APPARATUS FOR ADAPTABLE/VARIABLE TYPE MODULATION AND DEMODULATION IN DIGITAL TX/RX SYSTEM

• US 20110167317A1
• Filed: 06/16/2009
• Published: 07/07/2011
• Est. Priority Date: 06/16/2008
• Status: Abandoned Application

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Kyoung-Hweon, Ahn, Chung Hyun, Choi, Jin Soo, Kim, Sung-Hoon, Hong, Jin Woo, Kim, Chang-Joong, Lee, Ho-Kyoung, Lee, Eung Don
• Application Number:
  US12/999,539
• Publication Number:
  US 20110167317A1
• Time in Patent Office: Days
• US Class Current: 714/758
• CPC Class Codes: H03M 13/11 using multiple parity bits
• CPC Class Codes: H03M 13/63 Joint error correction and other techniques H03M13/31 and H03M13/33 take precedence
• CPC Class Codes: H03M 13/6325 Error control coding in combination with demodulation
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04L 27/0012 arrangements for identifying the type of modulation
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems

Abstract

Disclosed is an adaptable/variable type modulation/demodulation apparatus. A physical layer transmission apparatus for adaptable/variable type modulation, the transmission apparatus including a classification unit to classify a bit stream according to a standard that is determined in advance after receiving the bit stream, an uncoded bit group unit to group the bit stream not to be LDPC-coded by a predetermined number of bits, an LDPC encoder to perform LDPC-coding of the bit stream, a coded bit group unit to group the coded bit stream by the predetermined number of bits, a quadrature amplitude modulation (QAM) unit to select a symbol coset using the coded bit groups; and a convolutional interleaver to perform convolutional interleaving of the symbol.

Claims

1. A physical layer transmission apparatus for adaptable/variable type modulation, the apparatus comprising:

a classification unit to classify a bit stream into a bit stream to be low density parity check (LDPC)-coded and a bit stream not to be LDPC-coded according to a predetermined scheme, when receiving the bit stream;

an uncoded bit group unit to group the bit stream not to be LDPC-coded by a predetermined number of bits to output the uncoded bit groups;

an LDPC encoder to perform LDPC-coding of the bit stream to be LDPC-coded to output the coded bit stream;

a coded bit group unit to group the coded bit stream by the predetermined number of bits to output the coded bit groups;

a quadrature amplitude modulation (QAM) unit to select a symbol coset by using the coded bit group and to determine a symbol from the selected symbol coset by using the uncoded bit group; and

a convolutional interleaver to perform convolutional interleaving of the symbol determined by the quadrature amplitude modulation unit.

2. The apparatus of claim 1, further comprising:

a training sequence generation unit to output a predetermined training sequence symbol; and

a training sequence multiplexing unit to output the convolutional interleaved symbol while the convolutional interleaved symbol is received, and to output the training sequence symbol when the convolutional interleaved symbol is no longer received.

3. The apparatus of claim 1, further comprising an error correction code inserting unit to insert an error correction code for error correction,

wherein the bit stream that the classification unit receives has an insertion of the error correction code through the error correction code inserting unit.

4. The apparatus of claim 1, wherein the LDPC encoder is replaceable with the convolutional encoder that performs convolutional coding of the bit stream to be coded to output the coded bit stream.

5. A physical layer reception apparatus for adaptable/variable type demodulation, the apparatus comprising:

a convolutional deinterleaver to output a soft decision uncoded bit group and a soft decision coded bit group by convolutional deinterleaving a received signal;

an LDPC decoder to perform LDPC-decoding of the soft decision coded bit group to output a decoded bit group;

an LDPC encoder to perform LDPC-coding of the decoded bit group to output a coded bit group;

a symbol coset search unit to select a symbol coset by using the coded bit group;

a symbol search unit to select a symbol from the selected symbol coset that the symbol coset search unit selects, by using the soft decision uncoded bit group;

an uncoded bit extracting unit to extract an uncoded bit group from the symbol selected through the symbol search unit; and

a bit combining unit to combine the decoded bit group and the uncoded bit group to generate a bit stream.

6. The apparatus of claim 5, further comprising an equalizing unit to perform channel-equalizing of the received signal based on a predetermined training sequence and to transmit the channel-equalized signal to the convolutional deinterleaver.

7. The apparatus of claim 5, further comprising an error correction unit to correct an error by checking an error correction code included in the bit stream.

8. The apparatus of claim 5, wherein the LDPC decoder is replaceable with a Viterbi decoder that decodes the soft decision coded bit group to output a decoded bit group, and the LDPC encoder is replaceable with a convolutional encoder that performs convolutional coding of the decoded bit group to output the coded bit group.

9. The apparatus of claim 5, further comprising a decoder to receive the bit stream, to decode the received bit stream, and to obtain error detection information in a packet unit.

10. An application layer transmission apparatus, the apparatus comprising:

a forward error correction (FEC) code inserting unit to insert, to received robust data, an FEC code for error correction;

an error detection code inserting unit to insert, to the robust data where the FEC code is inserted, an error detection code to detect whether the error exists; and

a frame multiplexing unit to receive and multiplex normal data and the robust data where the FEC code and the error detection code are inserted and to output the multiplexed data to a physical layer.

11. The apparatus of claim 10, wherein the robust data is data to be coded being robust with respect to the error, the robust data including cost data, charged data, and important data.

12. The apparatus of claim 10, wherein the error detection code inserting unit constructs a transport stream (TS) packet by inserting the error detection code instead of a Moving Pictures Experts Group-TS (MPEG-TS) sync byte when the robust data where the FEC code is inserted through the FEC code inserting unit is constituted by the TS packet.

13. The apparatus of claim 10, wherein the FEC code inserting unit inserts, to the normal data, the FEC code for error correction, and the frame multiplexing unit receives and multiplexes the robust data where the FEC code and the error detection code are inserted and the normal data where the FEC code is inserted, and outputs the multiplexed data to the physical layer.

14. An application layer reception apparatus the apparatus comprising:

a frame demultiplexing unit to output data by classifying a normal data and robust data when receiving a data stream from a physical layer;

an error detecting unit to detect whether an error exists by checking an error detection code included in the robust data; and

an error correction unit to correct an error by checking an FEC code included in the robust data, when the error is detected by the error detecting unit.

15. The apparatus of claim 14, wherein the robust data is data to be coded being robust with respect to the error, the robust data including cost data, charged data, and important data.

16. The apparatus of claim 14, wherein the error detection unit detects the error by using the error detection code included in a section where an MPEG-TS sync byte is included when the robust data is constituted by a TS packet.