7, the time from the start of reception preparation to the completion of frame synchronization reception is Tg, the confirmation signal (1) 21 and the authentication signal (2 ) A value obtained by adding 18 bit synchronization lengths and frame synchronization lengths, which is a fixed value predetermined in a systematic manner. This fixed value is set as an “ideal value”, and the radio B7 is provided inside.

  Then, by comparing the Ta measured when actually receiving the confirmation signal (1) 21 with the ideal value, it is calculated how much its own internal clock is deviated from the internal clock of the wireless device A2. .

  Next, calculation and correction of the clock deviation of the wireless device B7 will be described with reference to FIG.

  In FIG. 6, “A” is a value obtained by adding the Tg, the bit synchronization length of the confirmation signal (1) 21 and the authentication signal (2) 18 and the frame synchronization length.

  Upon reception of the first confirmation signal (1) 21 that has shifted from the search mode to the authentication mode, the timer T1 ′ measured by the wireless device B7 is 6.4 milliseconds shorter than T1 measured by the wireless device A2 as described above. And shall be. Therefore, in FIG. 5, the timing at which the wireless device B7 starts to prepare for reception is 6.4 msec earlier than the timing at which the wireless device A2 starts to prepare for transmission. Therefore, the “ideal value” of Ta at this time is 6.4 ms + A.

  Therefore, when the first confirmation signal (1) 21 that has shifted from the search mode to the authentication mode is received (S14 in FIG. 7), the wireless device B7 compares the measured Ta with the ideal value of “6.4 ms + A”. (S16 in FIG. 7).

  For example, when the measured Ta is “7.0 msec + A” as shown in FIG. 6, the difference from “ideal value: 6.4 msec + A” is “+0.6 msec”. Therefore, this “+0.6 msec” is set as the correction amount (S21 in FIG. 7). Then, a value obtained by dividing the correction amount by 8 is calculated as a timing every 4 seconds (S22 in FIG. 7), and the timer T1 'is started.

  Then, at the reception timing of the simple ID 20 transmitted every 4 seconds from the wireless device A2, the wireless device B7 performs reception at the timing (S24 in FIG. 7) corrected by ΔT × n / 8 from the value of the timer T1 ′. .

  Here, the value of the timer T1 'not only considers "correction amount: +0.6 msec", but further subtracts 0.95 msec as the value of the timer T1'. This “0.95 ms” is an error in temperature fluctuation of the internal clocks of the wireless device A2 and the wireless device B7.

  That is, when the wireless device B7 receives the first confirmation signal (1) 21 that has shifted from the search mode to the authentication mode, the wireless device B7 has its own internal clock shifted from the internal clock of the wireless device A2. As described above, it is necessary to consider the absolute error ± 6.4 milliseconds considering the absolute accuracy of the watch as described above, but after receiving the confirmation signal (1) 21 once, Since the wireless device B7 can recognize in the form of “correction amount” how much its own internal clock deviates from the internal clock of the wireless device A2, an absolute error ± 6. There is no need to consider 4 ms.

What should be considered here is only the error of the temperature fluctuation of the internal clock for 32 seconds, which is the interval at which the wireless device A2 alternately transmits the confirmation signal (1) 21 and the authentication signal (2) 18. Assuming that the error of the temperature fluctuation for 32 seconds is 0.95 milliseconds, the wireless device B7 transmits the authentication signal (2) 18 at the next timing of receiving the authentication signal (2) 18. Must also start receiving 0.95 ms. Therefore, the value of the timer T1 ′ is set to a value obtained by subtracting 0.95 milliseconds from “correction amount: +0.6 milliseconds” (S23 in FIG. 7).

  Next, the wireless device B7 checks whether the time of the timer T1 ′ / 8 × n has elapsed (S1 in FIG. 7), and if it has elapsed, checks the number of times n (S2 in FIG. 7). Here, when n ≠ 8, the wireless device B7 determines that the reception timing of the simple ID signal 20 is reached, and increments the number of times n (S3 in FIG. 7), and the next 4-second timer (timer T1 ′ / 8). Is started (S4 in FIG. 7), and the simple ID signal 20 is received (S5 in FIG. 7).

