JPH02234523A - Selective call receiver - Google Patents

Abstract

PURPOSE:To extend the service life of a battery by providing a reception quality deciding means and a battery saving control means, using the reception quality deciding means so as to discriminate the reception quality from a reception signal at the reception of a group to which its own equipment belongs and controlling the reception of the group to which its own equipment belongs. CONSTITUTION:Reception electric field strength deciding means 41 monitors a synchronous word of a group to which its own equipment belongs as to whether or not the word is received accurately consecutively for, e.g. 10 frames, and it is decided that the reception electric field strength is sufficiently high when the synchronous word is accurately received. On the other hand, a battery saving control means 42 operates the reception circuit 10 at an internal of two frames when it is decided that the reception electric field strength is sufficiently high by the means 41. On the other hand, if the reception electric field strength which is sufficiently high is not obtained, the reception circuit 10 is operated for each frame. Thus, the power consumption when the selective call receiver is operated on the condition that the reception electric field strength is sufficiently high.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a selective call receiver with a battery saving function.

(Prior Art) As one of the selective calling systems, the following is known in the past. FIG. 3 shows an example of the signal format. In this calling method, one frame is time-divided into multiple groups (in fact, n groups) as shown in FIG. In this case, the data is time-divided into m words). When a caller sends a call request to a selective call receiver to a base station, the base station first creates a selective call signal into which the individual number code of the selective call receiver is inserted, and A selective calling signal is inserted into an empty calling word of the group to which the selective calling receiver belongs, as shown in (c), and then transmitted.

On the other hand, a selective call receiver is constructed as shown in FIG. 4, for example. That is, the selective calling signal sent from the base station is first received and demodulated via the antenna 1 by the radio circuit 2 and demodulation circuit 3 that constitute the reception circuit, and then introduced into the control circuit 4. Then, in the control circuit 4, the individual number code in the selective call signal is compared with the individual number code of the own machine, which is stored in advance in an individual number code memory (ID-ROM) 5. As a result of this comparison, if the codes match, it is recognized that a call has occurred to the own device, and a sound signal is supplied from the control circuit 4 to the speaker 7 via the drive circuit 6. Therefore, a ringing tone is generated from the speaker 7, thereby notifying the holder that a ringing has occurred.

Incidentally, this type of selective call receiver generally performs battery saving in order to reduce power consumption and extend battery life. This battery saving means that, after synchronization has been pulled in, power is supplied to the receiving circuit only during the reception period of the group (shaded area G) to which the own aircraft belongs for each frame, as shown in FIG. During the reception period of the group, the power supply to the reception circuit is cut off so that no reception operation is performed. In this way, if one frame is composed of n groups, the power consumption will be reduced by about 1/2 compared to the case where reception is always performed.
n, and battery consumption can be reduced accordingly.

(Problems to be Solved by the Invention) However, the conventional selective call receiver equipped with such a battery saving function has the following problems to be improved. That is, in general, each time a call request to a selective call receiver occurs, a base station sends a selective call signal into which the individual number code of the selective call receiver is inserted to each group of consecutive frames (for example, 3 frames). Insert and send each. On the other hand, the selective call receiver issues a call notification when it accurately receives the selective call signal among the three frames mentioned above, and in subsequent frames, even if the selective call signal of its own receiver is accurately received, the call notification is not sent. Avoid doing this. This type of system allows only one selective call signal to be received even if the selective call receiver is located in a place where the transmitted radio waves are weak or where it is difficult to accurately receive the selective call signal due to fading of the transmitted radio waves. This is extremely effective because if the call can be received accurately at any time, the call notification can be made. However, if the selective call receiver is located in a place where the received field strength is high, the receiver will always be able to accurately receive the selective call signal in the first frame.6 Therefore, in this case, the selective call receiver is 3 frames,
Even if the device is controlled so that it enters the receiving state only once in every month, no major harm will occur.

However, as shown in FIG. 5, the conventional selective call receiver unconditionally receives the group to which it belongs in every frame.

For this reason, the power consumption is still large, which leads to a shortened battery life.

Therefore, the present invention focuses on the above points, and an object of the present invention is to provide a selective calling receiver that can further reduce power consumption without causing the adverse effects of calling, and thereby further extend battery life.

