Method of searching the point which is the nearest from a characteristic of a received signal in an assembly of non-uniformly distributed points

A modem comprising:

• means for receiving analog signals;
• and
• means for decoding the received analog signals, said decoding means comprising means for selecting, in an assembly of non-uniformly distributed points, the point which is the nearest from the amplitude of the received analog signal,
• wherein a first interval is determined using a lowest and highest amplitude points, and wherein said selection means includes means for elaborating successive search intervals in the assembly, the successive search intervals being obtained by splitting up a previous search interval into two intervals, each interval including a respective number of points, the respective number of points being equal or different by one.

A transmission system comprising:

• at least a transmitter:
• and
• a receiver for receiving analog signals, the receiver including decoding means for selecting, in an assembly of non-uniformly distributed points, the point which is the nearest from a characteristic of the received signal,
• wherein a first interval is determined using a lowest and highest amplitude points, and wherein said decoding means includes means for elaborating successive search intervals in the assembly, the successive search intervals being obtained by splitting up a previous search interval into two intervals, each interval including a respective number of points, the respective number of points being equal or different by one.