摘要:
A method of securing a computer comprising a microkernel and a system for interfacing with at least one virtualized operating system are presented. The microkernel includes a clock drive, a scheduler and an inter-process communication manager. The system for interfacing forms at least one virtual machine associated with each operating system and allows execution of the latter without modification. The method includes, at the level of the system for interfacing, the steps of:—intercepting any communication between a means external to the operating system and the operating system,—verifying that predefined rules of access to said external means are validated by said communication;—transmitting the communication to the recipient if the rules are validated.
摘要:
To reduce interferences in signals received by a receiver through a propagation channel, each including symbols distributed according to frequency and time dimensions and corresponding to a common emitted signal, the receiver weights an estimate of the emitted signal and the received signals by weighting vectors evolving in vector subspaces representing time variations and frequency variations of the channels for propagating the signals between an emitter and the receiver. These vector subspaces are defined by matrices, some columns of which are suppressed as a function of frequency and time constraints of the channel. The receiver minimizes a function of the difference between the sum of weighted received signals and the weighted estimate of the emitted signal in order to estimate the emitted signal as a function of the weighting vectors and the received signals.
摘要:
The invention relates to a device for receiving a broadband multi-channel radiofrequency signal, consisting of a radiofrequency analog input stage (3) connected to an intermediate-frequency conversion stage (δ), said conversion stage comprising at least one conversion chain (13, 15) comprising a frequency mixer (17, 19) that transposes the signal to an intermediate frequency connected to the input of an analog-digital converter (29, 31) with a high frequency sampling rate, characterized in that the intermediate and sampling frequencies in each conversion chain are selected such that, considering the noise generated by the sampling overtones of the corresponding analog-digital converter, each of the radiofrequency signal channels has a signal/noise ratio that is greater at output than a predetermined value of at least one conversion chain.
摘要:
A method for managing two-way alternate communication in half-duplex mode between at least two end equipments of a packet switching transport network in non-connected mode, provides that an indicating element serves, when it is present with a first given value in the packets transmitted from one of said end equipments to a central equipment managing the communication, to indicate to said central equipment that said end equipment acknowledges receipt of the right to send which is granted to it by said central equipment and that it requests the maintaining of said right to send.
摘要:
The invention related to a method for encoding information using non-linear evenly distributed functions, that comprises the following steps for building such a function: selecting a first natural integer n, a first set En of cardinal n, a group G operating on said first set En, a second natural integer q and a second set Eq of cardinal q; defining a set OG of the orbits of the group G operating on vectors of n elements in the set Eq, a function II that, for each vector of the n elements of the set Eq, associates the corresponding orbit and a second function Φ allocating to each orbit of the group G a value of the set Eq; evenly distributing into a number q of sections the sums of the cardinals of the orbits of the group; defining a third function F comprising the first and second functions ΦoII.
摘要:
A secret element is shared with a cryptographic module. The secret element can be obtained from at least first and second partial secret information items. A first transmission transmits the first partial secret information item to the cryptographic module but not the first partial information item, this second transmission being separate from the first transmission. The secret element can then be obtained in the cryptographic module from the first and second partial secret information items transmitted.
摘要:
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.
摘要:
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. Advantage: the synchronization of a receiver which begins to receive the radio signal during a call or alternate turn is facilitated.
摘要:
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. On the other hand, the packet data services and protocols as well as the mobility management already developed for the switching and management infrastructure can be utilized.
摘要:
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.