KR20010028514A - Apparatus for intercepting Communication of Cellular Phone - Google Patents

Abstract

PURPOSE: An apparatus for cutting-off a call via a radio terminal is provided to cut off a call by generating a signal similar to a carrier frequency for radio communication and to adjust a cutoff area of radio communication by adjusting the amplification degree of output of the apparatus. CONSTITUTION: A certain bit stream is generated in a bit stream generating part(31) and a data in the bit stream is converted into an analog signal in an IF converting part(32). Then, the analog signal is amplified in an amplifier(34). The bit stream is also controlled by a peripheral circuit(33) comprised of a memory and a peripheral elements. A local signal having a certain frequency and continuously oscillated from a local oscillator(35), and the analog signal output from the IF converting part(32) and amplified in the amplifier(34) are summed in a mixer(36) to produce a carrier frequency for radio communication(e.g., a frequency band for PCS communication). Then, the carrier frequency is highly amplified in a high power amplifier(37) and broadcasted by an antenna(38).

Description

App blocking device of wireless terminal {Apparatus for intercepting Communication of Cellular Phone}

The present invention relates to a wireless communication cutoff system, and more particularly, a call of a wireless terminal of a simple method that can generate a signal similar to a wireless carrier carrier frequency in a specific public place to block a call by the intermodulation characteristic of the wireless terminal itself. It relates to a blocking device.

Recent developments in information and communication technology, changes in life styles, and economic growth are changing the form of communication culture rapidly.In the information age, the demand for high-speed information delivery is not limited to time and place. Mobile communication services, which can provide quality communication services economically even in an office, outdoor or general public environment, have become an indispensable communication medium in daily life.

Unlike the wide area method using the service area as one large area, such a mobile communication system divides the entire service area into a small service area called a cell, and allocates a certain number of radio channels available within each cell. Will be allocated.

In addition, wireless base stations (Cell Sites) installed in each cell are centrally controlled in a switching system, and as the demand for mobile communication increases rapidly, the cellular system increases the number of subscribers in a limited frequency band to accommodate more subscribers. In order to expand the service area to all regions, more and more wireless base stations and repeaters have been installed to increase the number of cells.

1 is a schematic block diagram of a general wireless communication repeater, and receives and receives a voice signal transmitted from a base station (or a wireless terminal) and transmits and receives a plurality of transmit and receive antennas 11-1 and 11-2 to a wireless terminal (or a base station). And a plurality of handsets (13-1 and 13-2) for receiving and transmitting a voice signal from or to a transmit / receive antenna and filtering and amplifying the voice signal in both directions, and a handset (13-1 and 13-2). Low noise amplifiers 15-1 and 15-2 for reducing noise generated in the audio signal output through the N-signal, and a signal of a desired frequency band among the signals output through the low noise amplifiers 15-1 and 15-2. The filter 17-1, 17-2 passing through the bay, and the audio signal output through the filters 17-1, 17-2 are amplified to a predetermined level, and then transferred to the handset converters 13-1, 13-2. Driving amplifiers 19-1 and 19-2 to output.

The repeater 10 configured as described above is installed in a public building or a basement and a mountain area where radio wave reception is weak, and amplifies and transmits radio waves to an area where radio wave reception is weak, thereby providing a high quality wireless communication service. And the communication of the wireless terminal 5 can be more faithfully serviced, thereby broadening the area of the mobile communication service.

However, due to the expansion of the coverage area, many people talk to wireless terminals in public places such as theaters, hospitals, and parliaments regardless of time and place. It hurts public interest.

In order to distinguish between time and place and use them more conveniently, a lot of research is being conducted by each telecommunications company.

Accordingly, an object of the present invention is to provide a communication blocking device of a wireless terminal which can fundamentally block a call of the wireless terminal only in a specific region.

In addition, another object of the present invention, by generating a signal similar to the wireless carrier carrier frequency can not only easily block the call by the intermodulation characteristics of the terminal itself, but also wireless communication that can adjust the call blocking area by adjusting the output amplification degree To provide a blocking device.

