KR20060125398A - Digital video broadcasting receiving module, and mobile communication terminal with the same - Google Patents

Abstract

A DVB(Digital Video Broadcasting) receiving module and a mobile communication terminal having the same are provided to improve the receiving sensibility of a mobile communication signal such as DVB-H(Handheld) by improving a removing characteristic of a mobile communication frequency band. The first band rejection filter(210) connects to a broadcasting receiving antenna for receiving a DVB signal, and removes a mobile communication frequency band from a signal received through the broadcasting receiving antenna. An LNA(Low Noise Amplifier)(220) performs the low noise amplification of the DVB signal through the first band rejection filter(210) at a predetermined gain. An RF(Radio Frequency) unit(240) processes the DVB signal through the LNA(220).

Description

Digital video broadcast receiving module and mobile communication terminal having the same {DIGITAL VIDEO BROADCASTING RECEIVING MODULE, AND MOBILE COMMUNICATION TERMINAL WITH THE SAME}

1 is a block diagram of a GSM telephone having a conventional digital video broadcasting reception function.

2 is a frequency characteristic diagram of the GSM filter of FIG.

3 is a block diagram of a mobile communication terminal having a digital video broadcasting reception function according to the present invention;

4 (a) and 4 (b) are frequency characteristics and total frequency characteristic diagrams of respective parts of the digital video broadcasting receiving module of FIG. 3;

Explanation of symbols on the main parts of the drawings

ANT1: Communication antenna ANT2: Broadcast receiving antenna

100: communication transmitting and receiving module 200: digital video broadcasting receiving module

210: first band elimination filter 220: low noise amplifier

230: second band elimination filter 240: RF unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to mobile communication terminals such as cellular phones, PDAs, and cordless telephones. In particular, the present invention improves the elimination characteristics of mobile communication frequency bands, such as the Global System for Mobile Communication (GSM) frequency band, thereby immunity to GSM communication signals. The present invention relates to a digital video broadcasting receiving module and a mobile communication terminal having the same, which can secure the receiver and improve the reception sensitivity of a mobile communication signal such as DVB-H.

Recently, with the advent of digital TV broadcasting service in Korea and the development of digital broadcasting technology, DMB (Digital Mutimedia Broadcasting) technology, which enables digital TV broadcasting service, has been attracting attention.

These DMBs are classified into satellite DMBs (approximately 2.6 GHz) and terrestrial DMBs (approximately 200 MHz) that target mobile broadcasting services through portable receivers (mobile phones, PDAs) or in-vehicle receivers. It is a digital multimedia broadcasting covering both video and data services, and is based on Eureka-147 (EUropean REserch Coordination Agency project-147), the technical standard for digital audio broadcasting (DAB) currently being implemented in Europe. .

In such DMB, video transmission and reception are possible in MPEG-4 and MOT protocol (Motion Object Transfer Protocol), and the world's attention is being paid to video receiving technology using MPEG-4 in such terrestrial DMB.

On the other hand, the European service corresponding to the Korean DMB service as described above is Digital Video Broadcasting (DVB-H) (Handheld devices), the module capable of receiving DVB-H is a mobile phone, etc. Is mounted on the mobile communication terminal.

1 is a block diagram of a GSM telephone having a conventional digital video broadcasting reception function.

The GSM telephone having the digital video broadcasting reception function shown in FIG. 1 performs GSM communication using a frequency band of approximately 900 MHz through a communication antenna ANT1, and is connected to the communication antenna ANT1 to transmit a signal SST. DVB-H receiving a digital video broadcasting (DVB) using a GSM communication module 10 including a power amplifier (PA) for amplifying the power of a power amplifier) and a frequency band of approximately 470 MHz to 860 MHz through a broadcast antenna ANT2. Receiving module 20 is included.

Since the GSM phone has a broadcast frequency and a communication frequency adjacent to each other, and the power of the transmission (TX) signal is very high among the communication signals, when such a high power transmission signal is input to the DVB-H reception module 20, the high power Since the interference between the transmission signal and the broadcast signal of the broadcast reception sensitivity is significantly reduced, the DVB-H reception module 20 should remove the frequency band of the GSM communication signal.

