Abstract: Protograph-based LDPC codes are obtained from z-row-orthogonal base matrices with some additional structure constraints, such as a diagonal and/or double-diagonal structure, in order to allow a high parallelization that is a multiple of z, while having an efficient encoding or decoding. A “big” base matrix is constructed from a structured square submatrix in order to have a WiMAX-like structure and a z-row-orthogonality. Also, starting from a “smaller” base matrix having a part arranged in a double-diagonal shape with tail-biting one, an expansion by a factor equal to z can be performed, followed by an addition of a single one-entry into the last column at a specific location, thereby obtaining a three-degree column, and followed by a row and/or column permutation in order to obtain a base matrix in a WiMAX-like structure.

Abstract: Protograph-based LDPC codes are obtained from z-row-orthogonal base matrices with some additional structure constraints, such as a diagonal and/or double-diagonal structure, in order to allow a high parallelization that is a multiple of z, while having an efficient encoding or decoding. A “big” base matrix is constructed from a structured square submatrix in order to have a WiMAX-like structure and a z-row-orthogonality. Also, starting from a “smaller” base matrix having a part arranged in a double-diagonal shape with tail-biting one, an expansion by a factor equal to z can be performed, followed by an addition of a single one-entry into the last column at a specific location, thereby obtaining a three-degree column, and followed by a row and/or column permutation in order to obtain a base matrix in a WiMAX-like structure.

Abstract: A method for recovery of lost data and for correction of corrupted data transmitted from a sending device to a receiver device, the method comprising the steps: encoding the data by an encoder connected to the sending device, transmitting the data from the sending device to the receiver device via a transmitting device, and decoding the data by a decoder connected to the receiver device, whereby lost and/or corrupted data is recovered during decoding is conducted by solving the system of equations of a parity check matrix H.

Abstract: The invention is related to a method of transmitting data whereby a transmission channel towards an access point (10) is shared among a plurality of users (12), the data being transmitted using the Contention Resolution Diversity Slotted ALOHA (CRDSA) method. According to the invention the number of copies (14a,14b, 14c; 16a, 16b, 16c; 18a,18b,18c) of data packet (14, 16, 18) transmitted simultaneously by a user (12) within one frame is varied.

Abstract: A method for recovery of lost data and for correction of corrupted data transmitted from a sending device to a receiver device, the method comprising the steps: encoding the data by an encoder connected to the sending device, transmitting the data from the sending device to the receiver device via a transmitting device, and decoding the data by a decoder connected to the receiver device, whereby lost and/or corrupted data is recovered during decoding is conducted by solving the system of equations of a parity check matrix H.

Abstract: A method for recovery of lost and/or corrupted data, whereby this data is encoded by means of an encoder connected to the transmitter device and transmitted via a transmission channel to the receiver device. The transmitted data is decoded by means of a decoder connected to the receiver device wherein lost and/or corrupted data is restored during decoding. Encoding and decoding are performed by using a convolutional code. According to the disclosure the window size, on which the decoder connected to the receiver device operates, is variable so that the window size can be adapted to the erasure rate of the transmission channel and/or to the delay service requirement.

Abstract: A method for recovery of lost and/or corrupted data transmitted from a transmitter device to a receiver device. The data is coded by an encoder connected to the transmitter device. The data is transmitted from the transmitter device to the receiver device via a transmission system and is decoded by means of a decoder connected to the receiver device. This is performed through application of a low density parity check method, wherein lost and/or corrupted data is restored during decoding. The decoding is performed by solving the equation system of the parity check matrix H. The parity check matrix H is brought into a triangular form by column and/or row permutations. Columns of a sub-matrix B of the matrix H which impede the triangulation process are shifted into a sub-matrix P of the matrix H so that the triangulation process can be continued until the matrix H except for the sub-matrix P has been completely brought into a triangular form.

Abstract: A method of transmitting data, whereby the data is transmitted by using a multiple access frame divided in logical slots. Each data packet is divided into k units which are decoded by an (n,k) decoder, producing n?k redundant units. The n units are transmitted within a multiple access frame in n different slots according to a time-hopping pattern, a frequency-hopping pattern or a combination of both. At the receiver side lost or corrupted data packets are recovered by using the redundant units, whereby the presence of a unit for each slot is detected. If a unit is present in a slot and has been transmitted without collisions, this unit is recovered. If a sufficient k+? amount of units composing a data packet is recovered, the packet level decoder is used to recover the remaining n?k?? units which experienced collisions in the respective slots.

Abstract: The invention is related to a method of transmitting data, whereby a transmission channel towards an access point is shared among a plurality of users. The data is transmitted by using a multiple access frame divided in logical slots. According to the invention each data packet is divided into k units which are decoded by an (n,k) decoder, producing n?k redundant units. The n units are transmitted within a multiple access frame in n different slots according to a time-hopping pattern, a frequency-hopping pattern or a combination of both. Thereby, the positions of the n units composing a data packet are written in a header appended to each unit. At the receiver side lost or corrupted data packets are recovered by using the redundant units, whereby the presence of a unit for each slot is detected. If a unit is present in a slot and has been transmitted without collisions, this unit is recovered.

Abstract: A method for recovery of lost and/or corrupted data, whereby this data is encoded by means of an encoder connected to the transmitter device and transmitted via a transmission channel to the receiver device. The transmitted data is decoded by means of a decoder connected to the receiver device wherein lost and/or corrupted data is restored during decoding. Encoding and decoding are performed by using a convolutional code. According to the disclosure the window size, on which the decoder connected to the receiver device operates, is variable so that the window size can be adapted to the erasure rate of the transmission channel and/or to the delay service requirement.

Abstract: The invention is related to a method of transmitting data whereby a transmission channel towards an access point (10) is shared among a plurality of users (12), the data being transmitted using the Contention Resolution Diversity Slotted ALOHA (CRDSA) method. According to the invention the number of copies (14a,14b, 14c; 16a, 16b, 16c; 18a,18b,18c) of data packet (14, 16, 18) transmitted simultaneously by a user (12) within one frame is varied.

Abstract: A method for recovery of lost and/or corrupted data transmitted from a transmitter device to a receiver device. The data is coded by an encoder connected to the transmitter device. The data is transmitted from the transmitter device to the receiver device via a transmission system and is decoded by means of a decoder connected to the receiver device. This is performed through application of a low density parity check method, wherein lost and/or corrupted data is restored during decoding. The decoding is performed by solving the equation system of the parity check matrix H. The parity check matrix H is brought into a triangular form by column and/or row permutations. Columns of a sub-matrix B of the matrix H which impede the triangulation process are shifted into a sub-matrix P of the matrix H so that the triangulation process can be continued until the matrix H except for the sub-matrix P has been completely brought into a triangular form.