KR20040016287A - Transmitter and receiver and control method thereof for digital broadcast - Google Patents

Abstract

PURPOSE: An apparatus for transmitting and receiving a digital broadcast, and a method for controlling the same are provided to easily move a receiving position of a digital broadcast by wirelessly connecting an outdoor receiving device of the digital broadcast with an indoor device. CONSTITUTION: A tuner(101) demodulates a broadcasting signal received through an antenna. A path selector(103) outputs the demodulated broadcasting signal by selecting a wanted path in a wire method or a wireless method according to selection of a user. A wireless output element outputs the demodulated broadcasting signal in the wireless method. The wireless output element is formed of a buffer(104) and a wireless LAN(Local Area Network) card(105). A wire output element directly outputs the demodulated broadcasting signal to a set-top box in the wire method. A CPU(Central Processing Unit)(103) controls each component.

Description

Digital broadcasting transceiver and control method thereof {TRANSMITTER AND RECEIVER AND CONTROL METHOD THEREOF FOR DIGITAL BROADCAST}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcast transceiver and a control method thereof, and more particularly, to a digital broadcast transceiver and a control method for wirelessly connecting an outdoor receiver and an indoor device of a digital broadcast.

Currently, in order to receive digital broadcasts using satellite or terrestrial waves, as shown in FIG. 1, an antenna (Ant) is installed on a roof of a building, and from that antenna to an indoor with a receiver (Set-Top Box, STB). The cable must be connected.

That is, in order to watch satellite broadcasts, an antenna and a low noise block down converter (LBN) are provided together outside the building, and a broadcast signal received therefrom is connected to an indoor receiver (STB) using a cable.

For reference, the basic configuration of the receiver STB is shown in FIG. 2, and the demodulator 20 demodulates or decodes a broadcast signal (RF signal) received through the tuner 10, and a transmission data selector. By selecting the desired data stream by the (Transport IC) 30 and decoding it through the MPEG decoder 40, it is possible to finally watch the display device such as a TV.

However, the above configuration requires a connection from the outdoor antenna to the indoor receiver by using a cable, and thus has a problem in that the aesthetics are not good and the display apparatus is difficult to move and watch.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and it is possible to wirelessly connect the outdoor reception apparatus and the indoor apparatus of the digital broadcast, thereby solving the problem of movement and aesthetic appearance of the digital broadcast. It is an object of the present invention to provide a digital broadcast transmitting and receiving device and a control method thereof.

The present invention for achieving the above object, the tuner for demodulating the broadcast signal received through the antenna; A path selector for selecting and outputting the demodulated signal by a user's selection in a wireless or wired manner; Wireless output means for wirelessly outputting a demodulated signal output through the path selector; Wired output means for directly outputting a demodulated signal output through the path selector to a receiver in a wired manner; A transmitter including a CPI for controlling each component, and a path selector for selectively receiving a demodulation signal received through a wireless path or a demodulation signal received through a wired path; A transmission data selection unit for outputting a desired data stream from the demodulation signal received through the path selector; An MPEG decoder for MPEG decoding the data stream output through the transmission data selector; Configuring a receiving device including a CPI for controlling each component, and establishing a link between the transmitting device and the receiving device; After the link setting of the transmission and reception apparatus, the demodulation data is wirelessly transmitted.

1 is an exemplary view showing a connection configuration of a device for receiving a conventional digital broadcast.

2 is a block diagram showing a general configuration of a satellite broadcast receiver (STB).

Figure 3 is a block diagram showing the configuration of a digital broadcast radio transmitter according to the present invention.

4 is a block diagram showing a configuration of a receiver for receiving a transmission signal of a wireless transmitter according to the present invention.

5 is an exemplary view showing a connection method of a wireless transmitter (Relay) and a receiver (STB) according to the present invention.

6 is a signal flow diagram illustrating a digital broadcast signal transmission process between a receiver and a wireless transmitter according to the present invention.

Figure 7 is an exemplary view showing a comparison of the structure of the data frame of the wireless LAN MAC in the prior art and the present invention.

8 is an exemplary diagram for explaining a transmission method of a control data frame according to the present invention.

9 is a signal flow diagram illustrating another broadcast signal transmission process between a receiver and a wireless transmitter according to the present invention.

*** Description of the symbols for the main parts of the drawings ***

101: tuner 102206: CPU

103,204: path selector 104,203: buffer

105,201: Wireless LAN card 106,202: Connector

205: Transmission data selector 207: MPEG decoder

The present invention comprises a wireless transmitter (Relay) for short-range wireless transmission of a broadcast signal received by attaching to an outdoor antenna, and a receiver (STB) for receiving a signal transmitted from the wireless transmitter (Relay).

