KR20070056312A - Ground wave digital multimedia broadcasting receiving system using the diversity antenna and method thereof - Google Patents

Abstract

A system and a method for receiving a terrestrial DMB(Digital Multimedia Broadcasting) program through a diversity antenna are provided to select at least two antennas among diversity antennas, calculate a bit error rate in each of the selected antennas and compare the calculated bit error rate with a threshold bit error rate in order to select one of the selected antennas which has good signal sensitivity. A antenna switch(120) selects at least two of antennas. A plurality of RF(Radio Frequency) filters(130a,130b) filters signals received via the antennas and generates analog signals. A plurality of ADCs(Analog-to-Digital Converters)(140a,140b) converts the analog signals into digital signals. A plurality of COFDM(Coded Orthogonal Frequency Division Multiplexing) demodulators(150a,150b) demodulates the digital signals and generates demodulated signals. A plurality of deinterleavers(160a,160b) rearranges the demodulated signals and generates rearranged signals. A plurality of Viterbi decoders(170,170b) decodes the rearranged signals by a Viterbi type and provides decoded signals to a channel switch(190). A bit error rate comparing part(180) calculates bit error rates of the decoded signals.

Description

Ground Wave Digital Multimedia Broadcasting Receiving System Using the Diversity Antenna And Method

1 is a block diagram showing a conventional diversity antenna receiver.

Figure 2 is a block diagram showing a terrestrial DMB receiving system using a diversity antenna according to an embodiment of the present invention.

3 is a flowchart illustrating a terrestrial DMB receiving method using a diversity antenna according to an embodiment of the present invention.

4 is a configuration diagram illustrating a DMB signal generation unit of FIG. 2.

5 is a block diagram showing a terrestrial DMB receiving system using a diversity antenna according to another embodiment of the present invention.

6 is a flowchart illustrating a terrestrial DMB receiving method using a diversity antenna according to another embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

10, 110: diversity antenna 20, 120: antenna switch

30, 130a, 130b: RF filter 40, 140a, 140b: ADC

50, 150a, 150b: COFDM decoder 60, 160a, 160b: deinterleaver

70, 170a, 170b: Viterbi decoder 180: bit error rate comparison unit

190: channel switch 200: DMB signal generation unit

The present invention relates to a terrestrial DMB receiving system and method using a diversity antenna, and more particularly, using a diversity antenna capable of providing high quality by selectively switching an antenna for receiving a better signal using two diversity antennas. The present invention relates to a terrestrial DMB receiving system and method.

Long time ago, due to the effort to provide a variety of services to the driver in the vehicle, another living space, there are a lot of facilities have recently been installed in the vehicle. For example, a variety of convenience facilities are installed, such as car analog TV, audio, cassettes, air conditioners, refrigerators, and the like. Among these various convenience facilities, the development of analog TV that can receive TV in a vehicle breaks the common sense of the fixed TV concept, and is positioned as a landmark installation applying a mobile TV. These analog TVs are entering the age of two channels, analog and digital TV, by DMB (Digital Multimedia Broadcasting), especially terrestrial DMB, which has been widely spread recently. However, at present, rather than installing a separate antenna for terrestrial DMB, a diversity antenna installed for analog TV in a vehicle is commonly used as a terrestrial DMB antenna. The analog TV determines the reception sensitivity of the antenna by the strength of the electric field, but the terrestrial DMB system evaluates the reception sensitivity of the antenna using this value after storing a certain amount of data. Therefore, unlike the analog TV, when the diversity function is used in a DMB system, the switching time of the antenna is inevitably generated, and when an error occurs after switching to another antenna and receiving data for a certain time, the signal is selected by selecting another antenna. Will be received.

FIG. 1 is a diagram illustrating a diversity antenna system using such a conventional diversity antenna as one antenna and used as an analog TV and a digital TV combined antenna.

Referring to FIG. 1, a conventional diversity antenna system using one antenna is connected to the diversity antenna 10 and the diversity antenna 10 so as to select one of a plurality of diversity antennas 10. An antenna switch 20, an RF filter 30 for filtering the signal received by the selected diversity antenna 10, an analog-digital converter 40 for converting the filtered analog signal into a digital signal, and the conversion. A COFDM demodulator 50 for demodulating the digital signal in a coded orthogonal frequency division multiplexing (COFDM) scheme, a deinterleaver 60 for rearranging the demodulated signal, and a Viterbi scheme for the rearranged signal. The Viterbi decoder 70, which decodes and supplies the channel decoder, compares the bit error rate of the decoded signal to the diversity antenna 10 having better signal sensitivity. And a BER comparison unit 80 that controls the positioning.