The DVB-H reception module 20 processes a GSM filter 21 for blocking input of a GSM communication signal included in a frequency band of approximately 900 MHz, and a digital video broadcast signal through the GSM filter 21. An RF unit 22 is included. The frequency characteristic of such GSM filter 21 will be described with reference to FIG.

2 is a frequency characteristic diagram of the GSM filter of FIG.

Referring to FIG. 2, the attenuation ratio of each GSM band 21 is about -20 dB in the frequency band of about 174 MHz to 230 MHz, and is about -2 dB in the frequency band of about 470 MHz to about 702 MHz. At higher frequencies, the attenuation is less than approximately -20 dB. At a frequency higher than the 470 MHz, the attenuation rate is approximately -45 dB in the 880 MHz to 915 MHz frequency band and the 1920 MHz to 1980 MHz frequency band.

In the DVB-H reception module 20 including the GSM filter 21 having such a frequency characteristic, a GSM transmission signal (eg, 900 MHz) having a high power of approximately 33 dBm is input to the DVB-H reception module 20. Looking at the rate of attenuation in the process, the high power transmission signal (33dBm) is a coupling attenuation rate (-13dB) between the broadcast antenna (ANT2) and the communication antenna (ANT1), attenuation rate (-10dB) of the broadcast antenna (ANT2) itself And attenuated by the attenuation rate of the GSM communication signal (-45 dB), so that the GSM transmission signal having the high power (33 dBm) (eg, 900 MHz) passes through the GSM filter 21 of the DVB-H receiving module 20. Attenuated by about 35dBm is input to the RF unit 22. In addition, the DVB-H receiving module 20 has a noise figure (NF) of about 6.1 dB.

However, in the DVB-H reception module of the conventional GSM phone, the attenuation rate for the GSM transmission signal must be -38 dB or more, and since this is not satisfied, signal interference due to the GSM communication signal is generated. There is a problem of lowering the reception sensitivity for DVB-H.

In addition, the noise index should be about 4dB, which does not satisfy this problem, so the reception sensitivity is significantly lowered.

The present invention has been proposed to solve the above problems, the object of which is applied to mobile communication terminals such as mobile phones, PDAs, wireless telephones, GSM communication signals by improving the removal characteristics of the mobile communication frequency bands, such as GSM frequency bands It is to provide a digital video broadcast receiving module which can secure cold resistance and can improve the reception sensitivity of a mobile communication signal such as DVB-H.

In addition, another object of the present invention is to improve the rejection characteristics of mobile communication frequency bands such as GSM frequency bands in mobile communication terminals such as mobile phones, PDAs, and wireless telephones, thereby ensuring cold tolerance to GSM communication signals. The present invention provides a mobile communication terminal including a digital video broadcasting reception module capable of improving reception sensitivity of a mobile communication signal such as -H.

In order to achieve the above object of the present invention, the digital video broadcast receiving module of the present invention is connected to a broadcast receiving antenna for receiving a digital video broadcast signal, thereby removing a mobile communication frequency band from the signal through the broadcast receiving antenna. A first band elimination filter; A low noise amplifier for low noise amplifying the digital video broadcast signal through the first band elimination filter with a preset gain; And an RF unit processing the digital video broadcast signal through the low noise amplifier.

The digital video broadcast receiving module may further include a second band cancellation filter between the low noise amplifier and the RF unit to remove a mobile communication frequency band included in a signal from the low noise amplifier.

The digital video broadcast receiving module is a DVB-H receiving module for receiving a DVB-H signal using a frequency band of approximately 460 MHz to 702 MHz.

The digital video broadcast receiving module is applied to a GSM telephone using a frequency band of approximately 900 MHz.

The first band elimination filter and the second band elimination filter are characterized in that the frequency band of approximately 880MHz ~ 915MHz is set as the elimination band.

The second band elimination filter may include a notch filter in which a frequency band of about 880 MHz to 915 MHz is set as the elimination band.

