Abstract: A receiver/decoder for use in a digital satellite radio or television system includes a decoder and means to accommodate a credit or bank card carrying a microprocessor, and means to interact with said microprocessor when the credit or bank card is inserted into an operative position in said receiver/decoder in order to enable data carried by said credit or bank card to be read and data to be input to the microprocessor carried by said credit or bank card. A PIN number may be transmitted to the receiver/decoder in a secure fashion by means of a remote controller, which is also described. Applications of the invention include Pay-Per-View television, teleshopping and telebanking.

Abstract: A data receiver, and transmitter/receiver combination, for transmitting data using statistic coding. A data transmitter transmits statistic encoded data representing successive sample series in a form having a variable number of bits followed by two self-synchronizing codes, each self-synchronizing code including a suffix formed by a codeword or a concatenation of codewords. A data receiver for use with such a transmitted signal includes a correction circuit which can store at least one sample series, and a write counter for forming address codes defining locations of samples to be stored in the storage portion of the correction circuit. Preferably a sequencer provides a window signal which validates the output of a synchronizing signal detector in a time interval when the synchronizing word will probably be received.

Abstract: A system for transmitting sequences of digital samples encoded by variable-length binary words is formed on the one hand by a transmitter device comprising a statistic encoding circuit for encoding in said variable-length words words of a fixed length appearing at its input in the shape of sample sequences, a synchronizing circuit for forming synchronizing words which define the position of the variable-length words in the sequences and a multiplexer circuit for combining, in view of their transmission, the synchronizing words with the variable-length words, and, on the other hand, a receiver device comprising a demultiplexer circuit for applying from one of its two outputs the variable-length words received to a statistic decoding circuit for recovering the fixed-length words and for applying from the other output the synchronizing word to a processing circuit for restituting, in the event of a transmission error, the position of the samples in the sequence.