The conventional diversity antenna system using one diversity antenna 10 having such a structure has a simpler module configuration than a module using a plurality of antennas by using only one antenna, and thus has low manufacturing cost. . However, such a conventional diversity antenna system uses only one antenna, and when an error occurs in the antenna more than a threshold value, it is required to switch to another antenna to detect a signal again. Feeling time has a very high instability that feels very long.

Accordingly, an object of the present invention is to select at least two antennas of diversity antennas, and to selectively operate an antenna having a better signal sensitivity by comparing bit error rates of the selected antennas, thereby reducing switching time that may occur between antenna switching. The present invention provides a terrestrial DMB receiving system and method using a diversity antenna to remove and select an antenna having a better signal sensitivity.

In order to achieve the above object, a terrestrial DMB receiving system using a diversity antenna according to an embodiment of the present invention is an antenna switch and connected to the diversity antenna, the antenna switch to select at least two antennas of the diversity antenna; First to n-th frequency filters for filtering the signals received by the selected first to n-th antennas to generate first to nth analog signals, and first to nth digital signals of the first to nth analog signals. First and nth analog-to-digital converters for converting the signal, and first to nth code orthogonal frequency division multiple demodulators for demodulating the converted first to nth digital signals to generate first to nth demodulated signals; First and nth deinterleavers for rearranging the first to nth demodulation signals to generate first to nth rearranged signals, respectively First and nth Viterbi decoders which decode 1 to nth rearranged signals in a Viterbi manner to generate first to nth decoded signals, and supply them to a channel switch, the first to nth decoded compared Calculate the bit error rate of the signal, control the channel switch to select one of the calculated bit error rates having a better signal sensitivity than the threshold value, and switch the other diversity antenna when the calculated bit error rate is greater than or equal to the threshold value. And a bit error rate comparison unit for controlling the antenna switch.

The channel switch is characterized in that for supplying the digital signal to the digital multimedia broadcasting signal generator selected by the bit error rate comparison unit.

The digital multimedia broadcasting signal generation unit includes: a channel decoder for channel decoding a signal transmitted from the channel switch; A digital audio broadcast audio decoder for converting the channel decoded signal into a voice signal; A data decoder for converting the channel decoded signal into a data signal; An external decoder for converting the channel decoded signal into a transport stream; And an image / data / voice reconstruction module for receiving the audio signal, the data signal, and the transport stream and outputting the audio and video signals.

A terrestrial DMB receiving method using a diversity antenna according to an embodiment of the present invention includes a first step of selecting first to n-1 of first to nth antennas and initializing a threshold of a bit error rate; Calculating a bit error rate of the selected first through n-th antennas; A third step of comparing the calculated bit error rates of the first to n-th antennas with a threshold value; And a fourth step of selecting an antenna having a bit error rate below the threshold.

Selecting a first to n-th one of the first to nth antennas and initializing a threshold of a bit error rate;

A terrestrial DMB reception method using a diversity antenna according to an embodiment of the present invention includes a second step of calculating bit error rates of the selected first through n-th antennas; Selecting a lowest bit error rate antenna having the lowest bit error rate among the calculated bit error rates of the first through n-th antennas; Compare the bit error rate of the lowest bit error rate antenna with the threshold, select the lowest bit error rate antenna when smaller than the threshold, and exclude the first to n-1 antennas when larger than the threshold. And selecting a antenna to calculate a bit error rate.

Other objects and features of the present invention in addition to the above objects will become apparent from the following description of the embodiments with reference to the accompanying drawings.

2 is a block diagram showing a terrestrial DMB receiving system using a diversity antenna according to an embodiment of the present invention.

