Patent ID: 7471735
Filing Date: 2008-12-30
Classification: H04H,H04N,Y02D

Abstract:
1. A method for transmitting signals, comprising: amplifying an upper layer signal with a first excess bandwidth ratio at a first power level within a frequency band; amplifying a lower layer signal with a second excess bandwidth ratio at a second power level within the frequency band, the second power level being exceeded by the first power level; and transmitting a layered modulation signal for at least one receiver, the layered modulation signal comprising both the upper layer signal and the lower layer signal interfering with each other within the frequency band such that the upper layer signal can be demodulated directly from the layered modulation signal and the lower layer signal can be demodulated after subtracting the upper layer signal from the layered modulation signal; wherein substantially no guard band is used within the frequency band.