KR20070116375A - Digital multimedia broadcasting terminal selectively having external antenna - Google Patents

Abstract

A DMB terminal selectively having an external antenna is provided to ensure the reception quality of a DMB signal according to reception areas by selectively using an embedded antenna or an external antenna. A digital multimedia broadcasting(DMB) terminal includes an embedded antenna receiving path(100), an external antenna receiving path(200), and a signal processing path(300). The embedded antenna receiving path(100) has an embedded antenna to receive a DMB signal. The external antenna receiving path(200) has an external antenna installed in an ear-phone or a head-phone, and is connected to the DMB terminal through a jack. The signal processing path(300) selectively receives the broadcasting signal from the embedded antenna receiving path(100) or the external antenna receiving path(200) through the switching operation to process the DMB signal.

Description

DMB terminal having an external antenna selectively {Digital Multimedia Broadcasting Terminal selectively having External Antenna}

1 is a block diagram illustrating a receiving end of a DMB terminal according to a first embodiment of the present invention.

2 is a block diagram illustrating a receiving end of a DMB terminal according to a second embodiment of the present invention.

3 is a block diagram illustrating a receiving end of a DMB terminal according to a third embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100, 400, 700: built-in antenna receive path

200, 500, 800: External antenna receive path

300, 600, 900: Signal Processing Path

310, 610, 910: switching unit

120: internal antenna matching circuit 230: external antenna matching circuit

620, 920: antenna matching circuit

The present invention relates to a DMB terminal for receiving terrestrial digital multimedia broadcasting (DMB: abbreviated as 'DMB'), and more particularly, to selectively receive and activate an internal antenna and an external antenna. It relates to a DMB terminal.

Recently developed DMB terminals add terrestrial DMB functions in addition to the normal data communication functions. DMB classified as mobile multimedia broadcasting is divided into terrestrial DMB and satellite DMB according to transmission media.

Terrestrial DMB is a method of receiving the contents transmitted by a terrestrial broadcasting center from a terrestrial transmission tower or repeater and transmitting it to a user's DMB terminal. Satellite DMB is a satellite receiving the contents transmitted by a broadcasting center through a repeater or directly. It is a method of transmitting to a user's terminal.

The above-described DMB service has a number of differences in service methods compared to conventional terrestrial and satellite broadcasting. In other words, while conventional terrestrial and satellite broadcasting services mainly consist of broadcasting viewing in a fixed place, DMB service enables the viewing of individual broadcasting anytime and anywhere without the limitation of space and time. For example, the existing satellite broadcaster guarantees the mobility of the broadcast service for a vehicle equipped with a vehicle antenna, but this is only a mobile type of broadcast service. However, in the case of DMB service, the service is provided to an individual through a satellite DMB terminal, a PDA, a dedicated terminal, or a vehicle terminal.

Therefore, the DMB service can be said to be the most optimized service for personal mobile broadcasting, and it has the advantage that it is possible to watch TV broadcasting as well as radio and data services while moving.

As described above, DMB is divided into terrestrial DMB and satellite DMB according to a transmission medium. In particular, terrestrial DMB is inferior to satellite DMB in terms of service coverage. However, since terrestrial DMB uses a lower frequency band than satellite DMB, it has a merit that there is less shadow area and less investment cost for GAP Filler serving as a repeater. Therefore, in the case of terrestrial DMB, since the straightness of the radio wave is less than that of the satellite DMB, it is easy to receive a broadcast signal.

In particular, the terrestrial DMB is a configuration of the antenna of the DMB terminal in order to receive a broadcast signal regardless of the location or moving. The antenna configuration of the terrestrial DMB DMB terminal is disclosed in Korean Utility Model Registration No. 0326831. The utility model is characterized in that the antenna for receiving the DMB broadcast is built into the ear microphone. Therefore, the DMB terminal does not have a separate antenna to receive the broadcast signal.

In addition, the Republic of Korea Patent No. 0498676 discloses an earphone antenna for receiving a high frequency broadcast. In the registered patent, the earphone antenna is divided into two conductive wire parts around the RF filter part, and operates as a dipole antenna. In addition, the RF filter unit has a configuration for filtering the voice signal and the received broadcast signal in both directions.

