A kind of automatic radio audio transmission method based on the FM frequency modulation technology
Technical field
The present invention relates to a kind of transmission method of wireless signal, particularly a kind of transmission method of the automatic radio audio based on the FM frequency modulation technology.
Background technology
In the technology of existing FM FM broadcasting, transmitter sends modulation signal with the frequency that configures, and receiving terminal need be known the frequency of emission, and tuner is transferred to (frequency sweep or directly setting) this frequency, can realize receiving.Described transmitting and receiving apparatus all works alone, and carrier frequency also needs to preestablish, and can't carry out any type of communication between the two (except that transmitting audio signal).
For example, in disclosed Chinese invention patent application CN 1700622A on November 23rd, 2005, a kind of method that is applied to the searching available frequency band of digital broadcast receiving and retransmitting device is disclosed, it searches untapped frequency band in a frequency range of setting, and with so that after should receive transmitting receiving digital broadcast signal, see through this frequency band and send respective signal and receive for a broadcast reception playing device.Its defective is, described receiving and retransmitting device has realized searching the process of dummy frequencies wave band, and the dummy frequencies wave band of being sought shown, by the user receive frequency of broadcast reception playing device is adjusted to above-mentioned dummy frequencies wave band again, can receive the broadcast singal that sends by receiving and retransmitting device.As seen from the above description, the disclosed technology contents of patent application CN 1700622A does not solve the technical problem of setting up communication channel between transmitter and receiving equipment automatically, and, still can't be between broadcsting transmitter (or its receiving and retransmitting device) and the receiving equipment except that the information communication transmitting broadcast singal.
Summary of the invention
The object of the present invention is to provide a kind of transmission method of the automatic radio audio based on the FM frequency modulation technology, realization is searched idle frequency automatically by transmitter in a frequency range of setting, automatically and receiving equipment set up communication channel, and by the idle frequency that searches to the receiving equipment transmitting audio signal.
The technical solution adopted in the present invention: a kind of automatic radio audio transmission method based on the FM frequency modulation technology, comprise reflector and receiver, its reflector is searched idle frequency automatically in a frequency range of setting, and by the idle frequency that searches to the receiver transmitting audio signal, it is characterized in that described automatic radio audio transmission method comprises: (a). reflector is searched idle frequency automatically in the frequency range of setting; (b). the idle frequency that reflector will search is sent to receiver by a fixing channel; (c). receiver receives above-mentioned idle frequency, and automatic tuning is to this free time frequency; (d). reflector and receiver with above-mentioned idle frequency as communication channel, transmitting audio signal.
The frequency range of above-mentioned reflector search comprises a minimum frequency and high frequency points, and reflector is searched idle frequency by minimum frequency to the incremental manner of high frequency points with certain frequency interval; Described reflector also can be certain frequency interval, search idle frequency by high frequency points to the mode of successively decreasing of minimum frequency.Wherein, the frequency range of described reflector search is 87.5MHz~108MHz, or 76MHz~90MHz; Frequency interval when described reflector is searched is 100KHz.
Above-mentioned reflector is that a quilt is searched frequency range channel in addition to the fixed channel that receiver sends idle frequency signal, and this fixed channel is 76.1MHz or 179.9MHz.
Above-mentioned reflector comprises microprocessor, modulating emission circuit, transmitting antenna and operating key, and the input/output terminal of microprocessor is electrically connected with operating key, modulating emission circuit respectively, and the output of modulating emission circuit is connected with transmitting antenna; Described reflector also comprises a FM reception circuit, is used for the frequency range that the automatic scan microprocessor is set, and searches idle frequency.
Above-mentioned receiver comprises microprocessor, FM reception circuit, reception antenna and operating key, and the input/output terminal of microprocessor is electrically connected with operating key, FM reception circuit respectively, and the input of FM reception circuit is connected with reception antenna; Described receiver also comprises a tuner, is used to adjust the receive frequency of receiver.
Automatic radio audio transmission method of the present invention is specifically realized by following steps:
Step a. user presses the operating key of receiver end, makes receiver automatically lock a fixed channel, waits for received signal;
Step b. user presses the operating key of emitter terminals, makes reflector automatic scan in the frequency range of setting, and searches best idle frequency;
The step c reflector finds idle frequency, should encode with certain data format by the free time frequency;
Steps d. reflector is sent to receiver to search frequency range fixed channel in addition with above-mentioned code signal;
Step e. receiver receives above-mentioned code signal, and automatically performs the decoding analysis by microprocessor, extracts the frequency values of idle frequency;
Step f. receiver transfers to above-mentioned idle frequency by tuner with receive frequency, sets up the communication channel with reflector;
Step g. reflector and receiver with above-mentioned idle frequency as communication channel, transmitting audio signal.
The present invention is by the improvement to existing FM frequency modulation technology, make FM frequency modulation transmitting terminal can set the idle channels an of this area automatically, and the information of this idle channels is sent to receiving equipment, make FM FM reception end obtain this frequency automatically, thereby between transmitting and receiving apparatus, realize the automatic UNICOM and the communication of minimum artificial intervention.The equally simple of this communication way fundamental sum Bluetooth technology all is to realize wireless interconnected between reflector and the receiver by a button directly, and that this method has more is with low cost, use characteristics fast and easily.Reflector of the present invention can be installed or be connected on any audio transmitting device, described receiver can be installed or be connected on any audio-frequence player device, by automatic radio audio transmission method of the present invention, realize the voice signal that audio transmitting device sends is transferred to the process of long-range audio-frequence player device.