  Then, when the timer T1 '/ 8x8 = T1', that is, when the time of 32 seconds has elapsed, "reception preparation" is started as before, and measurement of Ta is started (S7 in FIG. 7). Then, Ta when the response signal 18 is received is compared with the “ideal value”.

  Here, the “ideal value” to be compared with Ta is No. in FIG. 2 is “0.95 msec + A”. This is because, as described above, from the authentication signal (2) 18, the wireless device B7 starts receiving 0.95 milliseconds before the wireless device A. Accordingly, the wireless device B7 determines that it is not the first confirmation signal (1) 21 (S14 in FIG. 7), and compares the “ideal value” of “0.95 milliseconds + A” with the current error (S19 in FIG. 7). .

  Here, when Ta when receiving the authentication signal (2) 18 is “1.00 msec + A” as shown in FIG. 6, the difference from “ideal value: 0.95 msec + A” is “+0.05 msec. Is. Therefore, the reception timing of the authentication signal (2) 18 which is the next 32 seconds, ie, the timing of the third time, is “+0.6 msec” + “+ 0.05 msec” = 0.65 msec as shown in FIG. (S21 in FIG. 7). Of course, the subtraction of 0.95 msec, which is the error of the temperature fluctuation of the internal clock, is also considered (S23 in FIG. 7), and the radio B7 performs the authentication signal (2) at the next time, that is, the third 32 sec timing. The radio B7 performs reception at a timing (S24 in FIG. 7) corrected by ΔT × n / 8 from the value of the timer T1 ′, which is the reception timing of 18.

  By performing the above correction processing, subsequent reception timing of the simple ID 20 (first identification signal) and reception of the confirmation signal (1) 21 or the authentication signal (2) 18 (second identification signal) every 32 seconds. The timing can be matched with the transmission timing of the wireless device A2 without relative error. Thus, eliminating the relative error between the timepiece of the wireless device A2 and the timepiece of the wireless device B7 can minimize the reception time of the simple ID 20 and greatly contribute to the reduction of current consumption.

  Next, the operation in the case of retransmission will be described. As described above, the wireless device A2 cannot receive the authentication signal (1) 22 and the confirmation response signal (1) 19 from the wireless device B7 in response to the transmission of the confirmation signal (1) 21 and the authentication signal (2) 18. Retransmits the confirmation signal (1) the first retransmission 23 and the confirmation signal (1) the second retransmission 25 at most twice. This confirmation signal (1) the first retransmission 23 and the confirmation signal (1) the second retransmission 25 The preamble signal length in the re-transmission text is different from the preamble signal lengths of the confirmation signal (1) 21 and the authentication signal (2) 18 which are the initial transmissions. This is due to the following reason.

  Normally, when there is no other jamming radio wave or when the radio wave environment is good, the wireless device B7 transmits the authentication signal (1) first retransmission 23 or the authentication signal (1) second retransmission 25 which is the initial transmission transmitted by the wireless device A2. Can be normally received, and the authentication signal (1) 22 and the confirmation response signal (1) 19 are transmitted to the wireless device A2. The wireless device A2 transmits the authentication signal (1) 22 and the confirmation response signal (1) 19 to the wireless device A2. Receive correctly. Therefore, no retransmission occurs, and communication every 32 seconds is completed in one round trip.

  On the other hand, there are situations where devices of the same system exist in the vicinity, or other devices emit jamming waves, and the wireless device A2 receives the confirmation signal (1) 21 or the authentication signal (2) from the wireless device B7. If the radio 18 cannot be received correctly, the wireless device A2 performs retransmission.

  In order to reliably communicate with the maximum of two retransmissions, the influence of jamming radio waves must be eliminated as much as possible during retransmission. Therefore, the wireless device A2 transmits the confirmation signal (1) 21 and the authentication signal (2) 18 which are the initial transmissions by the four-value FSK, and the authentication signal (1) first retransmission 23 and the authentication signal (1) retransmission which are the retransmissions. The second time 25 is transmitted by binary FSK. This is because the binary FSK improves the reception sensitivity and the interference disturbance characteristics by about 10 dB compared to the 4-level FSK. That is, by using binary FSK, it becomes strong against interference and the reliability of retransmission communication is increased.