2, a terrestrial DMB receiving system using a diversity antenna according to an embodiment of the present invention is connected to a diversity antenna 110 and a diversity antenna 110 and includes at least one of a plurality of diversity antennas 110. An antenna switch 120 for selecting two antennas, and first and second RFs for filtering the signals received by the selected first and second antennas to generate first and second analog signals A1 and A2. First and second analog-to-digital converters for converting the filters 130a and 130b and the respective filtered first and second analog signals A1 and A2 into first and second digital signals D1 and D2. 140a and 140b and the first and second digital signals D1 and D2 demodulated in a coded orthogonal frequency division multiplexing (COFDM) scheme to generate first and second demodulated signals C1 and C2. Rearrange the first and second COFDM demodulators 150a and 150b and the first and second demodulated signals C1 and C2, respectively. Beats the first and second deinterleavers 160a and 160b and the first and second rearranged signals Ar1 and Ar2 to generate the first and second rearranged signals Ar1 and Ar2. First and second Viterbi decoders 170a and 170b, and first and second generating first and second decoded signals R1 and R2 by decoding in a Viterbi scheme and supplying them to the channel switch 190. The bit error rate of the decoded signals R1 and R2 is controlled by the channel switch 190 to select a channel having a signal sensitivity higher than the threshold bit error rate, for example, 6 × 10 ^−4. When the bit error rates of the first and second decoded signals R1 and R2 are greater than or equal to a threshold value, the BER comparison unit 180 controls the antenna switch 120 to switch other diversity antennas 110. Here, the channel switch 190 supplies the hand signal selected by the BER comparison unit 180 to the DMB signal generation unit 200.

The diversity antenna 110 has at least two antennas. That is, although the present invention is described based on the respective change signals according to the first and second antennas, it is obvious that the first to n-th antennas corresponding to the n antennas and the respective change signals may be included. .

The antenna switch 120 detects signal sensitivity by selecting at least two of the diversity antennas 110 according to the result of the BER comparison unit 180. Here, although the diversity antenna according to the embodiment of the present invention has been described with reference to an antenna having four channels, it is obvious that a diversity antenna having a larger number of antennas can be applied in the same manner.

The first and second RF filters 130a and 130b filter the signals received from the first and second antennas selected by the antenna switch 120. In the case of a broadcast signal, a process of processing an intermediate frequency IF may be included.

The channel switch 190 is supplied with the first and second decoded signals R1 and R2 decoded from the first and second Viterbi decoders 170a and 170b, respectively, and is provided by the BER comparison unit 180. One of the first and second decoded signals R1 and R2 is selected and supplied to the DMB signal generator 200.

The BER comparison unit 180 calculates bit error rates of the first and second decoded signals R1 and R2 supplied from the first and second Viterbi decoders 170a and 170b, so that the calculated bit error rates are critical. The channel switch 190 is controlled to select a channel having a better signal sensitivity than the value, and when the bit error rate is greater than or equal to the threshold, that is, when the bit error rate has a signal sensitivity that is worse than the threshold, another diversity antenna is selected. To control the antenna switch 120.

An antenna selection method of a diversity antenna system according to an embodiment of the present invention having such a structure will be described in detail with reference to FIG. 3.

Referring to FIG. 3, an antenna selection method of a terrestrial DMB system using a diversity antenna according to an embodiment of the present invention first undergoes an antenna initialization process.

In the antenna initialization process, the antenna switch 120 selects the first and second antennas, respectively, to form first and second channels A and B, and calculates the bit error rate in each channel by a threshold (6 ×). 10 ^-4 ) to generate antenna and channel switching signals. Here, for the sake of explanation, the first antenna and the first channel A are initialized to AR0, the second antenna and the second channel B are initialized to AR01, and the control value for controlling the channel switch is set to S value. Initialize to zero. Each of AR0 and AR1 may have values of "00", "01", "10", and "11", and are adjusted to not overlap each other. And "++" is defined as incrementing the value of one of the binary values.

When the initialization is completed, the bit error rates of the first and second channels A and B are calculated (S2).

That is, the BERs (A-BER and B-BER) of the selected first and second channels A and B are respectively calculated.

Then, it is compared whether one of the two channels, for example, the BER (A-BER) of the first channel A is smaller than or equal to the BER of the threshold value (S3).

If the BER (A-BER) of the first channel A is smaller than or equal to S3 in step S3, it is compared whether the BER (B-BER) of the second channel B is smaller than or equal to the BER of the threshold value. )

That is, it is checked whether the BER (A-BER) of the first channel A is less than or equal to the BER of the threshold and the BER (B-BER) of the second channel B is less than or equal to the threshold BER.

Even when the BER (A-BER) of the first channel is large in step S3, it is compared whether the BER (B-BER) of the second channel is smaller than or equal to the BER of the threshold value (S5).