The above-described registered utility model and registered patent are characterized by using an antenna for earphone to receive the terrestrial DMB broadcast signal. However, when the reception antenna is used only with the earphone, there is a problem that it is difficult to secure a predetermined reception quality depending on the viewing area. In addition, regardless of the surrounding environment, in order to use the DMB service, there is a restriction that the earphone must be used at all times.

An object of the present invention for solving the above problems is to provide a DMB terminal that can ensure the reception quality according to the reception area of the broadcast signal by selectively using an internal antenna or an external antenna.

The present invention for achieving the above object has a built-in antenna, a built-in antenna receiving path for receiving a broadcast signal; An external antenna reception path having an external antenna installed in earphones or headphones and connected to the DMB terminal through a jack; And a signal processing path for selectively receiving the broadcast signal from the internal antenna reception path or the external antenna reception path through a switching operation, and processing the broadcast signal.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. Hereinafter, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

First Example

1 is a block diagram illustrating a receiving end of a DMB terminal according to a first embodiment of the present invention.

Referring to FIG. 1, the receiving end of the DMB terminal has an internal antenna receiving path 100, an external antenna receiving path 200, and a signal processing path 300.

The embedded antenna receiving path 100 has a built-in antenna 110 and a built-in antenna matching circuit 120. Built-in antenna 110 is attached to the DMB terminal in a variety of forms, it is integrally provided in the DMB terminal has a structure that can not be removed. However, when receiving a broadcast signal, the built-in antenna 110 may be extended or modified to have a length suitable for reception.

In addition, the embedded antenna matching circuit 120 performs impedance matching to maximize reception of a broadcast signal. By the impedance matching, the reception sensitivity of the broadcast signal of the built-in antenna 110 is maximized.

In addition, the broadcast signal is a signal using a differential quadrature phase shift keying (DQPSK) modulation method in an orthogonal frequency division multiplex (OFDM). In particular, the multimedia and video broadcasting parts of the broadcast signal preferably use MPEG-4 compression encoding and bit error correction techniques.

The external antenna reception path 200 has an external antenna 210 and an external antenna matching circuit 230. The external antenna 210 is provided on the earphone or headphone 240. The earphone or headphone 240 may not only listen to a voice signal but also have a built-in microphone function. Therefore, the earphone or headphone 240 may have a built-in speaker, a switch, or a volume adjustment function. The external antenna 210 mounted on the headphones 240 may be provided in various forms. That is, the external antenna 210 may be provided in the head band, which is a connection member supporting the earphone units that listen to the voice in the headphones 240, or may be embedded in a wire connected to the earphone unit. However, when a broadcast signal to be received uses a frequency of 174MHz to 216MHz, and 200MHz is the center frequency, the length of the wavelength is about 1.5m. When the optimal antenna length for receiving a terrestrial DMB broadcast signal is calculated as λ / 4 (wavelength), the antenna length is about 37 cm. In order to make the length of the antenna shorter, it is about 18 cm when λ / 8 is calculated. Therefore, the external antenna 210 preferably has a length of about 37cm or about 18cm. The earphone or headphone 240 having the external antenna 210 is connected to the DMB terminal using the jack 250 to receive a broadcast signal.

The external antenna 210 connected to the DMB terminal through the jack 250 is connected to the external antenna matching circuit 230. The external antenna matching circuit 230 performs impedance matching to maximize the reception sensitivity of the external antenna 210.

The signal processing path 300 includes a switching unit 310, a filter unit 320, a low noise amplifier (LNA) 330, a demodulator 340, and a processor 350.

The switching unit 310 is connected between the built-in antenna matching circuit 120 and the filter unit 320. The switching unit 310 performs a switching operation according to a switching control signal from the processor 350. Preferably, the switching unit 310 is composed of a single pole single throw (SPST) type relay having one output terminal for one input. In addition, when the external antenna 210 is connected to the DMB terminal through the jack 250, the relay is turned off, and if the external antenna 210 is not connected to the DMB terminal, the relay is turned on. That is, when the external antenna 210 is connected, the external antenna receiving path 200 is activated in the DMB terminal, and when the external antenna 210 is not connected, the internal antenna receiving path 100 is activated in the DMB terminal. .