In addition, in order to achieve the object of the present invention, a mobile communication terminal of the present invention, a communication transmitting and receiving module for transmitting and receiving a mobile communication signal through the communication antenna; And a first band elimination filter connected to a broadcast receiving antenna to remove a mobile communication frequency band from a signal through the broadcast receiving antenna, and a digital signal broadcasting signal through the first band elimination filter with low noise amplification. And a digital video broadcast receiving module including a low noise amplifying unit and an RF unit for processing the digital video broadcasting signal through the low noise amplifying unit.

The digital video broadcast receiving module may further include a second band cancellation filter between the low noise amplifier and the RF unit to remove a mobile communication frequency band included in a signal from the low noise amplifier.

The digital video broadcast receiving module is a DVB-H receiving module for receiving a DVB-H signal using a frequency band of approximately 460 MHz to 702 MHz.

The mobile communication terminal is a GSM telephone using a frequency band of approximately 900 MHz.

The first band elimination filter and the second band elimination filter are characterized in that the frequency band of approximately 880MHz ~ 915MHz is set as the elimination band.

The second band elimination filter,

It is characterized by consisting of a notch filter set to approximately 880MHz ~ 915MHz frequency band as the removal band.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

3 is a block diagram of a mobile communication terminal having a digital video broadcasting reception function according to the present invention.

Referring to FIG. 3, the mobile communication terminal of the present invention uses a communication transmission / reception module 100 for performing GSM communication using a frequency band of approximately 900 MHz, and a digital video broadcast using a frequency band of approximately 470 MHz to 702 MHz. And a digital video broadcast receiving module 200 for receiving DVB-H).

The communication transmission / reception module 100 is connected to a communication antenna ANT1 and transmits and receives a mobile communication signal (eg, 900 MHz) through the communication antenna ANT1.

The digital video broadcast receiving module 200 is connected to a broadcast receiving antenna ANT2 and removes a mobile communication frequency band (eg, 900 MHz) from a signal through the broadcast receiving antenna ANT2 ( 210, a low noise amplifier 220 for low noise amplifying the digital video broadcast signal SB through the first band rejection filter 210 with a predetermined gain, and digital video through the low noise amplifier 220. An RF unit 240 for processing a broadcast signal is included.

In addition, the digital video broadcast receiving module 200 may include a mobile communication frequency band (eg, between the low noise amplifier 220 and the RF unit 240 included in a signal from the low noise amplifier 220). And a second band cancellation filter 230 for removing 900 MHz).

In addition, the digital video broadcast receiving module 200 may be implemented as a DVB-H receiving module that receives a DVB-H signal using a frequency band of approximately 460 MHz to 702 MHz. In addition, the mobile communication terminal may be implemented as a GSM telephone using a frequency band of approximately 900MHz.

The first band elimination filter 210 and the second band elimination filter 230 may be configured by setting a frequency band of about 880 MHz to 915 MHz as a elimination band.

The second band elimination filter 230 may include a notch filter in which a frequency band of about 880 MHz to 915 MHz is set as an elimination band.

Meanwhile, in the digital video broadcasting receiving module 200, adding the low noise amplifier 220 immediately after the first band elimination filter 210 may improve the gain and noise index (NF) of the system. The second band rejection filter 230 is added to a stage immediately after the low noise amplifier 220 to efficiently remove the GSM communication signal with less influence on the noise figure NF.

4 (a) and 4 (b) are frequency characteristics and total frequency characteristic diagrams of the respective parts of the digital video broadcasting receiving module of FIG. 3.

4A is a frequency characteristic diagram of each part of the mobile communication terminal of FIG. 3, (1) is a frequency characteristic of the first band elimination filter 210 of FIG. 3, and (2) is a low noise amplification of FIG. The frequency characteristic of the unit 220, (3) is the frequency characteristic of the second band elimination filter 230, (4) is a frequency characteristic showing the gain variable range of the RF unit 240 of FIG.

4B is an overall frequency characteristic diagram of the digital video broadcast receiving module of the present invention.

Hereinafter, the operation and effects of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIGS. 3 and 4, the operation of the mobile communication terminal of the present invention will be described first. First, the mobile communication terminal of the present invention is a GSM phone, and includes a communication transmission / reception module 100 to perform such GSM communication. And a digital video broadcast receiving module 200 for receiving DVB-H.