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

First, FIG. 3 is a block diagram showing the configuration of a digital broadcast wireless transmitter (Relay) according to the present invention. The broadcast signal received through an antenna (or LNB) is input to the tuner 101 and demodulated and output. The selector 103 selects an appropriate path according to the connection method with the receiver STB and outputs a demodulated signal.

That is, the signal transmission path is configured to the buffer 104 and the wireless LAN card 105 when connecting in a wireless manner, and to the receiver connection connector 106 when connecting in a wired manner.

In addition, when transmitting a broadcast signal in a wireless manner as described above, it is preferable to put a buffer between the tuner output and the wireless LAN card to temporarily store demodulated data of the tuner output and then transmit the data through the wireless LAN.

4 is a block diagram showing a configuration of a receiver for receiving a transmission signal of a wireless transmitter according to the present invention. When receiving data from the wireless transmitter in a wireless manner, the path selector 204 is a wireless LAN. The path through the card 201 and the buffer 203 is set as an internal signal transmission path, and when receiving in a wired manner, the signal transmission path through the connector 202 is selected.

In the subsequent process, a desired data stream is selected by the transmission data selector 205 and decoded by the MPEG decoder 207 to be viewed through a display device such as a TV.

At this time, in the configuration of the wireless transmitter (Relay) and the receiver (STB) shown in Figs. 3 to 4, the CPU (102, 206), the description is omitted serves to control each component of the device.

Next, Figure 5 is an exemplary view showing a connection method of the wireless transmitter (Relay) and the receiver (STB) according to the present invention, (a) is directly connected to the antenna and the wireless transmitter (Relay) in a short distance, the receiver (STB) Is a wireless connection, and the aesthetics are good and the receiver can be easily moved to another place to watch a broadcast.

In this case, the connection distance between the antenna and the wireless transmitter may be connected within an appropriate range depending on the transmission power of the wireless transmitter.

Next, Figure 5 (b) is a wired connection between the receiver (STB) and the wireless transmitter (Relay) using a connector, because it must be connected from the antenna (Ant) to the wireless transmitter (Relay) by a cable, Compared to this, the effect is not great, but it shows that the receiver can be connected directly to the wireless transmitter.

For reference, in order to transmit digital broadcast data by a wireless method, a wireless LAN card for IEEE 802.11a (or IEEE 802.11g) can be used, and since this method is capable of a data transmission rate of 54 Mbps, general digital TV and digital It can support the transmission speed of satellite broadcasting.

Of course, some satellite broadcasting may require a transmission speed of 54Mbps or more, but wireless LAN cards currently supporting IEEE 802.11a can support up to 72Mbps and 108Mbps. There is no difficulty in data transmission.

However, even when using a wireless LAN card, rather than using the MAC (Media Access Control) currently used in the wireless LAN card, it is preferable to add or modify some functions of the MAC to be suitable for digital broadcast data transmission.

Hereinafter, a digital broadcast signal transmission process of a receiver and a wireless transmitter according to the present invention will be described with reference to the signal flowchart of FIG.

First, when the receiver STB decides to receive demodulated data from a wireless transmitter in a wireless manner, the receiver STB performs a process for selecting a channel to be used for data reception (S101).

To this end, the receiver (STB) obtains existing user information for each channel by using the MLME-SCAN of the wireless LAN MAC (S102), and then selects the most suitable channel (no noise and stable channel) to know the wireless transmitter (Relay). Create an (Independent) Basic Service Set (hereinafter referred to as STB_BSS) using the SSID (Service Set Identification) (S103).

In addition, the wireless transmitter (Relay) continues the active scan (S104, S105) until the 'STB_BSS' information is obtained after the power is turned on (S104, S105), and makes the 'STB_BSS' in the receiver (STB) after the active scan When the 'STB_BSS' information is provided in response to the (Active Scan) (S106), the wireless transmitter (Relay) associates with the 'STB_BSS' (S107).

Subsequently, basic information setting procedures (S108 and S109) are performed between the receiver STB and the wireless transmitter, a wireless transmitter (Relay) is configured according to the basic setting information (S110), and demodulation of a digital broadcast signal is performed (S111). ). In the meantime, the receiver STB becomes a standby state (S112).

The above is the link connection process between the receiver and the wireless transmitter. When the link connection is completed by the above process, the data transmission process is performed.

