Patent ID: 7447288

Claim:
Method for demodulation of a digital signal received through a transmission channel, the method comprising: associating each received value of the received signal with a corresponding point in the modulation constellation, as a function of decision-making boundaries, plotted as a function of at least one phase and / or amplitude characteristic of the modulation, so as to associate a corresponding decision region of a reception space with each of the points in the constellation, said constellation being represented in an I/Q plane having I and Q axes, wherein each of four quadrants of said I/Q plane comprises a set of points, comprising at least one external point, which is the furthest from the center of said I/Q plane, and for each of said external points, constructing demodulation boundaries defining a decision region associated with said external point, comprising the following steps: association with said external point of at least one generating zone enclosing said external point with at least one of the points in the modulation constellation, the zone representing the potential effect of Gaussian additive noise; application of a rotation of π/2, limited by the I and Q axes, to the generating zone in the reception space, so as to define a surface scanned by the generating zone, representing the potential effect of a phase shift on said external point; definition of at least one boundary including a first arc of a circle from said I axis and a second arc of a circle from said Q axis, chosen such that said first and second arcs of circle correspond to said scanned surface.