[Structure of the Invention] (Means for Solving the Problems) The present invention receives only the group to which its own device belongs out of one frame transmitted from a base station, and receives the information in the selective paging signal inserted into this group. A selective calling receiver that compares an individual number code with its own individual number code and notifies that a call has occurred when both codes match, comprising reception quality determining means and battery saving control means, The reception quality determining means determines the reception quality from the received signal during the reception operation of the group to which the device belongs, and when the reception quality determining means determines that the reception quality is at a predetermined level or higher, The above-mentioned battery saving control means causes the receiving operation of the group of the own device to be performed every predetermined number of frames.

(Function) As a result, in the selective call receiver of the present invention, the condition is such that the selective call signal is always accurately received in all frames, such as when the receiver is located relatively close to the base station. If it is below, battery saving control is performed so that the receiving operation for the group to which it belongs is performed every predetermined number of frames. Therefore, compared to conventional receivers that unconditionally receive all frames for the group to which they belong, power consumption can be reduced to one-half of the predetermined number of frames, thereby extending battery life. can be further extended. Also,
If the group to which it belongs is received every predetermined number of frames as described above, even if a selective call signal to the own machine is inserted in a frame that is not received, it will not be possible to receive this. However, when calling one selective call receiver, the base station inserts a selective call signal into each group of consecutive frames and sends them out.
Moreover, if the selective call receiver is under conditions of good reception quality, it is possible to accurately receive the selective call signal in the frame that is in the receiving state. Therefore, there is no fear that the selective call receiver will miss the selective call signal.

(Embodiment) FIG. 1 shows the configuration of a selective call receiver in an embodiment of the present invention. In this figure, the same parts as those in FIG. 3 are given the same reference numerals and detailed explanations will be omitted.

The control circuit 40 is equipped with a microprocessor (CPU) as the main control unit, and its control functions include normal functions such as individual number code verification means and call notification control means, as well as reception quality judgment. The receiving electric field strength determining means 41 and the battery saving control means 42 are respectively provided.

First of all, the reception field strength determining means 41 monitors whether or not the synchronization word of the group to which the device belongs can be accurately received, for example, continuously in 10 frames, and determines whether the synchronization word can be accurately received in consecutive 10 frames. In this case, it is determined that the received electric field strength is sufficiently high. On the other hand, when the received electric field strength determination means 41 determines that the received electric field strength is sufficiently high, the battery saving control means 42 performs the following operations.
The power supply to the receiving circuit 10 is controlled so that the receiving operation for the group to which the own device belongs is performed every several frames, and when the receiving electric field strength is other than that, the receiving operation for the group to which the own device belongs is performed for every frame. Power supply control to the circuit 10 is performed.

Next, the operation of the selective call receiver configured as described above will be explained. In this case, when the base station calls the selective call receiver, it sends a selective call to each group in three consecutive frames. The explanation will be given assuming that the output signal is inserted and sent.

When the power of the receiver is turned on, frame synchronization is first performed by a frame synchronization circuit within the control circuit 40. When frame synchronization is established, the battery saving control means 42 of the control circuit 40 starts control for battery saving. That is, the battery saving control means 42 first supplies an on signal to the switch 9 to close the switch 9 every time the reception period of the group to which the own device belongs in each frame begins. Then, the output voltage Vcc of the battery 8 is supplied to the receiving circuit 10, whereby the receiving circuit 10 enters the receiving operation state. In this state, the verification means of the control circuit 40 verifies the individual number code received by the receiving circuit 10, and determines from this verification result whether or not a call has occurred to the own machine. At this time, the electric field strength determination means 41 determines the received electric field strength from the reception state of the synchronization word inserted at the beginning of the group to which the own device belongs for each frame. It should be noted that each time the reception period of the group to which the device belongs ends, the battery saving control stage 42 supplies an off signal to the switch 9 to open the switch 9.

Therefore, the power supply to the receiving circuit 10 is cut off, and the receiving circuit 1
0 returns to inactive state.

Now, let us assume that the selective calling receiver is located relatively close to the base station, and that a sufficiently high received field strength is thereby obtained. Then, the synchronization word will be received accurately without any errors in each of the above groups, so
The received electric field strength determining means 41 outputs a determination result indicating that the received electric field strength is sufficiently high after, for example, 10 frames have elapsed. Then, the battery saving control means 42 changes the power supply to the receiving circuit 1O from 111 to 111, which had been performed for each frame as shown in FIG.
As shown in Figure 2(b), the power supply is changed to every two frames.

In other words, if power is supplied to the receiving circuit 10 in frame 1 as shown in FIG. 2, then the following frame 2
In frame 3, power supply is stopped, and in frame 4, power is supplied to the receiving circuit 10 again. The device receives the group to which it belongs every three frames. Here, the reason why the reception operation is set to be performed at three frame intervals is that when calling the selective call receiver, the base station inserts a selective call signal into each group to which it belongs in three consecutive frames and sends it out. It is from.

