Abstract: A signal is received in a telecommunication network in the form of P signals received on P corresponding antennas, where P is greater than or equal to 1. The received signals correspond to a multi-carrier signal transmitted in the form of frames comprising symbols occupying corresponding positions distributed along a time axis and along a frequency axis; a frame comprising M blocks each having at least N reference symbols. The reference symbols in each of the blocks satisfy a first maximum spacing between each other along the time axis and a second maximum spacing between each other along the frequency axis, less than a first value and a second value respectively, M being an integer number equal to at least two. M estimated noise power values are determined at frame level, each related to one of the M emitted reference symbol blocks. Values of the estimated noise power for the other symbols in the frame are then obtained from the determined estimated noise power values.

Abstract: In a method and apparatus for optimizing a data link between a mobile station and a main base station, the link is formed by an uplink radio signal from the mobile station and a downlink radio signal from the main base station, both of which include frames that carry data and protocol information. A radio receiver of a complementary receiving station has an antenna system for receiving both the downlink radio signal and uplink radio signal. An interface circuit cooperates with a baseband processor for decoding the uplink radio signal based on information obtained from decoding the downlink radio signal. The interface circuit enables establishment of a separate data link between the complementary receiving station and the main base stations, for transmitting information obtained from decoding the uplink radio signal.

Abstract: An emission chain is suitable for receiving an input signal and for providing a signal to be emitted. It comprises a processing pathway for the input signal which includes a digital signal decomposition according to N signal components, with N an integer greater than or equal to 2, said N signal components, on the one hand, being converted from a digital form into an analog form and, on the other hand, following respectively distinct physical pathways, said physical pathways inducing first respective delays on the N signal components. The input chain comprises a power amplifier. A delayed input signal is obtained by applying a second delay (?) having a value greater than or equal to the maximum value of the first delays. Next, N correction delays (???i) are applied respectively to the N signal components, this step being carried out on the basis of a comparison between said input signal delayed by the second delay and the signal to be emitted.

Abstract: In order to convert a complex analog signal into a complex digital signal in an analog-digital conversion device having two channels, I and Q respectively, in quadrature, each comprising an input and an associated output, each output being fed back onto said associated input so as to form a first and a second feedback loops each comprising a digital-analog converter, the device comprising a complex filter with a first stage and a last stage, after sampling (508), a signal integration is performed in a first stage (501) of the filter without introducing any substantial delay. Then, an integration is performed in the last stage (502) of the filter. A substantial delay (507) is then introduced and the output signal of the last stage is converted into a digital signal over several bits. The digital signal is injected into the feedback loop (108) of said channel and the digital signal is converted into a feedback signal.

Abstract: A mobile terminal of a digital cellular radiocommunication system that is in the receiving phase in a group call while roaming in a current cell, indicates to a fixed network element of the system, a given destination cell out of a number N of cells adjacent to the current cell The system uses a time and/or frequency division multiple access method, and any modulation method. The mobile terminal sends an identification sequence of the destination cell in a time slot of an inbound signalling channel which is a contention channel.

Abstract: A method of synchronization on the uplink channel of a Simulcast network with a plurality of fixed receivers (BS1-BS4) and a selection unit (20), comprises the following steps. All the receivers are placed in a synchronization search mode (702), in which they search for a synchronization pattern sent by the mobile terminal over the uplink channel. When a receiver detects the synchronization pattern, it produces an initial synchronization context (SC3(0)), which indicates the delay of the radio signal relative to a time reference of the network, and transmits it (705) to the selection unit. The latter broadcasts it (707) to all the receivers that use it to start processing the radio signal. Then, each receiver maintains its synchronization context and transmits it (708-712) to the selection unit on each frame. At regular intervals, the value of an updated synchronization context (SC2(i)) is broadcast (714) to the receivers.

