Maximizing power and spectral efficiencies for layered and conventional modulations
First Claim
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.
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Accused Products
Abstract
Methods and apparatuses for maximizing power and spectral efficiencies in a wireless communication system are disclosed. The invention is particularly useful for layered modulation applications because power levels for such applications are relatively high. A layered modulation signal comprises an upper and a lower layer signal that interfere with each other within the same 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 first layer signal from the layered modulation signal. The invention applies one or more of the following four signal schemes in a communication signal including varying the symbol rate (rather than the code rate), reducing or eliminating the guard band, reducing excess signal bandwidth and employing layered modulation within the guard band of the legacy signal.
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Citations
23 Claims
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1. A method for transmitting signals, comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system for transmitting signals, comprising:
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a first amplifier for amplifying an upper layer signal with a first excess bandwidth ratio at a first power level within a frequency band; a second amplifier for 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 at least one antenna for transmitting a layered modulation signal to 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. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A system for transmitting signals, comprising:
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means for amplifying an upper layer signal with a first excess bandwidth ratio at a first power level within a frequency band; and means for 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; means for transmitting a layered modulation signal for at least one receiver means, 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.
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Specification