Abstract: A system for transmitting data packets includes at least one access point and at least one terminal. The access point receives data packets transmitted by the terminal in compliance with a multiple access protocol including carrier detection, and transmits to the terminal at least the width of the contention window that the terminal is to observe for transmitting a packet. The transmitted packets are coded using an erasure code and the access point is further adapted to decode the received packets. The system may be applied to networks such as WLANs.

Abstract: A system for transmitting data packets includes at least one access point and at least one terminal. The access point receives data packets transmitted by the terminal in compliance with a multiple access protocol including carrier detection, and transmits to the terminal at least the width of the contention window that the terminal is to observe for transmitting a packet. The transmitted packets are coded using an erasure code and the access point is further adapted to decode the received packets. The system may be applied to networks such as WLANs.

Abstract: A device emits bit sequences (SB1-SB3) from a plurality of light sources (SL1-SL3) that emit radiation combined into substantially white light. Each light source has a different signal-to-noise ratio depending on the wavelength of the emitted radiation. The device includes a coder (COD) for coding the bit sequence (SB3) to be emitted by the light source (SL3) having the lowest signal-to-noise ratio by a code (CB3) having a minimum distance the product of which by the lowest signal-to-noise ratio is substantially equal to the highest signal-to-noise ratio. The minimum distance of the code is equal to the minimum number of bits that differ between two words of the code. The bit error rate of the source emitting the coded sequence is reduced and the bit error rates of the various light sources are homogenized.

Abstract: The invention concerns a method for jointly decoding and equalizing a digital signal protected by a trellis-defined code and transmitted though a channel. The method consists in carrying out a maximum likelihood estimate of each current bit xn by minimizing the quadratic error between the observed symbol Vn and the current symbol in the channel output zn, the quadratic error being calculated (1002) from the set of observed symbols based on the branch metric of the last transition en1(X)?en(X) according to the relationship (I); wherein k represents the rank of the coefficients of transverse filtering introduced by the radioelectric channel. The branch metric is calculated by backtracking through the successive states and the error propagating process is inhibited (1003) while backtracking through the successive states by storing at each node S survivors and by updating each survivor at the next time.

Abstract: The interfacing device handles asynchronous/synchronous adaptation and rate control between the ATM flows and the flows transmitted on the wireless interface. It transposes the ATM cells (53 octets) into packets which can be transmitted directly on the wireless interface (40 octets in the case of DECT). Similarly, at the receiving end, it reconstructs the original ATM cell flow on the basis of the packets received. In order to guarantee a certain transmission quality at the level of the wireless link, the device uses a data acknowledgement and retransmission mechanism adapted to the characteristics of the synchronous wireless channel. In order to fulfil the quality of service requirements of the various applications in terms of error rates and transmission delays, the device allows the data protection mechanism to be set for each ATM connection depending on the characteristics of the service.

Abstract: A method of detecting, blind, the coding mode used to encode digital data, for data transmitted in frames of n bits, partially subjected to a convolutional coding. A soft syndrome value is calculated over a sequence of bits representative of a transmission error probability in these bits, and a likelihood value V(&agr;,&bgr;), where &agr;, &bgr; denote the number of coded bits and non-coded bits respectively, is then calculated on the basis of the mean value m and the variance &sgr; of the distribution of the absolute soft syndrome values. The likelihood value V(&agr;,&bgr;) is maximised as a function of &agr; or &bgr; which makes it possible to determine the coding mode used on the basis of the corresponding values &agr; or &bgr;.