JPH10136456A - Time correction method for selective call receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly perform time correction even in a weak electric field by performing the time correction with time TB shown by the time correction data of a time correct signal received after the lapse of specified interval when the time TB is settled within the allowable range of time adding the specified interval to reference time. SOLUTION: A receiver is composed of a reception part 1 for receiving a radio signal and a control part 2 for processing the received signal, and a timer 3 is provided inside the control part 2. Then, the built-in timer 3 is started by the 1st time correct signal received without fail, and the time to receive the next time correct signal is measured. The error between this measured time and the time shown by the really received time correct signal is judged and when that error is within the allowable range, the time correction is performed by the received time correct signal but in the other case, the time correction is not performed. Thus, the correction to the erroneous time is prevented, a time correcting function is prevented from being disabled for a long time as well and the time correction can be properly performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a selective calling receiver, and more particularly to a time correcting method for a selective calling receiver which can appropriately correct time in the selective calling receiver.

[0002]

2. Description of the Related Art FLE, a new type of selective calling system
A method for correcting the time of the selective call receiver in X-TD will be described. In FLEX-TD, a time correction signal including "year, month, day," and "hour, minute, second" is transmitted from a base station as a radio signal about once an hour to correct the current time of the selective call receiver. Had become.

Here, the selective calling receiver updates the internal current time when the "year / month / day" and "hour / minute / second" are correctly received. However, since the time correction signal is a radio signal, an error occurs in the time correction signal in a place where the reception electric field is weak. Therefore, the selective calling receiver detects the number of error bits, and detects the number of error bits within a predetermined number of error bits. If so, error correction is performed to allow an error, and time correction is performed by making it easier to receive time correction data.

However, in the above case, as a result of error correction, correct time correction data may not be obtained, and if time correction is performed using this incorrect data, the current time may be different. is there.

Therefore, it is conceivable to perform time correction only when there is no error in the received time correction signal. In this case, if the state where the reception electric field is weak continues for a long time, the selective calling receiver returns to the state of normal reception. It takes a long time to be completed, and time correction is not easily performed.

[0006]

As described above, in the above-mentioned conventional selective call receiver, incorrect time correction in a weak electric field is performed, and the time correction function is not easily performed in some cases, so that the selective call is not performed. There was a problem that time correction could not be properly performed by the receiver.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a time correction method for a selective call receiver which can appropriately perform time correction even in a weak electric field.

[0008]

According to the first aspect of the present invention, there is provided a method for receiving a time correction signal at a specific interval to correct the current time in a selective call receiver. In the correction method, a time TA obtained by adding the specific interval to the reference time indicated by the time correction data of the time correction signal received without error and a time TB indicated by the time correction data of the time correction signal received after the specific interval has elapsed. In comparison, if the time TB is within the allowable range with respect to the time TA, the time is corrected at the time TB, so that the time can be properly corrected.

According to a second aspect of the present invention, there is provided a time correction method for receiving a time correction signal at a specific interval Δt and correcting the current time in a selective call receiver. Assuming that the number of receptions of the correction signal is N,
The time ΔT1 obtained by adding (N−1) · Δt to the reference time T1 indicated by the time correction data of the time correction signal received without error.
+ (N−1) · Δt} and the time (N
−1) · Δt is compared with the time TN indicated by the time correction data of the time correction signal received when the time TN is equal to the time {T1 + (N−1) · Δt}. If the time is within the range, the time is corrected at the time TN, and the time can be properly corrected.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the claimed invention will be described with reference to the drawings. The time correction method of the selective call receiver according to the present invention provides a method for correcting a first call received without error.
The built-in timer is started from the time correction signal, and the reception time of the next time correction signal is measured, and an error between the measured time and the time indicated by the actually received time correction signal is determined. If the time is within the allowable range, the time is corrected using the received time correction signal, and if not, the time is not corrected. The time can be properly corrected without functioning for a long time.

A configuration of a selective call receiver (main selective call receiver) according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic block diagram of the selective call receiver. As shown in FIG. 1, the selective call receiver basically includes a receiving unit 1 for receiving a radio signal and a control unit 2 for processing the received signal. Is provided. Here, the processing in the control unit 2 is a characteristic of the present invention. In addition, this selective call receiver is provided with a means for notifying reception, a means for displaying data included in a received signal, and the like, similarly to a normal selective call receiver.

Next, the processing of the control unit 2 of the selective call receiver will be described with reference to FIG. FIG. 2 is a flowchart showing the processing of the control unit 2 of the selective call receiver.
As shown in FIG. 2, when the processing is started, a time correction signal is received (S1), and then the built-in timer 3 is started (S2). Then, error detection of the received time correction signal is performed (S3). If there is an error (Yes), the process returns to step S1, and if there is no error (No), the process proceeds to the next process.

