×

Reduction of average-to-minimum power ratio in communications signals

  • US 7,675,993 B2
  • Filed: 05/26/2006
  • Issued: 03/09/2010
  • Est. Priority Date: 10/22/2001
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method of reducing the average-to-minimum magnitude ratio (AMR) of a communications signal having a sequence of symbols, comprising:

  • obtaining a digital message for generating the communications signal having a sequence of symbols;

    applying a pulse-shaping technique to an instance of a pulse of a given form to generate a communications signal s(t);

    obtaining a minimum value ρ

    (tmin) of the magnitude of the generated communication signal s(t) at a time instant t_min in a time interval between two distinct time instants t1 and t2 (t1<

    t2);

    generating, in the time interval between the time instants t1 and t2, a correction signal with a predetermined impulse response r(t−

    tmin) which is obtained based on the minimum value and the predetermined signal envelope minimum if it is determined that ρ

    (tmin) is smaller than a predetermined signal envelope minimum; and

    adding the correction signal to the communications signal to generate a modified communications signal, whereinthe communications signal is represented within a signal plane having an origin denoting a signal of zero magnitude;

    the minimum value of the magnitude of the communications signal is calculated from a distance from the origin to a first straight line spanning a coordinate of the communications signal s(t1) and a coordinate of the communications signal s(t2), and the method further comprises;

    determining the first straight line spanning the coordinate of the communications signal s(t1) and the coordinate of the communications signal s(t2) and a second straight line passing through the origin and being orthogonal to the first straight line; and

    calculating the minimum value ρ

    (tmin) of the magnitude of the communications signal from a distance from the origin to an intersection point of the first straight line and the second straight line.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×