초록 ▼

A device for the transmission of digital data with at least two levels of protection, of the type providing for the distribution of the data to be transmitted in the form of digital elements in the time-frequency space and the transmission of symbols each formed by a multiplex of N orthogonal carrie

A device for the transmission of digital data with at least two levels of protection, of the type providing for the distribution of the data to be transmitted in the form of digital elements in the time-frequency space and the transmission of symbols each formed by a multiplex of N orthogonal carriers modulated by a set of the digital elements, and transmitted simultaneously, the device including channel .[.encoding.]. .Iadd.encodes .Iaddend.means comprising at least two types of modulation and/or at least two encoding efficiency levels. This enables to optimize the use of the transmission channel by assigning differentiated transmission techniques to portions of data of a same digital train as a function of the different levels of protection sought, against transmission errors.

대표청구항 ▼

[ What is claimed is:] [17.] A device for transmission of digital data with at least two levels of protection, comprising:means for distribution of the data to be transmitted in the form of digital elements in time-frequency space and transmission of symbols each formed by a multiplex of N orthogona

[ What is claimed is:] [17.] A device for transmission of digital data with at least two levels of protection, comprising:means for distribution of the data to be transmitted in the form of digital elements in time-frequency space and transmission of symbols each formed by a multiplex of N orthogonal carriers modulated by a set of said digital elements, and transmitted simultaneously, wherein for at least some of said symbols, said N orthogonal carriers are organized into at least two different sets of orthogonal carriers,first channel encoding means providing for a first encoding efficiency level, said first channel encoding means delivering first digital elements to be transmitted by a first of said sets of orthogonal carriers, andat least second channel encoding means providing for a second encoding efficiency level different from said first encoding efficiency level, said second channel encoding means delivering second digital elements to be transmitted by a second of said sets of orthogonal carriers, so that at least some of said symbols include simultaneously carriers with digital elements coded with the first encoding efficiency level and carriers with digital elements coded with the second encoding efficiency level. .Iaddend..Iadd.