That is, it is checked whether the BER (A-BER) of the first channel A is greater than the BER of the threshold value and the BER (B-BER) of the second channel B is less than or equal to the threshold BER.

In the step S4, if the BER (A-BER) of the first channel (A) is less than or equal to the BER of the threshold value, and if the BER (B-BER) of the second channel (B) is less than or equal to the threshold value BER, return to before the step S2 When the BER (A-BER) of the first channel A is equal to or less than the BER of the threshold and the BER (B-BER) of the second channel B is equal to or greater than the threshold BER, by selecting S = 0, The antenna AR1 value of the second channel B is increased by one (S6).

As a result, S = 0 means first channel selection.

In step S6, it is checked whether the increase value of the antenna AR1 of the second channel B is equal to the value of the antenna AR0 of the first channel A. (S7)

In step S7, if not, return to step S2, and in the same case, increase the value of antenna AR1 of the second channel B by one more, and return to step S2.

In step S5, when the BER (A-BER) of the first channel (A) is greater than the BER of the threshold, and the BER (B-BER) of the second channel (B) is less than or equal to the threshold BER, setting S = 1 The antenna AR0 of the first channel A is increased by one (S9).

As a result, S = 1 means second channel B selection.

It is checked whether the increased value of the antenna AR0 of the increased first channel A is equal to the value of the antenna AR1 of the second channel B (S10).

In step S10, if the values of the antennas AR0 and AR1 of the first channel A and the second channel B are not the same, the operation returns to the step S2, and if it is the same, the antenna AR0 of the first channel A is the same. ) Increase by one more, and return to step S2.

In step S5, if the BER (A-BER) of the first channel (A) is greater than the BER of the threshold, and the BER (B-BER) of the second channel (B) is greater than the threshold BER, the main micom (MAIN) MICOM) is notified and the binary values of the antenna AR0 and AR1 values of the first and second channels A and B are taken, and then the process returns to step S2.

As shown in FIG. 4, the DMB signal generator 200 performs channel decoding on a decoded signal received from the channel selected by the channel switch 190 to generate a channel decoded signal CH_sig, and The DAB audio decoder 230 and the data decoder 220 are respectively supplied. The DAB audio decoder 220 generates a voice signal MUSICAM.

The data decoder 220 converts the channel decoded signal CH_sig into video data and supplies it to the external decoder 250. The data decoder 220 generates data signals PAD and NPAD.

The external decoder 250 converts the video data signal to a video signal, that is, a transport stream, using the convolutional deinterleaver 252 and the Reed-Solomon decoder 254.

The image, data, and audio restoration module (multimedia chip) 240 transmits the audio signal (MUSICAM) of the DAB audio decoder 230, the data signals (PAD, NPAD) and the external decoder 250 of the data decoder 220. Audio and video are output by restoring a stream.

The terrestrial DMB receiving system and method using the diversity antenna according to the embodiment of the present invention having the structure as described above can reduce the data detection time according to the antenna switching by using two antennas so that the user can watch the medium continuously. .

In the present invention, the antenna switch selects two antennas among the diversity antennas as an example, but as illustrated in FIG. 5, two or more of the multi-channel diversity antennas, for example, selects three antennas. In addition, according to the above-described apparatus and method of the selected antenna, an antenna having good signal sensitivity may be selected and a channel may be selectively formed.

In the present invention, the BER comparator controls to select an antenna having a bit error rate greater than or equal to a threshold value, but as shown in FIG. A method of selecting an antenna having higher sensitivity, comparing a bit error rate of the selected antenna with a threshold value, and determining whether the compared value is greater than or equal to the threshold value can be used. Here, the BER threshold is 6 × 10 ⁻⁴ , and the selected antennas are defined as AR0 and AR1, respectively, and AR0 and AR1 may be represented by binary numbers such as “00, 01, 10, 11”, and the like.

This will be described in detail with reference to FIG. 6. First, an initialization process is performed as in FIG. 4 (S21).

The first and second bit error rates A-BER and B-BER of the first and second channels are respectively calculated (S22).

The calculated first and second bit error rates A-BER and B-BER are compared (S23).

In step S23, when the first bit error rate A-BER is smaller than the second bit error rate B-BER, it is determined whether the first bit error rate A-BER is smaller than a threshold value.