The communication transmission / reception module 100 performs transmission and reception for a telephone call using a frequency band of approximately 900 MHz. In this case, the communication transmission / reception module 100 transmits a transmission signal through an internal power amplifier PA. STX is amplified by about 33dBm with a fairly high power and transmitted through the communication antenna ANT1.

At this time, even if the high power transmission signal STX is input to the digital video broadcasting reception module 200, the digital video broadcasting reception module 200 of the present invention transmits the high power transmission signal STX of the GSM telephone. The reception sensitivity of the digital video broadcast signal can be improved by sufficiently attenuating the range allowed by the specification so that the high-power transmission signal does not cause interference with the digital video broadcast signal.

Specifically, in the digital video broadcasting receiving module 200 of the present invention, the first band removing filter 210 is included in a frequency band of approximately 900 MHz included in a signal received through the broadcast receiving antenna ANT2. The GSM communication signal is removed at a predetermined attenuation rate and output to the low noise amplifier 220.

Here, the first band elimination filter 210 has a frequency filtering characteristic as shown in (1) of FIG. 4 (a). For example, in the frequency band of about 175 MHz to 230 MHz, the attenuation rate is about -20 dB. In the 470 MHz to 702 MHz frequency band, the attenuation ratio is about -2 dB, and in the 880 MHz to 915 MHz frequency band and the 1920 MHz to 1980 MHz frequency band, the attenuation is about -45 dB.

Next, the low-noise amplifier 220, the DVB-H signal included in the frequency band of approximately 470MHz ~ 702MHz, which is a digital video broadcast signal (SB) through the first band rejection filter 210 with a preset gain The low noise amplification is output to the second band elimination filter 230. Here, as shown in (2) of FIG. 4A, the low noise amplifier 220 sets an amplification gain of about 10 dB, and amplifies the DVB-H signal by about 10 dB.

Next, the second band elimination filter 230 removes the mobile communication frequency band included in the signal from the low noise amplifier 220 once again at a predetermined attenuation rate and transmits it to the RF unit 240. As shown in (3) of FIG. 4A, the second band rejection filter 230 has an attenuation rate of about -5 dB for a frequency band of about 880 MHz to 915 MHz, and thus the frequency of 880 MHz to 915 MHz. Attenuate the mobile communication frequency band included in the band by approximately -5dB.

The RF unit 240 amplifies the digital video broadcasting signal input through the second band rejection filter 230 with a preset gain. In this case, the gain of the RF unit 240 is shown in FIG. As shown in (4) of), it can be set in a gain range of approximately 4dB to 80dB.

As described above, in the process of processing the digital video broadcast signal in the digital video broadcast receiving module 200, the digital video broadcast signal (470MHz to 702MHz) from the broadcast signal antenna ANT2 to the RF unit 240. The gain of is as shown in Figure 4 (b), summarized in Table 1 below.

Reference level 1st band elimination filter Low noise amplifier 2nd band elimination filter RF section Overall gain Invention 0 dB -2 dB +10 dB 0 dB 4 to 80 dB 12 to 88 dB Conventional 0 dB -2 dB × × 4 to 80 dB 2 to 78 dB

As shown in Table 1, the overall gain in the digital video broadcast receiving module 200 of the present invention is in the range of about 12 to 88 dB, while the overall gain in the conventional digital video broadcasting receiving module is about 2 to 78 dB. As a range, it can be seen that in the digital video broadcast receiving module 200 according to the present invention, the gain for the received signal is increased.

In addition, in the process of processing the digital video broadcast signal in the digital video broadcast receiving module 200, attenuation rates for the GSM communication signals (880MHz to 915MHz) are shown in Table 2 below.

