TW200421729A - Method of eliminating irritating noise at the end of communication for a walkie talkie - Google Patents

Abstract

A method of eliminating irritating noise at the end of communication for a walkie talkie which has a receiving loop. The method includes providing a first detector; determining whether a radio frequency signal in a predetermined frequency range received by the walkie talkie belongs to a non-standard squelch signal by using the first detector; and if so, stopping the walkie talkie from receiving following radio frequency signals.

Description

200421729

The technical field to which the invention belongs is a method for avoiding the noise generated by the radio intercom, and the method of generating noise when the radio intercom ends the call. In the prior art ..., walkie-talkie uses a continuous audio coding silence system (CTCSS) to achieve the function of multi-party communication (grown communication). The advantage is that it can be directly point-to-point 'without any basic facilities, as long as both parties tune to the same frequency, they can transmit or receive information at any time. In the field of wireless communication, the continuous audio coding mute system uses a low CTCSS tone to distinguish it from a signal transmitted on a communication channel, so that multiple users in a communication area can make calls. . Please refer to FIG. 1. FIG. 1 is a schematic diagram of a frequency range used in a conventional continuous-tone encoding mute system. As shown in the figure, the frequency range between frequencies 62 · 5Hz and 250Hz is used to transmit the above 7 ^ low frequency audio signal, and the frequency range between frequencies 300Hz and 3.4 · KHz is used to transmit a user's voice The signal (speech signal) is briefly described as follows. For a conventional portable radio, 'a ^' uses 14 communication channels (channe 1) P f ···· P i for signal transmission.

Page 5 200421729 V. Description of the invention (2) ^ Send and receive. The 14 communication channels are physical channels (phySlcal channels). In addition, each communication channel can be based on 38 different frequencies of audio signals Tf •• … Τ 3 涞 generates a total of 532 (1 4 * 38) logical channels. When a speaker sets the physical channel used by the portable radio as p # and the audio signal used is T!, That is, The caller sets its logical channel to P 1 (T 1) 'When the caller presses the push-to-talk (PTT) button of the portable radio, the caller can output through the physical channel P The voice signal is in the predetermined communication range corresponding to the portable radio, if there are three other users in the predetermined communication range, and the logical channel used by them is set to P 1 (TJ, P i (T 38) , PJT!), For the first user, because his portable radio is connected to the physical channel P to transmit and receive signals, the portable radio intercom of the first user starts to receive the address of the speaker. Voice signal from the portable radio, and the portable radio walkie-talkie judges that the audio signal used by the caller is also T !, that is, the caller and the first user both set the same logical channel P 1 (TJ, so the first A user ’s portable radio will output the voice signal received to the caller through a speaker, so the first user can hear the voice signal of the caller. For the second user, Since its portable radio is connected to the physical channel P for signal transmission and reception, the portable radio of the second user will also start to receive the voice signal output by the speaker. However, the portable radio judges that the speaker is using The audio signal is T i instead of T 38, that is, the speaker and the

200421729 V. Description of the invention (3) --- ---- f a t, the user sets different logical channels Pl (and PJ T38) respectively ^ The portable radio of the second user will not connect to 4 § The voice signal of the caller is output through the system of 17.8, so the first caller cannot hear the voice signal of the caller. For the third user, because of his portable radio intercom system, Receive a corrective place A on the physical channel p media line transmission tray. Therefore, the second user ’s portable radio, 4 /, and the speaker use different communication channels, so the user ’s portable radio can not be based on (Received signal strength indicator (RSSI))

The detected signal strength starts to receive the signal sent by the caller, so the portable radio of the third user will not receive the voice signal of the caller, and will not output the call through a speaker Voice signal of the speaker, so the second and third users cannot hear the voice signal of the speaker, that is, the portable radios of the second and third users start squelch function by judging the audio signal. In month b, in other words, users with the same logical channel can communicate with each other to achieve the purpose of the group call. Please refer to Figure 2. Figure 2 is a functional block diagram of a conventional radio two-way radio. The radio intercom includes an antenna 11 ', a transceiver 12, a selector (selector) 1, 4, a processor 16, a voice signal processing unit 2, and a speaker. 17, and a microphone 18. Wireless radio 10 can receive and transmit carrier RF via antenna 11.

