Inmarsat Limited

Inmarsat Global Limited

Panagiotis Fines

Paul R Febvre

David Denis Mudge

Eyal Trachtman

Edward Arthur Jones

Siu Wah Wong

Carole Plessy-Gourdon

Ekaterina Christofylaki

In a frame sync method, a receiver searches for the presence of an N-symbol long unique word pattern. For each possible frame sync detected, the receiver proceeds to demodulation and FEC processing. After each iteration of the FEC decoder, the detected unique word pattern is compared to the expected one and the frame sync is detected if the number of unique word errors has decreased.

Communication method and apparatus

In a wireless communications system, transceivers transmit short bursts to a base station, which determines timing corrections from the time of receipt of the burst and transmits the timing corrections to the respective transceivers. In one aspect, the base station indicates to the transceivers a plurality of time slots, each transceiver selects one of the time slots at random, formats a burst including an indicator of the selected time slot and transmits the burst in that slot. In another aspect, the base station transmits to each transceiver a timing uncertainty value, which determines how the timing correction will be modified by the tranceiver as the interval since last receiving a timing correction increases. Data bursts are transmitted in a format comprising a first unique word, a content field and a second unique word, in that order. The bursts are transmitted in a TDMA channel format which can accommodate both short and long bursts in a block format of constant periodicity.

Method and apparatus for timing correction in communications systems

Method and apparatus for timing correction in communication systems

FFT receiver for MFSK

Growing community of inventors

London, United Kingdom

Panagiotis Fines