Method and device for reducing the crest factor in digital transmission procedures

A method for reducing the crest factor in digital signal transmission, said method comprising the steps of:

• obtaining digital information to be transmitted;
• generating a plurality of alternative, information-equivalent sequences;
• modifying the digital information by a sequence which is selected from said plurality of alternative, information-equivalent sequences, the selected sequence being favorable in respect of a peak value of a transmitted digital signal, to achieve a modified digital signal;
• transmitting said modified digital signal;
• partitioning a block carrier A.sub.u into V subblocks A.sub.u.sup.(v) v=1, . . . ,V, which are separately transferred into partial transmit sequences;
• and
• combining the subblocks and modifying the subblocks with arbitrary factors b.sub.1, . . . ,b.sub..nu., to form an optimal information-equivalent sequence, wherein b.sub.1, . . . ,b.sub..nu. has a complex value, the absolute value of which is .vertline.b.sub.1 .vertline.= . . . =.vertline.b.sub..nu. .vertline.=1,
• wherein the modifying of the digital information is through transformation which generates a multicarrier transmission procedure.

A device for reducing the crest factor in digital signal transmission procedures, the device comprising:

• a representation device for mapping digital information to carrier values (A.sub.u);
• a multiplier, for multiplying the carrier values (A.sub.u) with arbitrarily eligible values (P.sub..nu..sup.(u));
• a transformer, for transforming the carrier values into a plurality alternative information-equivalent sequences;
• a means for selecting a sequence from the plurality of alternative information-equivalent sequences to yield a modified digital signal having a favorable peak value associated therewith;
• and
• a transmitter for transmitting the modified digital signal,
• wherein the modified digital signal is transformed from the digital information through a multicarrier transmission procedure.