After a while, the next time correction signal is received (S5), and error detection of this time correction signal is performed (S5).
6). Then, it is determined whether or not the error of the time correction signal is within the allowable range (S7). If the error is not within the allowable range (No), the process proceeds to S5. If it is within the allowable range (Ye
In the case of s), it is determined whether or not the time correction data TN indicating the current time of the received time correction signal is within a specific range (S8). Is not performed, the process proceeds to step S5, and if it is within a specific range (in the case of Yes), the time is corrected using the time correction data TN (S9). Then, the process proceeds to step S5,
The receiving process of the next time correction signal is performed.

Next, the above processing will be supplemented with reference to FIG.
FIG. 3 is a time chart of the processing of the control unit of the selective call receiver. As shown in FIG. 3, if the first time correction signal having no error is received and the time correction data of the signal is the time T1, the internal timer 3
Counts ΔT. This ΔT is predetermined so as to be the next time when the time correction signal is received.

When ΔT elapses from time T 1 (T 1 + ΔT), the next time correction signal is received. If the time correction data of the signal is T 2, T 1 + ΔT and T 2
Compare with If the time T2 is within ± 1 minute of the time (T1 + ΔT), the time T of the received time correction data
2 Perform time correction. If the time is not within ± 1 minute, the time is not corrected.

In this manner, the time TN of the received time correction data is compared with T 1 + (N−1) · ΔT counted by the built-in timer 3 also for the N-th time correction signal reception. Time TN is time (T1 + (N-1) .. DELTA.T)
If it is within ± 1 minute, the time is corrected at the time TN of the received time correction data, and if it is not within ± 1 minute, the time is not corrected.

Incidentally, the specific judgment of the process S8 is made by the following equation according to the example shown in FIG.
Here, N indicates the number of receptions, and the unit is seconds. T1 + (N-1) · ΔT-60 ≤ TN ≤ T1 + (N-1) · ΔT
+60

According to the time correction method of the selective call receiver, the built-in timer 3 becomes the next and subsequent reception times based on the time T1 of the time correction data of the first time correction signal normally received. Is counted and compared with the time TN of the time correction data of the received time correction signal, and the time TN becomes the time (T1 + (N-1)
If the time correction is within ± 1 minute of ΔT), the time is corrected at the time TN of the received time correction data. Therefore, even if the received time correction signal has an error in a weak electric field state. , The time TN is the time (T1 + (N-1). [Delta]
T), the time is not corrected unless it is within ± 1 minute. Therefore, the time is not corrected to another time that is significantly different from the time, and the time TN is set to the time (T1 + (N−1) · Δ
If the time is within ± 1 minute of T), the time is corrected.
There is an effect that the time correction function can be properly performed without the time correction function being executed for a long time.

Even if the accuracy of the timer (clock clock) built in the selective call receiver is not so high, the time is corrected as described above, so that an inexpensive clock clock can be used. Therefore, there is an effect that an inexpensive selective call receiver can be provided.

[0020]

According to the first aspect of the present invention, the time TA obtained by adding the specific interval to the reference time is compared with the time TB indicated by the time correction data of the time correction signal received when the specific interval has elapsed. Is within the permissible range with respect to the time TA, the time correction method of the selective call receiver for performing the time correction at the time TB is employed, so that there is an effect that the time can be properly corrected.

According to the second aspect of the present invention, assuming that the number of times of reception of the time correction signal is N, (N-1)
The time {T1 + (N-1) .DELTA.t} to which .DELTA.t is added is compared with the time TN indicated by the time correction data of the time correction signal received when the time (N-1) .DELTA.t elapses from the reference time T1. If the time TN is within an allowable range of a certain time with respect to the time {T1 + (N-1) .multidot..DELTA.t}, the time correction method of the selective call receiver performing the time correction at the time TN is used.
There is an effect that time correction can be appropriately performed.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a selective call receiver.

FIG. 2 is a flowchart showing a process of a control unit 2 of the selective call receiver.

FIG. 3 is a time chart of a process of a control unit of the selective call receiver.

[Explanation of symbols]

 1: receiving unit, 2: control unit, 3: built-in timer

Claims (2)

[Claims] 1. A time correction method for receiving a time correction signal at a specific interval and correcting a current time in a selective calling receiver, wherein the specific time interval is set at a reference time indicated by time correction data of the time correction signal received without error. Is compared with the time TB indicated by the time correction data of the time correction signal received at the elapse of the specific interval, and if the time TB is within the allowable range with respect to the time TA, the time TB is calculated at the time TB. A time correction method for a selective calling receiver, wherein the time is corrected. 2. In a time correction method for receiving a time correction signal at a specific interval Δt and correcting the current time in a selective calling receiver, if the number of times of reception of the time correction signal is N, the time correction signal received without error. At the time when (N−1) · Δt is added to the reference time T1 indicated by the time correction data
(N−1) · Δt} and the time (N−
1) Comparing the time correction signal received after the lapse of .DELTA.t with the time TN indicated by the time correction data, and determining that the time TN is within an allowable range of a certain time with respect to the time {T1 + (N-1) .DELTA.t}. If the time is within the time, the time is corrected at the time TN.