KR20050005238A - Wireless transmitting/receiving system having PIP function - Google Patents

Abstract

PURPOSE: A wireless transmitting/receiving system having a PIP(Picture In Picture) function is provided to simultaneously transmit transport streams of HD(High Definition) and SD(Standard Definition) by wireless at a transmitting stage and to implement a PIP function at a receiving stage. CONSTITUTION: An HD transport stream detecting member(220) detects the first transport stream from an HD image signal by a packet unit. An SD transport stream change member(230) encodes an SD image signal as a predetermined format and changes the encoded signal into the second transport stream by a packet unit. A multiplexing member(240) multiplexes the first and second transport streams with a predetermined ratio according to read and write timing control. A transmission module member(250) modulates the transport stream produced by the multiplexing member to a wireless signal with a predetermined bandwidth.

Description

Wireless transmitting / receiving system having PIP function {Wireless transmitting / receiving system having PIP function}

The present invention relates to a wireless transmit / receive system, and more particularly, to a wireless transmit / receive system in which a transmitter transmits a high definition (HD) class and a standard definition (SD) class transformer stream wirelessly to implement a PIP function at a receiver.

Conventional analog or digital TV receivers process high definition (HD) signals or NTSC (National Television System Committe) signals, respectively, digital and analog signals, and PIP (Picture In Picture) with the processed two types of signals. The function was implemented. In addition, the DTV receiver implements PIP using two MPEG decoders. Such conventional analog and digital TV receivers and HD TV receivers all receive signals by wire. Recently, a wireless transmission / reception system for transmitting and receiving video signals wirelessly has been developed.

Typically, a wireless transmit / receive system includes a television set wirelessly connected to a set-top box. The set-top box converts the digital video signal received from the antenna into an analog video signal. The television set displays a video signal input from the set-top box on the screen. The television set and the set-top box can be located remotely from each other because they can transmit and receive wirelessly. However, such a wireless transmission and reception system has a disadvantage in that there is no way to view two screens at the same time as a wired TV receiver because only one signal can be displayed on the screen.

An object of the present invention is to provide a wireless transmission / reception system for transmitting a high definition (HD) class and a standard definition (SD) class transport stream wirelessly at a transmitting end simultaneously to implement a PIP function at a receiving end.

In order to solve the above technical problem, in the wireless transmission and reception system capable of transmitting and receiving wirelessly HD and SD video signals of the present invention,

A set-top box converts input HD and SD video signals into a transport stream, and multiplexes each transport stream and wirelessly decodes the transport stream received from the set-top box. And a display device for extracting SD video signals, synthesizing the video signals and displaying them on a PIP screen.

The set top box is

An HD transport stream detector for detecting a first transport stream on a packet basis from an input HD video signal;

An SD transport stream converter for encoding an input SD video signal into a predetermined format and converting the received SD class video signal into a second transport stream in a packet unit;

A multiplexer unit multiplexing the first and second transport streams at a predetermined ratio according to read and write timing control;

A transmission module unit configured to modulate the transport stream generated by the multiplexer into a wireless signal of a predetermined band,

The display device

A receiving module unit for demodulating the modulated radio signal into a multiplexed transport stream;

A signal separation unit for separating the HD transport stream and the SD transport stream based on the header information from the transport stream multiplexed by the reception module unit;

A decoder for decoding the HD and SD transport streams separated by the signal separation unit into video signals of a predetermined format, respectively;

And a PIP processor configured to display the analog video signal decoded by the decoder in a preset main screen region and a PIP region.

1 is a conceptual diagram of a wireless transmission and reception system capable of wireless transmission and reception according to the present invention.

FIG. 2 is a detailed view of the set top box of FIG. 1.

3 is a detailed view of the multiplexer unit of FIG. 2.

4 is a detailed view of the display apparatus of FIG. 1.

FIG. 5 is an embodiment of a signal multiplexed in the multiplexer of FIG. 3.

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

1 is a conceptual diagram of a wireless transmission and reception system capable of wireless transmission and reception according to the present invention.