A call blocking device of the present invention for achieving the above object, the bit string generation unit for generating a predetermined CDMA bit string;

A local oscillator for oscillating a constant local signal at a predetermined frequency;

An intermediate frequency converting unit receiving bit string data output from the bit string generating unit and converting the bit string data into an analog signal and generating an analog signal having an intermediate frequency;

An amplifier for amplifying the intermediate frequency output from the bit string generator;

A mixer configured to receive and add an intermediate frequency signal output from the amplifier and a local signal output from the local oscillator, and convert the received intermediate signal into a carrier frequency of a predetermined wireless communication terminal; And

It characterized in that it comprises a high output amplifying means for amplifying the analog signal of the predetermined frequency band output from the mixer to a high output and then transmitting to the wireless terminal to interrupt the decoding of the voice signal transmitted to the wireless terminal to block the call.

1 is a schematic block diagram of a general wireless communication repeater,

2 is a view for explaining a wireless communication blocking method according to the present invention,

3 is a block diagram showing a communication blocking device according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

30: call blocking device 31: bit string generation unit

32: intermediate frequency (IF) conversion unit 33: peripheral circuit

34: IF amplifier 35: local oscillator

36: Mixer 37: High Power Amplifier

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 2 is a diagram illustrating a wireless communication blocking method according to the present invention, and illustrates a base station or repeater 1, 10, a wireless terminal 5, and a call blocking device 30.

The wireless terminal 5 communicates with users while transmitting and receiving voice data with the base station 1 or the repeater 10 as a signal of a predetermined frequency band based on a predetermined wireless communication protocol.

However, after the call blocking device 30 is installed in a specific service area capable of wireless communication, when a frequency similar to the use frequency of the wireless terminal 5 is generated and outputted, the minute signal transmitted from the base station 1 or the repeater 10 is fine. A voice signal and a large output carrier signal output from the call interrupter 30 are simultaneously received by the wireless terminal 5 from the base station 1 or the repeater 10 by mutual interference of two signals of the terminal 5 itself. The transmitted voice signal cannot be decoded.

Therefore, wireless communication of the wireless terminal 5 in the area (dashed line area) corresponding to the output range of the call interruption device 30 becomes virtually impossible.

In addition, the repeater 10 illustrated in FIG. 1 may be divided into two types according to a signal processing method, one of which is a RF (Radio Frequency) direct method and the other is an IF (Intermediate Frequency) conversion. That's the way.

The RF method extracts signals of a desired frequency band using only a filter's inherent filtering band without providing a local signal, and the IF (Intermediate Frequency) method converts an RF signal into an IF signal using a local oscillation signal and then performs a filtering process. By performing the method, the IF method has superior noise removal and amplification characteristics than the RF method, but there are advantages and disadvantages in that the size of the relay equipment is increased and the cost is increased. FIG. 1 shows the RF method and the present invention is independent of any method. Do.

3 is a block diagram showing a communication interruption apparatus according to an embodiment of the present invention, including a bit string generator 31, an intermediate frequency converter 32 (hereinafter referred to as an IF converter), and a peripheral circuit 33. And an IF amplifier 34, a local oscillator 35, a mixer 36, and a high power amplifier 37.

The bit string generator 31 is configured to generate a predetermined CDMA bit string, and the IF converter 32 receives bit string data output from the bit string generator 31 and converts the bit string data into an analog signal. It is configured to generate an analog signal of intermediate frequency (IF), and the peripheral circuit unit 33 adjusts and sets the bits and output frequencies generated by the bit string generator 31 including a memory and a peripheral device. The IF amplifier 34 is configured to amplify the analog signal of the intermediate frequency output from the IF converter 32 to a predetermined level.

