Multiplex communications – Generalized orthogonal or special mathematical techniques – Particular set of orthogonal functions
Reexamination Certificate
2005-08-23
2005-08-23
Sam, Phirin (Department: 2661)
Multiplex communications
Generalized orthogonal or special mathematical techniques
Particular set of orthogonal functions
C375S260000, C375S346000
Reexamination Certificate
active
06934246
ABSTRACT:
An improved multicarrier modulation system and method, which has the advantages of both isotropic orthogonal transfer algorithm orthogonal frequency division multiplexing (IOTA OFDM) and scalable advanced modulation (SAM), is introduced. The invention is root raised cosine (RRC) OFDM using the most spectrally efficient RRC filter without sacrificing the compact subchannel spacing of OFDM. The invention further provides an adjacent channel interference (ACI) suppression scheme and a modified RRC for better suppressing ACI of RRC OFDM. The ACI suppression scheme can also be applied to SAM with the modified RRC and to IOTA OFDM with a modified IOTA. The invention greatly improves a major problem of conventional OFDM namely ACI due to the use of a wide subchannel filter. Thus, the invention allows OFDM to meet even the strictest ACI requirements, which was not possible by using a conventional raised cosine windowing method.
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“Wideband Air Interface Scalable Adaptive Modulation (SAM) Physical Layer Specification Public Safety Wideband Data Standards Project Digital Radio Technical Standards,” TIA-902.BAAB, Feb. 2002.
Sam Phirin
Wilson Robert W.
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