Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
237 words
A method for turbo-coding in a communications system, comprising: turbo-encoding source information using a parallel concatenation of first and second convolutional codes, the step of turbo-encoding comprising first and second encoding steps, the first encoding step applying the first convolutional code to the source information to provide a first group of code bits, the second encoding step applying the second convolutional code to the source information after interleaving the source information to provide a second group of code bits; puncturing the first and second groups of code bits; storing the punctured first and second groups of code bits in memory; transmitting the first and second groups of non-punctured code bits to a receiver via a channel; storing data samples corresponding to the first and second groups of non-punctured code bits in memory; turbo-decoding the data samples corresponding to the first and second groups of code bits in at least two decoding stages and determining whether the transmitted code bits have been received in error; if a transmission error is detected, maintaining the data samples corresponding to the first and second groups of non-punctured code bits in memory and transmitting at least a predetermined portion of the stored punctured code bits to the receiver, and then turbo-decoding in at least two stages by combining the data samples corresponding to the first and second groups of non-punctured code bits with data samples corresponding to the transmitted punctured code bits.
Claim 2
Independent Claim
237 words
A method for turbo-coding in a communications system, comprising: turbo-encoding source information using a parallel concatenation of first and second convolutional codes, the step of turbo-encoding comprising first and second encoding steps, the first encoding step applying the first convolutional code to the source information to provide a first group of code bits, the second encoding step applying the second convolutional code to the source information after interleaving the source information to provide a second group of code bits; puncturing the first and second groups of code bits; storing the punctured first and second groups of code bits in memory; transmitting the first and second groups of non-punctured code bits to a receiver via a channel; storing data samples corresponding to the first and second groups of non-punctured code bits in memory; turbo-decoding the data samples corresponding to the first and second groups of code bits in at least two decoding stages and determining whether the transmitted code bits have been received in error; if a transmission error is detected, maintaining the data samples corresponding to the first and second groups of non-punctured code bits in memory and transmitting at least a predetermined portion of the stored punctured code bits to the receiver, and then turbo-decoding in at least two stages by combining the data samples corresponding to the first and second groups of non-punctured code bits with data samples corresponding to the transmitted punctured code bits.
Claim 3
Dependent Claim
37 words
The method of claim 1 wherein the step of puncturing comprises deleting code bits according to a predetermined puncturing pattern, and the step of turbo-decoding comprises a depuncturing function for inserting neutral values for the punctured bits.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein the first and second convolutional codes comprise systematic convolutional codes.
Claim 5
Dependent Claim
30 words
The method of claim 3 wherein the step of puncturing comprises transmitting a single copy of the first and second code bits, which copy is used in each turbo-decoding stage.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein the step of determining whether the code bits have been received in error comprises a 16-bit cyclic redundancy check code.
Claim 7
Dependent Claim
242 words
A communications system, comprising: a transmitter comprising: a turbo-encoder for turbo-encoding source information, said turbo-encoder comprising a parallel concatenation of first and second convolutional codes, the turbo-encoder applying the first convolutional code to the source information to provide a first group of code bits, and applying the second convolutional code to the source information after interleaving the source information to provide a second group of code bits; a puncturing unit for puncturing the first and second groups of code bits; memory for storing the punctured first and second groups of code bits; said transmitter transmitting the first and second groups of non-punctured code bits via a channel to a receiver; the receiver comprising: memory for storing data samples corresponding to the first and second groups of non-punctured code bits; a turbo-decoder for turbo-decoding the data samples corresponding to the first and second groups of code bits in at least two decoding stages and determining whether the transmitted code bits have been received in error; upon detection of a transmission error, the turbo-decoder maintaining the data samples corresponding to the first and second groups of non-punctured code bits in memory and requesting transmission of at least a predetermined portion of the stored punctured code bits to the receiver, the turbo-decoder then turbo-decoding in at least two stages by combining the data samples corresponding to the first and second groups of non-punctured code bits with data samples corresponding to the transmitted punctured code bits.
Claim 8
Dependent Claim
242 words
A communications system, comprising: a transmitter comprising: a turbo-encoder for turbo-encoding source information, said turbo-encoder comprising a parallel concatenation of first and second convolutional codes, the turbo-encoder applying the first convolutional code to the source information to provide a first group of code bits, and applying the second convolutional code to the source information after interleaving the source information to provide a second group of code bits; a puncturing unit for puncturing the first and second groups of code bits; memory for storing the punctured first and second groups of code bits; said transmitter transmitting the first and second groups of non-punctured code bits via a channel to a receiver; the receiver comprising: memory for storing data samples corresponding to the first and second groups of non-punctured code bits; a turbo-decoder for turbo-decoding the data samples corresponding to the first and second groups of code bits in at least two decoding stages and determining whether the transmitted code bits have been received in error; upon detection of a transmission error, the turbo-decoder maintaining the data samples corresponding to the first and second groups of non-punctured code bits in memory and requesting transmission of at least a predetermined portion of the stored punctured code bits to the receiver, the turbo-decoder then turbo-decoding in at least two stages by combining the data samples corresponding to the first and second groups of non-punctured code bits with data samples corresponding to the transmitted punctured code bits.
Claim 9
Dependent Claim
28 words
The system of claim 6 wherein the puncturing unit deletes code bits according to a predetermined puncturing pattern, and the decoder inserts neutral values for the punctured bits.
Claim 10
Dependent Claim
16 words
The system of claim 6 wherein the first and second convolutional codes comprise systematic convolutional codes.
Claim 11
Dependent Claim
28 words
The system of claim 6 wherein the puncturing unit transmits a single copy of the first and second code bits, which copy is used in each turbo-decoding stage.
Claim 12
Dependent Claim
26 words
The system of claim 6 wherein the decoder determines whether the code bits have been received in error by using a 16-bit cyclic redundancy check code.