JP3495794B2 - Wireless transceiver - Google Patents

Abstract

PURPOSE: To discriminate ID signals by frequency discrimination with simple circuit constitution. CONSTITUTION: A transmitter 1 for outputting transmission ID frequency signals f1 and a receiver 2 for inputting the transmission ID frequency signals are provided. The receiver is provided with multipliers 9a and 9b for respectively multiplying the received transmission ID frequency signals with the orthogonal signals of reference ID frequency signals f2 , low-pass filters 10a and 10b for passing through low-band frequency components from the output of the multipliers, squaring circuits 11a and 11b for respectively squaring the output of the low-pass filters and an addition circuit 12 for adding the output of the squaring circuits. This ID signal discrimination circuit is provided with reference signal generators 3 and 19, frequency dividers 4 and 20 for inputting reference signals from the reference signal generators and performing frequency division and setting switches 5 and 21 for supplying the frequency division ratio of the frequency dividers so as to respectively generate the transmission ID frequency signals and the reference ID frequency signals.

Description

DETAILED DESCRIPTION OF THE INVENTION [0003] FIELD OF THE INVENTION [0004] The present invention relates to a radio transceiver, no particular circuit configuration can ID signal identified by simple frequency discriminator
Related to line transceivers . 2. Description of the Related Art Conventionally, a call detection circuit using wireless communication shown in FIG. 2 has been proposed. In this call detection circuit, the radio transmitter 2
By pressing one switch 22, a tone signal of one frequency is generated from the tone signal generating circuit 23 as an ID code. This tone signal causes the high-frequency oscillation circuit 2
The high frequency signal generated in step 4 is modulated by the modulation circuit 25,
The signal is amplified by an amplifier 26 and transmitted as a radio wave by a transmission antenna 27. [0007] In the radio receiver 28, the radio transmitter 21
The signal transmitted from the transmitting antenna 27 is received by the receiving antenna 29, amplified by the amplifier 30, demodulated by the demodulation circuit 31, and amplified by the amplifier 32 to pass through a filter 33 as an ID code selection. The filter 33 has a band through which a tone signal having a frequency to be discriminated passes. [0008] The signal from the filter 33 is transformed into a waveform shaping circuit 3
After waveform shaping in step 4, the envelope is detected by the envelope detection circuit 35 and displayed by the display circuit 36. In this conventional call detection circuit, the filter 3
The frequency discrimination has been performed through No. 3, but when the frequency interval of the tone signal is narrowed, a steep (ie, large Q) filter is required, and there is a problem that a constant needs to be changed for each ID. SUMMARY OF THE INVENTION [0010] The present invention has been made to solve such a problem, and an object of the present invention is to provide a wireless transceiver having a simple circuit configuration and capable of identifying an ID signal by frequency discrimination. . [0011] In order to achieve this object, the present invention provides a radio transmission
The receiver includes a transmitter that outputs a transmission ID frequency signal, and a receiver to which the transmission ID frequency signal is input, and the receiver converts the received transmission ID frequency signal into a quadrature signal of the reference ID frequency signal. A multiplier for multiplying, a low-pass filter for passing low-frequency components from the output of the multiplier, a squaring circuit for squaring the output of the low-pass filter, and an adding circuit for adding the output of the squaring circuit. A reference signal generator for generating a transmission ID frequency signal and a reference ID frequency signal, and a frequency divider to which a reference signal from the reference signal generator is input and frequency-divided,
A setting switch for giving a frequency division ratio of the frequency divider. The transmission ID frequency signal is output from the transmitter, and the transmission ID frequency signal is input to the receiver. In the multiplier of the receiver, the received transmission ID frequency signal is multiplied by the orthogonal signal of the reference ID frequency signal. The output of the multiplier passes low frequency components by a low-pass filter. The outputs of the low-pass filters are each squared by a squaring circuit. The output of the squaring circuit is added in the adding circuit. If the frequency of the transmission ID frequency signal matches the frequency of the reference ID frequency signal, the added output is only a DC component having no AC component, and if the frequency does not match, no output is output, so that the ID signal can be identified. . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a radio transceiver according to the present invention will be described in detail with reference to FIG. FIGS. 1A and 1B show an ID signal identification circuit.