The filter unit 320 filters the broadcast signal input through the switching unit 310. That is, the noise component except the broadcast frequency band is removed from the received signal. The broadcast signal from which the noise component is removed is input to the LNA 330.

The LNA 330 has a low gain for the noise component included in the broadcast signal, and has a relatively high gain in the region corresponding to the broadcast signal frequency. The broadcast signal output from the LNA 330 is a signal corresponding to the broadcast frequency band, and becomes an amplified signal, but the noise portion has a relatively low magnitude. The signal is input to demodulator 340.

The carrier signal is removed from the signal input to the demodulator 340 and output as a baseband signal. That is, the baseband signal on the carrier is extracted by the demodulator 340 and input to the processor 350.

The processor 350 receives a baseband signal and processes a plurality of multimedia information or video signals included in the baseband signal. The processor 350 is preferably a preprocessor of the DMB broadcast signal. That is, it may serve to separate stream data and packet data from the broadcast signals received from the internal antenna 110 or the external antenna 210. In the DMB terminal, stream data may be used as multimedia information, and packet data may be used as data information. Multimedia information and data information is utilized for the operation of the application program via the platform provided in the DMB terminal.

In addition, the processor 350 detects whether a jack 250 such as an earphone or a headphone 240 is connected to the external antenna matching circuit 230. When the processor 350 detects that the jack 250 of the headphone 240 is connected to the external antenna matching circuit 230, the processor 350 controls the switching unit 310 through a switching control signal. That is, the switching unit 310 is turned off by the switching control signal, and the external antenna receiving path 200 is connected to the signal processing path 300. If it is determined that the external antenna 210 is not connected, the processor 350 controls the switching unit 310 to an on state through a switching control signal. Thus, the embedded antenna receive path 100 is coupled to the signal processing path 300.

In the present embodiment, the internal antenna 110 and the external antenna 210 are selectively activated according to the connection state. In addition, the external antenna 210 may be an antenna of various types such as a monopole type, a dipole type, or a loop type. In the case of the monopole, it is mainly used as the internal antenna 110, but may also be used as the external antenna 210, and may be mixed with the helical type of the coil type therein. In the case of a dipole, wires may be provided by both earphone modules such as the headphones 240, and the wires may be connected to a central portion of the headphones 240. In addition, in the case of the loop type, the conducting wire of the antenna element is made in a round ring shape and can be easily installed along the connection member for connecting both earphone modules, such as the headphones 240.

Therefore, according to the environment of the DMB terminal, the user can select the internal or external antenna. That is, according to the present embodiment, the user can selectively utilize the antenna suitable for the reception environment.

2nd Example

2 is a block diagram illustrating a receiving end of a DMB terminal according to a second embodiment of the present invention.

Referring to FIG. 2, the receiving end of the DMB terminal has an internal antenna reception path 400, an external antenna reception path 500, and a signal processing path 600.

The embedded antenna reception path 400 has a built-in antenna 410, and a broadcast signal received through the built-in antenna 410 is input to the signal processing path 600. The built-in antenna 410 is attached to the DMB terminal in various forms, and is integrally provided in the DMB terminal to have a structure that is not removable. However, when receiving a broadcast signal, the built-in antenna 410 may be extended or modified to have a length suitable for reception. Therefore, the built-in antenna 410 follows the configuration of the built-in antenna provided in a conventional DMB terminal.

The external antenna receive path 500 has an external antenna 510. The external antenna 510 is provided on the earphone or the headphone 520. The configuration of the external antenna 510 is the same as that disclosed in the first embodiment. Therefore, the external antenna 510 mounted on the earphone or headphone 520 may be provided in various forms. That is, the external antenna 510 may be provided in the head band, which is a connection member supporting the earphone units that listen to the voice in the headphones 520, or may be embedded in a wire connected to the earphone unit. The earphone or headphone 520 having the external antenna 510 is connected to the DMB terminal using the jack 530 to receive a broadcast signal.