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Page 7 200421729 V. Description of the invention (4) In terms of receiving carrier RF, the transceivers 12 and 2 amplify the weak high-frequency carrier signal, then convert the high-frequency carrier into a low-frequency intermediate-frequency signal, and then do the IF signal. After the FM demodulation, the baseband voice signal Rx is obtained and transmitted to the selector 14. Since the selector 14 determines the transmission path according to the signal input / output state, in other words, when the radio is in the receiving state, that is, when the selector 1 4 When receiving an input signal from the transceiver 12, the output terminal A will be selected to output the baseband signal Rx. Conversely, when a radio is in the transmitting state, the selector 14 will select the input terminal B for transmission. The processor 16 determines the frequency of the audio signal based on the baseband signal Rx. Generally speaking, the processor 16 includes an analog low-pass filter circuit (Low Pass fi 1 ter) to filter the baseband signal Rx between The signal between frequency 62.5 Hz and frequency 25 0Hz, and determine the audio signal corresponding to the fundamental frequency signal Rx to determine whether to use the same logical channel. If the logical channel corresponding to the fundamental frequency signal Rx is set with the radio intercom 1 〇 The logical channels are the same, the processor 16 will start °° 17 to perform subsequent signal output processing, and the voice signal processing unit 20 also contains two analog filter circuits for capturing low-pass filtering at a frequency of 30 Hz. The signal between the high-pass filter with the frequency of 3.4KHz is finally output through La Ba 17. Conversely, if the logical channel corresponding to the baseband signal Rx is different from the logical channel set by the radio walkie-talkie 10, the processor 16 will not start the voice signal processing unit 20 and π 818, so the radio walkie-talkie 1 0 will not output any signal transmitted through different logical channels. For transmitting carrier RF, when a user presses the call key, the selector 14 selects the input terminal B, and at the same time, the processor 16 activates the microphone 18, so the user's voice signal

Page 8 200421729 can be input to the voice signal processing unit 20. As mentioned above, the voice signal processing unit 20 uses its filter circuit to capture signals between frequency 300 Hz and frequency 3.4KHz, and then output To the processor 16, the processor 16 will add the corresponding frequency of 5 tigers to 5 voices according to the logical channel set by the radio intercom 10 to process the output signal of the early yuan 20 to generate the baseband signal Tx. Finally, After the baseband signal is FM-modulated and converted into a high-frequency carrier RF via the transceiver 12, it is output through the antenna 11. In theory, when the terminal receives a high-frequency RF signal, the received signal strength indicator (RSSI) will be higher than a critical value of the receivable strength. When the high-frequency signal disappears, the received signal strength indicator will be lower than the critical value, and the receiver will turn off the speaker 17 at this time. However, at the end of the call, that is, after the sender releases the call button that was originally pressed, the high-frequency RF signal will stop transmitting. At this time, the strength of the received signal will change from strong to weak. Transceiver 1 2 is still in the receiving state, so it will demodulate the received noise and output a harsh noise (irritating no i se) from the output of La <17. In this way, the user will feel quite uncomfortable. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for preventing a radio intercom from generating a voice when ending a call, so as to solve the above problem. The patent application scope of the present invention provides a way to avoid a radio intercom.

200421729 V. Description of the invention (6) A method for generating noise at the end of a call. The radio includes a receiving circuit. The method includes providing a first detection circuit in the radio. When the radio receives a When the radio signal is within a predetermined frequency range, use the first detection circuit to detect whether the radio signal belongs to a non-standard mute audio signal; and if the first detection circuit detects that the radio signal belongs to the non-standard mute audio signal Signal, the radio intercom will stop receiving subsequent radio signals. Another patent application scope of the present invention is to provide a method for transmitting a radio signal by a radio intercom. The radio intercom includes a call key. The method includes using the radio intercom to output a standard mute audio signal when the call key is touched; and when When the call button is released after the call button is touched, the radio interphone is used to output a non-standard mute audio signal for a predetermined period of time. Please refer to FIG. 3, FIG. 4 and FIG. 5 for implementation. FIG. 3 is a schematic diagram of the appearance of the radio walkie-talkie 30, 40 of the present invention, FIG. 4 is a functional schematic diagram of the radio walkie-talkie 30, 40, and FIG. Timing diagram. The radio intercom 30 includes a call key 32, a microphone 34, a processor 36, and a transmitter 38. The radio walkie-talkie 40 includes a receiver 4 and a selection key 4 2, a processor 4 3, a speaker 4 4, a first detection circuit 4 6, a second detection circuit 48, and a receiver. Circuit 4 5.

