Peak-to-average power ratio reduction in a multi-carrier signal

A device for transmitting a multi-carrier source signal comprising symbols constituted by a set of carriers that are to be sent out simultaneously, and comprising carriers reserved for at least one processing operation to reduce the peak-to-average power ratio of said source signal, and data carriers, said device comprising:

• a processor;
• and
• a non-transitory computer-readable medium comprising instructions stored thereon, which when executed by the processor configure the device to perform acts comprising:
• generation of an additional signal and the addition to said source signal of said additional signal, delivering an optimized signal having a peak-to-average power ratio smaller than the peak-to-average power ratio of said source signal,
• transmission of said optimized signal,
• wherein said generation and addition of an additional signal comprises, for each symbol of said source signal, obtaining M time samples representing said symbol, and further comprises:
• detecting P time samples among said M time samples representing said symbol, said P samples being the P samples of highest amplitude among said M samples, or said P samples having power above a pre-determined threshold,
• activating at least one of said reserved carriers of said symbol, by addition of a pre-determined power value to said at least one of said reserved carriers,
• for each activated reserved carrier:
• obtaining M time samples representing said activated reserved carrier,
• applying a phase shift, taking account of said P detected samples, to said M time samples representing said activated reserved carrier, delivering M time samples representing an additional signal associated with said activated reserved carrier,
• adding M time samples, representing said additional signal associated with said activated reserved carrier, to said M time samples representing said symbol, delivering M time samples representing said symbol to be used for the detection step of the following iteration.

A non-transitory computer-readable medium comprising comprising a computer program product stored thereon, which comprises program code instructions for implementing a method of transmission of a multi-carrier source signal, when the instructions are executed by a processor of a transmission device, wherein the multi-carrier source signal comprises symbols constituted by a set of carriers, intended to be sent out simultaneously and comprising carriers reserved for at least one processing operation for reducing the peak-to-average power ratio of said source signal, and data carriers, and wherein the instructions configure the transmission device to perform acts comprising:

• generation of an additional signal and addition to said source signal of said additional signal, delivering an optimized signal having a peak-to-average power ratio smaller than the peak-to-average power ratio of said source signal,
• transmission of said optimized signal,
• wherein said act of generation and addition of an additional signal comprises, for each symbol of said source signal, an act of obtaining M time samples representing said symbols and at least one iteration of the following acts:
• detection of P time samples from among said P time samples representing said symbol, said P samples being the P samples of the highest amplitude among said M samples, or said P samples presenting a power value above a pre-determined threshold,
• in the frequency domain, activation of at least one of said reserved carriers of said symbol, by the addition of a pre-determined power to said at least one of said reserved carriers,
• for each activated reserved carrier:
• obtaining M time samples representing said activated reserved carrier,
• applying a phase shift, taking account of said P detected samples, to said M time samples representing said activated reserved carrier, delivering M time samples representing an additional signal associated with said activated reserved carrier,
• adding the M time samples representing said additional signal associated with said activated reserved carrier to said M time samples representing said symbol, delivering M time samples representing said symbol to be used for the detection act of the next iteration.