Image Number 14 for United States Patent #7633999.
In accordance with one embodiment of the present invention, a power spectral density (PSD) mask for spectral shaping of a dual bit map (DBM) mode downstream transmission is provided. The PSD mask is represented by the equation:.times..times..function..pi..times..pi..times..times..times. .circleincircle..circleincircle..infin. ##EQU00001## where PSD.sub.DBMsOL represents the PSD mask, K.sub.ADSL.sub..sub.OL represents a constant value, C represents a constant value, f represents a frequency of the downstream transmission, f.sub.0 represents a constant value, f.sub.LP3dB represents a 3 decibel (dB) low pass frequency and f.sub.f.sub.HP3dB represents a 3 dB high pass frequency. K.sub.ADSL.sub..sub.OL preferably has a value between 0.0900 watts and 0.1200 watts and more preferably has a value of 0.1104 watts. The constant f.sub.0 preferably has a value between 2.100 megahertz and 2.300 megahertz and more preferably has a value of 2.208 megahertz. The constant f.sub.LP3dB has a value substantially equal to ##EQU00002## The constant f.sub.HP3dB has preferably has a value between 100 kilohertz and 150 kilohertz and more preferably has a value of 130 kilohertz. The constant C preferably has a value between 0.1 and 10 and more preferably has a value of 2.
