U.S. Philips Corporation

Benoit Gelin

Michel Lebourg

Method and apparatus for bit synchronization in a receiver for digital data transmission in which the received short-length packets of bit pulses are first converted into normalized 1 or 0 samples at the rate nFb, where Fb is the bit rate and n a small even integer. For each packet or sub-packet of M bits, the following steps are performed:

Method and arrangement for bit synchronization in a receiver for digital

The method ensures the coherent demodulation by digitally processing a continuous-phase modulated signal (for instance, of the GMSK type). The received signal is transposed in the baseband, converted into a digital signal and transferred to a signal processor. Each transmitted data packet has a known preamble sequence of N bits which allows for approximate estimation of the frame-synchronization and the bit-synchronization and also the initial phase and the residual frequency offset. The progressive refinement of the estimation is obtained with two interleaved digital loops: a slow loop for detecting the bit-synchronization and a fast loop effecting intermediate decisions over additional blocks of bits for the estimation of the initial phase and the residual frequency offset.

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Bonneuil, France

Benoit Gelin