JPH0354926A - Radio selective call receiver - Google Patents

Abstract

PURPOSE:To surely receive a radio wave by comparing a radio call signal with previously stored information and selecting a vertical or horizontal polarization antenna. CONSTITUTION:A switch part 3 switches the horizontal and vertical polarization antennas 2, 1 to receive a signal by either one of the antennas 2, 1. The received signal is inputted to a decoder 9, and when an error bit of a frame synchronizing signal (c) is less than a prescribed value, an access to the self-equipment is decided. The signal is inputted also to logical circuits 22, 23, a call signal (b) is compared with the signal (c) outputted from the decoder 9 and a difference signal (d) is outputted. The signal (d) is discriminated as the signal received by the antenna 2 or 1 through a logical circuit 31 or 32. Thus, the radio selective call receiver compares a frame synchronizing signal received by one antenna with the previously stored frame synchronizing signal and controls antenna switching by a difference signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radio selective paging receiver that receives a radio paging signal and reports a paging.

[Conventional technology]

This type of radio selective calling receiver uses an antenna to
A radio paging signal is being received. An example of this radio selective calling receiver is shown in FIG.

In FIG. 4, a radio paging signal is received by an antenna 101, and amplified and demodulated by a receiving section (RX section) 102. Then, the calling signal is output as an electrical signal. The calling signal that is DC detected and output from the RX section 102 is
When the power of the radio paging signal is low, there is a lot of noise. After passing through a low-pass filter (LPF) 103, the calling signal is shaped into a waveform by a filter 104 and sent to a decoder 1.
Sent to 06.

An example of a calling signal input to this decoder 106 is
It is shown in FIG. As shown in FIG. 5, this paging signal is composed of a preamble signal 110, a frame synchronization signal (SC) 111, and an individual paging signal 112.

When such a call signal is input to the decoder 106, the decoder 106 performs bit synchronization using the preamble signal 110 and detects the preamble signal. When the detection is confirmed, the process moves to detection of SC111, which is a frame synchronization signal.

On the other hand, a frame synchronization signal 111 as shown in FIG.
The pattern of RO with its own ringing signal 112
It is stored in advance in M105. A ROM like this
When the preamble signal 110 and frame synchronization signal 111 in the paging signal output from the limiter 104 are detected in the decoder 106 connected to the limiter 104, the reception timing of the individual paging signal 112 is determined.
Then, the calling number stored in advance in the ROM 105 and the individual calling signal 112 are compared and verified, and if it is determined that the calling party is calling itself, the speaker 107 notifies the user of the calling.

[Problem to be solved by the invention]

Since the conventional radio selective paging receiver described above has one antenna, it has the disadvantage that it can only receive radio waves of either the vertically polarized wave or the horizontally polarized wave of the radio paging signal. Furthermore, the radio selective calling receiver is often carried in a bag or pocket, and cannot be fixed horizontally or vertically.

Therefore, there is approximately a half probability that the transmitted polarization and the received polarization do not match.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such drawbacks and provide a radio paging receiver that can receive calls with high sensitivity at any time.

[Means for Solving the Problems] The present invention provides a radio selective paging receiver that receives a radio paging signal, which includes: a first antenna that receives horizontally polarized waves of the radio paging signal; and a first antenna that receives horizontally polarized waves of the radio paging signal; a second antenna for receiving; a switching means for switching between the first antenna and the second antenna using a switching signal and outputting a signal based on a radio paging signal from the switched antenna; and a signal from the switching means. and a first output means for outputting a signal related to the reception state of the radio paging signal by comparing the information with pre-stored information; and a second output means for outputting a switching signal to the switching means to alternately switch the antenna to the antenna and then switch to the antenna that outputs a strongly polarized radio paging signal based on the signal from the comparison means. It is a feature.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. This radio selective calling receiver has antennas 1.
2, a switch section 3, a receiving section (RX section) 4, a discreet 5, a low pass filter (LPF) 6, a limiter 7, a ROMB, a decoder 9, a speaker 10,
It is composed of a difference signal generation section 20 and a comparison section 30.

The antenna 1 of the radio selective call receiver having such a structure receives vertically polarized waves, and the antenna 2 receives horizontally polarized waves.

The switch unit 3 switches the radio paging signal from the antenna 1 or the antenna 2 according to the switching signal j from the decoder 9.
selects and outputs a radio paging signal from

The receiving section 4 amplifies and frequency-converts the radio paging signal from the switch section 3.