Description of drawings
Fig. 1 is the theory diagram of reflector of the present invention;
Fig. 2 is the theory diagram of receiver of the present invention;
Fig. 3 is the flow chart of frequency searching method of the present invention.
Embodiment
The present invention is described in further detail below in conjunction with specific embodiment and accompanying drawing, but embodiments of the present invention are not limited thereto.
Be the theory diagram of reflector of the present invention and receiver as shown in Figure 1, 2, wherein:
Reflector 1 comprises microprocessor 11, modulating emission circuit 12, transmitting antenna 13, operating key 14 and indicator light 15,16, the input/output terminal of microprocessor 11 is electrically connected with operating key 14, modulating emission circuit 12 respectively, and the output of modulating emission circuit 12 is connected with transmitting antenna 13; Described reflector 1 also comprises a FM reception circuit 17 and reception antenna 18 thereof, and FM reception circuit 17 is connected with microprocessor 11, is used for the frequency range that the automatic scan microprocessor is set, and searches idle frequency.The operation principle of reflector 1 is: press operating key 14, microprocessor 11 is promptly controlled FM reception circuit 17 and search idle frequency in the frequency range of setting, after finding idle frequency, microprocessor 11 should be encoded with certain data format by the free time frequency, the code signal (code) of transmitting control commands (command) and idle frequency makes modulating emission circuit 12 launch the code signal of idle frequency with fixed channel to modulating emission circuit 12.
Receiver 2 comprises microprocessor 21, FM reception circuit 22, reception antenna 23, operating key 24 and indicator light 25,26, the input/output terminal of microprocessor 21 is electrically connected with operating key 24, FM reception circuit 22 respectively, and the input of FM reception circuit 22 is connected with reception antenna 23; Described receiver 2 also comprises a tuner, and this tuner is integrated in the microprocessor 21, is used to adjust the receive frequency of receiver.The operation principle of receiver 2 is: press operating key 24, microprocessor 21 is that transmitting control commands (command) is to FM reception circuit 22, make FM reception circuit 22 receive the idle frequency code signal that sends by reflector 1, FM reception circuit 22 is exported to microprocessor 21 with the code signal (code) that receives, the analysis of decoding of 21 pairs of above-mentioned code signals of microprocessor, extract the frequency values of idle frequency, and receive frequency is transferred to idle frequency by tuner, set up communication channel with reflector 1.
During use, above-mentioned reflector 1 is installed or is connected on the audio transmitting device, receiver 2 is installed or is connected on the audio-frequence player device, set up communication channel by operating key 14,24 control reflectors 1 and receiver 2.Then, the audio signal of audio transmitting device inputs to the modulating emission circuit 12 of reflector 1, transfer to the FM reception circuit 22 of receiver 2 by the communication channel of above foundation, export audio-frequence player device then to, realize the voice signal that audio transmitting device sends is transferred to the process of long-range audio-frequence player device.
As shown in Figure 3, reflector 1 of the present invention is implemented in and searches idle frequency in the frequency range of setting automatically, and by the idle frequency that searches to receiver 2 transmitting audio signals, the automatic radio audio transmission method is realized by following steps:
Step a. user presses the operating key 24 of receiver end, and (76.1MHz is used in the European and American areas to make receiver 2 automatically lock a fixed channel; Japan Area uses 179.9MHz), wait for received signal, but external at this moment output sound;
Step b. user presses the operating key 14 of emitter terminals, and (if to the European and American areas, the scope of scanning is 87.5MHz~108MHz in the frequency range of setting to make reflector 1; If for Japan Area, the scope of scanning is the automatic scan of 76MHz~90MHz), searches best idle frequency;
The step c reflector finds idle frequency F, should encode with certain data format by free time frequency F;
Steps d. (76.1MHz is used in the European and American areas to reflector 1 to be searched frequency range fixed channel in addition; Japan Area uses 179.9MHz) above-mentioned code signal is sent to receiver 2, finish this action rear indicator light 15 and transfer green automatically to;
Step e. receiver 2 receives above-mentioned code signal, and automatically performs the decoding analysis by microprocessor 21, extracts the frequency values of idle frequency F;
Step f. receiver 2 transfers to above-mentioned idle frequency F by tuner with receive frequency, and the communication channel of foundation and reflector 1 is finished this action rear indicator light 25 and transferred green automatically to;
Step g. reflector 1 with receiver 2 with above-mentioned idle frequency F as communication channel, transmitting audio signal.
So far, automatic communication and butt joint have been finished in reflector 1 and receiver 2 two ends, realize the wireless transmission of stereo audio.
The frequency range that above-mentioned reflector 1 is searched comprises a minimum frequency L and high frequency points H, and reflector 1 is with certain frequency interval, searches idle frequency F by minimum frequency L to the incremental manner of high frequency points H; Described reflector 1 also can be certain frequency interval, search idle frequency F by high frequency points H to the mode of successively decreasing of minimum frequency L.If to the European and American areas, the frequency range of search is 87.5MHz~108MHz; If for Japan Area, the frequency range of search is 76MHz~90MHz; Frequency interval during search is 100KHz.When reflector 1 sends idle frequency F to receiver 2, be to be carrier wave, the code signal of idle frequency F is sent to receiver 2 with a frequency that is lower than minimum frequency L (European and American areas use 76.1MHz) or is higher than high frequency points H (Japan Area uses 179.9MHz).
The foregoing description is a preferred implementation of the present invention; but embodiments of the present invention are not restricted to the described embodiments; other any do not deviate from change, the modification done under spirit of the present invention and the principle, substitutes, combination, simplify; all should be the substitute mode of equivalence, be included within protection scope of the present invention.