In addition, the local oscillator 35 is a PLL (Phase Locked Loop) circuit unit which controls to oscillate a local signal of a constant voltage at a predetermined frequency at all times, and the mixer 36 is an IF output from the IF amplifier 34. The signal and the local signal output from the local oscillator 18 are configured to be converted and then converted into a carrier frequency of a predetermined wireless communication terminal 5, and the high power amplifier 37 outputs a constant output from the mixer 36. It is configured to amplify the analog signal of the frequency band to a high output and then to transmit to the wireless terminal 5 through the antenna 38.

Referring to the communication blocking device shown in the Figure for example a terminal system for PCS (Personal Communication Service) as follows.

The bit string generator 31 generates a CDMA bit string based on the protocol defined in IS-95-A and outputs the CDMA bit string to the IF converter 32.

The IF converter 32 converts the bit string data output from the bit string generator 31 into an analog signal and generates a signal having an intermediate frequency of 220.38 MHz with a filtering bandwidth of 10 MHz. In addition, the bit strings generated by the bit string generator 31 are adjusted and controlled by the peripheral circuit unit 33 including a memory and a peripheral device.

The local oscillator 35 continuously oscillates a local signal having a center frequency of 1634.62 MHz and a bandwidth of 30 MHz and supplies the mixer 36 to the mixer 36 at a period of 100 Hz. 1840MHz to 1870 of the PCS frequency band with the center frequency of 1855MHz and the bandwidth of 30MHz by adding the signal of 220.38MHz and the signal of the center frequency output from the local oscillator 35. It outputs a signal of MHz.

The high power amplifier 37 amplifies the PCS frequency band (1840 MHz to 1870 MHz) signal output from the mixer to a high output and then continuously transmits to the individual wireless terminal 5 through the one-way antenna 38.

Therefore, the mobile terminal 5 carried by each individual simultaneously receives the fine signal transmitted from the base station 1 or the repeater 10 and the large CDMA signal outputted from the call blocking device 30 and mutually interfering with each other. Due to this, it is not possible to decode the signal transmitted from the base station 1 or the repeater 10, thereby preventing a telephone call in a specific region.

In addition, the high power amplifier 37 is configured to adjust the amplification degree arbitrarily by the user according to the control signal (Control) it is possible to adjust the radius and area of the call blocking zone according to the set output amplification degree.

Although a specific embodiment of the present invention has been described and illustrated in FIG. 3, it is obvious that the present invention can be applied to a cellular phone by changing the output frequency of the call blocking device as well as the PCS.

Such embodiments should not be individually understood from the technical spirit or the prospect of the present invention, and such modified embodiments should fall within the appended claims of the present invention.

Therefore, in the present invention, by outputting a call blocking signal to a specific public place, to prevent noise caused by the call of the cellular phone in the public place to improve the public environment as well as to arbitrarily adjust the output amplification degree of the blocking signal call It is effective to adjust the blocking area.

Claims (3)

A bit string generator for generating a predetermined CDMA bit string; A local oscillator for oscillating a constant local signal at a predetermined frequency; An intermediate frequency converting unit receiving bit string data output from the bit string generating unit and converting the bit string data into an analog signal and generating an analog signal having an intermediate frequency; An amplifier for amplifying the intermediate frequency output from the bit string generator; A mixer configured to receive and add an intermediate frequency signal output from the amplifier and a local signal output from the local oscillator, and convert the received intermediate signal into a carrier frequency of a predetermined wireless communication terminal; And And a high output amplifying means for amplifying the analog signal of a predetermined frequency band output from the mixer to a high output and then transmitting the signal to the wireless terminal to interrupt the decoding of the voice signal transmitted to the wireless terminal to block the call. Call blocking device on the terminal. The method of claim 1, The high power amplifying means, The call blocking device of the wireless terminal, characterized in that the user can arbitrarily adjust the output amplification degree to adjust the call blocking area. The method of claim 1, And a peripheral circuit unit configured to adjust and set a bit and an output frequency generated by the bit string generator.