The disk drive 5 performs DC detection on the radio paging signal from the receiving section 4 and generates a paging signal a.

The low-pass filter 6 removes noise components from the calling signal a output from the disc 5.

The limiter 7 shapes the waveform of the calling signal output from the low-pass filter 6.

The ROMB stores in advance the pattern of the frame synchronization signal as well as its own paging signal.

When the decoder 9 determines that the calling signal outputted from the limiter 7 is its own calling signal based on the stored contents of the ROM 8, the decoder 9 notifies the speaker 10 that there is a calling signal. Further, the decoder 9 outputs the frame synchronization signal C from the ROMB to the difference signal generation section 20, and outputs the output signals e,
f is output to the comparison section 30. Furthermore, the decoder 9 outputs a switching signal j based on the comparator output signal i from the comparator 30.

The difference signal generator 20 includes a limiter 21 and a logic circuit 22.
, 23. It is organized as 24. Then, the difference signal detection section 20 detects the difference signal d based on the calling signal a from the disk drive 5 and the frame synchronization signal C from the decoder 9.

The comparison unit 30 includes a logic circuit 31. 32 and resistance 33. 3
4 and capacitor 35. 36 and comparator 37. Then, the comparison section 30 compares the difference signal d from the difference signal generation section 20 with the output signal e from the decoder 9.
, ``The comparator output signal i is outputted to the decoder 9 based on .

Next, the operation of this radio selective call receiver will be explained with reference to the time chart of FIG.

The switch unit 3 switches between the antenna 2 for horizontal polarization reception and the antenna 1 for rectangular polarization reception in response to the switching signal j from the decoder 9, and transmits the radio paging signal received by either antenna to the reception unit 4. send. The receiving section 4 amplifies the wireless signal, converts the frequency, and sends it to the disc 5. Diskly 5 performs DC detection on the radio paging signal,
It is sent to the low-pass filter 6 as a calling signal a. The calling signal a has some noise removed by a low-pass filter 6, has its waveform shaped by a limiter 7, and is sent to a decoder 9. An example of this call signal is shown in FIG. As shown in FIG. 5, the paging signal includes a frame synchronization signal 111 and an individual paging signal 112 regularly alternating.

Such a paging signal is input to the decoder 9, and when a paging signal preamble is found, the decoder 9 waits for timing to receive a frame synchronization signal following the preamble. At the same time as receiving the frame synchronization signal, the frame synchronization signal previously written in the ROMB is sent to the decoder 9.
Compare with the frame synchronization signal from limiter 7. If the error bits of the frame synchronization signal sent from the limiter 7 are less than a certain number, and the individual call signal following the frame synchronization signal is determined to be its own call, the speaker IO will notify that there is a call. do.

By the way, the disc 5 sends the calling signal a to the low-pass filter 6 and also to the limiter 2l of the difference signal generation section 20. Calling signal a is limiter-2l
The waveform is shaped by the logic circuit 22. 23.

On the other hand, the frame synchronization signal is output from the ROM 8 to the decoder 9 and simultaneously output from the terminal 9B. terminal 9
The frame synchronization signal C output from the logic circuit 22.
It will be man-powered on the 23rd.

Logic circuits 22, 23. By 24, riξ ivy 21
The paging signal b from the decoder 9 and the frame synchronization signal C from the decoder 9 are compared in phase. As a result of this waveform comparison, a difference signal d is output from the logic circuit 24.

The difference signal d is sent to the logic circuit 31 . 32. On the other hand, in the logic circuit 3l, the terminal 9 of the decoder 9
The frame synchronization signal is determined by the output signal e from D when the timing at the time of reception is ≥T. to T2, a difference signal due to the antenna is output. Between this timing T1 and T2,
The switching signal j from the terminal 9A of the decoder 9 is at the "-" level, and the switch section 3 selects the antenna 2.

Therefore, the difference signal from the antenna 2 is output from the logic circuit 3l between timings T1 and T2.

Similarly, in the logic circuit 32, the terminal 9C of the decoder 9
The output signal f from the antenna outputs a difference signal due to the antenna between the timings T2 and T when the frame synchronization signal is received. Between timings T2 and T3, the switching signal j from the terminal 9A of the decoder 9 is at the "high" level, and the switch section 3 selects the antenna l.

Therefore, between timings T2 and T3, the logic circuit 32 outputs the difference signal from the antenna 1.