By controlling in this way, the receiving circuit 10 performs a receiving operation every two frames, and as a result, the power consumed by the receiving circuit 10 is reduced to one-third of the conventional power.

Furthermore, if a receiving operation is performed every two frames, for example, if a selective call signal to the own aircraft is inserted in the group G2 to which it belongs in frame 2 in FIG. This means that the signal cannot be detected. However, since the same selective call signal is sent from the base station for three consecutive frames, the selective call signal to the own machine is reliably received when the belonging group G4 is received in frame 4.

Therefore, the problem that the selective calling signal transmitted from the base station cannot be received at all due to the above-mentioned battery saving every two frames does not occur, and as a result, the selective calling receiver is reliably called.

On the other hand, suppose that the selective call receiver moves far away from the base station, or moves to a place where it is difficult to receive radio waves, such as inside a tunnel or behind a building. In this case, the received electric field strength of the received signal decreases, so the received electric field strength determining means 41
A determination result indicating that a sufficiently high received electric field strength cannot be obtained is output. Then, the battery saving control means 42 changes the power supply to the receiving circuit 10 from every two frames to every frame. Therefore, from now on, if the selective call receiver receives a selective call signal in any of the three frames into which the selective call signal is inserted, it will be possible to recognize the occurrence of a call and make a notification. Become.

As described above, in this embodiment, the received electric field strength is determined during the receiving operation, and if the received electric field strength is sufficiently high, the receiving circuit 10 is operated every two frames; If this is not possible, the receiving circuit 10 is operated for each frame, so power consumption can be reduced when the selective calling receiver is used under conditions where the receiving field strength is sufficiently high. This allows the life of the baptizer 8 to be extended. Since selective calling receivers are generally used under conditions where the received field strength is sufficiently high, their practical effects are extremely large.

Note that the present invention is not limited to the above embodiments. For example, the receiving quality determining means may be configured to determine by detecting the S/N of the received signal. Further, in the embodiment described above, the receiving operation is performed every two frames under the condition that the receiving electric field strength is sufficiently high, but the receiving operation may be performed every other frame.

In addition, the structure of the reception quality determining means, the structure and control contents of the battery saving control means, the circuit for performing battery saving, etc. can be modified in various ways without departing from the gist of the present invention.

[Effects of the Invention] As described in detail above, the present invention includes a reception quality determination means and a battery saving control means, and the reception quality determination means determines whether a received signal of a group to which the own device belongs during reception operation is provided. If it is determined by this reception quality determination means that the reception quality is at a predetermined level or higher, the battery saving control means controls the reception operation of the group of the own device at intervals of a predetermined number of frames. By doing so, it is possible to further reduce power consumption without causing the adverse effects of calling, thereby providing a selective calling receiver that can further extend battery life.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the functional configuration of a selective call receiver in an embodiment of the present invention, FIG. 2 is a timing diagram used to explain the operation of the receiver, and FIG. 3 is an example of the format of a selective call signal. FIG. 4 is a circuit block diagram showing the basic configuration of a conventional selective call receiver, and FIG. 5 is a timing diagram for explaining a battery saving system of the conventional selective call receiver. 1... Antenna, 2... Radio circuit, 3... Demodulation circuit, 5... Individual number code memory (ID-ROM),
6... Drive circuit, 7... Sveaker, 8... Battery, 9... Switch, 10... Receiving circuit, 40...
- Control circuit, 41... Received electric field strength determination means, 42.
...Battery saving control means. Applicant's agent Patent attorney Takehiko Suzue Figure 4 Figure 5

Claims (2)

[Claims] (1) Receive only the group to which the own machine belongs out of one frame transmitted from the base station, compare the individual number code in the selective call signal inserted in this group with the individual number code of the own machine, and In a selective calling receiver that notifies that a call has occurred when the codes match, a receiving quality determining means determines the receiving quality from the received signal during the receiving operation of the group to which the receiver belongs, and the receiving quality determining means 1. A selective call receiver comprising: battery saving control means for performing a reception operation for its own group every predetermined number of frames when it is determined that reception quality of a predetermined level or higher is obtained. (2) Claim (1) characterized in that the reception quality determining means detects the received electric field strength of the received signal and determines whether this received electric field strength is equal to or higher than a predetermined level.
Selective call receiver as described.