Abstract: A signal of OFDM type received in a radio receiver via a propagation channel includes symbols distributed according to frequency and time. The receiver determines likelihoods of the symbols, decodes the received signal to yield a decoded signal as a function of the likelihoods of the symbols, and estimates an instantaneous noise power of the received signal as a function of a difference between the received signal and a reconstructed noise-free signal derived from the decoded signal. A filtering module determines a bounded distribution of the instantaneous noise power as a function of frequency and/or time, and filters the distribution to yield a filtered noise variance as a function of a frequency and/or time parameter of the propagation channel. A corrector weights the likelihoods of the symbols of the received signal to be decoded as a function of the filtered noise variance.

Abstract: A signal is received by P antennas. It includes frames having symbols occupying respective positions distributed along an axis of time and of frequency, a frame including M blocks having N reference symbols M groups of P weighting coefficients are determined, each one of the groups relating to one of the blocks emitted, with the coefficients of a group being associated to the blocks which are received on the P antennas and which correspond to the block emitted relating to the group. The coefficients are determined so as to increase via a threshold value, an error value for each block emitted, between the reference symbols of the block emitted, and the symbols obtained using the symbols received on each antenna at the positions of reference symbols corresponding to the block emitted and the associated coefficients.

Abstract: A switching and management infrastructure of a mobile communications network is connected to a gateway node by a standard interface initially defined to be used in an other packet-mode communication network, in order to provide a packet-mode connection to an external communication network. As a consequence, the protocols and signaling messages already defined and developed for this standard interface can be used for activating, deactivating and updating a logical packet data context between the infrastructure and the gateway packet node as well as to tunnel data packets therebetween. Also standard gateway packet node and all the existing interworking function thereof can be used for providing packet data services and interworking for the mobile network. Thereby the need for developing and defining a special packet data routing and interworking for the mobile network will be avoided or minimized.

Abstract: A method and an arrangement maintain end-to-end synchronization on a telecommunications connection transmitting data in frames substantially in real time and using synchronized end-to-end encryption, wherein at least a part of the telecommunications connection is a packet-switched connection, in which case the reproduction delay of the data to be transmitted can be increased by adding one or more extra frames to the frame string being transmitted, wherein the arrangement defines, based on the number of received frames, an initialization vector value corresponding to a frame received at the receiving end of the telecommunications connection and used in decrypting the frame, adjusts the reproduction delay to mark the frame to be added to increase the reproduction delay as an extra frame, and defines the initialization vector value to count only the frames not marked as extra frames in the number of received frames.

Abstract: There is disclosed a method of inserting a secondary stream of binary information into a main symbol stream of at least one standard digital modulation. The stream to be transmitted resulting from the insertion of the secondary stream in the main stream is a symbol stream of a modified digital modulation. The stream to be transmitted has the same symbol rate as the main stream. The sequence of symbols of the stream to be transmitted is encoded according, cumulatively, to a first condition over at least two consecutive symbols of the main stream, on the one hand; and to a second condition on a current bit or a plurality of current bits of the secondary stream, on the other hand.

Abstract: A method for estimating a transmission channel from a multicarrier signal transmitted through said transmission channel, comprising real pilot symbols and so-called pure imaginary pilot symbols, consists in selecting one or several values zk of the received signal corresponding respectively to one or several real pilot symbols, and one or several values zl of the received signal corresponding respectively to one or several pure imaginary pilot symbols. The pilot symbols are sufficiently close both in frequency and in time such that it can be assumed that the fading of the signal through the transmission channel has a complex value ? substantially identical for the symbols. An estimated value {circumflex over (?)} of ? for the pilot symbols concerned is then determined by minimizing a least square equation involving the values zk and the values zl.

Abstract: A method of activating a packet data protocol context for a roaming terminal in a telecommunication system including a home network, a gateway support node to external packet networks, the node being used in the home network, at least one terminal and a visited network. When the terminal requests for packet data protocol context activation in the visited network, the visited network defines the gateway support node address on the basis of the network identifier and a subscriber identifier transmitted by the terminal. On the basis of the defined address, a request for packet data protocol context activation is transmitted from the visited network to the gateway support node and the activation of the packet data protocol context is finished.

