Abstract: A method of decoding a received data word (r) having been transmitted over a radio communication channel, the corresponding sent data word (m) having been encoded as a code word (c), the method includes: multiplying of the received data word by a parity-check matrix, and if the result of the multiplication is zero: performing an algebraic decoding of the received data word without error correction, otherwise performing an error correction by estimating the transmission error, subtracting the estimated error from the received data word, and performing an algebraic decoding of the result of the subtraction, wherein for estimation of the transmission error is used to identify an approximate location of potential errors and the Viterbi algorithm is only applied for these locations, thus avoiding iterations in error-free areas.

Abstract: The present invention relates to a method of decoding a received data word (r) having been transmitted over a radio communication channel, the corresponding sent data word (m) having been encoded as a code word (c), the method comprises the steps of multiplying of the received data word by a parity-check matrix, and if the result of the multiplication is zero: performing an algebraic decoding of the received data word without error correction, otherwise performing an error correction by estimating the transmission error, subtracting the estimated error from the received data word, and performing an algebraic decoding of the result of the subtraction, wherein for estimation of the transmission error R.H? is used to identify an approximate location of potential errors and the Viterbi algorithm is only applied for these locations, thus avoiding iterations in error-free areas.

Abstract: A method for adjusting the length of a data block in a time-division multiple access communication system includes estimating the impulse response of a communication channel from received symbols of a reference sequence, estimating a signal-to-noise ratio from the channel impulse response, and estimating a maximum Doppler shift. Using these estimations, upper and lower limit functions of a normalized estimated mean squared error are calculated, and the length of the data block is adjusted to an optimal length determined from the upper and lower limit functions.

Abstract: The present invention concerns a learning sequence for estimating a transmission channel and an estimator device adapted to use a sequence of this kind. The learning sequence for estimating a transmission channel of length L comprises a guard sequence of length L followed by a reference sequence of length N such that its total length N+L is greater than or equal to 2L+1 and such that the transmission matrix A associated with it defined by the product of the Hermitian transpose A.sup.H of the transmission matrix by the transmission matrix A is inversible.

Abstract: In mobile radio communications systems using time-division multiple access (TDMA), intersymbol interference caused by time differences in multipath media is avoided by equalizing data blocks. When a data block (BD) is received, the impulse response of the channel on which the block was transmitted is estimated, a set of receive parameters (PP) is evaluated, an optimal length (Nopt) of the block (BD) is determined from the parameters (PP), and when the optimal length (Nopt) is less than the actual length (N) of the block (BD), channel variation tracking (PO) is undertaken.

Abstract: A method for determining the transmittance of a filter circuit adapted to transform the impulse response of a filter into a minimal phase response entails computing the theoretical frequency response of the filter circuit and the minimal phase frequency impulse response with a causality condition applied to the cepstrum of the minimal phase response, determining the theoretical transmittance as the inverse fast Fourier transform of the theoretical frequency response, estimating the transmittance of the filter circuit by truncation of the theoretical transmittance of which only a predetermined number of coefficients are retained and determining the minimal phase global response from a limited expansion of the cepstrum.

Abstract: An anti-theft device for an automotive vehicle includes a lock and key housed separately and remote from a bolt and its actuating mechanism. The bolt portion is located in an inaccessible housing and connected to the lock by means of a burglar-proof connection. The electronic lock arrangement employed permits of a large number of combinations and thereby increases the security of the anti-theft device. By placing the bolt in an inaccessible housing, direct tampering with the locking bolt is precluded.