The external antenna 510 connected to the DMB terminal through the jack 530 is connected to the signal processing path 600.

The signal processing path 600 includes a switching unit 610, an antenna matching circuit 620, a filter unit 630, a low noise amplifier (LNA) 640, a demodulator 650, and a processor 660.

The switching unit 610 transmits the broadcast signal received from the internal antenna 410 or the external antenna 510 to the antenna matching circuit 620. The switching unit 610 performs a switching operation according to a switching control signal from the processor 660, and electrically connects one of the internal antenna 410 and the external antenna 510 to the antenna matching circuit 620.

When the external antenna 510 is connected to the DMB terminal through the jack 530, the switching unit 610 connects the external antenna reception path 500 to the antenna matching circuit 620. If the external antenna 510 is not connected to the DMB terminal, the switching unit 610 connects the internal antenna reception path 410 to the antenna matching circuit 620. That is, when the external antenna 510 is connected, the external antenna receiving path 500 is activated in the DMB terminal, and when the external antenna 510 is not connected, the internal antenna receiving path 400 is activated in the DMB terminal. .

The antenna matching circuit 620 performs impedance matching to maximize reception sensitivity of the internal antenna 410 or the external antenna 510 connected through the switching unit 610. The broadcast signal whose reception sensitivity is maximized through the antenna matching circuit 620 is input to the filter unit 630.

The filter unit 630 filters the broadcast signal input through the antenna matching circuit 620. That is, the noise component except the broadcast frequency band is removed from the received signal. The broadcast signal from which the noise component is removed is input to the LNA 640.

The LNA 640 has a low gain for the noise component included in the broadcast signal and has a relatively high gain in the region corresponding to the broadcast signal frequency. The broadcast signal output from the LNA 640 is a signal corresponding to the broadcast frequency band, and becomes an amplified signal, but the noise portion has a relatively low magnitude. The signal is input to demodulator 650.

The signal input to the demodulator 650 is removed from the carrier, and output as a baseband signal. That is, the baseband signal carried on the carrier is extracted by the demodulator 650 and input to the processor 660.

The processor 660 receives a baseband signal and processes a plurality of multimedia information or video signals included in the baseband signal. The processor 660 is preferably a preprocessor of the DMB broadcast signal.

In addition, the processor 660 detects whether a jack 530 such as an earphone or a headphone 520 is connected to the DMB terminal. When the processor 660 detects that the jack 530 such as the headphone 520 is connected to the DMB terminal, the processor 660 controls the switching unit 610 through a switching control signal. That is, the switching unit 610 connects the external antenna path 500 to the antenna matching circuit 620 by the switching control signal. If it is determined that the external antenna 510 is not connected, the switching unit 610 connects the internal antenna path 400 to the antenna matching circuit 620 through the switching control signal supplied from the processor 660. Let's do it.

In the present embodiment, the internal antenna 410 and the external antenna 510 are selectively activated according to the connection state. In addition, the external antenna 510 may be various types of antennas such as a monopole type, a dipole type, or a loop type. The monopole is mainly used as an internal antenna, but can also be used as an external antenna, and can be mixed with a helical type having a coil shape therein. In the case of a dipole, wires may be provided by both earphone modules such as headphones, and the wires may be connected to a central portion of the headphones. In addition, in the case of the loop type, the conductor wire of the antenna element is made into a round ring shape and can be easily installed along a connecting member for connecting both earphone modules such as headphones.

In addition, in the present embodiment, the antenna matching circuit receives the output signal of the switching unit, and there is no separate antenna matching circuit for the internal antenna and the external antenna, and the internal antenna and the external antenna may use a common antenna matching circuit.

The third Example

3 is a block diagram illustrating a receiving end of a DMB terminal according to a third embodiment of the present invention.

Referring to FIG. 3, the receiving end of the DMB terminal has an internal antenna receiving path 700, an external antenna receiving path 800, and a signal processing path 900.

The embedded antenna reception path 700 has a built-in antenna 710, and a broadcast signal received through the built-in antenna 710 is input to the signal processing path 900. In addition, the built-in antenna 710 has the same configuration as disclosed in the first and second embodiments.