Abstract: In a system of radiocommunication with mobile terminals, the invention proposes to establish a vote configuration or a simulcast configuration for intercellular handover of a communication set up between a mobile terminal (60) and a base station (11) of a current cell (10), said configuration including the current cell (10) and adjacent cells (20, 30) which are eligible for said handover, so as to enable a soft intercellular handover when the terminal (60) moves towards the adjacent cells (20, 30). The invention provides the advantage of reducing the interference level in the neighbouring cells, hence of increasing the frequency re-use rate.

Abstract: For the transmission of information with verification of transmission errors, a useful information message (M) is transmitted in a determined frame while being associated with a determined number p of transmission error verification bits (CRC,S) also transmitted in the frame. In order to have an element allowing the verification of intentional errors, determined number p1 of the transmission error verification bits form a seal (S) obtained from a determined sealing function, where p1 is a number less than p. Application to radiocommunications equipment requiring the verification of the integrity and the authentication of the messages transmitted.

Abstract: A carrier frequency is apportioned to timeslots, and logical channels are formed between the base station and mobile terminals to support services in connection with these mobile terminals. Each of the logical channels consists of recurring timeslots allocated to at least one mobile terminal on the carrier frequency. To implement one of the services which involves transmission of periodically updated information, a recurrence frequency is selected from a plurality of possible values, as being substantially the inverse of the updating period for said information, and a logical channel is formed between the base station and a mobile terminal by allocating timeslots having the selected recurrence frequency on the carrier frequency.

Abstract: A method of synchronization on the uplink channel of a Simulcast network with a plurality of fixed receivers (BS1-BS4) and a selection unit (20), comprises the following steps. All the receivers are placed in a synchronization search mode (702), in which they search for a synchronization pattern sent by the mobile terminal over the uplink channel. When a receiver detects the synchronization pattern, it produces an initial synchronization context (SC3(0)), which indicates the delay of the radio signal relative to a time reference of the network, and transmits it (705) to the selection unit. The latter broadcasts it (707) to all the receivers that use it to start processing the radio signal. Then, each receiver maintains its synchronization context and transmits it (708-712) to the selection unit on each frame. At regular intervals, the value of an updated synchronization context (SC2(i)) is broadcast (714) to the receivers.

Abstract: A radio system comprising a switching and management infrastructure arranged to deliver voice and data between a plurality of communicating parties, and a mobile station. Said radio system comprises a multiplicity of traffic channels, each traffic channel being associated with a unique coding scheme. The switching and management infrastructure is arranged to receive a plurality of paging messages from a plurality of communicating parties, and to combine the paging messages received during a pre-defined time period into a paging frame comprising a multiplicity of address data blocks for identifying the mobile station(s) for which the paging frame comprises a paging message. At least one of the traffic channels of the radio system is dedicated to delivery of downlink paging messages, and associated with a coding scheme that comprises at least one error protection algorithm.

Abstract: During a communication, a channel is shared by several transmitting/receiving stations comprising a single master station and one or more slave stations. A station becomes a master station by transmitting traffic information on the channel. After the master station has stopped transmitting traffic information without the communication being concluded, it continues to transmit signaling information authorizing each slave station in turn to transmit traffic information on the channel. This transmission of signaling information continues for as long as the communication lasts, until one of the slave stations becomes the master station in turn by beginning to transmit traffic information on the channel or until the same station begins to transmit traffic information again, hereby remaining the master station.

Abstract: For the transmission of a secondary information flow between a transmitter and a receiver, the secondary information flow is inserted at a parametric vocoder of the transmitter which generates a main information flow. The main information flow is a speech data flow encoding a speech signal and is transmitted from the transmitter to the receiver. Bits from the secondary information flow are inserted into only some of the frames of the main information flow, these frames being selected by a frame mask which is known to the transmitter and the receiver, and/or into a determined frame of the main information flow, by imposing a constraint on only some of the bits of the frame, these bits being selected by a bit mask known to the emitter and the receiver.