If the first bit error rate (A-BER) is less than the threshold value in step S24, the channel switch is controlled to select the first channel (A) formed by the first antenna (AR0), and if it is large, selecting another antenna To this end, the binary value of the first antenna AR0 is increased (S25), and the increased value is compared with the binary value of the second antenna AR1 (S26).

If the value of the first antenna AR0 increased in step S26 is different from the binary value of the second antenna AR1, the process returns to the step S23, and in the same case, after further increasing the value of the first antenna AR0, S27) Return to before the step S23.

If the second bit error rate B-BER is smaller than the first bit error rate A-BER in step S23, the second bit error rate B-BER is compared with the threshold BER.

In operation S28, when the second bit error rate B-BER is smaller than the threshold BER, the channel switch is controlled to select a second channel formed by the second antenna AR1. Increase the binary value (S29).

It is compared whether the binary value of the increased second antenna AR1 is equal to the binary value of the first antenna AR0 (S30).

In step S30, if the binary values of the first and second antennas AR0 and AR1 are different, the process returns to before step S23. In the same case, after further increasing the binary values of the second antenna AR1 (S31), Return to the previous step S23.

As described above, a terrestrial DMB receiving system and method using a diversity antenna according to an embodiment of the present invention selects a plurality of antennas, that is, at least two or more antennas among diversity antennas, calculates a bit error rate of each antenna, and a threshold value. Compared to the bit error rate of, by selecting an antenna having a good signal sensitivity and substantially eliminating antenna switching time felt by the user, the user's concentration and dissatisfaction with the medium can be eliminated.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (8)

First to nth antennas; An antenna switch configured to select at least two antennas from the first to nth antennas; First to n-th frequency filters that filter the signals received by the selected first to n-th antennas to generate first to n-th analog signals; First and nth analog-to-digital converters for converting the first to nth analog signals into first to nth digital signals; A first to n-th code quadrature frequency division multiple demodulator for demodulating the converted first to n-th digital signals to generate first to nth demodulated signals; First and nth deinterleavers for rearranging the first to nth demodulation signals to generate first to nth rearranged signals; First and nth Viterbi decoders which decode the first to nth rearranged signals in a Viterbi manner to generate first to nth decoded signals and supply them to a channel switch; And Calculating a bit error rate of the compared first to nth decoded signals, and controlling the channel switch to select one of the calculated bit error rates having a better signal sensitivity than a threshold value, wherein the calculated bit error rate is equal to or greater than a threshold value In case of terrestrial DMB receiving system using a diversity antenna, characterized in that it comprises a bit error rate comparing unit for controlling the antenna switch to switch the other diversity antenna. The method of claim 1, The channel switch is The terrestrial DMB receiving system using a diversity antenna, characterized in that for supplying a hand signal selected by the bit error rate comparison unit to a digital multimedia broadcasting signal generator. The method of claim 2, The digital multimedia broadcasting signal generator A channel decoder for channel decoding the signal transmitted from the channel switch; A digital audio broadcast audio decoder for converting the channel decoded signal into a voice signal; A data decoder for converting the channel decoded signal into a data signal; An external decoder for converting the channel decoded signal into a transport stream; And And a video / data / voice reconstruction module for receiving the audio signal, the data signal, and the transport stream and outputting the audio and video signals. The method of claim 1, The threshold is Terrestrial DMB receiving system using diversity antenna, characterized in that less than 6 × 10 ^-4 . Selecting a first to n-th one of the first to nth antennas and initializing a threshold of a bit error rate; Calculating a bit error rate of the selected first through n-th antennas; A third step of comparing the calculated bit error rates of the first to n-th antennas with a threshold value; And And a fourth step of selecting an antenna having a bit error rate less than or equal to the threshold value. The method of claim 5, And a fifth step of transmitting the signal received by the selected antenna to the digital multimedia broadcasting signal generating unit. The method of claim 5, In the first step, the threshold is less than 6 × 10 ^-4 terrestrial DMB receiving method using a diversity antenna. Selecting a first to n-th one of the first to nth antennas and initializing a threshold of a bit error rate; Calculating a bit error rate of the selected first through n-th antennas; Selecting a lowest bit error rate antenna having the lowest bit error rate among the calculated bit error rates of the first through n-th antennas; Compare the bit error rate of the lowest bit error rate antenna with the threshold, select the lowest bit error rate antenna when smaller than the threshold, and exclude the first to n-1 antennas when larger than the threshold. And selecting a antenna to calculate a bit error rate.

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