Patent ID: 6914942

Claim:
A method for selecting a swapping technique from a group consisting of a bit-swapping and a gain-swapping techniques in a discrete multi-tone (DMT) system having multiple sub-channels, gain factor constraints, a threshold index value (T), and a maximum mean square error (MSE max ) and a minimum mean square error (MSE min ), the method comprising: determining a first index value (I) and a second index value (J) based on MSE max , MSE min and said gain factor constraints according to a predetermined manner, I denoting range of improvement when adopting the gain-swapping as the swapping technique, and J denoting range of improvement when adopting a combination of the gain-swapping and the bit-swapping as the swapping technique; determine whether larger one of I and J is larger than T; if the larger one of I and J is larger than T, determining whether I is equal to or larger than J; and selecting the gain-swapping as the swapping technique if I is equal to or larger than J.