In this way, the difference signal d is generated by the logic circuit 31. 32 into those received by antenna 2 and antenna 1.

Note that the period from the start of the frame synchronization signal to the timing T1 is always a constant time.

Also, between timing T and T2, and timing T
The time lengths from 2 to T3 are the same.

The difference signal from the logic circuit 31 is connected to the resistor 33 and capacitor 3.
5 and is charged by an RC circuit consisting of ξ and T,
The voltage is maintained until after that. Then, this voltage becomes a tie waveform g. Further, the difference signal from the logic circuit 32 is charged by an RC circuit including a resistor 34 and a capacitor 36, and the voltage is held until after timing T3.

This voltage becomes the timing waveform h.

The tie selection waveform g and the timing waveform h are input to a comparator 37 that outputs an antenna selection signal. Since the voltage of the timing waveform h (on the antenna 2 side) is higher than the timing waveform g, the comparator output signal i becomes "high". During this period, the discharge occurs and “O
(zero)" potential. The comparator output signal i is input to the terminal 9E of the decoder 9. The decoder 9 uses the comparator output signal i only from timing T3 to T4. That is, the timing T:l Since the comparator output signal i is high from 1 to T4, the switching signal j from the terminal 9A of the decoder 9 is fixed at the ``-゜ level'' until the timing T of the next frame synchronization signal. Ru. The switch section 3 selects the antenna 2 by this "low" level switching signal j.

Timings T3 to T4 are controlled by an antenna switching detection signal within the decoder 9.

On the other hand, when the calling signal a as shown in FIG. It is output from 20. When this difference signal d is input manually, the comparator 30 detects timing waveforms g and h that are opposite to the timing waveform shown in FIG. Timing waveform g from timing waveform h (antenna 1 side)
Since the voltage of the frame synchronization signal is high, the comparator output signal i becomes "low". Since the comparator output signal i is "low" from timing T to T4, the timing T. of the frame synchronization signal is high. Until then, the switching signal j from the terminal 9A of the decoder 9 is fixed at the "high" level. this"
'The switch section 3 selects the antenna 1 by a high level switching signal.

In this way, the radio selective calling receiver includes at least an antenna for receiving vertically polarized waves, an antenna for receiving horizontally polarized waves, a first means for switching between these two antennas, and one of the two antennas. The second frame synchronization signal received by the receiver is compared with the frame synchronization signal written in advance in the receiver, and the error is output as a difference signal.
Since the third means controls the first means in response to the second means, it is possible to perform antenna switching control.

〔Effect of the invention〕

As explained above, in the present invention, the horizontally polarized antenna and the orthogonally polarized antenna are selected by comparing the radio paging signal with pre-stored information. Only one demodulator is required, making it unsuitable for downsizing. Also, since the antenna with stronger horizontal polarization or vertical polarization is used, even if you put the receiver in a bag, etc.
High-sensitivity reception is possible at any time regardless of the storage state of the receiver.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. FIG. 3 is a time chart of the embodiment shown in FIG. 1, FIG. 4 is a bronch diagram showing an example of a conventional radio selective calling receiver, and FIG. 5 is a format of a calling signal. 1.2...Antenna 3 ・ ・ ・ ・ 4 ・ ・ ・ ・ 5 ・ ・ ・ 6 ・ ・ ・ 7 ・ ・ ・ ・ 8 ・ ・ ・ ・ 9 ・ ・ ・ ・ 10 ・ ・ ・ 20・ ・ 21・ ・ ・ ・ 22, 23.24 ・ 30 ・ ・ ・ 31.32 ・ ・ 33.34 ・ ・ 35.36 ・ 37 Pass filter, limiter, ROM, decoder, speaker, difference signal generator, rigator, logic circuit, comparison section, logic circuit, resistor, capacitor, comparator

Claims (1)

[Claims] (1) A radio selective paging receiver that receives a radio paging signal, comprising: a first antenna that receives horizontally polarized waves of the radio paging signal; a second antenna that receives vertically polarized waves of the radio paging signal; a switching means for switching between a first antenna and a second antenna using a switching signal and outputting a signal based on a radio paging signal from the switched antenna; and comparing the signal from the switching means with information stored in advance. a first output means for outputting a signal related to the reception state of the radio paging signal, and alternately switching between the first antenna and the second antenna based on a predetermined signal of the paging signal; and second output means for outputting, to the switching means, a switching signal for switching to an antenna that outputs a strongly polarized radio paging signal based on a signal from the comparison means.