Page 10 200421729 V. Description of the invention (7)

When the call key 32 is started to be touched, that is, t 0 in FIG. 5, the processor 36 will control the microphone 34 to start receiving a voice signal, and generate a standard mute audio signal according to a preset frequency of the user, and finally pass the transmitter 38 Send the standard mute audio signal and the voice signal together with the preset carrier. For example, as shown in Figure 1, since the frequency of general voice signals is between 300Hz ~ 3400Hz, and the frequency of audio signals is between 62 · 5Hz ~ 250Hz, there are 38 different frequency audio signals. Will be distributed between 62. 5Hz ~ 250Hz, if a user sets the logical channel of his radio intercom 30 to P i (T 38), that is, the carrier of the physical channel P, and the 38th audio signal (its frequency 250Hz) is transmitted with the voice signal. When the user releases the call button 32, that is, t 峙 in Figure 5, the standard audio signal and voice signal will no longer continue to be transmitted along the carrier of the physical channel P, but just after the call button 32 is released ' Radio walkie-talkie 3 will output a non-standard mute audio signal T 39 for a period of time along with the carrier. The purpose will be described in detail later. After that, 'radio walkie-talkie 30 presses the call key 32 until t3 at t2, and then radio walkie-talkie 3 0 will output a non-standard mute audio signal J along with the carrier for a period of time t. Please note that the frequency of the non-standard mute audio signal τ 3 系 is in the range of 62 · 5Hz ~ 250Hz, but does not include the defined frequency of the standard mute audio signal. In addition, the standard mute audio signal and the non-h quasi-mute audio signal Both belong to the same frequency domain. In order to avoid misjudgment, when the standard mute audio signal is sent during the design, the non-standard mute audio signal will not be sent.

Page 11 200421729 V. Description of the invention (8) ^ ______ The radio signal from the receiver 4 of the radio walkie-talkie 40, and the radio from the machine 30, here it is; ^ to receive the radio talk-back is determined to be only able to receive the entity The wave of channel P. The receiver U is used to select whether the receiver judges whether the receiver is 41 rounds / in. The optional key 42 is used to make the standard mute audio signal T 39. 1 Whether the input radio signal contains non-dropping to determine the reception of the second detection circuit 4 8 is used to determine whether the receiver's mute audio signal T number contains a predetermined standard mute audio signal 4 1 round-in radio signal In this embodiment, the predetermined standard mute audio is convenient for explanation.

2 50 Hz. The receiving circuit 45 is used to change the radio signal 遽 τ ^ to sound waves, and the La Ba 44 4 is used to output sound waves. The voice signal of the command is shown in Figure 6, which is a flowchart of the non-operation shown in Figure 4. Operation package of radio two-way radio 40, eight radio two-way radio 40 Step 1 0 0: Start; s has the following steps: No .; Step 1 0 2: Receiver 41 1 receives the radio signal using the physical communication P, then execute the steps

Step 104: Whether the selection key 42 is selected. If it is 106, if not, go to step 10; otherwise, if the radio signal is yes, go to step 11 2 and step 10 6: use the first detection circuit 4 6 Determine whether it contains a non-standard mute audio signal T39, and if not, go to step 102; step 108: use the second test circuit 48 to list whether the benefit includes a standard mute audio signal τ38, and if so, perform a vv line step Electric number two:

200421729 V. Description of the invention (9) If no, go to step 1 1 4; Step 1 10: send the radio signal to the receiver 1 ^ ^ receiving circuit 45 send the radio signal to two receivers / receive two receivers = produce and use again Use tA 44 to output the sound wave; ^ 5.3 signal is converted into sound wave, step 11 2: End. To make =: 2 = the operation is described below. After the receiver receives the hotline number of the receiver ^ P (step 102), the processor determines whether the radio signal input by the receiver 41 contains a non-standard according to whether the selection key 42 is selected (step 104). Mute audio signal T39 'If the selection key 42 is selected, the processor 43 will use the first detection circuit 46 and the second detection circuit 48 to determine the radio input by the receiver 41

Does the signal contain a non-standard mute audio signal T3 and a standard mute audio signal T? For example, suppose that the non-standard mute audio signal τ 3 妁 frequency is 65 Hz (but this frequency does not belong to any defined standard mute audio signal frequency). When the selection key 4 2 is selected, the first detection circuit 4 6 will determine whether the radio signal input by the receiver 41 includes a 65 Hz radio signal (step 106). If a 65 Hz frequency is detected (that is, tr 5 ti + butterfly and t 3 ~ t 3 + braid at) in FIG. 5, it means that the radio intercom 30 The user has released the call button 3 2, at this time the radio intercom 40 will stop receiving subsequent radio signals. At this time, because the radio intercom 40 no longer receives radio signals, La Ba 44 will not output the radio signal again. Voice signal. If no 65Hz signal is detected, it means that the radio walkie-talkie 40 is still in the standby state (that is, t A butterfly ~ t2 in Figure 5).

