Multiplex communications – Generalized orthogonal or special mathematical techniques – Quadrature carriers
Patent
1996-08-13
1999-03-30
Hsu, Alpus H.
Multiplex communications
Generalized orthogonal or special mathematical techniques
Quadrature carriers
375261, 375331, 375344, 455208, 455517, H04J 1100
Patent
active
058897593
ABSTRACT:
A synchronizing apparatus for a differential OFDM receiver that simultaneously adjust the radio frequency and sample clock frequency using a voltage controlled crystal oscillator to generate a common reference frequency. Timing errors are found by constellation rotation. Subcarrier signals are weighted by using complex multiplication to find the phase differentials and then the timing errors. The reference oscillator is adjusted using the timing errors. Slow frequency drift may be compensated using an integral of the timing error. Frequency offset is found using the time required for the timing offset to drift from one value to another.
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Implementation of a High Performance Wireless LAN, Grant McGibney, Abu Sesay, John McRory, Brad Morris, TR Labs, Calgary, Alberta, Canada, conference proccedings of "Wireless 94", Jul. 11-13, 1994, Calgary, pp. 645-650.
Hsu Alpus H.
Lambert Anthony R.
Telecommunications Research Laboratories
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