JPS5850651Y2 - selective call receiver - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a selective call receiver having a pantry saving function.

Selective call receivers, such as pagers (nicknames),
In order to extend the life of the built-in battery, many devices have a so-called battery saving function that turns on the power only when there is a possibility of a call.

Figure 1 schematically shows a selective call signal sent from the master station to this type of selective call receiver. This figure shows the structure of a selective call signal for one group.

This selective call signal for one group is composed of a synchronization word consisting of a frame synchronization code common to each group belonging to the l frame and a group synchronization code unique to each group, and n call words. This figure shows an example of the conventional configuration of a selective call receiver, in which 1 is a receiving antenna, 2 is a radio section, 3 is a demodulation section, 4 is a code matching section attached with a timing pulse generation section 4a, and 5
is a storage unit, 6 is an amplifier, 7 is a speaker, 8 is a main power source such as a battery, and 9 is a power supply control unit. With this configuration, the signal received by the antenna 1 is processed by the radio unit 2. After being demodulated and converted into a baseband time-division multiplexed signal in the demodulation section 3, it is sequentially compared with its own group synchronization code and call number code stored in the storage section 5 in the code matching section, and if they match, it is If a match signal is obtained, the matching signal is supplied to the speaker 7 via the amplifier 6, and a ringing tone is generated.

Incidentally, the power supply from the main power source 8 to the radio section 2, demodulation section 3, and storage section 5 is controlled by a power supply control section 9 and performed periodically.

That is, the power supply control section 9 starts supplying power in accordance with the timing pulse from the timing pulse generation section 4a in approximately synchronization with the cycle in which the calling signal (FIG. 1b) of the group to which the selective calling receiver belongs, arrives. The main power supply 8 is set so that the receiving operation is possible only while the calling signal is arriving.
supply and control power from

In fact, power is always supplied to at least the timing pulse generator 4a.

FIG. 3 shows this state.

A in the figure shows a group calling signal, and the figure shows the output of the power supply control section 9. Only while this output is on, the radio section 2, the demodulation section 3, and the storage section 5 are ready for receiving operation.

Further, C in the same figure is the output of the demodulator 3, and shows a baseband time division multiplexed signal.

However, in the above operation, rising or falling noise when the radio section 2 and the demodulating section 3 are powered on or off is superimposed on the output of the demodulating section 3, resulting in the noise shown in FIG.
N1. Since the demodulated signal appears as shown in N2, there is a strong possibility that this demodulated signal will be different from the calling signal.

In this case, even though the ringing signal is received, the code matching section 4 cannot match the contents stored in the storage section 5, and there is a problem that a ringing tone cannot be generated.

In addition, the receiver is equipped with a function that determines whether the S/H is good or bad based on the demodulated signal and stops the calling operation if it is not good, but the calling operation stops due to noise generated in the receiver itself. There was the inconvenience of being forced to do so.

This idea was made in view of the above points. 1. In a selective calling receiver with a battery saving function, the noise generated when the power supply rises and falls is removed and an accurate demodulated signal is output. It is an object of the present invention to provide a selective calling receiver that can perform stable receiving operations.

An embodiment of this invention will be described below with reference to the drawings.

FIG. 4 shows the configuration of a selective calling receiver according to an embodiment of this invention, and the same parts as in FIG. 2 are designated by the same reference numerals.

Therefore, the explanation of the overlapping parts will be omitted.

This embodiment differs from FIG. 2 in that a control section 10 is interposed between the demodulation section 3 and the code matching section 4.

This control section 10 is composed of a circuit having a gate function, for example, an AND circuit, and one input terminal receives the demodulated signal from the demodulation section 3, and the other input terminal receives the timing pulse 2 generation section 4a. A pulse is input as a gate signal.

The timing pulse given to the control section 10 uses a signal whose rise is delayed by a predetermined time with respect to the timing pulse given to the power supply control section 9, and whose fall is simultaneous with the timing pulse given to the power supply control section 9.