When demodulation of the digital broadcast signal is completed, the wireless transmitter (Relay) starts the transmission of the demodulated data (S113, S114), the receiver STB transmits a control signal to the wireless transmitter every predetermined time (S115), the wireless transmitter Transmits the response signal (Ack) (S116), the control signal is examined to change the configuration of the radio transmitter if necessary (S117), and transmits demodulation data (S118).

In this process, the error between the receiver and the wireless transmitter does not request retransmission or send an acknowledgment (Ack) according to the wireless LAN standard.

Meanwhile, in the process of transmitting the demodulated data to the receiver, the receiver and the wireless transmitter need to use this channel exclusively, and for this purpose, by partially modifying the wireless LAN MAC, the receiver can be implemented with only the smallest possible change.

In this case, the wireless LAN MAC is CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance), and anyone can use the channel if the channel is not used for a certain period (PIFS or DIFS). Can not be done.

In order to satisfy the above conditions, the present invention has a data frame structure as shown in FIGS.

First, FIG. 7 (a) shows the structure of a general data frame of a wireless LAN MAC. When the received signal is normal for each data fragment, an acknowledgment (Ack) is sent every time to receive data normally. Notify.

However, the present invention has a data frame structure as shown in FIG. 7B from the viewpoint of digital broadcasting and a very high transmission speed.

That is, when demodulated data is sent from the radio transmitter (Relay) to the receiver (STB), regardless of whether the signal is normally received, the response signal (Ack) is not transmitted, and the radio transmitter continuously transmits the demodulated data, The time required to transmit the response signal Ack can be allocated to the data transmission, thereby increasing the data transmission efficiency.

Of course, there is a problem that the error cannot be recovered even if an error occurs in the received data because the response signal Ack is not used. However, since the data is unidirectional A / V data, it is not a problem.

Another frame structure used in the present invention is a frame structure for transmitting the control signal shown in FIG.

In order to receive digital broadcasting, it is necessary to send a control signal from a receiver to a wireless transmitter (Relay).

For example, if the program desired by the broadcast viewer is not on the current reception channel but on another channel, the tuner must change the channel. As another example, the time information (TimeStamp) is controlled to synchronize the wireless LAN with the receiver and the wireless transmitter. It can also be included in the signal and sent.

The transmission interval of the control signal as described above may be set during the link connection process, and since the transmission and reception time information of the control signal is shared during the link connection process, it is possible to know when the control signal is transmitted.

In a normal case, as shown in FIG. 8A, when the wireless transmitter transmits demodulated data and the control data reception time arrives, transmission of the demodulated data is stopped and the signal is switched to the reception state. Of course, the receiver STB is switched from the demodulated data reception state to the control data transmission state to transmit control data.

In this case, unlike the demodulation data, the control data needs to confirm whether the wireless transmitter has received the correct information. Therefore, when the wireless transmitter correctly receives the control signal, it transmits a response signal (Ack), and (b) to (d) of FIG. In order to compensate for the case where the same error occurs, the number of repetitions is set. When the number of repetition of control data is set to 2 as in the present embodiment, data is transmitted once again.

(B) of FIG. 8 is a case where an error occurs in the first control signal on the received signal, (c) is a case in which the received signal itself is not received, and (b) and (c) is a signal in the second control signal transmission. Is correctly received, but in case (d), an error occurs in both control data transmissions.

However, even in the above case, since the control data transmission interval is set within a range not exceeding a few ms and a long, about 100 ms, this is not a problem.

However, it is a serious problem that the control signal transmission response is sent to the retry continuously for a considerable time or more. In this case, the receiver STB performs a request operation such as checking a connection state abnormality on the screen.

9 is a signal flow diagram illustrating another broadcast signal transmission process between a receiver and a wireless transmitter according to the present invention, in which a link connection process is modified in the broadcast signal transmission process shown in FIG.

That is, in the process of FIG. 6, the receiver STB makes 'STB_BSS' and the radio transmitter is associated with the channel information to obtain channel information. In the process of FIG. 9, the user controls the channel information. By using such as, to inform the wireless transmitter (Relay) to perform a link connection.

Referring to FIG. 9, when the receiver STB selects data reception by a wireless method (S201), the channel (frequency) state is examined to select an available channel (S202), and the selected channel is displayed on the screen. In addition (S203), the user transmits the channel information to a wireless transmitter (Relay) using a remote control or the like (S204).

