National Semiconductor Corporation

Ahmad R S Bahai

John Matthew Cioffi

Jeffrey Anthony Morroni

Gianpaolo Lisi

Ali Djabbari

Ali Kiaei

Gerard G Socci

Ghazi Al-Rawi

Tareq Al-Nafouri

In a wireless power transfer system with multiple receivers, receiver management may be necessary to effectively provide power to the multiple receivers. In one implementation, receiver management includes sweeping or stepping the transmitter resonant and/or operating frequency. In another implementation, receiver management includes receiver self-management, in which the receiver load current duty cycle is controlled to maintain receiver voltage even in the presence of multiple receivers. In another implementation, receiver management includes receiver self-management, in which one or more receivers use a time-sharing heuristic to identify when other receivers are charging and wait to begin receiving a transfer of power until another receiver has stopped receiving a transfer of power.

Resonant system for wireless power transmission to multiple receivers

An apparatus for demodulating a coded orthogonal frequency division multiplexing (OFDM) signal in a coded OFDM receiver. The coded OFDM signal comprises systematic bits, error control bits, and a cyclic prefix. The apparatus performs channel estimation quickly and accurately using the error control bits, the channel spread constraint, and the cyclic prefix portion of the received coded OFDM signal.

Coded OFDM system using error control coding and cyclic prefix for channel estimation

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Lafayette, CA, United States of America

Ahmad R S Bahai