Referring to FIG. 1, the set top box 120 is wired to an external device such as a DVD 130 or a VCR 140, and is wirelessly connected to a display device 120 corresponding to a television set. Therefore, the set-top box 120 multiplexes the SD-level video signal and the HD-level video signal inputted from an antenna or an external device at a predetermined ratio and transmits the same to the WLAN. The display device 110 separates the SD video signal and the HD video signal received from the set-top box 120 to display on the screen in the form of PIP.

2 is a detailed view of the set top box 120 of FIG.

The set-top box of FIG. 2 includes an HD transport detector 220, an SD transport converter 230, a multiplexer 240, a transmission module 250, and a controller 280. The HD transport stream detector 220 includes a first tuner 223, an IF unit 225, and a channel demodulator 227. The SD transport stream converter 230 includes a second tuner 231, An IF unit 233, an analog decoder 237, and an MPEG encoder 239 are provided.

Referring to FIG. 2, the first tuner unit 223 receives a DTV (Digital TV) signal according to the Advanced Television Sub-Committee (ATSC) standard. That is, the first tuner 223 tunes the digital ATSC signal received from the antenna 212 according to the tune control signal of the controller 280. The first IF unit 225 converts the tuned digital ATSC signal into an IF signal corresponding to the baseband signal. The channel demodulator 227 extracts a first transport stream in a packet unit by performing various error correction and decoding processes from the IF signal. In one embodiment, the channel demodulator 240 uses a VSB (Vestigial Side Band) demodulator.

The second tuner unit 231 receives an analog TV signal in accordance with the National Television Systems Committee (NTSC) standard. That is, the second tuner 231 tunes the analog NTSC signal received from the antenna 262 according to the tune control signal of the controller 280. The second IF unit 233 converts the tuned analog NTSC signal into an IF signal corresponding to the baseband signal. The switching unit 235 outputs any one of a baseband signal extracted by the second IF unit 235 or an analog external image signal input from an external device according to the selection signal of the controller 280. The analog decoder 237 converts either the baseband signal or the external video signal output from the switching unit 235 into an analog video signal of CCIR601 or 656 format. The MPEG encoder 239 encodes a video signal of CCIR601 or 656 format converted by the analog decoder 237 according to the encoding control signal of the controller 280 in MPEG standard. Accordingly, the controller 280 converts the video signal encoded by the MPEG encoder 239 into a second transport stream in a packet unit.

The multiplexer unit 240 outputs the first and second transport streams in predetermined packet units output from the channel demodulator 227 and the MPEG encoder 239 at a predetermined ratio according to the read and write timings generated by the controller 280. Multiplex. For example, the multiplexer unit 240 multiplexes one SD TS per three HD TSs as shown in FIG. 4.

The transmission module unit 250 modulates the transport stream multiplexed by the multiplexer unit 240 into an Orthogonal Frequency Division Multiplexor (OFDM) signal of a predetermined band, for example, a 5 GHz band, and transmits it wirelessly through the antenna 290.

3 is a detailed view of the multiplexer unit 240 of FIG. 2.

Referring to FIG. 3, the first memory 310 stores the HD transport stream input from the channel demodulator 227 according to a clock signal generated by the PLL unit 330. The second memory 320 stores the SD transport stream input from the MPEG encoder 239 according to the clock signal generated by the PLL unit 330.

The multiplexer 340 is configured to store the multiplexed transport streams of the HD and SD transport streams stored in the first memory 310 and the second memory 320 at a predetermined ratio, for example, 3: 1 or 4: 2. Create Each transport stream includes header information for recognizing HD / SD signal information for each packet according to the MPEG standard.

The PLL unit 330 generates a timing clock for storing and reading in the control unit first memory 310 and the second memory 320.

The control unit 350 controls the timing clock of the PLL unit 330 that stores and reads the HD class stream and the SD class stream in the first memory 310 and the second memory 320. In step 340, the HD transport stream and the SD transport stream are multiplexed at a predetermined ratio. For example, the controller 350 reads an HD class transport stream of three packets and then reads an SD class transport stream of one packet.

4 is a detailed view of the display device 140 of FIG. 1.

