Pulse or digital communications – Systems using alternating or pulsating current – Plural channels for transmission of a single pulse train
Reexamination Certificate
2011-01-11
2011-01-11
Puente, Eva Y (Department: 2611)
Pulse or digital communications
Systems using alternating or pulsating current
Plural channels for transmission of a single pulse train
C375S141000, C375S130000, C375S347000, C375S146000, C375S147000, C342S373000, C342S379000, C370S208000, C370S311000, C370S203000
Reexamination Certificate
active
07869530
ABSTRACT:
The Energy spectral density of OFDM signals inherently rolls off slowly. Slow OFDM spectral rolloff has system level implications traditionally mitigated by some combination of the following: addition of bandlimiting filtering; use of significant guard bands of zeroed tones; and, guard time shaping. Each of these techniques negatively impact system performance and/or flexibility. This application presents a methodology for active cancellation of out of band spectral energy. The technique can be used by itself or in conjunction with above traditional methods to help control out of band emission. Examples of the use of the new technique are provided. Computational cost of the new technique is also discussed.
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Norin John L.
Popoli Robert F.
Puente Eva Y
The DIRECTV Group Inc.
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