Multi-frequency frequency modulation broadcast system capable of switching in critical alarm speech signal
A technology for FM broadcasting and voice signals, which is applied to broadcasting circuit devices, etc., can solve the problems of reduced alarm information release efficiency, inability to meet listening needs, affecting the improvement of useful signal power, etc., and achieves the effect of convenient operation and maintenance and disaster prevention management.
Active Publication Date: 2012-05-30
CRSC COMM & INFORMATION
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Problems solved by technology
[0005] 1) Limitation of the introduced signal: Due to the driver's preference and other reasons, the broadcast channels selected by the vehicle radios of the vehicles driving in the tunnel are different
This technology only introduces a single FM radio frequency point (generally the traffic station in the local area), which will cause the car radio stations receiving other FM radio channels to be unable to meet the listening needs in the tunnel, and cannot meet the public demand
[0006] 2) The utilization rate of the alarm function is poor: When an emergency occurs in the tunnel, the tunnel operator can switch the alarm information and dispatch notification of the wired broadcast to the FM broadcast, and the system will release it to the tunnel through the FM broadcast channel, and the vehicles in the tunnel will receive it through the on-board broadcast The machine can obtain the notification of the tunnel status and the countermeasures to deal with the status
Since only a single FM radio channel is introduced, when the vehicle-mounted radio station is in the receiving state of other frequency points, it cannot receive the alarm information from the tunnel operator, which greatly reduces the efficiency of alarm information release
[0007] 3) Uniformity of system use: the system must be linked with cable broadcasting
When the interference signal is in the frequency band, the interference signal cannot be filtered out, thus affecting the power boost of the useful signal
When the power of the received interference signal is higher than that of the available signal, it will affect the normal relay amplification of the FM broadcast signal by the signal relay equipment, and in severe cases, it will cause large signal blocking and affect the normal operation of the system
[0013] 3) The alarm function is not available: Since this technology only amplifies the FM broadcast signal on the carrier frequency and does not do any processing on its audio signal, the alarm cut-in function cannot be realized
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[0030] Such as image 3 As shown, a multi-frequency FM broadcasting system capable of cutting into emergency alarm voice signals includes a first signal splitter and combiner 2, a second signal splitter and combiner 3, a signal modulation and demodulation unit 4, and a multi-frequency FM broadcast host centralized The control circuit 5, the first signal divider and combiner 2, the signal modulation and demodulation unit 4, and the second signal divider and combiner 3 are connected in sequence. The signal modem unit 4 includes a modem circuit 10 and a test modem circuit 11 . The first signal divider and combiner has 16 output ports, the second signal divider and combiner has 15 input ports, the modulation and demodulation circuit has 15, and the test modulation and demodulation circuit has one. The radio frequency signal input ports of 15 modulation and demodulation circuits 10 and 1 testing modulation and demodulation circuit 11 are respectively connected with 16 output ports...
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The invention relates to a multi-frequency frequency modulation (FM) broadcast system capable of switching in a critical alarm speech signal, comprising a first signal splitter / combiner, a second signal splitter / combiner, a signal modulation-demodulation unit, a multi-frequency FM broadcast host centralized control circuit, a power supply unit, a speaker, a key control unit and a liquid crystal display, wherein the first signal splitter / combiner, the signal modulation-demodulation unit and the second signal splitter / combiner are connected in sequence; the signal modulation-demodulation unit is connected with the multi-frequency FM broadcast host centralized control circuit; and the power supply unit, the speaker, the key control unit and the liquid crystal display are respectively connected with the multi-frequency FM broadcast host centralized control circuit. Compared with the prior art, the system has the following advantages: the invention can ensure the whole-band frequency FM broadcast signals to cover tunnels and other closed sections and can switch in the critical alarm speech signal during broadcast, etc.
Description
technical field [0001] The invention relates to an FM broadcasting device, in particular to a multi-frequency FM broadcasting system capable of cutting into emergency alarm voice signals. Background technique [0002] Technology 1: Single-frequency FM broadcasting introduces emergency alarm communication [0003] Most of the completed river and highway tunnels only introduce local FM radio traffic stations (such as Shanghai 105.7MHz traffic station). Such as figure 1 As shown, the system introduces the traffic station information through the cable broadcasting of the tunnel integrated monitoring system, modulates the traffic station audio signal of the wired broadcasting station through the FM transmitter according to the traffic station frequency, and covers the signal into the tunnel through the antenna feeder system and signal relay equipment various regions. [0004] Technology has flaws: [0005] 1) Limitation of the introduced signal: Due to the driver's preference...
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IPC IPC(8): H04H20/48
Inventor 谌静维赵正连赵祎博张哲任朝辉徐佳
Owner CRSC COMM & INFORMATION