  On the other hand, quaternary FSK has twice the effective transmission rate as compared to binary FSK. That is, even if the same message is transmitted, the four-value FSK requires half the transmission time of the binary FSK. The shorter the transmission time, the shorter the time during which the wireless device A2 and the wireless device B7 perform wireless transmission / reception, and inevitably less current consumption.

  That is, normally, communication is completed every 32 seconds in the first round trip (4-value FSK), so that the current consumption can be reduced. On the other hand, the retransmission that occurs when the wireless device A2 cannot correctly receive the confirmation signal (1) 21 or the authentication signal (2) 18 from the wireless device B7 is reliable communication even if the current consumption increases. The emphasis is on.

  In the configuration as described above, the wireless device A2 transmits the confirmation signal (1) 21 and the authentication signal (2) 18 which are the initial transmissions by four-value FSK, and the authentication signal (1) the first retransmission 23 and the authentication which is the retransmission. Since the signal (1) second retransmission 25 is transmitted by binary FSK, when viewed from the radio B7 side, the confirmation signal (1) 21 and the authentication signal (1) first retransmission 23 or the authentication signal (1) retransmission are transmitted. The second time 25 has different preamble signal lengths because of different transmission rates. Therefore, as described above, the “ideal value” compared with Ta when the wireless device B 7 calculates the clock error ΔT is different.

  Specifically, in FIG. 6, “A” is a value obtained by adding Tg, the bit synchronization length of the confirmation signal (1) 21 and the authentication signal (2) 18 and the frame synchronization length as described above. The synchronization length and the frame synchronization length are the initial transmission values of the confirmation signal (1) 21 and the authentication signal (2) 18.

  Therefore, in the case of retransmission, the radio B7 compares the “ideal value” using the value “B” using the binary FSK bid synchronization length and the frame synchronization length with TaA measured at the time of retransmission. Then, the clock error is calculated (S17, S20 in FIG. 7).

  As a result, the wireless device A2 starts the timer T1 again at the timing of transmitting the authentication signal (1) retransmission first time 23 and the authentication signal (1) second retransmission time 25, which are retransmissions, and changes the timing base point of 32 seconds. Even in this case, ΔT can be calculated and error correction can be performed when the authentication signal (1) retransmission first time 23 and the authentication signal (1) second retransmission 25 are received.

  As described above, in communication in the authentication mode between the wireless device A2 and the wireless device B7, the wireless device B7 can reliably calculate the deviation of its internal clock with respect to the wireless device A2 and accurately calculate the next reception timing. It becomes possible. As a result, the power-on time of the wireless unit to be turned on when the wireless device B7 performs wireless reception can be suppressed to the minimum necessary, and the current consumption of the wireless device can be greatly reduced, and the system Has a huge effect on the spread of

  In addition, the numerical value demonstrated by the said embodiment is an example for demonstrating, and is not limited to this.

  1 described in this embodiment uses hardware resources such as a CPU (or microcomputer), a RAM, a ROM, a storage / recording device, an electric / information device including an I / O, a computer, a server, and the like. You may implement in the form of the program made to cooperate. In the form of a program, new functions can be easily distributed / updated and installed by recording them on a recording medium such as magnetic media or optical media or distributing them using a communication line such as the Internet.

  As described above, the present invention can provide, for example, an electronic device that can achieve both the battery life and misplacement of the wireless key and the convenience of preventing theft. In addition, it can be used in a wireless device that requires low power consumption.

  For example, in the present embodiment, a mobile phone authentication system has been described as an example, but in addition, a personal computer authentication system, a home or office lock / unlock authentication system, an automobile or other lock / unlock system, Entrance / exit management of buildings and offices, provision of services using location information, start / stop of supply of lifelines such as electricity, gas, and water, start / stop of boiling water heaters, AV equipment such as TVs, radios, and PCs It can be used for devices and systems in various fields such as lighting, washing machine, air conditioner, refrigerator, microwave oven ON / OFF control of home appliances, heating / cooling heating / cooling ON / OFF control of toilet seats.