, A transmitter ₁ that outputs a transmission ID frequency signal f ₁ and a receiver 2 that receives the transmission ID frequency signal f ₁
And The transmitter 1 generates a transmission ID frequency signal f ₁ by a reference signal generator 3 and a frequency divider 4 to which a reference signal from the reference signal generator 3 is input and frequency-divided.
A setting switch 5 such as a DIP switch for giving a frequency division ratio of a frequency divider; a modulation circuit 7 for modulating a high-frequency signal generated by a high-frequency oscillation circuit 6 to which a transmission ID frequency signal f ₁ is input; Transmitting antenna 8 connected to the output side of
And The receiver 2 includes an amplifier 14 for amplifying the high-frequency signal received by the receiving antenna 13, a demodulation circuit 15 for demodulating the amplified signal, and an amplifier 16 for amplifying the demodulated transmission ID frequency signal f1. Multipliers 9a and 9b for respectively multiplying the transmission ID frequency signal f ₁ by the orthogonal signal of the reference ID frequency signal f ₂ , low-pass filters 10a and 10b for passing low-frequency components from the outputs of the multipliers,
Square circuit 1 for squaring the output of each low-pass filter
1a, 11b and an addition circuit 1 for adding the output of the squaring circuit
And 2. The low-pass filters 10a and 10b
Can be configured by an integrator. In order to generate the reference ID frequency signal f ₂ , a reference signal generator 19, a frequency divider 20 to which a reference signal from the reference signal generator is inputted to divide the frequency, and a frequency divider of the frequency divider Setting switch 2 like DIP switch to give ratio
And 1. The quadrature signal of the reference ID frequency signal f _{2 is} a signal obtained by phase-shifting the signal Sinω ₂ obtained from the frequency divider 20 and the signal obtained from the frequency divider 20 by 90 ° by the 90 ° phase converter 22.
It is generated by the Cosω _2. The output side of the adder circuit 12 is connected to one input terminal of a comparator 17, and the other input terminal receives a reference voltage. The output side of the comparator 17 is connected to the display circuit 18. In the ID signal discriminating circuit configured as above, the reference signal generated by the reference signal generator 3 of the transmitter 1 is divided by the setting switch 5 and divided by the dividing ratio (1/1).
n) the frequency division by the modulation frequency is outputted the transmission ID frequency signal f ₁ is determined by the frequency divider 4 is set. This setting division ratio how many divide the switch 5 is set, so that the ID signal is provided by outputting a transmission ID frequency signal f ₁ determined modulation frequency. The transmission ID frequency signal f ₁ is obtained by modulating a high-frequency signal generated by the high-frequency oscillation circuit 6 by the modulation circuit 7 and transmitting it as a radio wave from the transmission antenna 8. The radio wave transmitted from the transmitting antenna 8 is received by the receiving antenna 13 of the receiver 2, amplified by the amplifier 14, demodulated by the demodulation circuit 15, and amplified by the amplifier 16. The demodulated transmission ID frequency signal f ₁ is represented as Sin (ω ₁ + ψ) ‥‥‥‥ (1). Here, ψ is a phase difference when the demodulated transmission ID frequency signal f ₁ and the reference ID frequency signal f _{2 have} the same frequency. The reference signal generated by the reference signal generator 19 is frequency-divided by the frequency divider 20 at the frequency division ratio (1 / n) set by the setting switch 21, and the reference ID frequency signal f
₂ is obtained. The frequency-divided reference ID frequency signal f ₂
From the signal Sinω ₂ directly obtained from the frequency divider 20 and the signal obtained from the frequency divider 20 by the 90 ° phase converter 22
° quadrature signal with the phase signal cos .omega ₂ is generated. Here, the transmission ID frequency signal f ₁ and the reference I
If the frequencies of the D frequency signals f ₂ match, ω ₁ = ω ₂
And the orthogonal signal of the reference ID frequency signal f ₂ is represented as Sin ω ₁ ‥‥‥‥‥‥‥‥‥ (2) Cos ω ₁ ‥‥‥‥‥‥‥‥‥ (3). Here, it is assumed that the amplitudes of the equations (1), (2) and (3) are the same and that they are 1. The signals of formula (1) of the transmission ID frequency signal f ₁ demodulated by the multipliers 9 a and 9 b are converted into signals of formulas (2) and (3), which are orthogonal signals of the reference ID frequency signal f ₂ , respectively. is _{multiplied, Sin (ω 1 + ψ)} · Sinω 1 ‥‥ (4) Sin (ω 1 + ψ) · Cosω 1 ‥‥ (5) is generated. Solving equation (4), (1/2) · {Cos (ω ₁ + ω ₁ −ψ) −Cos (ω ₁ + ω ₁ + ψ)} = (1/2) · {Cos} −Cos (2ω ₁ + ψ)｝ ‥‥‥ (6), but the output of the multiplier 9a is a low-pass filter 10a