GSM transmit power Coupling Loss Between Antennas Antenna loss 1st band elimination filter Low noise amplifier 2nd band elimination filter Overall decay rate Invention 33 dBm -13 dBm -10 dBm -45 dB 0 dB -5 dB -40 dBm Conventional 33 dBm -13 dBm -10 dBm -45 dB 0 dB × -35 dBm

As shown in Table 2, in the digital video broadcast receiving module 200 of the present invention, it can be seen that the attenuation rate for the GSM communication signal is improved compared to the prior art, and accordingly, the GSM frequency band of the mobile communication terminal of the present invention. It can be seen that the removal characteristic is improved.

As described above, in the digital video broadcasting receiving module 200 of the present invention, the noise figure NF of the digital video broadcasting receiving module 200 is approximately 3.4 dB by applying a low noise amplification unit, compared to the conventional 6.1 dB. In addition, since the GSM communication signal increases with the increase of the digital video broadcasting signal according to the use of the low noise amplifier, a second band cancellation filter is used to attenuate the GSM communication signal to the size required for system use. As a result, the attenuation rate for the GSM communication signal is also improved.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, but is defined by the claims, and the apparatus of the present invention may be substituted, modified, and modified in various ways without departing from the spirit of the present invention. It is apparent to those skilled in the art that modifications are possible.

According to the present invention as described above, in a mobile communication terminal such as a mobile phone, a PDA, a wireless telephone, it is possible to secure immunity to the GSM communication signal by improving the removal characteristics of the mobile communication frequency band such as the GSM frequency band. Therefore, the reception sensitivity of a mobile communication signal such as DVB-H can be improved.

Claims (12)

A first band elimination filter connected to a broadcast receiving antenna for receiving a digital video broadcast signal and removing a mobile communication frequency band from a signal through the broadcast receiving antenna; A low noise amplifier for low noise amplifying the digital video broadcast signal through the first band elimination filter with a preset gain; And RF unit for processing the digital video broadcast signal through the low noise amplifier Digital video broadcast receiving module comprising a. The method of claim 1, wherein the digital video broadcast receiving module, A second band cancellation filter between the low noise amplifier and the RF unit to remove a mobile communication frequency band included in a signal from the low noise amplifier; Digital video broadcast receiving module further comprising. The digital video broadcasting receiving module according to claim 2, And a DVB-H receiving module for receiving a DVB-H signal using a frequency band of approximately 460 MHz to 702 MHz. The digital video broadcasting receiving module according to claim 2, Digital video broadcast receiving module, characterized in that applied to the GSM phone using a frequency band of approximately 900MHz. The filter of claim 2, wherein the first band removing filter and the second band removing filter are Digital video broadcast receiving module, characterized in that the approximately 880MHz ~ 915MHz frequency band is set to the removal band. The filter of claim 2, wherein the second band pass filter A mobile communication terminal comprising a notch filter configured to remove an approximately 880 MHz to 915 MHz frequency band. A communication transmission / reception module connected to a communication antenna and transmitting and receiving a mobile communication signal through the communication antenna; And A first band rejection filter connected to a broadcast receiving antenna and removing a mobile communication frequency band from a signal through the broadcast receiving antenna, and a low noise amplification of a digital video broadcast signal through the first band removing filter with a predetermined gain. A digital video broadcast receiving module comprising a low noise amplifying unit and an RF unit for processing a digital video broadcasting signal through the low noise amplifying unit. Mobile communication terminal comprising a. The method of claim 7, wherein the digital video broadcast receiving module, A second band cancellation filter between the low noise amplifier and the RF unit to remove a mobile communication frequency band included in a signal from the low noise amplifier; A mobile communication terminal further comprising. The method of claim 8, wherein the digital video broadcast receiving module A mobile communication terminal comprising a DVB-H receiving module for receiving a DVB-H signal using a frequency band of approximately 460 MHz to 702 MHz. The method of claim 8, wherein the mobile communication terminal, A mobile communication terminal, characterized by a GSM telephone using a frequency band of approximately 900 MHz. The method of claim 8, wherein the first band elimination filter and the second band elimination filter A mobile communication terminal, characterized in that the approximately 880MHz ~ 915MHz frequency band is set to the removal band. The method of claim 8, wherein the second band pass filter A mobile communication terminal comprising a notch filter configured to remove an approximately 880 MHz to 915 MHz frequency band.

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