Page 13 200421729 V. Description of Invention (ίο) Machine 40 will continue to detect radio signals. If the selection key 4 2 is not selected, the processor 43 will only use the second detection circuit 48 to detect the presence of the standard muted audio signal T38 * in the 250112 frequency range (step 108). If the standard muted audio signal of 250Hz is present T38 exists (that is, t0 ~ tl and t2 ~ t3 in FIG. 5), then the processor 43 uses the receiving circuit 45 to convert a voice signal between a frequency of 300Hz to 3.4KHz into a sound wave (step 11). Finally, the receiving circuit 45 converts the voice signal into a sound wave and outputs it to La Ba 44 so that the user of the radio walkie-talkie 40 can hear the voice of the radio walkie-talkie 30. When the carrier is pressed on the call key 32 (t0 ~ tl, t2 ~ t3 in Fig. 5), the transmitter 38 of the radio intercom 30 will transmit the voice signal input to the microphone 34 and the audio signal at the frequency of 2 50 Hz, and When the call key 3 2 is released (tl ~ tl + braid t in Fig. 5), the transmitter M of the radio intercom 30 will not transmit a 65Hz non-standard mute audio signal τ 3 to transmit the voice of the input microphone 34 Signal, because the radio walkie-talkie 40 is connected to the receiving circuit ^ non-standard mute audio signal T3 spleen to stop the receiver 41 ^ = subsequent radio signals, so the radio walkie-talkie 40 will not be at the moment when the call ends Makes annoying noise. Compared with the conventional technology, at the end of the call, the radio transceiver at the receiving end will receive background noise in the air because it is in the receiving state (white η: 2 after the key is still pressed, it will be sent; one of them: To release the call + mute the audio signal T3 modulation 200421729 V. Description of the invention (11) —---- The carrier goes out while receiving the prostitute τ 3 rain to turn off the speaker. Use this to detect non-standard mute audio signals The clear radio walkie-talkie = method allows users to use this. At the end of the s, there will be no voice left. The above description is only a preferred embodiment of the present invention, and the scope of patents claimed according to the present invention All equal changes and modifications are covered by the patent of the present invention. End of chapter

Page 15 200421729 Brief description of the diagram Brief description of the diagram Figure 1 is a schematic diagram of the frequency range used in the conventional continuous audio coding mute system. Figure 2 is a functional block diagram of a conventional radio. FIG. 3 is a schematic diagram of the appearance of a radio intercom according to the present invention. -Figure 4 is a functional diagram of a radio intercom according to the present invention. FIG. 5 is a timing diagram of transmitting signals according to the present invention. ‘Figure 6 is a flowchart of the operation of the radio intercom shown in Figure 4. Explanation of symbols in the drawing Φ 10 '30 ^ 40 radio intercom 11 antenna 12 transceiver 14 selector 16' 36 processor 17, 44 port 18 '34 microphone 20 voice signal processing unit 32 call button 38 radio transmitter 41 radio reception Selector 42 Selector 43 Processor 45 Receiver circuit 46 First detection circuit 48 Second detection circuit

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Claims (1)

200421729 VI. Application for Patent Scope 1. A method to avoid, when the radio signal is used, the radio uses a non-standard quiet audio signal if the first detection standard mute audio signal is transmitted to the receiving radio radio. The interphone that generates noise during a call includes a receiving circuit. The method includes: providing a first detection circuit in the interphone; the interphone receives wireless in a predetermined frequency range, and the first detection circuit detects whether the radio signal is sound. Audio signals; and, the circuit detects that the radio signal belongs to the non-signal, then the radio intercom stops receiving the subsequent radio signals after the radio signal is routed. 2. If the scope of the patent application includes a second detection circuit, if the first detection circuit picks up the mute audio signal, whether the j signal belongs to a predetermined. If the second detection circuit is a standard mute audio signal, the channel 0 The method of item 1, wherein the radio pair circuit further comprises: the remaining radio signal does not belong to the non-standard use of the second detection circuit to detect the standard mute audio signal of the radio; moving to the radio signal If it belongs to the reservation, then the radio signal is transmitted to the receiver 3. If the scope of the patent application is, the selection keys; and the method of adjusting the item i, which further includes providing a predetermined frequency range ^ Key to make the radio receive the circuit for detection. …, The wire signal can be transmitted to the first detection 200421729 VI. Patent application scope 4. The method described in item 1 of the patent application scope, wherein the frequency of the non-standard mute audio signal is between 62. 5Hz ~ 2 5 0Hz, but does not include the frequency defined for standard mute audio signals. 5.-A radio that implements the method described in item 1 of the patent application. 6. A method for transmitting a radio signal by a radio intercom, the radio intercom including a call key, the method comprising: when the call key is touched, using the radio intercom to output a standard mute audio signal; and ψ after the call key is touched When the call button is released, the radio is used to output a non-standard mute audio signal for a predetermined period of time. 7. The method as described in item 6 of the scope of patent application, wherein the frequency of the non-standard silent audio signal is between 62.5 Hz and 250 Hz, but does not include the defined frequency of the standard mute audio signal. 8.-A radio that implements the method described in item 6 of the patent application. Page 18