In response to this, a procedure (S206, S207) confirming that the use channel information is received from the wireless transmitter is performed, and the basic information setting procedure is sequentially performed from the receiver STB to the wireless transmitter (S208, S209).

Hereinafter, since the data transmission process is the same as that of FIG. 6, description thereof will be omitted.

As described above, when the path selector input of the wireless transmitter is changed to receive the A / V digital data of the DVD device instead of the tuner output, the A / V device and the display device are interlocked. Wireless connectivity allows you to watch DVDs from anywhere.

That is, when the device according to the present invention is slightly modified to fit the digital device to be connected, there is a characteristic that any data as well as a digital broadcast signal can be applied.

As described above, according to the present invention, the digital broadcasting transmitting / receiving apparatus and the control method thereof can wirelessly connect the outdoor receiving apparatus and the indoor apparatus of the digital broadcasting, thereby facilitating the movement of the receiving position of the digital broadcasting and eliminating the need for connection lines between the devices. There is an effect that aesthetics improves.

Claims (12)

An apparatus for short-range wireless transmission of digital broadcast data, A tuner for demodulating broadcast signals received via an antenna; A path selector for selecting and outputting the demodulated signal by a user's selection in a wireless or wired manner; Wireless output means for wirelessly outputting a demodulated signal output through the path selector; Wired output means for directly outputting a demodulated signal output through the path selector to a receiver in a wired manner; And a CPI for controlling each of the components. 2. The apparatus of claim 1, wherein said wireless output means comprises: a buffer for temporarily storing demodulated data of a tuner output; And a wireless LAN card for outputting the buffered data in a wireless manner. The digital broadcast transmission apparatus as claimed in claim 1, wherein the wired output means comprises a connection connector capable of directly connecting a transmitter and a receiver. An apparatus for receiving digital broadcast data transmitted short-range wirelessly, A path selector for selectively receiving a demodulation signal received through a wireless path or a demodulation signal received through a wired path; A transmission data selection unit for outputting a desired data stream from the demodulation signal received through the path selector; An MPEG decoder for MPEG decoding the data stream output through the transmission data selector; And a CPI for controlling each of the components. The wireless communication system of claim 4, further comprising: a wireless LAN card for receiving demodulated data wirelessly transmitted from a transmitting device; And a buffer for temporarily storing demodulated data received through the LAN card. In wireless transmission of digital broadcast data and receiving the data, Establishing a link between the digital broadcast data transmitting apparatus and the receiving apparatus; And wirelessly transmitting demodulated data after the link setting of the transmitting / receiving device is performed at all times. The method of claim 6, wherein the link establishment step, Receiving channel information from a receiving device to generate a 'BSS (Basic Service Set)', and transmitting device performing an active scan to obtain the 'BSS' information; Receiving, at the transmitting device, 'BSS' information from the receiving device and associating with 'BSS', and then performing basic information setting procedure between the transmitting and receiving devices; And transmitting, by the transmitter, basic information for transmitting a demodulation signal, such as a transmission channel, according to the basic configuration information. The method of claim 6, wherein the transmitting of the demodulated data comprises: Transmitting a demodulated digital broadcast signal from a transmitter; Transmitting a control signal to a transmitting device at a predetermined time by the receiving device; And re-transmitting demodulated data after the change when the configuration of the transmitter is changed by the control signal. The method of claim 6, wherein the link establishment step, Selecting a usable channel by examining a channel (frequency) state at a receiving device; Displaying the selected channel on a screen and transmitting the channel information to a transmission device by a user using a remote controller; Performing a procedure of confirming that the use channel information has been received by a transmitting device; Performing a basic information setting procedure between the transmitting and receiving devices; And transmitting, by the transmitter, basic information for transmitting a demodulation signal, such as a transmission channel, according to the basic configuration information. 7. The receiving apparatus according to claim 6, wherein the receiving apparatus that has received the demodulated data transmitted from the transmitting apparatus does not transmit the response signal Ack regardless of whether the data is normally received, and the transmitting apparatus does not receive the response signal regardless of the reception. And a method for continuously transmitting demodulated data. The method of claim 6, wherein when the control device transmits a control signal to the transmission device for channel conversion or synchronization, the reception device repeatedly transmits the control signal at least twice, and the transmission device receives the control signal. And a response signal (Ack) must be transmitted to the receiving device. 7. The method of claim 6, wherein when the control device receives a control signal while transmitting the demodulated data, the transmitting device stops transmitting demodulated data and switches to the received state, and the receiving device reversely switches from the demodulated data receiving state to the control signal transmitting state. And a control signal is transmitted.