Joint source-channel decoding with source sequence augmentation

A method for augmenting a source message bit sequence with two or more synchronization sequences placed at different bit positions within the source message in order to facilitate better source decoding, the method comprising:

• a. placing each one of said two or more synchronization sequences at a different bit position within the source message bit sequence wherein said two or more synchronization sequences are for jointly decoding the encoded source message bit sequence, and said two or more synchronization sequences are selected from a plurality of sets of defined synchronization sequences, each set corresponding to said different bit positions within the source message bit sequence, wherein the size of each said set is at least M≧1 and at least one said set is of size M≧2;
• b. for each source message bit sequence, selecting a specific synchronization sequence from said plurality of sets, wherein each set has M available synchronization sequences for a specific position, wherein the selection of said specific synchronization sequence is based on one or more characteristics of a source sequence comprising weight modulo-q said weight modulo-q of the source message bit sequence corresponding to the remainder of the weight of the source message bit sequence divided by q, said weight corresponding to the number of bits in the source message bit sequence equal to 1;
• and
• c. inserting each said selected specific synchronization sequence at said specific position.

A method for augmenting segments of a source message bit sequence with additional bits in order to facilitate better source decoding, wherein the segments may include one or more symbols, groups of symbols, fields and groups of fields, the method comprising:

• a. selecting a segment of a source message bit sequence to augment;
• and
• b. inserting one or more synchronization sequence bits in, or appending said one or more synchronization sequence bits to, based on one or more characteristics of the source message bit sequence, said characteristics comprising weight modulo-q of the source message bit sequence, said weight modulo-q of the source message bit sequence corresponding to the remainder of the weight of the source message bit sequence divided by q, said weight corresponding to the number of bits in the source message bit sequence equal to 1;
• one of the selected segments to maximize the distance of the segment values or to minimize the probability of erroneous decoding of the segment,
• wherein said one or more synchronization sequence bits are for jointly decoding the selected segment, and
• wherein the selected segment for augmentation occurs more frequently than other segments and is important for decoding or interpreting other segments in the source message bit sequence.

A method for encoding of a source packet for unequal error protection of selected parts of the source packet which consists of multiple fields of source bits, the method comprising:

• a. partitioning the source packet into two or more subpackets, wherein each subpacket comprises one or more source encoded fields, and wherein each subpacket has a different level of error protection;
• b. for one or more of said subpackets containing one or more source encoded fields, encoding selectively at a transmitter said one or more subpackets with a code for resolving errors to provide additional error protection for more reliable decoding of said one or more subpackets in order to achieve a desired level of performance after decoding, wherein said code for resolving errors is at least one synchronization sequence for jointly decoding the subpacket from a set of at least two defined synchronization sequences, and said encoding comprises:
• selecting an alternating synchronization sequence from the set of at least two defined synchronization sequences based on one or more characteristics of the subpacket, said characteristics comprising weight modulo-q of the subpacket, said weight modulo-q of the subpacket corresponding to the remainder of the weight of the subpacket divided by q, said weight corresponding to the number of bits in the subpacket equal to 1;
• inserting said selected synchronization sequence into the subpacket,
• c. encoding each subpacket with a CRC code to produce a CRC bit sequence to facilitate separate error concealment of said two or more subpackets in a decoder, wherein the length of different CRC bit sequences may be different depending at least in part on one or more of the subpacket length and the desired level of required error protection, wherein said code for resolving errors and said CRC code facilitate resolving errors during joint decoding of each subpacket at a receiver.