Abstract: Method to synchronize at least one mobile unit to at least one base transceiver station belonging to a digital telecommunication network, in which radio signals transmitted and received by said base station are subdivided in frames (Fn) having pre-determined duration and each frame is subdivided in a pre-determined number of timeslots (Tn) and codes (Cn), said signals including at least a synchronization signal (S), which is transmitted by the base transceiver station and includes a sequence of modulation elementary units suitable to identify the timeslot (T1) and the code (C1) of a service channel containing system messages (M), said method including the following operational steps: marking the synchronization signal (S) in at least one frame (Fx) by the base transceiver station; transmitting a pointer message (P) in the service channel of said frame (Fx) or of a subsequent frame (Fx+n) by the base transceiver station; detecting the marked synchronization signal (S?) by the mobile unit; receiving the poin

Abstract: The present invention relates to adaptive phy mode systems, in which the modulation type and the forward error correction, jointly called phy mode, depend on the addressed terminal. Specifically, the present invention defines a power control technique for the terminal stations that also commands the phy mode switching. In particular, the peripheral stations transmit with the several phy modes so that the signals are received at the master station making a given performance related parameter equal. Then a hysteresis is defined which regulates the phy mode switching, setting suitable power thresholds of the signal. To keep the received power close to the working point of the appropriate phy mode, the master station relies on the received power level together with information regarding the unused power, which is available in the peripheral station. Thus, interference is reduced, and link coverage and throughput are optimized.

Abstract: The invention discloses a method to perform downlink Power Control in packet switching cellular systems with dynamic allocation of the RF channel, such as GPRS/EGPRS. The performances concern a scenario in which a radio block transmitted from the Base Station (BTS) on a downlink channel has to be received from at least two MSs simultaneously, a first MS being the addressee of the data/control packet on the downlink TBF while the second MS being the addressee of the Uplink State Flag (USF) for scheduling transmission of the next data/control packet from an uplink TBF to an uplink shared channel. First MS transmits to the BTS a first measurement report including measures of BCCH level and interference level on all the timeslots, while the second MS transmits a NC report including measures of BCCH level only, that because detailed interference measure on the downlink channel are prevented due the absence of a concurrent downlink TBF.

Abstract: A method and a system are described to assign bandwidth in a point-to-multipoint ATM transmission system, comprising a centralized unit or Master Station (MS) and a plurality peripheral stations (PSs), in particular to assign transmission bandwidth on the channel from PSs to MS, by assigning transmission abilitations in defined time slots sending messages called Grants on the channel from MS to PSs. The system assigns bandwidth in the system using three different bandwidth allocation modalities, a static modality, and two separate dynamic modalities.

Abstract: A testing system includes simulation equipment for generating a radiofrequency test signal for the receivers of a base transceiver station, which is equipped with an intelligent array antenna having N sensors. The simulation equipment generates a complex signal consisting of N identical radiofrequency signals with differing phases. These signals are conveyed towards N antenna input connectors of the receivers to be tested. The N test signals are obtained by generating as many groups of N digital isofrequential carriers as are required to simulate the directions of a useful signal with an arbitrary number of echoes, and the directions of an arbitrary number of isofrequential interferent carriers. The N carriers of each group are appropriately modulated and digitally multiplied by the same number of relevant beamforming coefficients to produce, within each group, gradually increasing phase values.

Abstract: A broad band digital radio receiver for multicarrier signals employs a quadrature demodulator to directly shift the radiofrequency signal in a base band. A local oscillator has frequency f0 placed at the center of the radiofrequency BW band, so channel pairs, symmetric versus f0, are superimposed in the lower base half-band. Base band equivocation is then solved by numeric-type second orthogonal demodulators, which supply pairs of twice-demodulated signals that can be grouped in four equation systems in four unknown values consisting of in-phase and quadrature components of the two channels of each pair. Subsequent reconstruction networks solve the relevant systems and give the two components of each single channel for each pair. One network in the receiver measures amplitude and phase dissymmetries in the two branches of the analog demodulator and supplies four corresponding digital coefficients to the reconstruction network, which can then counterbalance at output the effects of dissymmetry.

Abstract: It is described a broadband radio transmitter for a digital signal consisting of a plurality of not necessarily equispaced, digitally modulated carriers. The transmitter selects the second replica of the spectrum of the signal coming out from a digital-to-analogue converter DAC to increase the space of the useful signal from the continuous in comparison of the direct use of the base band spectrum would involve. The object of the invention is in fact to obtain a wider transition band and consequently a less stringent local oscillator residue and image filter at radio frequency. To eliminate or reduce the effect of the sin(&pgr;fT)/(&pgr;fT) function that envelopes the signal coming out from the DAC, the invention foresees the use of an equalization of the analogue type, or the adoption of a zero insertion technique (of the digital or analogue type) or in general a digital x/sin x equalizer.

Abstract: The present invention relates to a duplexer set up by two decoupling filters for high frequency transceivers of the temperature self-compensating type and implemented by means of a pair of mechanic bodies (2), each one of which including a plurality of resonance cavities (3). Inside of the cavity (3) of the superior body (2) of the duplexer, a corresponding adjustment disc (7) is lodged in a removable and coaxial way which is provided with a supporting stem (8) coming out of a passage hole (12) obtained on the summit of the cavity (3). The bodies (2) are bound between them, so that the cavities of one or the other turn out to be coaxially facing each other. The passage hole (12) of the filter according to the invention is threaded. Moreover at each filter at least one bush (9) is associated having one portion (11) engaged in the hole (12) and inside of which the stem (8) of the disc (7) is housed.

Abstract: An antenna duplexer including an elongated hollow body realized with two opposed half shells is disclosed. The duplexer also includes a first opening or antenna port and a second and a third opening, or ports of the transmitter and of the receiver. A filtering structure is provided including a plurality of metal inserts available to uncouple the transmitter from the receiver. The duplexer has at least an additional portion of waveguide structured in order to keep the wave “under the cut-off frequency”, interposed between at least second or third opening and the relative end wall of the elongated body. An additional portion of wave guide includes an additional metal insert, forming part of the above mentioned filtering structure, which determines an exponential attenuation of the signal, thus nullifying the negative effects deriving from the mechanical tolerance of the hollow body.

Abstract: The following description regards a frequency converter (1) for applications on millimetric radio waves. The circuit structure comprises a diplexer filter realized in thin film on an alumina layer connected to a balun set up by a quartz plate on which two mixing diodes in GaAs have been mounted, placed in the center of a rectangular cavity (2) closed on one side by a short circuit plate and on the opposite side communicating with a rectangular waveguide (4) transporting a radio frequency signal (RF). On the upper side of the plate three parallel metallic bands have been put in the sense of the width of the cavity, between the bands the diodes are connected in series. The most external bands are welded to the walls of the cavity (2), the central one on the other hand is connected to the point common to both sections of the diplexing filter by means of a metallic strap in the air welded to a microstrip.

Abstract: A method and a system to obtain the Primary Receiver Scan Carrier Number (PSCN) starting from the data regarding the multiframe number (MFN) in a personal telephone system realized according to the DECT standard. The following steps are present calculating the minimum common multiple (m.c.m.) between the duration of a multiframe (160 ms) and the period necessary for the complete scanning of the frequencies by a radio fixed part (RFP); dividing this minimum common multiple (m.c.m.) by the duration of a multiframe and taking the quotient to obtain a periodicity value; waiting that the multiframe number (MFN) assumes a whole multiple value of the periodicity calculated as indicated above and beginning and the scanning starting from the known frequency (x) which is common to all fixed radio parts (FRP) to be synchronized.