The external antenna receive path 800 has an external antenna 810. The external antenna 810 is provided on the earphone or headphone 820. The configuration of the external antenna 810 is the same as that disclosed in the first and second embodiments. Therefore, detailed description of the external antenna 810 will be omitted in order to avoid overlapping descriptions and to facilitate understanding of the present embodiment.

The external antenna 810 connected to the DMB terminal through the jack 830 is connected to the signal processing path 900.

The signal processing path 900 includes a switching unit 910, an antenna matching circuit 920, a filter unit 930, a low noise amplifier (LNA) 940, a demodulator 950, and a processor 960.

The switching unit 910 transmits the broadcast signal received from the internal antenna 710 or the external antenna 810 to the antenna matching circuit 920. The switching unit 910 performs a switching operation according to a switching control signal supplied from the processor 960, and transmits one of the internal antenna 710 and the external antenna 810 to the antenna matching circuit 920. Connect with

The antenna matching circuit 920 performs impedance matching to maximize reception sensitivity of the internal antenna 710 or the external antenna 810 connected through the switching unit 910. The broadcast signal whose reception sensitivity is maximized through the antenna matching circuit 920 is input to the filter unit 930.

The filter unit 930 filters the broadcast signal input through the antenna matching circuit 920. That is, the noise component except the broadcast frequency band is removed from the received signal. The broadcast signal from which the noise component is removed is input to the LNA 940.

The LNA 940 has a low gain for the noise component included in the broadcast signal, and has a relatively high gain in the region corresponding to the broadcast signal frequency. The broadcast signal output from the LNA 940 is a signal corresponding to the broadcast frequency band, and becomes an amplified signal, but the noise portion has a relatively low magnitude. The signal is input to demodulator 950.

The signal input to the demodulator 950 is removed from the carrier, and output as a baseband signal. That is, the baseband signal carried on the carrier is extracted by the demodulator 950 and input to the processor 960.

The processor 960 receives a baseband signal and processes a plurality of multimedia information or video signals included in the baseband signal. The processor 960 is preferably a preprocessor of the DMB broadcast signal.

In addition, the processor 960 checks and compares the reception sensitivity of the broadcast signal received through the internal antenna 710 and the external antenna 810. For example, when the reception sensitivity of the broadcast signal received through the internal antenna 710 is superior to the external antenna 810, the processor 960 may transmit the internal antenna 710 to the antenna matching circuit 920 through a switching control signal. To be connected. In addition, when the reception sensitivity of the external antenna 810 is superior to the reception sensitivity of the internal antenna 710, the processor 960 allows the external antenna 810 to be connected to the antenna matching circuit 920 through a switching control signal. .

That is, when the first broadcast signal is received, the switching unit 910 receives the broadcast signal through the built-in antenna 710, and the processor 960 measures the reception sensitivity. Subsequently, the switching unit 910 receives a broadcast signal through the external antenna 810, and the processor 960 compares the reception sensitivity of the internal antenna 710 with the reception sensitivity of the external antenna 810. By comparing the reception sensitivity, the processor 960 generates a switching control signal so that the switching unit 910 selects an antenna having superior reception sensitivity.

In the present embodiment, the internal antenna 710 and the external antenna 810 are selectively activated according to the connection state. In addition, the external antenna 810 may be various types of antennas such as a monopole type, a dipole type, or a loop type. The monopole is mainly used as an internal antenna, but may also be used as an external antenna 810 and may be mixed with a helical type having a coil shape therein. In the case of the dipole, the conductors may be installed in both earphone modules such as the headphones 820, and the conductors may be connected to the central portion of the headphones 820. In addition, in the case of the loop type, the conducting wire of the antenna element is made in a round ring shape and can be easily installed along a connection member connecting both earphone modules, such as the headphone 820.

In addition, in the present embodiment, the antenna matching circuit 920 receives the output signal of the switching unit 910, and there is no separate antenna matching circuit for the internal antenna 710 and the external antenna 810, the internal antenna The 710 and the external antenna 810 may use a common antenna matching circuit 920.

