OUTER CODING METHODS FOR BROADCAST/MULTICAST CONTENT AND RELATED APPARATUS

• US 20080141094A1
• Filed: 11/29/2007
• Published: 06/12/2008
• Est. Priority Date: 08/21/2003
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Grilli, Francesco, Vayanos, Alkinoos Hector
• Application Number:
  US11/947,699
• Publication Number:
  US 20080141094A1
• Time in Patent Office: Days
• US Class Current: 714/751
• CPC Class Codes: H03M 13/15 Cyclic codes, i.e. cyclic shifts of codewords produce other codewords, e.g. codes defined by a generator polynomial, Bose-Chaudhuri-Hocquenghem [BCH] codes H03M13/17 takes precedence
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/2707 Simple row-column interleaver, i.e. pure block interleaving
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services

Abstract

Transmission techniques are provided that improve service continuity and reduce interruptions in delivery of content that can be caused by transitions that occur when the User Equipment (UE) moves from one cell to the other, or when the delivery of content changes from a Point-to-Point (PTP) connection to a Point-to-Multipoint (PTM) connection in the same serving cell, and vice-versa. Such transmission techniques enable seamless delivery of content across cell borders and/or between different transmission schemes such as Point-to-Multipoint (PTM) and Point-to-Point (PTP). Mechanisms for adjusting different streams and for recovering content from each data block during such transitions are also provided so that data is not lost during a transition. In addition, mechanisms for realigning data during decoding at a receiving terminal are also provided.

Claims

1. A Point-to-Multipoint (PTM) transmission system that enables variable rate transmission, out-of-sequence reception, and segmentation and concatenation of a Point-to-Multipoint (PTM) transmission of a variable rate source, comprising:

a network, comprising;

a receiver buffer that stores Forward Error Correction (FEC) Service Data Units (SDUs);

a segmentation and concatenation entity that segments and concatenates FEC SDUs into rows of an encoder matrix comprising a first number of information rows, wherein each row of the encoder matrix occupies an independent transmission time interval;

a scheduling entity that generates a start command to start the encoding once a predetermined amount of data is received to thereby reduce padding added to each row of encoder packet during encoding;

an asynchronous outer encoder that generates encoder packets responsive to the start command, wherein each encoder packet comprises the first number of information rows, a second number of parity rows, and padding at the end of the encoder packet;

a sequencer that adds an outer header comprising a sequence number to each row of the encoder packet after outer encoding is performed; and

a transmit buffer that receives the encoder packets, formats them into composite code blocks, and transmits the composite code blocks over a radio interface.

2. A system according to claim 1, further comprising:

a terminal that receives the composite code blocks, comprising;

a receive unit that accumulates the rows of the encoder packets and delays decoding by delaying decoding by a time-offset between different logical streams;

wherein the receive unit, responsive to the sequence number, determines which encoder packet each Forward Error Correction (FEC) PDUs belongs and each Forward Error Correction (FEC) PDUs position in the encoder packet such that the receive unit uses the sequence number to perform duplicate detection and re-ordering of the received blocks;

a removal unit that removes the sequence numbers;

an outer decoder that decodes the information rows; and

a transmit buffer that reassembles the information rows.

3. A system according to claim 2, wherein the sequencer adds an inner header that provides information for re-constructing the SDUs, wherein the header is encoded into length indicators (LIs) included in the RLC-PDU to which it refers, wherein the presence of the first LI is indicated by a flag in the sequence number header of the RLC-PDU.

4. A system according to claim 3, wherein the inner header is added at the very beginning of the EP.

5. A system according to claim 4, wherein the inner header is added at the beginning of each encoder packet row.

6. A system, according to claim 1, wherein each encoder packet row comprises a Forward Error Correction (FEC) Protocol Data Unit (PDU), a parity block and/or padding.

7. A system according to claim 1, wherein the row sizes of the encoder packets are variable.

8. A system according to claim 1, wherein the row sizes of the encoder packets have a constant size.

9. A system according to claim 1, wherein the sequence number identifies the particular Encoder Packet (EP) and the PDU within that EP