FIG. 5 shows the signal states of each part in FIG. 4, and a"c in the figure is the same as a"c in FIG. 3.

In addition, d in the figure shows a gate signal given to the control section 10, that is, a timing pulse from the timing generation section 4a, and this timing pulse starts feeding power to specific parts such as the radio section 2 and the demodulation section 3. t from the time when
After an hour, stand up and meditate.

This time t is defined as at least the time until the power supply state to the radio section 2, demodulation section 3, etc. is completely turned on.

Because of the above configuration, when power supply to the radio section 2 and demodulation section 3 is started, noise is generated at the rising edge of the power supply, and this rising noise is generated when the demodulated signal from the demodulation section 3 (at baseband) is generated. Even if the noise Nl appears superimposed on the divided multiplexed signal as shown by N1 in FIG.
It is gate-controlled by 0 and is not input to the code matching section 4.

That is, since a timing pulse having a rise delay of time t as shown in FIG. As a result, the demodulated signal is input to the code matching section 4 from which the rising noise N1 as shown in FIG. 5e has been removed.

Also, when the power supply to the radio section 2 and demodulation section 3 is stopped,
Noise when the power supply falls appears to be superimposed on the demodulated signal from the demodulator 3 as shown by N2 in FIG. Not entered.

That is, one input terminal of the control section 10 receives the power from the power supply control section 9 as shown in FIG.
Since a timing pulse is supplied that turns off at the same time as Figure b) turns off, this gates the
As a result, the demodulated signal from which the falling noise N2 has been removed is input to the code matching section 4 as shown in FIG. 5e.

In this way, the demodulated signal of the portion that is not affected by the rising and falling noises that occur when the power is turned on or off is input to the code matching section 4.

As described in detail above, according to the present invention, in a selective call receiver having a battery saving function, power is turned on to a specific part for a predetermined period of time from the start of a specific period in which the receiver may be selectively called. and prohibits the supply of demodulated codes to the code matching section from the power-on start point to the start point of the specific period, and supplies the demodulated codes to the code matching section after the end point of the specific period. By controlling the gate to prohibit the power supply, it is possible to prevent the noise generated when the power supply is turned on from affecting the specific period to which the own receiver belongs, and to ensure that the noise generated when the power supply is turned on and off does not affect the specific period to which the receiver belongs. Even if this noise is generated and superimposed on the demodulated signal, it is possible to prevent this signal from being introduced to the code matching section, which allows the code matching section to perform accurate comparison operations and stabilize the receiving operation. It is possible to provide a selective call receiver that can improve performance.

[Brief explanation of drawings]

FIGS. 1a and 1b are diagrams schematically showing the structure of a selective call signal using a time division multiplexing system, FIG. 2 is a block diagram showing the structure of a conventional selective call receiver, and FIGS. 3a to 3c are FIG. 4 is a block diagram showing the configuration of a selective call receiver according to an embodiment of the invention, and FIGS. 5 a to 5e show partial operations of the same embodiment. It is a time chart showing. 2... Radio section, 3... Demodulation section, 4... Code checking section, 4a... Timing pulse generation section, 5... Storage section, 8... Main power supply, 9... Power supply Control unit, 10...control unit.

Claims (1)

[Scope of utility model registration request] In response to a selective call signal sent from the transmitting side to multiple selective call receivers in a time-sharing manner, power is turned on to a specific part only for a short period of time, including a specific period during which there is a possibility that the receiver itself may be selectively called. In a selective call receiver that performs a reception demodulation operation and checks the demodulated code with a pre-stored code,
a power supply control means for starting power-on of the specific part a predetermined time before the start point of the specific period; and prohibiting supply of demodulated codes to the code matching unit from the time the power-on starts to the start point of the specific period. and gate control means for prohibiting the supply of demodulated codes to the code collation unit after the end of the specific period.