7-channel transmission, compatible with 5-channel transmission and 2-channel transmission

A method of encoding a plurality of digital information signals, the method comprising the steps of:

• receiving a first digital information signal,
• receiving a second digital information signal,
• receiving a third digital information signal,
• receiving a fourth digital information signal,
• receiving a fifth digital information signal,
• receiving a sixth digital information signal,
• receiving a seventh digital information signal,
• matrixing means the first to seventh digital information signals for generating a first and a second digital composite signal, the matrixing step including the substeps of:
• combining the second and third digital information signal for generating a first combination signal,
• combining the fifth and sixth digital information signal so as to obtain a second combination signal,
• combining the third, fourth and fifth digital information signals so as to obtain a third combination signal,
• combining the first digital information signal and the first and third combination signal so as to obtain the first composite signal,
• combining the seventh digital information signal and the second and third combination signal so as to obtain the second composite signal,
• the method further comprising the steps of:
• data compressing the first and second composite signal so as to obtain first and second data reduced digital composite signals,
• selecting one signal from a first group of five information signals so as to obtain a first auxiliary signal, the first group of five information signals including the first and seventh digital information signals and the first, second and third combination signals, selecting another one of the first group so as to obtain a second auxiliary signal and again another one of the first group so as to obtain a third auxiliary signal, selecting one signal from a second group of five information signals so as to obtain a fourth auxiliary signal, the second group of five signals including the second to sixth digital information signals and selecting another one of the second group so as to obtain a fifth auxiliary signal,
• data compressing the first, second, third, fourth and fifth auxiliary signal respectively so as to obtain first, second, third, fourth and fifth data reduced auxilairy signals respectively,
• combining and formatting the first and second data reduced composite signals and the first, second, third, fourth and fifth data reduced auxiliary signals so as to obtain a transmission signal suitable for transmission via a transmission medium.

Apparatus for decoding a transmission signal, received so as to obtain a plurality of digital information signals, comprising:

• input means for receiving the transmission signal,
• deformatting means for retrieving first and second data reduced composite signals and first, second, third, fourth and fifth data reduced auxiliary signals from the transmission signal,
• first, second, third, fourth, fifth, sixth and seventh data expansion means for data expanding the first and second data reduced composite signals and the first, second, third, fourth and fifth data reduced auxiliary signal respectively so as to obtain first and second composite signals and first, second, third, fourth and fifth auxilairy signals respectively,
• dematrixing means for generating first, second, third, fourth, fifth, sixth and seventh digital information signals from the first and the second digital composite signal and the first to fifth auxiliary signals, the dematrixing means including first dematrixing means adapted to receive the first and second composite signals and a plurality of auxiliary signals, for converting those signals into a plurality of combination signals and a plurality of M digital information signals, and including second dematrixing means adapted to receive the plurality of combination signals and a second plurality of auxiliary signals, for converting those signals into the remaining 7-M digital information signals, where M is an integer and M>0,
• first output means for supplying the first digital information signal,
• second output means for supplying the second digital information signal,
• third output means for supplying the third digital information signal,
• fourth output means for supplying the fourth digital information signal,
• fifth output means for supplying the fifth digital information signal,
• sixth output means for supplying the sixth digital information signal,
• seventh output means for supplying the seventh digital information signal.

Apparatus for decoding a transmission signal received so as to obtain a plurality of digital information signals, comprising:

• input means for receiving the transmission signal,
• deformatting means for retrieving first and second data reduced composite signals and first, second, third, fourth and fifth data reduced auxiliary signals from the transmission signal;
• first, second, third, fourth, fifth, sixth and seventh data expansion means for data expanding the first and second data reduced composite signals and the first, second, third, fourth and fifth data reduced auxiliary signal respectively so as to obtain first and second composite signals and first, second, third, fourth and fifth auxilairy signals respectively;
• dematrixing means for generating first, second, third, fourth, fifth, sixth and seventh digital information signals from the first and the second digital composite signal and the first to fifth auxiliary signals;
• first output means for supplying the first digital information signal;
• second output means for supplying the second digital information signal;
• third output means for supplying the third digital information signal;
• fourth output means for supplying the fourth digital information signal;
• fifth output means for supplying the fifth digital information signal;
• sixth output means for supplying the sixth digital information signal;
• seventh output means for supplying the seventh digital information signal;
• the deformatting means further being adapted to retrieve a selection control signal from the transmission signal, the dematrixing means further being adapted to generate the first, second, third, fourth, fifth, sixth and seventh digital information signals from the first and the second digital composite signal and the first to fifth auxiliary signals, in response to the selection control signal.

Apparatus for decoding a transmission signal received so as to obtain a plurality of digital information signals, comprising:

• input means for receiving the transmission signal;
• deformatting means for retrieving first and second data reduced composite signals and first, second, third, fourth and fifth data reduced auxiliary signals from the transmission signal;
• first, second, third, fourth, fifth, sixth and seventh data expansion means for data expanding the first and second data reduced composite signals and the first, second, third, fourth and fifth data auxiliary signal respectively so as to obtain first and second composite signals and first, second, third, fourth and fifth auxilairy signals respectively;
• dematrixing means for generating first, second, third, fourth, fifth, sixth and seventh digital information signals from the first and the second digital composite signal and the first to fifth auxiliary signals;
• first output means for supplying the first digital information signal;
• second output means for supplying the second digital information signal;
• third output means for supplying the third digital information signal;
• fourth output means for supplying the fourth digital information signal;
• fifth output means for supplying the fifth digital information signal;
• sixth output means for supplying the sixth digital information signal;
• seventh output means for supplying the seventh digital information signal;
• the apparatus further being adapted to receive a transmission signal including frames, a frame including a first block of information containing data corresponding to the data reduced first and second digital composite signal, a second block of information containing data corresponding to the data reduced first, second and third auxiliary signals, and a third block of information containing data corresponding to the data reduced fourth and fifth auxiliary signals, the third signal block containing an identifier for identifying the information contained in the third signal block.