The block diagram of the radio | wireless system in embodiment of this invention Communication sequence diagram in search mode of wireless system in an embodiment of the present invention Communication sequence diagram in authentication mode of wireless system in the embodiment of the present invention Message configuration diagram of request signal and response signal in authentication mode in the embodiment of the present invention Timing chart at the time of receiving a request signal in the authentication mode in the embodiment of the present invention Error determination diagram from ideal value and actual measurement value of authentication mode in the embodiment of the present invention Operation flowchart of receiving-side radio apparatus in authentication mode in the embodiment of the present invention

Explanation of symbols

1 First antenna 2 Radio A
3 First transmission / reception means 4 First time control means 5 First authentication means 6 Second antenna 7 Radio B
8 Second transmission / reception means 9 Second time control means 10 Second authentication means 11 Mobile phone

Claims (6)

It consists of radio A and radio B,
The wireless device A wirelessly transmits a first identification signal at a predetermined period, transmits at least one of the first identification signals, and then performs a second identification at T1 which is a period that is an integral multiple of the predetermined period. In a wireless system for transmitting signals wirelessly,
The wireless device B receives the second identification signal transmitted by the wireless device A, thereby measuring a transmission cycle interval T1 of the second identification signal with an internal clock of the wireless device B, and The time error ΔT is calculated from the value measured by the clock and the transmission cycle interval T1, and then the internal clock of the wireless device B is used to measure the timing of transmitting the second identification signal from the wireless device A. In the configuration of measuring the (T1 + ΔT) time and starting receiving the second identification signal next time at the timing of the (T1 + ΔT) time,
The wireless device A wirelessly transmits the first identification signal at the predetermined cycle, and when the wireless device B receives the first identification signal transmitted at the predetermined cycle, ΔT is a predetermined integer. The divided value is regarded as the clock error of the radio device A and the radio device B per the predetermined period, and the timing for receiving the signal including the first identification signal is determined by correcting the clock error. With configuration,
The time error ΔT calculated by the internal clock when receiving the second identification signal is added to the previous time error every time the second identification signal is received, and the result is the current time error, A value obtained by dividing the current time error by a predetermined integer is regarded as the current time error of the wireless device A and the wireless device B per predetermined cycle, and the time error per predetermined cycle is measured by the internal clock. A wireless system that starts receiving the next first identification signal at the timing when the measurement is completed. The wireless device B uses the time error ΔT as a base point when a code for identifying the head of data in a preamble signal included in the second identification signal transmitted from the wireless device A is detected. The wireless system according to claim 1, wherein the wireless system is configured to calculate. The wireless device B identifies the head of data in the preamble signal from the timing of starting to receive the second identification signal when there is no error between the internal clock of the wireless device A and the internal clock of the wireless device B. In order to identify the leading time of data in the preamble signal from the timing at which reception of the second identification signal is started in advance by calculating the time until detection of a code for performing as an ideal value. The wireless system according to claim 1 , wherein the time until the sign is detected is compared, and the difference is defined as the time error ΔT. The wireless device B has an ideal value A to be compared when the second identification signal is received in a state where the error between the T1 measured by the wireless device A and its own internal clock is unknown, and the wireless device A The T1 to be measured and an ideal value B to be compared when the second identification signal is received in a state where the error of its own internal clock is known,
When the second identification signal is received in a state where the difference between the T1 measured by the wireless device A and its own internal clock is not known, the preamble signal is transmitted from the timing at which reception of the second identification signal is started. The time until the code for identifying the head of the data in the medium is detected and the ideal value A are compared, and the difference is set as the time error ΔT,
When the second identification signal is received in a state where the error between the T1 measured by the wireless device A and its own internal clock is known, the preamble signal is transmitted from the timing when the reception of the second identification signal is started. 4. The radio system according to claim 3 , wherein a time until a code for identifying a head of data therein is detected and the ideal value B are compared and the difference is set as the time error ΔT. The wireless device A transmits a plurality of the second identification signals having different preamble signal lengths to the wireless device B, and the wireless device B transmits a plurality of preamble signal lengths for each preamble signal length of the second identification signal. The wireless system according to claim 3, wherein the wireless system has the ideal value. The program for making a computer implement | achieve at least one part of the radio | wireless system of any one of Claims 1-5 .

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