Translation table design for a PCM modem

A method for generating scaling factors for a modem having a frame having a plurality of slots, comprising steps:

• a) obtaining digital impairment learning (DIL) sequence information from another modem;
• b) from said DIL sequence information, generating at least one ordered table of levels;
• c) finding a plurality of distances between adjacent levels of said ordered table for each slot;
• d) utilizing substantially only typical distances of said plurality of distances between adjacent levels in order to find at least one scaling factor.

A method of selecting a scaling factor for a modem having a frame having a plurality of slots, comprising steps:

• a) obtaining digital impairment learning (DIL) sequence information from another modem;
• b) from said DIL sequence information, generating at least one ordered table of levels;
• c) finding a non-robbed-bit signaling (RBS) slot of said plurality of slots;
• d) for at least said RBS slot, calculating a PAD estimation function utilizing said ordered table of levels;
• e) comparing a function of said PAD estimation function to at least one threshold to find an indication of PAD attenuation;
• and
• f) choosing a scaling factor based on said indication of PAD attenuation.

A method of selecting a scaling factor for a modem having a frame having a plurality of slots, comprising steps:

• a) obtaining digital impairment learning (DIL) sequence information from another modem;
• b) from said DIL sequence information, generating at least one ordered table of levels;
• c) utilizing a distance function Ldel(i,Δ)=L(i)−2L(i−Δ) to find commonly recurring distances LdelC, where L(i) is the value of the i-th level of said ordered table of levels, and Δ is a given shift between compared indexes;
• d) determining a threshold Th1;
• e) comparing distances Ldel(i,16) to said threshold Th1 and averaging said distances Ldel(i,16) which exceed Th1;
• f) utilizing said average value as an estimate D1 in selecting a scaling factor.