The display device of FIG. 4 includes a receiving module unit 410, an HD / SD separation unit 420, a first MPEG decoder 430, a second MPEG decoder 430, a PIP processing unit 440, and a control unit 460.

Referring to FIG. 4, the reception module unit 410 demodulates a radio signal of OFDM received in a 5 GHz band into a transport stream.

The HD / SD signal separator 420 reads header information for each packet unit from the demodulated transport stream and distinguishes the HD transport stream from the SD transport stream. Accordingly, the HD / SD signal separator 420 outputs the separated HD transport stream and the SD transport stream to the first MPEG decoder 430 and the second MPEG decoder 435, respectively.

The first MPEG decoder 430 converts the HD transport stream separated by the HD / SD signal separator 420 according to the decoding control signal of the controller 460 into analog / digital R, G, B / Y, Pb, Demodulate with Pr signal.

The second MPEG decoder 435 may convert the SD transport stream separated by the HD / SD signal separator 420 according to the decoding control signal of the controller 460 into analog / digital R, G, B / Y, Pb, Demodulate with Pr signal.

The PIP processor 440 synthesizes the HD and SD analog video signals decoded by the first and second MPEG decoders 430 and 435 and scans them into a preset main screen area and a PIP area. Since the PIP process is a known technique, detailed description thereof will be omitted.

The display unit 450 displays the video signal processed by the PIP processing unit 440 on the screen.

Those skilled in the art will understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

As described above, according to the present invention, the HD transmission signal and the SD transmission signal are simultaneously transmitted and wirelessly transmitted in a wireless transmission / reception system, thereby displaying a double screen or a PIP screen. Viewers can also view PIP screens wirelessly from display devices located remotely from the set-top box.

Claims (6)

In the wireless transmission and reception system capable of transmitting and receiving HD and SD video signals wirelessly, A set-top box converts input HD and SD video signals into a transport stream, and multiplexes each transport stream and wirelessly decodes the transport stream received from the set-top box. It includes a display device for extracting the SD-grade video signal, synthesizing the video signal to display on the PIP screen, The set top box is An HD transport stream detector for detecting a first transport stream on a packet basis from an input HD video signal; An SD transport stream converter for encoding an input SD video signal into a predetermined format and converting the received SD class video signal into a second transport stream in a packet unit; A multiplexer unit multiplexing the first and second transport streams at a predetermined ratio according to read and write timing control; And a transmission module unit for modulating the transport stream generated by the multiplexer into a wireless signal of a predetermined band. The method of claim 1, wherein the HD transport stream detector An IF unit for extracting a baseband signal from the tuned IF signal; And a channel demodulator extracting a transport stream from the baseband signal extracted from the IF unit. The method of claim 1, wherein the SD transport stream conversion unit An IF unit for extracting a baseband signal from the tuned IF signal; An analog decoder for converting any one of a baseband signal extracted from the IF processor or a video signal of an external device into a video signal of a predetermined format; And an encoder unit encoding the video signal converted by the analog decoder unit into a predetermined format and forming a transport stream in a predetermined packet unit. The wireless transmission / reception system according to claim 3, further comprising a switching unit for outputting any one of a baseband signal extracted by the IF unit or an analog external video signal input from an external device according to a selection signal. The method of claim 1, wherein the multiplexer unit A first memory for storing the HD transport stream; A second memory for storing the SD class transport stream; A multiplexer for multiplexing the HD transport stream and the SD transport stream stored in the first memory and the second memory at a predetermined ratio within a predetermined unit; And a controller which stores the HD transport stream and the SD transport stream in the first memory and the second memory, and reads them at a predetermined ratio. The display apparatus of claim 1, wherein the display device is A receiving module unit for demodulating the modulated radio signal into a multiplexed transport stream; A signal separation unit for separating the HD transport stream and the SD transport stream based on the header information from the transport stream multiplexed by the reception module unit; A decoder for decoding the HD and SD transport streams separated by the signal separation unit into video signals of a predetermined format, respectively; And a PIP processor configured to display the analog video signal decoded by the decoder in a preset main screen area and a PIP area.