The low frequency component is passed through and the high frequency component is removed, so that (1/2) · Cosψ ψ (7), and the frequency of the transmission ID frequency signal f ₁ and the frequency of the reference ID frequency signal f ₂ are If they match (ω ₁ = ω ₂ ), they are components of only the phase term. Similarly, in the equation (5), the output of the multiplier 9b is passed by the low-pass filter 10b so that the low-frequency component is passed and the high-frequency component is removed, so that (1/2) · Sinψ ‥‥‥ ( 8) The output of the low-pass filter (7)
(8) is squared by squaring circuits 11a and 11b, respectively.
The output of the squaring circuit is added by the adding circuit 12 to obtain (1/4) · Cos ² ψ + (1/4) · Sin ² ψ = 1/4, and there is only a DC component without an AC component. The output of the adder circuit 12 is connected to one input terminal of a comparator 17 and a reference voltage is input to the other input terminal, so that the output of the comparator 17 is only a signal exceeding the reference voltage. And the transmission ID frequency signal f ₁ and the reference ID
When the frequency of the frequency signal f ₂ matches (ω ₁ = ω ₂ ),
It is displayed on the display circuit 18. Next, the transmission ID frequency signal f ₁ and the reference ID
When the frequency of the frequency signal f ₂ is a mismatch, transmission ID frequency signal f ₁ is transmitted from the transmitter 1, the signal Sin at the receiver 2
If (ω ₁ + ψ) = Sinω ₀ is received, the receiver 2
Of the reference ID frequency signal f ₂ of the above (ω ₁ =
ω ₂ ), the outputs of the multipliers 9 a and 9 b are Sin ω ₀ · Sin ω ₁ ‥‥ (9) Sin ω ₀ · Cos ω ₁ ‥‥ (10) Solving the equation (9) gives (1/2) · {Cos (ω ₀ −ω ₁ ) −Cos (ω ₀ + ω ₁ )}｝ (11) The component of ω ₀ + ω _{1 in} the output of the multiplier 9a is removed by the low-pass filters 10a and 10b, and ω ₀ -ω ₁
Is a tone frequency interval, so the low-pass filter 1
0a, be selected time constant T of 10b to _{T "2π / ω 0 -ω 1} , (11) equation signal is not output anything removed. As described above, according to the ID signal discrimination circuit of the present invention, it is not necessary to use a steep (ie, large Q) filter to perform tone frequency discrimination in the receiver, and the discrimination frequency can be set arbitrarily. ID signals can be identified by frequency discrimination. In the above embodiment, the case of transmitting and receiving wirelessly between the transmitter 1 and the receiver 2 has been described as an example. However, the present invention is similarly applicable to wired (two signal lines). it can. Further, in the above embodiment, the case where the transmitter and the receiver 2 modulate and demodulate wirelessly and transmit and receive them has been described as an example.
The present invention can be similarly applied to the case of transmitting and receiving in baseband. [Effect of the Invention] [0038] No of the invention as is clear from the above description
According to the line transceiver , the circuit configuration is simple and the ID signal can be identified by frequency discrimination.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of an ID signal identification circuit for a wireless transceiver according to the present invention. FIG. 2 is a circuit diagram of a conventional ID signal identification circuit. [Description of Signs] 1 {transmitter 2} receiver f ₁ ‥‥‥ transmission ID frequency signal f ₂ ‥‥‥ reference ID frequency signal Sinω ₁ , Cosω ₁ ‥‥‥ quadrature signal (Sinω ₂ , Cosω ₂ ) 9a, 9b {multipliers 10a, 10b} low-pass filters 11a, 11b {squaring circuit 12} addition circuit 3, 19 {reference signal generator 4, 20} {Divider 5, 21} Setting switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H04B ⁷ /24-7/26 H04Q 7/00-7/38 H04Q 1/30-1/50 H04B 1 / 16

Claims (1)

(57) A transmitter for outputting a transmission ID frequency signal;
A receiver to which the transmission ID frequency signal is input,
The receiver is a multiplier that multiplies the received transmission ID frequency signal by a quadrature signal of a reference ID frequency signal, a low-pass filter that passes a low-frequency component from the output of the multiplier, and a low-pass filter. It possesses a squaring circuit for squaring outputs respectively, and an adding circuit for adding the output of the squaring circuit, the transmission ID frequency signal and
To generate each reference ID frequency signal, the reference
A signal generator and a reference signal from the reference signal generator are input.
A frequency divider that is driven to divide the frequency, and a frequency division ratio of the frequency divider
Radio, characterized in that it comprises a setting switch which gives
Transceiver .