In addition, in the present embodiment, the processor 960 may sequentially check the reception sensitivity of the internal antenna 710 and the reception sensitivity of the external antenna 810, and may receive a broadcast signal through an antenna having excellent reception sensitivity. Therefore, according to the receiving environment of the user, the DMB terminal according to the present embodiment can select an antenna having excellent reception sensitivity from the internal antenna and the external antenna, and thus can receive a good quality broadcast.

According to the present invention as described above, the DMB terminal receiving the broadcast signal can selectively use the internal antenna and the external antenna. In addition, since the external antenna is mounted on earphones or headphones, a separate member for installing the antenna is not required. Therefore, the external antenna can be easily installed, and according to the superiority of the reception sensitivity, it is possible to efficiently select the internal antenna or the external antenna and receive broadcast of excellent quality.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (7)

A built-in antenna receiving path having a built-in antenna for receiving broadcast signals; An external antenna reception path having an external antenna installed in earphones or headphones and connected to the DMB terminal through a jack; And And a signal processing path for selectively receiving the broadcast signal from the internal antenna reception path or the external antenna reception path through a switching operation and processing the broadcast signal. The method of claim 1, wherein the signal processing path, A switching unit for selectively activating the internal antenna reception path or the external antenna reception path by a switching operation; A filter unit for receiving and filtering a broadcast signal from the switching unit; An LNA which receives an output of the filter unit, has a low gain with respect to a noise component, and has a relatively high gain in a region corresponding to a broadcast signal frequency; A demodulator for receiving the output of the LNA and extracting a baseband signal carried on a carrier; And And a processor for preprocessing the broadcast signal from the demodulator and generating a switching control signal to control the switching operation of the switching unit. The method of claim 2, wherein when the processor detects that the external antenna is connected to the DMB terminal through a jack, the processor activates the external antenna reception path through the switching control signal, and the external antenna is connected to the DMB terminal. If not determined, DMB terminal, characterized in that for activating the built-in antenna receiving path via the switching control signal. The method of claim 3, The built-in antenna receiving path has a built-in antenna provided fixed to the DMB terminal and a built-in antenna matching circuit for maximizing the reception sensitivity of the built-in antenna, The external antenna reception path has an external antenna provided to be detachable to the DMB terminal through the jack and an external antenna matching circuit for maximizing the reception sensitivity of the external antenna. The method of claim 1, wherein the signal processing path, A switching unit for selectively activating the internal antenna reception path or the external antenna reception path by a switching operation; An antenna matching circuit connected to the switching unit and configured to maximize reception sensitivity of an external antenna or an internal antenna; A filter unit for receiving and filtering a broadcast signal from the antenna matching circuit; An LNA which receives an output of the filter unit, has a low gain with respect to a noise component, and has a relatively high gain in a region corresponding to a broadcast signal frequency; A demodulator for receiving the output of the LNA and extracting a baseband signal carried on a carrier; And And a processor for preprocessing the broadcast signal from the demodulator and generating a switching control signal to control the switching operation of the switching unit. The method of claim 5, wherein the processor senses a connection state of the external antenna to activate an external antenna reception path through a switching control signal when the external antenna is connected to the DMB terminal, and connects the external antenna to the DMB terminal. If not, the DMB terminal, characterized in that for activating the built-in antenna receiving path via the switching control signal. The method of claim 1, wherein the signal processing path, A switching unit for selectively activating the internal antenna reception path or the external antenna reception path by a switching operation; An antenna matching circuit connected to the switching unit and configured to maximize reception sensitivity of an external antenna or an internal antenna; A filter unit for receiving and filtering a broadcast signal from the antenna matching circuit; An LNA which receives an output of the filter unit, has a low gain with respect to a noise component, and has a relatively high gain in a region corresponding to a broadcast signal frequency; A demodulator for receiving the output of the LNA and extracting a baseband signal carried on a carrier; And And a processor for preprocessing the broadcast signal from the demodulator, comparing the reception sensitivity of the internal antenna reception path and the external antenna reception path, and selecting an antenna reception path having a superior reception sensitivity through a switching control signal. Characterized in DMB terminal.

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